text: It is also likely that differences in host susceptibility are important determinants of disease severity in response to GAS infection (Stevens et al., 1989; Obrien et al., 2002; Carapetis et al., 2005; Chuang et al., 2002; Thomas et al., 2008; Forni et al., 1995; Mencarelli et al., 2005; Tyrrell et al., 2005; Davies et al., 1996; Talkington et al., 1993; Baxter and McChesney, 2000; Darenberg et al., 2004; Eriksson et al., 1999; Norrby-Teglund et al., 2005; Zurawski et al., 1998; Ekelund et al., 2005).