1. Department of Infectious Diseases and Tropical Medicine, Ludwig-Maximilians-University, Munich, Germany.
2. U.S. Military HIV Research Program (USMHRP), Henry M. Jackson Foundation, Rockville, Maryland.
3. Muhimbili University College of Health Sciences, University of Dar es Salaam, Tanzania.
4. USMHRP, Walter Reed Army Institute of Research, Rockville, Maryland.
5. Mbeya Medical Research Programme, Ministry of Health, Tanzania.
6. Mbeya Regional Medical Office, Ministry of Health, Tanzania.