About Lyme Disease- Minnesota Dept. of Health

About Lyme Disease

Lyme disease is a bacterial infection caused by the bite of an infected blacklegged tick (also known as the deer tick or bear tick). The disease affects both humans and animals. The health department is monitoring the spread of the disease across the state and working with residents to limit exposure to the ticks causing the disease.

On this page:
Fact Sheets
Signs and symptoms
Treatment following a tick bite
More from other web sites

Fact Sheets


  • Lyme disease is one of several tickborne diseases in Minnesota.
  • In order to get Lyme disease, a person must be bitten by a blacklegged tick (also known as deer tick or bear tick) that is infected with the Lyme disease bacteria.
      • On average, about 1 in 3 adult blacklegged ticks and 1 in 5 blacklegged tick nymphs (immature stage) are infected with Lyme disease bacteria.
    • The tick must be attached for at least 24-48 hours to transmit the bacteria.
    • The chance of getting Lyme disease increases the longer the tick is attached.


  • Preventing Tickborne Diseases
    Learn how to minimize your risk to Lyme disease and other tickborne diseases.

  • Lyme Disease Vaccine
    Sales of the Lyme disease vaccine Lymerix (the only Lyme disease vaccine for humans) were discontinued in 2001. Research for new Lyme disease vaccines is currently ongoing.

Signs and symptoms

The signs and symptoms of Lyme disease vary among individuals. A person may not have all of these symptoms. People often feel like they have "the flu."

  • Three to 30 days after a blacklegged tick bite, look for:
  • Days to weeks after onset of illness, one or more of these signs and symptoms may occur:
    • Multiple rashes
    • Facial paralysis on one side of the face
    • Fever
    • Stiff neck
    • Headache
    • Weakness, numbness or pain in arms or legs
    • Irregular heart beat
    • Dizziness, feeling lightheaded, or heart palpitations
    • Persistent weakness and fatigue

  • Weeks to months after onset of illness, some of these signs or symptoms may appear:
    • Joint swelling from arthritis in one or more joints, usually the knees
      • Arthritis can also have other causes.
    • Problems with the nervous system
    • Persistent weakness and fatigue


  • If a person suspects Lyme disease, he or she should contact a doctor immediately.
    • Diagnosis includes:
      • Physical examination (signs and symptoms, presence of a rash)
      • History of possible exposure to blacklegged ticks
      • Blood tests may be performed
    • A thorough physical examination and history of exposure are required for proper diagnosis and treatment.

    • Blood tests may be negative within the first 2-3 weeks of illness. A blood test is not required for diagnosis of early Lyme disease when the characteristic rash is present. The blood test is an important part of diagnosis for patients who have been ill for more than one month.
  • Early recognition of signs and symptoms of Lyme disease is very important for prompt diagnosis and treatment.

  • Early diagnosis and treatment can reduce the time a person is ill and the severity of the disease.


  • Here are a few general statements about the treatment of Lyme disease:
    • The disease is treated with antibiotics. Antibiotics are very effective in killing the bacteria.
    • Treatment is most effective early in the course of Lyme disease. Lyme disease detected later is also treatable with antibiotics, but can cause symptoms that may take longer to go away, even after the antibiotics have killed the Lyme disease bacteria.
  • Most people have a complete resolution of their symptoms after treatment. A small percentage of patients (especially those diagnosed in the later stages of the disease) have persistent complaints after treatment.
  • Specific questions about treatment should be discussed with your health care provider.

Treatment following a tick bite

  • In some circumstances, a single dose of antibiotic (doxycycline) given within 72 hours of a tick bite might prevent the development of Lyme disease. Several criteria must be met:
    • The tick must be identified as the blacklegged tick (deer tick).
    • The tick must have been attached for at least 36 hours (if it is engorged -- puffed up with blood -- then it was probably on this long).
    • The tick bite occurred in a highly endemic area (see High Risk Areas for Tickborne Diseases in Minnesota)
  • Talk to your doctor about the single dose antibiotic treatment if you meet these criteria. You can also take a "wait-and-see" approach and watch for signs and symptoms of Lyme disease. Prompt treatment of the disease is very effective and will prevent more severe signs and symptoms.


  • Lyme disease is the most common tickborne disease in the United States.

  • The disease was named in 1975, when a group of children in Connecticut were reported to have juvenile arthritis.

  • The Minnesota Department of Health began collecting information on people diagnosed with Lyme disease in 1982. In 1985, Lyme disease became a reportable disease in the state.

  • During the 1980s, the Minnesota Department of Natural Resources, Metropolitan Mosquito Control District, and other organizations were also participating in Lyme disease activities.

  • Lyme disease has now become endemic throughout most of Minnesota, affecting thousands of residents each year.

More from other web sites:

  • CDC Lyme Disease
    Centers for Disease Control and Prevention general information about Lyme disease.

Updated Wednesday, 17-Mar-2021 11:12:31 CDT