RICKETTSIAL DISEASES: A. TRENCH FEVER. B. EPIDEMIC TYPHUS,

A. Trench Fever. Synthetic Juvenile Hormone was lethal for body lice. CF antigens from R. quintana propagated on blood agar were used to establish etiology of cases of trench fever and to begin to determine the geographic distribution of the disease. An antigenic relationship may exist between R. quintana and Canadian Vole Agent. Two rickettsia-like agents were isolated from guinea pigs. Tests suggested that positive reactions of Mexican donkey sera to soluble typhus antigen were probably non-specific. The etiology of a small typhus epidemic in Mexico was serologically confirmed. B. Epidemic Typhus. Over the past 15 years studies have been carried out to determine the immune status of communities subjected over many years to epidemics of typhus. By means of a vaccine response test applied to sample groups of Bosnians in 1951, 1958 and 1966, it has been demonstrated that over 90 of the inhabitants born before 1941 were infected with typhus. Only an occasional infection has occurred in people born after the war. Residual typhus antibodies have been shown to be steadily declining. Positive Weil-Felix responses in the recrudescent Brill Zinsser disease cases were demonstrated to be more frequent as the interval between the primary and recrudescent attack widened. Author