Rocky Mountain spotted fever can no longer be regarded a disease restricted to the Rocky Mountain region. "Spotted fever" is now reported beyond the boundaries in which the common vector of the disease, the wood tick, is found. Recent studies1 show that the disease is prevalent in the eastern and southeastern parts of the United States where typhus, with which Rocky Mountain spotted fever is sometimes confused, is endemic. Rumreich, Dyer and Badger have also established the fact that the dog tick (Dermacentor variabilis) is the vector of the disease in these areas. This tick is found in eastern and midwestern states and on the west coast and to some extent overlaps the distribution of Dermacentor andersoni. In these areas, sporadic cases of typhus already have been reported.
Because of the increasing distribution and incidence of the disease, the problem of recognition and treatment has become of interest to