The experiments reported were designed to determine the influence of malarial
infection (Plasmodium inui?),
splenectomy, or both combined, upon the course and character of experimental
infection with Bartonella bacilliformis in monkeys (Macacus rhesus and M. cynomolgus). Blood withdrawn from a monkey showing spontaneous malarial
infection was inoculated intravenously into monkeys (a) 1 month prior to inoculation with virulent verruga material, (b) simultaneously with the verruga material, and (c) during
convalescence from verruga
infection of moderate severity. All the monkeys contracted the malarial
infection and suffered one to three paroxysms during a period of about a month. The verruga lesions appeared in the inoculated animals in due course, were of average size, remained for the usual length of time, and Bartonella bacilliformis was recovered in culture from blood which also contained the plasmodia. The lesions in the convalescent animals continued to heal at the normal rate, and blood cultures were negative for Bartonella bacilliformis, as is usual during
convalescence. One of the recovering animals was reinoculated with virulent verruga material a month after the injection of the malarial blood, but neither did new lesions arise nor old ones recur. The malarial
infection, therefore, had no effect upon the course of verruga or upon the establishment of immunity to Pattonella bacilliformis, hence it would appear that
malaria and verruga may coexist in the same individual without unfavorable effect of one disease upon the course of the other. Similarly,
splenectomy led to no appreciable aggravation of
Bartonella infection. One monkey subjected to
splenectomy and inoculated with verruga material shortly afterwards had an unusually severe reaction, but another, which was infected with material from the first and simultaneously splenectomized, reacted only moderately, while the non-splenectomized control showed a severer type of cutaneous
infection. Even the combination of
splenectomy and malarial
infection did not appreciably aggravate the experimental verruga. Neither relapse of verruga nor
reinfection with Bartonella bacilliformis was induced in convalescent or recovered monkeys as a result of
splenectomy.