[1] Ctr Dis Control & Prevent, Div Parasit Dis & Malaria, Atlanta, GA USA
[2] Ctr Dis Control & Prevent, Div Foodborne Waterborne & Environm Dis, Atlanta, GA USA
[3] Univ Nacl Salta, Inst Invest Enfermedades Trop, San Ramon Nueva Oran, Argentina
[4] Johns Hopkins Univ, Wilmer Eye Inst, Dana Ctr Prevent Ophthalmol, Baltimore, MD 21218 USA