Lyme Disease Transmission

The Lyme disease bacterium,

Borrelia burgdorferi, normally lives in

mice, squirrels and other small

animals. It is transmitted among

these animals—and to humans—

through the bites of certain species

of ticks.

In the northeastern and northcentral

United States, the blacklegged tick (or

into its body along with the blood meal. The bacterium then lives in the gut of the tick. If the tick feeds again, it can

transmit the bacterium to its new host. Usually the new host is another small rodent, but sometimes the new host is a

human. Most cases of human illness occur in the late spring and summer when the tiny nymphs are most active and

human outdoor activity is greatest.

Although adult ticks often feed on deer, these animals do not become infected. Deer are

nevertheless important in transporting ticks and maintaining tick populations.

There is no evidence that Lyme disease is transmitted from person-to-person. For example, a person cannot get

infected from touching, kissing or having sex with a person who has Lyme disease.

Lyme disease acquired during pregnancy may lead to infection of the placenta and possible stillbirth, however, no

negative effects on the fetus have been found when the mother receives appropriate antibiotic treatment. There are no

reports of Lyme disease transmission from breast milk.

Although no cases of Lyme disease have been linked to blood transfusion, scientists have found that the Lyme disease

bacteria can live in blood that is stored for donation. As a precaution, the American Red Cross and the US Food and

Drug Administration ask that persons with chronic illness due to Lyme disease do not donate blood. Lyme disease

patients who have been treated with antibiotics and have recovered can donate blood beginning 12 months after the last

dose of antibiotics was taken.

Although dogs and cats can get Lyme disease, there is no evidence that they spread the disease directly to their

owners. However, pets can bring infected ticks into your home or yard. Consider protecting your pet, and possibly

yourself, through the use of tick control products for animals.

You will not get Lyme disease from eating venison or squirrel meat, but in keeping with general food safety principles

meat should always be cooked thoroughly. Note that hunting and dressing deer or squirrels may bring you into close

contact with infected ticks.There is no credible evidence that Lyme disease can be transmitted through air, food,

water, or from the bites of mosquitoes, flies, fleas, or lice.