[1] London Sch Hyg & Trop Med, Fac Epidemiol & Populat Hlth, Dept Noncommunicable Dis Epidemiol, London, England
[2] Univ Edinburgh, Usher Inst, Ctr Global Hlth, Edinburgh, Scotland
[3] London Sch Hyg & Trop Med, Fac Epidemiol & Populat Hlth, Dept Populat Hlth, London, England
[4] MRC UVRI & LSHTM Uganda Res Unit, Entebbe, Uganda
[5] African Populat & Hlth Res Ctr APHRC, Nairobi, Uganda
[6] London Sch Hyg & Trop Med, Fac Epidemiol & Populat Hlth, Dept Infect Dis Epidemiol, London, England
[7] Norwegian Inst Publ Hlth, Ctr Fertil & Hlth, Oslo, Norway
[8] London Sch Hyg & Trop Med, Dept Noncommunicable Dis Epidemiol, Keppel St, London WC1E 7HT, England