Health
Summer is the time for Lyme
■ An occasional snapshot of current facts and trends in medicine.
Quick View. Posted July 7, 2008
The annual number of Lyme disease cases has more than doubled since it became a nationally notifiable condition in 1991.
Summertime is peak season for Lyme disease, the most common vector-borne disease in the United States. The disease, caused by the spirochete Borrelia burgdorferi, is transmitted to humans by the bite of infected black-legged ticks. Its early manifestations include fever, headache, fatigue and a characteristic rash, erythema migrans. Left untreated, late manifestations involving the joints, heart and nervous system can occur. In 2006, 19,931 cases of Lyme disease were reported, yielding a national average of 8.2 cases per 100,000 people. In the 10 states where Lyme disease is most common -- for surveillance purposes, these are considered reference states -- the average was 30.2 cases per 100,000 people. In general, most cases occur in northeastern, mid-Atlantic and north-central states. But since 1993, confirmed cases have occurred in every state.
Note: Total exceeds 100% because more than one clinical finding was reported for some patients.
Source: Centers for Disease Control and Prevention