In the United States, Lyme disease is caused by the bacterium Borrelia burgdorferi and rarely, Borrelia mayonii. It occurs most commonly in the Northeast, mid-Atlantic, and upper-Midwest regions. Lyme disease bacteria are spread to humans through the bite of infected blacklegged ticks. Typical symptoms include fever, headache, fatigue, and a characteristic skin rash called erythema migrans. If left untreated, infection can spread to joints, the heart, and the nervous system. Lyme disease is diagnosed based on symptoms, physical findings (e.g., rash), and the possibility of exposure to infected ticks. Laboratory testing is helpful if used correctly and performed with FDA-cleared tests. Most cases of Lyme disease can be treated successfully with a few weeks of antibiotics.

Signs and symptoms

Untreated Lyme disease can produce a wide range of symptoms, depending on the stage of infection. These include fever, rash, facial paralysis, an irregular heartbeat, and arthritis.

How it spreads

Lyme disease bacteria causing human infection in the United States are spread to people by blacklegged (Ixodes) ticks.

Testing and diagnosis

CDC recommends the use of FDA-cleared antibody tests for laboratory diagnosis of Lyme disease.

What CDC is doing

CDC has a program of service, research, and education focusing on the prevention and control of Lyme disease. Activities of this program include:

  • Maintaining and analyzing national surveillance data for Lyme disease
  • Conducting epidemiologic investigations
  • Offering diagnostic and reference laboratory services
  • Developing and testing strategies for the control and prevention of this disease
  • Supporting education of the public and healthcare providers