1. Clinical Research Centre
2. Division of Parasitic Diseases, Center for Infectious Diseases, Centers for Disease Control, Public Health Service, U.S. Department of Health and Human Services, Atlanta, Georgia 30333
3. Biomedical Sciences Research Centre, Kenya Medical Research Institute, P.O. Box 54840, Nairobi, Kenya
4. U.S. Army Medical Research Unit-Kenya, Box 401, APO New York 09675