Lyme disease is a bacterial infection transmitted by certain ticks. The disease is caused by two kinds of bacteria, Borrelia burgdorferi and B. mayonii, that infect several species of ticks found in woodlands, brushy areas, and coastal grasslands. These ticks also are carried on the bodies of certain animals, especially white-tailed deer and white-footed field mice. People get Lyme disease after being bitten by an infected tick. The tick must remain attached for at least 36 hours for infection to occur. The disease is most commonly transmitted during the summer.
The symptoms of Lyme disease vary in type and severity. In most people, the first sign of infection is a rash. It spreads from the site of the tick bite two days to two weeks after the bite. The surest way to diagnose Lyme disease is to see the rash. However, more than a fourth of the people infected do not develop one. Other early symptoms include fever, headache, fatigue, and pain in the muscles and joints. Physicians use antibiotics to treat Lyme disease. When the illness is diagnosed and treated early, most patients make a full recovery. If untreated, the disease can lead to arthritis, heart abnormalities, and disorders of the nervous system.
People can reduce their risk of getting Lyme disease by taking precautions against ticks that transmit it. In woody or brushy areas, people should inspect their skin daily for ticks and remove them promptly. It also helps to wear long-sleeved shirts and long pants tucked into socks, and to use insect repellent. A vaccine that provides some protection against Lyme disease is available.
Lyme disease occurs in many parts of the world, including Africa, Asia, Australia, and Europe. In the United States, it is most common in the Northeast, in Minnesota, and in California. The disease gets its name from the town of Lyme, Connecticut, where a cluster of cases occurred in the early 1970’s.
