THE INFLUENCE OF BIOTIN UPON SUSCEPTIBILITY TO MALARIA.

Biotin-deficient chickens and ducks developed much more severe infections with Plasmodium lophurae than did non-deficient control animals. While a very mild degree of biotin deficiency sufficed to increase susceptibility, even an extreme degree of pantothenic acid deficiency had no effect. Biotin deficiency also increased the susceptibility of ducks to P. cathemerium. In animals infected with P. lophurae, the concentration of biotin in the plasma as well as in the red cells rose during the course of the infection, reached a peak at about the same time as the parasite number reached its peak, and then returned to normal as the infection subsided. While the administration of additional biotin to animals partially deficient in biotin could be considered a specific measure tending to lessen the severity of infection with P. lophurae, the injection of biotin into animals fed a diet adequate in this vitamin had no antimalarial effects, perhaps because the excess biotin was rapidly removed from the blood.