“…A total of 19 out of 24 studies were case-control studies (Arias et al, 2014;Bozza et al, 2008;Brasier et al, 2012;Butthep et al, 2012;Chen et al, 2005;Furuta et al, 2012;Green et al, 1999a, b;Guerrero et al, 2013;Houghton-Triviño et al, 2010;De La Cruz Hern andez et al, 2014;Laur et al, 1998;Levy et al, 2010;Malavige et al, 2013a;Nguyen et al, 2004;Del Moral-Hern andez et al, 2014;P erez et al, 2004;Soundravally et al, 2014;Wang et al, 2007), and the remaining 5 studies were prospective cohort studies (de-Oliveira-Pinto et al, 2012;Kurane et al, 1991Kurane et al, , 1993Suharti et al, 2003). Comparison groups were healthy controls, patients with other febrile illness (OFI) or non-severe disease patients (DF or non-SD); however, comparisons made between SD and non-SD cases were considered most ideal for the purpose of this review.…”