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Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What symptoms did the people had?

{'answer_start': [3200], 'text': ['acute gastroenteritis']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What type of samples were analyzed?

{'answer_start': [1835], 'text': ['stool samples']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What caused the event?

{'answer_start': [4357], 'text': ['heavy faecal contamination of the raw water from Gta lv river']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What symptoms did people report?

{'answer_start': [1760], 'text': ['acute gastroenteritis']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What were the first steps of investigation?

{'answer_start': [1590], 'text': ['questionnaires']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What is the date of the event?

{'answer_start': [71], 'text': ['2008']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What is the location of the event?

{'answer_start': [61], 'text': ['Sweden']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What pathogen was connected to the outbreak?

{'answer_start': [3738], 'text': ['faecal indicator bacteria and coliphages']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What is the source that started the event?

{'answer_start': [4224], 'text': ['contaminated drinking water']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

How was the event first detected?

{'answer_start': [152], 'text': ['unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

How many people were ill?

{'answer_start': [3069], 'text': ['2000']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What are the pathogens?

{'answer_start': [3119], 'text': ['NoV']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What is the concentration of the contaminant after analysis?

{'answer_start': [3780], 'text': ['300 plaque- forming units (p.f.u.)/100 ml']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What are the symptoms?

{'answer_start': [222], 'text': ['gastrointestinal symptoms']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What is the concentration of the pathogen?

{'answer_start': [3924], 'text': ['between 4 and 42 p.f.u./100 ml']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What is the event?

{'answer_start': [0], 'text': ['A large waterborne outbreak of NoV']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What are the initial steps of investigation?

{'answer_start': [786], 'text': ['identify the causative agents, the extent of the outbreak and possible sources of infection']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What are the first steps of mitigation?

{'answer_start': [699], 'text': ['boil water recommendation']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What type of samples were examined?

{'answer_start': [2041], 'text': ['Water samples']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What did the authorities do to mitigate the event?

{'answer_start': [905], 'text': ['inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms.']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What was the age of the affected people?

{'answer_start': [1697], 'text': ['19 and 75 years']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What is the source of contamination?

{'answer_start': [644], 'text': ['drinking water']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What was the alert of the event?

{'answer_start': [1308], 'text': ['notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms']}

Contamination Question Answering

A large waterborne outbreak of NoV occurred in Lilla Edet in Sweden in 2008. On 11 September 2008, the County Medical Ofcer (CMO) was informed about an unusually high number of individuals who had suddenly fallen ill with gastrointestinal symptoms during the previous days in Lilla Edet, a small municipality in southwest Sweden. Cases of gastroenteritis were reported from different places in the municipality, e.g. from the nursery schools, schools, nursing homes and from the Primary Healthcare Centre (PHC). The CMO notified the Environmental Office in the municipality about the ongoing outbreak. As the initial information indicated that drinking water was a possible source of the outbreak a boil water recommendation was issued on the same day. Investigations were initiated to identify the causative agents, the extent of the outbreak and possible sources of infection. Efforts were also made to inform the inhabitants in the municipality about the ongoing outbreak, the issued boil water recommendation, and medical advice for people with gastrointestinal symptoms. Information was spread via the media, the homepage of the municipality website, posters and local radio as VMA, i.e important message to the public. In addition to the cases reported from the municipality of Lilla Edet, the CMO was notified that 7/17 athletes of a team that had visited the municipality during the afternoon on 7 September had fallen ill with gastrointestinal symptoms 2 days after their visit. To estimate the proportion of the 13000 inhabitants in Lilla Edet that fell sick during the outbreak, questionnaires were sent by mail on 19 September to 1199 randomly selected inhabitants between the ages of 19 and 75 years. A case was defined as a household member with acute gastroenteritis with date of onset between 5 and 21 September. Fifty stool samples from outpatients with symptoms of acute gastroenteritis attending Lilla Edet PHC during 12-26 September were collected and examined for enteric pathogens, as described by Nenonen et al. [20]. Water samples, i.e. raw water from the Gta lv river, drinking water from different parts of the distribution network, and water from reservoirs in Lilla Edet, were collected on 12 September and analyzed at the microbiological laboratory at SMI for the presence of E. coli and coliform bacteria by Colilert 18 (IDEXX, USA), intestinal enterococci by Enterolert (IDEXX), (oo)cysts of Giardia spp. and Cryptosporidium spp. according to ISO 15553:2006, Clostridium perfringens according to ISO/CD 6461-2:2002, somatic coliphages according to ISO 10705-1:2000, Campylobacter spp. by culture on CCDA agar (in-house method), Salmonella spp. according to ISO 6340:1995, Verotoxin-producing E. coli (VTEC) by PCR screening for vt genes and NoV by seminested PCR [22]. Additional water samples were collected on 17 September and analyzed for presence of NoV and coliphages. From the questionnaire survey it could be calculated that out of the 7500 inhabitant that lived in households supplied by drinking water from Lilla Edet WTP, about 2000 (26.7%) fell ill with acute gastroenteritis. NoV was detected in 33/50 stool samples collected from patients with symptoms of acute gastroenteritis. NoV strains of genogroup I (GI) predominated in 31 of these samples and mixed genotypes of GI infections occurred in ve samples, as described by Nenonen et al. [20]. Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples. In samples from the drinking water system in Lilla Edet collected on 12 September, E. coli, coliforms, enterococci, Giardia, Cryptosporidium, Clostridium, Campylobacter or NoV could not be detected, while faecal indicator bacteria and coliphages [300 plaque- forming units (p.f.u.)/100 ml] were found in raw water samples from the Gta lv river. However, somatic coliphages in concentrations between 4 and 42 p.f.u./100 ml were detected in samples from the drinking water system collected on 17 September and in samples from the raw water collected on the same date. In the Lilla Edet outbreak early detection of NoV strain diversity in stool samples strengthened the initial hypothesis that contaminated drinking water was the point source. Thus, the waterborne outbreak in Lilla Edet was most probably a consequence of the heavy faecal contamination of the raw water from Gta lv river [20].

