[1] Ctr Geog Med Res Coast, Kenya Med Res Inst, Wellcome Res Labs, Kilifi, Kenya
[2] Makerere Univ, Fac Med, Dept Paediat & Child Hlth, Mulago Hosp, Kampala, Uganda
[3] UCL, Neurosci Unit, Wolfson Ctr, Inst Child Hlth, London WC1N 2AP, England
[4] St Marys Hosp, Imperial Coll, Wellcome Trust Ctr Trop Med, London W2 1NY, England
[5] Fac Med, Dept Paediat, London W2 1NY, England