Lyme Disease

What is Lyme Disease?

Lyme disease is an infectious disease caused by any of at least three species of a special kind of bacteria called a spirochete (Borrelia). It is the most common tick-borne disease in the Northern Hemisphere. 

How do you get Lyme Disease?

Lyme disease is transmitted to humans through the bite of ticks infected with the bacteria, Borrelia.  The bacteria exist in a natural reservoir among rodents, and the tick transfers the bacteria to humans.  Most infections are caused by ticks in the nymphal stage when they are very small and feed for long periods of time undetected.

Susceptibility and Resistance

All persons are likely susceptible. Re-infection has occurred in those treated with antibiotics for early disease.

Incubation Period

The incubation period for Lyme Disease is 3-32 days.

What are the Symptoms?

Symptoms of Lyme disease include a characteristic expanding rash, called erythema chronicum migrans, at the site of the tick bite.  Other symptoms include fever, arthritis, and neurological problems, including facial palsy (paralysis and loss of sensation in the face). Late, delayed, or inadequate treatment can lead to late manifestations of Lyme disease which can be disabling and difficult to treat. Some Lyme disease patients who have completed a course of antibiotic treatment continue to have symptoms such as severe fatigue, sleep disturbance, and cognitive difficulties.

Preventative Measures

Avoid direct contact with ticks, especially in warm summer months when ticks are most active. Avoid wooded and bushy areas with high grass.  Use insect repellent containing 20 percent or more of DEET. After possible exposure in outdoor settings, bathe as soon as possible and carefully check skin over the entire body surface. Remove any ticks immediately.


If the Lyme disease rash or other symptoms of Lyme disease occur, the patient should seek early medical attention. Lyme disease can usually be cured by an appropriate course of antibiotic treatment.


Where Does It Commonly Occur?

Lyme disease is spread by ticks that carry the Borrelia bacteria, therefore, the disease can be found wherever infected ticks are found. In northern Africa, the ticks that carry Borrelia occur in Morocco, Algeria, Egypt and Tunisia. They may also be present in Kenya. In Asia, these ticks can be found in Japan, northwest China, Mongolia, Nepal, Thailand, and far eastern Russia. In North America, these ticks are found in many parts of Canada and in the eastern United States. In Europe, these ticks are found mainly in central Europe (Slovenia and Austria), but also in almost every other country on the continent. The ticks can be found in the United Kingdom and the Republic of Ireland. In South America, the ticks have been found in Brazil, Colombia, and Bolivia.