[1] Africa Hlth Res Inst, Kwa Zulu, South Africa
[2] UCL, Inst Global Hlth, London, England
[3] Univ KwaZulu Natal, Durban, South Africa
[4] Univ Southampton, Southampton, Hants, England
[5] Univ Witwatersrand, MRC Wits Rural Publ Hlth & Hlth Transit Res Unit, Gauteng, South Africa
[6] Harvard TH Chan Sch Publ Hlth, Dept Epidemiol, Boston, MA USA
[7] Harvard TH Chan Sch Publ Hlth, Harvard Ctr Populat & Dev Studies, Boston, MA USA
[8] London Sch Hyg & Trop Med, London, England