Rocky Mountain Spotted Fever in the Eastern United States

Abstract

The majority of 13 cases of Rocky Mountain spotted fever from an endemic focus of the disease in the Cape Cod area of Massachusetts were diagnosed late, and two patients died. However, earlier diagnosis, earlier initiation of specific therapy, and prevention of fatalities should have been possible. Clinical, epidemiologic and laboratory data highly suggestive of the disease were almost all available early in the first week of illness to help in the diagnosis. There was high fever, severe headache, toxicity, mental confusion and myalgia. A generalized measles-like rash involved the palms and soles in almost all cases. Cases occurred seasonally between April and September, sharply restricted geographically to a known endemic focus, and predominantly in children. Complement-fixing and Weil-Felix antibodies rose late in the second week and were of no help in early diagnosis. Thrombocytopenia was surprisingly frequent, occurring in seven of 11 patients tested.