Rocky Mountain spotted fever (tick-borne typhus) in South Carolina: an educational program and tick/rickettsial survey in 1973 and 1974.

Because the incidence of spotted fever is increasing in South Carolina, campaigns were carried out in 1973 and 1974 to provide the public and medical practitioners, through pamphlets and news media, with information about spotted fever and the ticks which transmit the causative agent, Rickettsia rickettsii. People were also invited to save and submit live ticks removed from vegetation, animals and humans, for examination by the hemolymph test. A total of 1,186 ticks consisting of 987 Dermacentor variabilis, 103 Rhipicephalus sanguineus, and 96 Amblyomma americanum were examined. Rickettsiae identified by direct immunofluorescence as members of the spotted fever group were detected in 49 (4.9%) of the D. variabilis, and 16 (16.6%) of the A. americanum ticks. Two hundred and twenty (199 D. variabilis, 17 A. americanum, and 4 R. sanguineus) were recorded as having been attached to 199 persons. Nine of these ticks (8 D. variabilis, and 1 A. americanum) were hemolymph test-positive for spotted fever-group rickettsiae. Infected ticks originated from each of the three major South Carolina biogeographic regions, namely Piedmont, Sandhill, and Coastal Plain. Since education is the first and most important step in preventing spotted fever, educational programs and tick examination services similar to those decribed, are suggested for other states with high spotted fever incidence.