A study of 452 cases of murine typhus fever occurring in Southwest Georgia from January, 1945, to January, 1953, showed a seasonal peak of rural cases during the summer but an even distribution of urban cases throughout the year. Incidence rates were about twice as high in rural as in urban areas, and about eight times greater in the white than in the colored race. Age-specific incidence rates were low in childhood, rising to a peak during the fourth and fifth decades. Farmers and their families made up 70 per cent of the cases studied. The mean titer of the Weil-Felix test was high in the first week and then rapidly declined, whereas the mean titer of the complement fixation test reached a peak during the second week and remained high over the next 50–60 weeks after which it slowly declined. In cases treated with aureomycin, there was a consistent lowering of mean titers for the complement fixation test, but very little effect on the Weil-Felix titers was demonstrated.
Present address: National Institutes of Health, National Heart Institute, Bethesda 14, Md.