1. Division of Viral Diseases, Center for Infectious Diseases, Centers for Disease Control, Public Health Service, U.S. Department of Health and Human Services, Atlanta, Georgia, USA
2. United States Peace Corps, Nairobi, Kenya
3. Clinical Research Centre, Kenya Medical Research Institute and U.S. Army Medical Research Unit, Nairobi, Kenya
4. United States Department of State, Nairobi, Kenya
5. Virus Research Centre, Kenya Medical Research Institute, Nairobi, Kenya
6. Office of Medical Services, United States Peace Corps