[1] Mahidol Univ, Fac Trop Med, Mahidol Oxford Trop Med Res Unit, Bangkok 10400, Thailand
[2] Univ Oxford, Ctr Trop Med & Global Hlth, Nuffield Dept Clin Med, Oxford OX3 7FZ, England
[3] Univ Amsterdam, Acad Med Ctr, NL-1000 GG Amsterdam, Netherlands
[4] Battambang Prov Hlth Dept, Mohatep St, Battambang, Cambodia
[5] Natl Ctr Parasitol Entomol & Malaria Control, 477 Betong, Khan Sen Sok, Phnom Penh, Cambodia
[6] Univ Amsterdam, Ctr Social Sci & Global Hlth, NL-1018 WV Amsterdam, Netherlands
[7] Amsterdam Inst Global Hlth & Dev, NL-1105 BP Amsterdam, Netherlands