Effect of Sulfanilamide and Sulfapyridine on the Avian Malarias. ∗

Abstract

The effect of sulfanilamide and sulfapyridine on some of the bacterial infections has been so striking that these drugs have been tried on many others, including some of the malarias, both of man and of animals. The results obtained have been of considerable interest, and not the less so because they have varied a great deal with the species. Coggeshall, 1 for example, found that sulfanilamide was effective in eradicating Plasmodium knowlesi infection in monkeys, but was apparently without any action on Plasmodium inui in the same host. He suggested that the difference might be due to the much more rapid metabolism of the former species. This seems probable in view of the generally accepted idea that sulfanilamide is effective because oxidation products are formed from it which destroy catalase, and hence interfere with the metabolic activities of the cell. Since the malaria parasites are present in the blood stream they are presumably more exposed to this effect than if they were segregated somewhere in the tissues.

Against the malaria parasites of man sulfanilamide and its derivatives appear not to be of great value, although the reports are conflicting, and there seems to be but one report of its use in avian malaria. Coggeshall 2 states that when administered to chicks infected with Plasmodium lophurœ and canaries infected with Plasmodium cathemerium it was without noticeable influence. It has also been used on Hemoproteus columbœ, but failed to exert any effect (Durand and Villain 3 ).

Since it is well-recognized that the various species of malaria plasmodia react quite differently to even the same drug, trial of sulfapyridine and ssulfanilamide on some of the other species of avian malaria has been uundertaken. So far all the tests have been made on blood-induced infections because such infections are more easily produced in the numbers required for extensive experimenting, and also because mosquitocs have not been available.