Interest in malaria has been stimulated in the United States by the high incidence of relapsing malaria in troops returning from service in endemic malaria areas. It has been observed in all hospitals receiving these patients that the relapse rate is high, particularly in Plasmodium vivax malaria. The recognized failure of quinine, atabrine and plasmochin in various dosages, singly and in combinations, to affect the relapse rate materially is a matter of concern and serves to emphasize the importance of developing new methods of treatment. For this reason and because the amount of available quinine has been considerably reduced, a search for more satisfactory compounds continues.
In monkeys the virulent Plasmodium knowlesi strain of malaria is highly susceptible to sulfanilamide.1
Reports concerning the effectiveness of related drugs on human strains have appeared in the literature during the past few years.2 While these reports have been somewhat conflicting, the