[1] Univ Cape Town, Fac Hlth Sci, Inst Infect Dis & Mol Med, Desmond Tutu HIV Ctr, ZA-7925 Cape Town, South Africa
[2] London Sch Hyg & Trop Med, Dept Infect & Trop Dis, Clin Res Unit, London WC1, England
[3] Malawi Country Off, Minist Hlth, HIV Unit, Lilongwe, Malawi
[4] Malawi Country Off, Family Hlth Int, Lilongwe, Malawi
[5] Programme PAC CI, Abidjan, Cote Ivoire
[6] Ctr Rech Epidemiol & Biostat, U897, INSERM, Bordeaux, France
[7] Univ Cape Town, Fac Hlth Sci, Sch Publ Hlth & Family Med, Infect Dis Epidemiol Unit, ZA-7925 Cape Town, South Africa
[8] Columbia Univ, Mailman Sch Publ Hlth, Dept Epidemiol, New York, NY USA