1. Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom.
2. Kenya Medical Research Institute, Centre for Global Health Research, Kisumu, Kenya.
3. Nyanza Reproductive Health Society, Kisumu, Kenya.
4. Division of Global HIV and AIDS, Centers for Disease Control and Prevention, Kisumu, Kenya.
5. Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Kisumu, Kenya.
6. Division of Global Health Protection, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia.