1. Division of Parasitic Diseases, National Centers for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333.
2. Division of AIDS, STD, and TB Laboratory Research, National Center for HIV, STD, and TB Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia 30333.
3. Center for Vector Biology and Control Research, Kenya Medical Research Institute, Kisumu, Kenya.
4. New Nyanza Provincial General Hospital, Ministry of Health, Kisumu, Kenya.