[1] SESH Global, Guangzhou, Guangdong, Peoples R China
[2] Univ N Carolina, Chapel Hill, NC 27515 USA
[3] London Sch Hyg & Trop Med, Infect & Trop Dis, London, England
[4] London Sch Hyg & Trop Med, Dept Global Hlth & Dev, London, England
[5] Monash Univ, Cent Clin Sch, Melbourne, Vic, Australia