[1] London Sch Hyg & Trop Med, LSHTM TB Ctr, Keppel St, London, England
[2] London Sch Hyg & Trop Med, Dept Clin Res, Keppel St, London, England
[3] Zambart, Ridgeway Campus, Lusaka, Zambia
[4] Univ Stellenbosch, Dept Paediat & Child Hlth, Desmond Tutu TB Ctr, ZA-7600 Stellenbosch, South Africa
[5] UCL, Gower St, London, England
[6] London Sch Hyg & Trop Med, Dept Infect Dis Epidemiol, Keppel St, London, England