College of American Pathologists
Printable Version

  Lyme Disease Information




Updated July 31, 2009

What is Lyme disease?

Lyme disease was named for Lyme, Connecticut, when, in 1977, arthritis was observed in a cluster of children in and around the city. Other clinical symptoms and environmental conditions suggested that this was an infectious disease probably transmitted by an anthropod, later found to be the bacterium Borrelia burgdorferi transmitted to humans via the bite of infected deer ticks.

The latest figures from the Centers for Disease Control project more than 200,000 new cases annually, with the highest number of cases reported in the northeastern portion of the United States.

Global warming may increase the severity of Lyme Disease by changing the feeding habits of the deer ticks that transmit it. As our planet warms, longer gaps between nymphal and larval feeding will result in stronger and more persistent strains of Lyme disease.

Lyme disease is transmitted mainly through tick bites and develops most often during the late spring and summer months from May through August.

Ticks tend to live in low bushes and tall grasses. As a result, individuals who frequent the outdoors (ie...campers, hunters, sports enthusiasts) are at a greater risk for contracting Lyme disease.

What are the symptoms of Lyme disease?

Early stage symptoms of Lyme disease are:

  • Solid red or bull’s eye rash, usually at the site of bite
  • Swelling or lymph glands near tick bite
  • Generalized aches
  • Headaches
  • Two or more rashes not at site of bite
  • Migrating pains in joints/tendons
  • Stiff, aching neck
  • Abnormal pulse
  • Sore throat
  • Changes in vision
  • Fever of 100 to 102 degrees Fahrenheit
  • Severe Fatigue

How can I prevent Lyme disease?

Prevention measures can be effective in reducing exposure to infected ticks. Take the following precautions in or near grassy or wooded areas to help prevent Lyme disease:

  • Wear enclosed shoes and light-colored clothes with a tight weave to spot ticks easily
  • Scan clothes and any exposed skin frequently for ticks while outdoors
  • Stay on cleared, well-traveled trails
  • Use insect repellant containing DEET on skin or clothes if you intend to go off-trail or into overgrown areas
  • Avoid sitting directly on the ground or on stone walls (havens for ticks and their hosts)
  • Keep long hair tied back, especially when gardening
  • Do a final, full-body tick-check at the end of the day (also check children and pets)

What are the risk factors of obtaining Lyme disease?

The biggest risk factors continue to be location, time of year, and conducting outdoor activities in overgrown areas.

Having a risk factor or several risk factors does not mean that you will get Lyme disease.

In the United States, Lyme disease is mostly localized to states in the northeastern, mid-Atlantic, and upper north-central regions, and to several counties in northwestern California. It is most common during the late spring and summer months from May through August.

Individuals who reside or work in residential areas surrounded by tick-infested woods or overgrown brush are most at risk of getting Lyme disease. People who work or play in their yard, participate in recreational activities away from home such as hiking, camping, fishing and hunting, or even play golf; or those who engage in outdoor occupations, such as landscaping, brush clearing, forestry, and wildlife and parks management in endemic areas may also be at risk of getting Lyme disease.

How can I treat Lyme disease?

According to medical experts, antibiotic treatment is generally effective in early disease. Other antibiotics can be used for those individuals who are allergic to penicillin or who cannot take tetracyclines. Later stages of disease—particularly when patients experience neurologic difficulties—may require treatment with intravenous ceftriaxone or penicillin for four weeks or more, depending on disease severity. In later disease, treatment failures may occur and retreatment may be necessary.