[1] London Sch Hyg & Trop Med, Dept Populat Hlth, Keppel St, London WC1E 7HT, England
[2] Univ Roma La Sapienza, Dept Publ Hlth & Infect Dis, I-00185 Rome, Italy
[3] London Sch Hyg & Trop Med, Dept Med Stat, London WC1E 7HT, England
[4] Univ Nagasaki, Sch Trop Med & Global Hlth, Nagasaki 8528102, Japan
[5] Africa Innovat Inst AfrII, POB 34981, Kampala, Uganda
[6] Kyambogo Univ, Dept Nutr Sci & Dietet, POB 1, Kampala, Uganda
[7] Univ Greenwich, Nat Resources Inst NRI, Kent ME4 4TB, England