Rocky Mountain spotted fever on Long Island. Epidemiologic and clinical aspects

From 1941 to 1970 260 cases of Rocky Mountain spotted fever were documented in Suffolk County, Long Island. A marked decline in the over-all attack rate during the past three decades and in incidence during the last decade was observed. The decline in incidence corresponds well with the period of maximum suburbanization in Suffolk County, Long Island, and may be related to land cultivation and use of insecticides which eliminate favorable flora and animal hosts for the tick vector, Dermacentor variabilis.