[1] Univ Calif San Francisco, Sch Med, Dept Med, 505 Parnassus Ave,Box 0119, San Francisco, CA 94143 USA
[2] Univ Amsterdam, Amsterdam Inst Global Hlth & Dev, Acad Med Ctr, Dept Global Hlth, NL-1012 WX Amsterdam, Netherlands
[3] Univ Cape Town, Inst Infect Dis & Mol Med, Desmond Tutu HIV Ctr, ZA-7925 Cape Town, South Africa
[4] Univ Cape Town, Fac Hlth Sci, Dept Med, ZA-7925 Cape Town, South Africa
[5] Univ Cape Town, Inst Infect Dis & Mol Med, Clin Infect Dis Res Initiat, ZA-7925 Cape Town, South Africa
[6] Khayelitsha Dist Hosp, Dept Med, Cape Town, South Africa
[7] Univ London Imperial Coll Sci Technol & Med, Dept Med, London SW7 2AZ, England
[8] London Sch Hyg & Trop Med, Fac Infect & Trop Dis, Dept Clin Res, London, England