Ticks and Tickborne Diseases

Rocky Mountain Spotted Fever

Rocky Mountain spotted fever is characterized by a sudden onset of symptoms and can be fatal if not treated. Between 1974 and 1982, an annual average of 112 cases and 3 deaths were reported in MD-DC-VA. In recent years, only about 30 cases and less than 1 death per year have been reported. Nearly all cases occur in spring and summer months.

In MD-DC-VA, the dog tick (Dermacentor variabilis) commonly carries the organism that causes Rocky Mountain spotted fever. The tick is usually attached for 4 to 6 hours before it transmits the disease.

The Symptoms

Early symptoms of Rocky Mountain spotted fever, which start 2 to 14 days after the tick bite, include fever, deep muscle pain, severe headache, chills, and upset stomach or vomiting. Around the third day a red, spotted rash usually appears beginning on the wrists and ankles. It spreads quickly to the palms and soles and then to much of the rest of the body.

Blood tests can confirm the presence of the disease, but two tests spaced several weeks apart may be required.

The Treatment

Treatment should start as soon as possible based on symptoms and history of tick exposure rather than waiting for blood test confirmation. Antibiotics in the tetracycline family are usually administered to treat the disease in adults. Other antibiotics are prescribed for children.