Surveillance of Rocky Mountain spotted fever in the United States, 1981-1983.
Surveillance of Rocky Mountain spotted fever (RMSF) in the United States has revealed a stable incidence of the disease from 1981 to 1983, with a median of 0.48 cases/100,000 population per year (range, 0.42-0.52). During this three-year period an increase in both the number and the percentage of total cases reported from the West South Central states was observed when compared with previous three-year periods. An expanded case report form, which was introduced in 1981 for use by state health departments, was received for 2,850 (87%) of the 3,294 cases reported in 1981-1983. Of these 2850 cases, 1375 (48%) were laboratory confirmed. Death from RMSF was more common in persons greater than or equal to 30 years of age (case-fatality ratio of 8.4%) than in persons less than 30 years (2.2%, P less than .001). Fatality was also associated with failure to obtain a history of a tick bite within 14 days before onset of illness (P less than .05) and with lack of treatment with tetracycline or chloramphenicol (P less than .01).
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D012373:Rocky Mountain Spotted Fever / Q000453:epidemiology* / Q000401:mortality; D012737:Sex Factors; D013997:Time Factors; D014481:United States