Affiliation: | Hospital for Tropical Diseases, London NW1 OPE U.K.;Ahmadu Bello University, Zaria, Nigeria;Concord Hospital, Concord 2139, Sydney, Australia;St. Thomas''s Hospital, London SE1 7EH U.K.;Medical Research Council Laboratories, Fajara, The Gambia;Universidade de Brasilia, Brazil;AMREF, P.O. Box 30125, Nairobi, Kenya |