1. Department of Health Behavior & Health Education, University of Michigan School of Public Health, Ann Arbor, Michigan, USA
2. Health Options for Young Men on HIV/AIDS/STI (HOYMAS), Nairobi, Kenya
3. National AIDS and STI Control Programme, Ministry of Health, Government of Kenya, Nairobi, Kenya
4. The Centre for Global Public Health, Department of Community Health Sciences, University of Manitoba, Winnipeg, Canada
5. Department of Medical Microbiology, University of Manitoba, Winnipeg, Canada
6. Centre for the AIDS Programme of Research in South Africa (CAPRISA), Durban, South Africa
7. Department of Medical Microbiology, University of Nairobi, Nairobi, Kenya