Lyme disease is an infection with a corkscrew-shaped bacteria called Borrelia burgdorferi. It is passed to humans through tick bites.
What is going on in the body?
After an infected tick bites an individual, the Borrelia burgdorferi organism can cause early local Lyme disease. This may cause a mild flu-like illness and a rash at the site of the bite. If the organism spreads through the body by the bloodstream, it can affect many body systems. This widespread infection is known as disseminated Lyme disease.
What are the causes and risks of the infection?
Lyme disease is caused by Borrelia burgdorferi. This bacteria is carried by certain species of ticks, including the following:
deer ticks in the northeastern and north-central parts of the United States
sheep ticks in Europe
Taiga tick in Asia
western black-legged ticks in other parts of the U.S.
A person in these areas increases his or her risk of acquiring Lyme disease from a tick bite with the following activities:
living in a wooded or overgrown environment
Lyme disease can also be passed to an unborn child if the baby's mother has the disease during pregnancy.