What is it?

Lyme disease is an infection caused by the bacteria called Borrelia burgdorferi and is transmitted to humans through the bite of infected black-legged ticks (also known as deer ticks).

Where are deer ticks most prevalent?

In the United States, deer ticks live in wooded areas of the Northeast, from Virginia to Maine; North-central states, mostly in Wisconsin and Minnesota; and the West Coast, particularly northern California.

What are the symptoms of Lyme disease?

Symptoms of early stage Lyme disease include one or more of the following:

• A characteristic skin rash, called erythema migrans, which can appear as a red, circular, expanding rash 3 to 14 days after the bite of an infected tick; the center of the rash might clear as it enlarges, resulting in the classic “bull’s-eye” appearance.
• Fatigue
• Chills and fever
• Headache
• Muscle and joint pain
• Swollen lymph nodes

Symptoms of late-stage Lyme disease include one or more of the following:

• Pain and swelling in one or more large joints, especially the knees
• Numbness, pain, nerve paralysis (often of the facial muscles, usually on one side), and meningitis (fever, stiff neck, and severe headache)
• Irregularities of the heart rhythm (rarely)
• Problems with memory or concentration, fatigue, headache, and sleep disturbance

How is it diagnosed?

Lyme disease is diagnosed based on symptoms, physical findings (e.g., rash), and knowledge of recent exposure to infected ticks; laboratory testing can also be used.

How is it treated?

Most cases of Lyme disease can be treated successfully with a few weeks of antibiotics. Patients treated with antibiotics in the early stages of the infection usually recover rapidly and completely. Patients with late-stage Lyme disease usually respond well to antibiotics, but might require additional courses of antibiotic treatment to eliminate symptoms. Lyme disease is rarely life-threatening.

How can it be prevented?

• Avoid tick-infested areas. The risk of exposure to ticks is greatest in wooded, brushy, and grassy places and in the edge area between lawns and woods. Ticks can also be carried by animals onto lawns and gardens and into houses by pets.

• Use insect repellent. Insect repellents containing DEET, picaridin, IR3535, oil of lemon eucalyptus, para-menthane-diol, or 2-undecanone can be applied to the skin, and permethrin can be applied to clothes (especially pants, socks, and shoes).

• Perform daily tick checks. Check for ticks after being outdoors, even in your own yard. Remove attached ticks with tweezers. Because a tick usually must be attached for a day before transmitting the infection, the sooner the tick can be removed the better. Cleanse the area with rubbing alcohol or soap and water after removing the tick.

• Bathe or shower. Bathe or shower as soon as possible after coming indoors from tick-infested or high-risk areas (preferably within 2 hours).

• Tumble dry exposed clothes in the dryer. After being outdoors, tumble dry clothing in a hot dryer for 10 minutes to kill any ticks that are attached to clothing.

• Landscape your yard to create tick-safe zones.  “Tick-safe landscaping” techniques are provided on www.cdc.gov/Lyme.
• Chemically treat high-risk areas. Pesticide application should be supervised by a licensed professional pest control expert and should be conducted when nymphal tick populations are at their local peaks.

• Discourage deer. A complex relationship exists between the abundance of deer and the abundance of disease-carrying ticks in the eastern United States. Remove plants that attract deer and construct fences or other barriers to discourage tick-infested deer from coming near your homes. Lists of deer-resistant plantings are available from garden centers, nurseries, or local extension agents.

SOURCE: Adapted from Centers for Disease Control and Prevention. Lyme disease. Last updated January 19, 2018. https://www.cdc. gov/Lyme/. Accessed February 13, 2018. NH