[1] London Sch Hyg & Trop Med, Dis Control & Vector Biol Unit, Dept Infect & Trop Med, London WC1E 7HT, England
[2] Univ Oxford, Dept Zool, TALA Res Grp, Oxford OX1 3PS, England
[3] KEMRI, Wellcome Trust Collaborat Programme, Nairobi 00100, Kenya
[4] Minist Hlth, Div Malaria Control, Nairobi, Kenya
[5] Minist Hlth, Natl Malaria Control Programme, Kampala, Uganda
[6] London Sch Hyg & Trop Med, London WC1B 3DP, England
[7] Univ Rotterdam, Ctr Med, Dept Publ Hlth, Erasmus MC, NL-3000 DR Rotterdam, Netherlands