[1] Tulane Univ, Ctr Hlth Sci, Dept Trop Med, New Orleans, LA 70112 USA
[2] Khon Kaen Univ, Fac Med, Dept Parasitol, Khon Kaen 40002, Thailand
[3] Queensland Inst Med Res, Australian Ctr Int & Trop Hlth & Nutr, Brisbane, Qld 4029, Australia
[4] George Washington Univ, Dept Microbiol & Trop Med, Washington, DC 20037 USA