Rocky Mountain spotted fever in the United States: use of age-specific incidence to determine public health policy for a vector-borne disease.

The increasing national and regional incidence of Rocky Mountain spotted fever (RMSF) during the past two decades led us to look at nationally collected epidemiologic data on reported cases of RMSF for 1975 through 1978, paying special attention to age-specific incidence in the states where the disease is most common. The group aged 5 to 9 years was the cohort at highest risk of contracting RMSF, but it was the 40- to 59-year age group that had the highest case fatality rate (CFR), 11.3%. Control efforts should include an educational program aimed at school-aged children and their parents, as well as instructions for physicians (particularly family practitioners and internists) on the early recognition and proper treatment of this illness.