Rocky Mountain spotted fever acquired in Florida, 1973-83.

From 1973 to 1983, 49 Florida residents were reported with confirmed Rocky Mountain spotted fever (RMSF), 25 of whom were considered to have had Florida-acquired disease. Although there was no history of tick exposure for six of these 25 persons, all had contact with dogs or outdoor activities during the incubation period. The tick vectors of RMSF are widely distributed throughout Florida. We conclude that RMSF, although rare in Florida, can be acquired in the state.