[1] Univ KwaZulu Natal, Ctr AIDS Programme Res South Africa CAPRISA, Durban, South Africa
[2] Columbia Univ, Dept Med, Div Infect Dis, 630 West 168th St,PH 8W, New York, NY 10032 USA
[3] Univ KwaZulu Natal, Dept Med Microbiol, Durban, South Africa
[4] Natl Hlth Lab Serv, Durban, South Africa
[5] Univ Cape Town, Inst Infect Dis & Mol Med, Div Med Virol, ZA-7700 Rondebosch, South Africa
[6] Univ Cape Town, Inst Infect Dis & Mol Med, Div Immunol, ZA-7700 Rondebosch, South Africa
[7] Columbia Univ, Mailman Sch Publ Hlth, Dept Epidemiol, 630 West 168th St,PH 8W, New York, NY 10032 USA