[1] UNIV CAMBRIDGE,DEPT PATHOL,CAMBRIDGE CB2 1QP,ENGLAND
[2] MINIST HLTH,DIV VECTOR BORNE DIS,NAIROBI,KENYA
[3] KENYAN MED RES INST,NAIROBI,KENYA
[4] UNIV LONDON LONDON SCH HYG & TROP MED,DEPT MED HELMINTHOL,LONDON WC1E 7HT,ENGLAND
[5] MINIST HLTH,DIV DIS CONTROL & RES,NAIROBI,KENYA