What were the associated pathogens of concern?

{'answer_start': [3389], 'text': ['Adenovirus was detected in one, sapovirus in one and rotavirus in three stool samples. Campylobacter spp. were isolated from two stool samples.']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

What type of samples were analyzed?

{'answer_start': [461], 'text': ['Stool specimens']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

What caused the event?

{'answer_start': [1380], 'text': ['contamination of a coastal lagoon']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

What symptoms did people report?

{'answer_start': [2333], 'text': ['vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

What is the initial cause of the event?

{'answer_start': [591], 'text': ['sewage contamination event impacting the lagoon']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

What is the date of the event?

{'answer_start': [125], 'text': ['January 2017']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

What is the location of the event?

{'answer_start': [111], 'text': ['South Africa']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

What pathogen was connected to the outbreak?

{'answer_start': [2558], 'text': ['Aeromonas, enterovirus and EPEC']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

What is the source that started the event?

{'answer_start': [2936], 'text': ['lagoon']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

How was the event first detected?

{'answer_start': [51], 'text': [' reported by healthcare workers']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

How many people were ill?

{'answer_start': [2183], 'text': ['311 cases']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

What are the pathogens?

{'answer_start': [2485], 'text': ['NoV']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

What is the concentration of the contaminant after analysis?

{'answer_start': [2709], 'text': ['The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

What are the symptoms?

{'answer_start': [917], 'text': ['diarrhoea and/or vomiting']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

What is the concentration of the pathogen?

{'answer_start': [2848], 'text': ['The E. coli level was 1.93* 10^3 cfu/100 ml']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

What is the event?

{'answer_start': [26], 'text': ['gastroenteritis cases was reported by healthcare workers']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

What are the initial steps of investigation?

{'answer_start': [181], 'text': ['A case-control study was conducted']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

What is the duration of the event?

{'answer_start': [1043], 'text': ['between 14 December 2016 and 5 January 2017']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

From when until when the event happened

{'answer_start': [1529], 'text': ['during December 2016 and January 2017']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

What type of samples were examined?

{'answer_start': [1996], 'text': ['Water samples']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

What was the age of the affected people?

{'answer_start': [2260], 'text': ['21 years']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

What is the source of contamination?

{'answer_start': [632], 'text': ['lagoon']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

What was the alert of the event?

{'answer_start': [736], 'text': ['the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms']}

Contamination Question Answering

An unexpected increase in gastroenteritis cases was reported by healthcare workers on the KwaZulu-Natal Coast, South Africa, January 2017 with >600 cases seen over a 3-week period. A case-control study was conducted to identify the source and risk factors associated with the outbreak so as to recommend control and prevention measures. Record review identified cases and controls and structured-telephonic interviews were conducted to obtain exposure history. Stool specimens were collected from 20 cases along with environmental samples and both screened for enteric pathogens. A reported sewage contamination event impacting the lagoon was the likely source with person-to-person spread perpetuating the outbreak. On 5 January 2017, the Outbreak Response Unit (ORU) of the National Institute for Communicable Diseases (NICD), SA, was alerted to a high number of persons falling ill with gastrointestinal symptoms (diarrhoea and/or vomiting) on the coast of KZN Province. The alert from health authorities in the KZN Province indicated that between 14 December 2016 and 5 January 2017, 690 people presented with gastrointestinal symptoms at a private hospital on the KZN south coast. Based on the available information at the time, which included local newspaper and online articles that reported a sewage spillage into a nearby lagoon; the investigating team hypothesised that contamination of a coastal lagoon could have led to the outbreak. The outbreak occurred within an urban community on the south coast of KZN Province during December 2016 and January 2017. A case-control study was conducted, with a case defined as a person of any age who presented to the private hospitals emergency department between 19 December 2016 and 6 January 2017 with an acute onset of diarrhoea and/or vomiting. Twenty acute phase stool specimens were collected from cases presenting to the hospital between 6 and 10 January 2017 and sent cooled to the Centre for Enteric Diseases (CED), NICD, for testing. Water samples were collected from the lagoon and a nearby wastewater treatment works discharge (final effluent), which drains into a river that flows into the lagoon (Fig. 1). A total of 311 cases and 126 controls were identified. The median age for the cases was 21 years (interquartile range 1040 years). The most common symptoms were vomiting (85%; 133/157), diarrhoea (73%; 115/157) and abdominal cramps (31%; 49/157). Of the 20 clinical specimens tested, 11 (55%) tested positive for NoV; nine were positive for NoV GI, while two were positive for NoV GII. Aeromonas, enterovirus and EPEC were also detected in one NoV GI-positive specimen and STEC in another NoV GI-positive specimen. Environmental samples The total coliform and thermotolerant (faecal) coliform counts in the lagoon water were 2.39* 10^4 and 9.5* 10^3 cfu/100 ml, respectively. The E. coli level was 1.93* 10^3 cfu/100 ml. These data support the hypothesis that the lagoon was the source of the outbreak among holiday-makers on the KZN Coast. The lagoon was reportedly contaminated by the wastewater treatment works effluent, which drained into the river flowing into the lagoon.

What were the associated pathogens of concern?

{'answer_start': [2616], 'text': ['NoV GI']}