[1] Univ Zimbabwe, Coll Hlth Sci, Harare, Zimbabwe
[2] UCL, MRC, Clin Trials Unit, London WC2B 6NH, England
[3] Univ London Queen Mary, Ctr Paediat, Blizard Inst, London, England
[4] Mulago Hosp, Paediat Infect Dis Clin Baylor Uganda, Kampala, Uganda
[5] Joint Clin Res Ctr, Kampala, Uganda
[6] Uganda Res Unit AIDS, Uganda Virus Res Inst, Entebbe, Uganda
[7] Uganda Res Unit AIDS, MRC, Entebbe, Uganda