The need for adequate protection against chloroquine-resistant malaria led to the evaluation of diformyl diaminodiphenyl sulfone (DFD) as a chemoprophylactic agent. In this study the prophylactic value of weekly DFD (400 mg) and chloroquine (300 mg) against a chloroquine-resistant strain of Plasmodium falciparum is compared with that of two other commonly used regimens which require daily administration of 4,4′-diaminodiphenylsulfone (DDS; dapsone). Protection against mosquito-induced infections was achieved in 5 of 8 volunteers who received weekly DFD and chloroquine, 6 of 8 who received daily DDS (25 mg) and weekly chloroquine (300 mg), and 7 of 8 who received daily DDS (25 mg) and weekly chloroquine (300 mg) and primaquine (45 mg).
Walter Reed Army Institute of Research, Army Medical Research Project, Box 112, Joliet, Illinois 60434.
Department of Medicine, University of Chicago, Chicago, Illinois 60637.
Department of Medicine, University of Michigan, Ann Arbor, Michigan 48104.
Recipient of a Research and Career Development Award from the United States Public Health Service.