Abstract
The name Rocky Mountain spotted fever is now obviously geographically incorrect, since this disease has been found in forty-seven of the forty-eight states. Ten years ago 70 per cent of the cases occurred in the Mountain and Pacific states, while in 1945 87 per cent were reported from the Central and Eastern states. Its incidence and importance to public health in the United States are shown by the occurrence of 400 to 560 cases with 90 to 137 deaths each year during the past decade. Formerly it was believed that the eastern variety of Rocky Mountain spotted fever was mild, but in 1944 the mortality in 61 cases from the Rocky Moutain states was 32 per cent and in 241 cases from the South Atlantic states, 25 per cent. Because of the tremendous area over which the cases occur it is probable that few physicians are afforded the opportunity to