Lyme disease is caused by a bacteria known as the B. burgdoferi and is carried in the gut of certain ticks that feed off mice or deer. When the tick carrying Lyme disease finds a human being and feeds, its stomach contents go into the person's bloodstream and cause a skin rash starting at the point where the tick attaches itself. This rash, called erythema migrans, is typical. Several weeks later, flu-like symptoms develop, sometimes with severe inflammation of the brain and nervous tissue, and occasionally of the heart. The long-term consequences of Lyme disease can be serious and debilitating and cause chronic fatigue, arthritis, and damage to the peripheral nerves and brain. Even though Lyme disease can be treated with antibiotics, many patients have persistent symptoms and other patients who have been treated late or remain undiagnosed may have long-term symptoms.

The best treatment is to avoid the disease in the first place. Wearing long pants tucked inside boots or shoes, long sleeved shirts, and a hat are useful but may not be practical when it's hot.

The best practice is to avoid places with ticks that carry Lyme disease, but if that is not possible, the most important thing is to check yourself for the ticks. It is probably the easiest, safest, and non-toxic way to prevent the disease. A tick carrying Lyme disease must feed for 48 hours before it can actually transmit the disease. Develop a checking routine - say checking yourself in the shower for ticks and removing them. This way you will not get the disease. Checking for ticks is extremely important because ticks that carry Lyme disease also carry other infections, some of which may be even more serious than Lyme disease, such as Babesia and Ehrlichia.

Ticks that carry these diseases like moist, warm areas of the human body, such as the belt line, sock line, and armpits. The tick that carries Lyme disease is the size of a sesame seed. When fed, it can bloat to 10 times the size. People who live in Lyme disease areas find it convenient to rub their hands over their body during a shower. The tick feels like a little scab that doesn't come off. It should be removed without irritating it. Don't cover it with Vaseline or kerosene, or touch a match to it, because it could cause the tick to regurgitate its stomach contents. Ticks should be pulled on slowly and firmly with tweezers or, if you don't have them, your finger nails. It's not that difficult and it will save you a lot of grief.

A Lyme disease vaccine is available but, though approved by the Food and Drug Administration in the United States, there has been some concern about its long-term safety. Studies are being done to evaluate whether the vaccine may cause problems. If you are getting vaccinated, you will need to get the shots early on in the season because you will need at least 2 to 3 injections to provide immunity.

Matthew H. Liang, MD, MPH