Lyme disease

Fact sheet about Lyme disease

What is Lyme disease?

Lyme disease is caused by bacteria (germs) that are spread by infected black-legged (deer) ticks.  Both people and animals can have Lyme disease.

How is Lyme disease spread?

Lyme disease is spread by the bite of an infected black-legged tick.  The tick usually must be attached to a person for at least 24 hours before it can spread the germ.  Black-legged ticks in Massachusetts can also carry the germs that cause babesiosis, human granulocytic anaplasmosis,Powassan virus disease, and Borrelia miyamotoi infection.  These ticks are capable of spreading more than one type of germ in a single bite.

What are the symptoms of Lyme disease?

Early stage (days to weeks): The most common early symptom is a rash (erythema migrans) where the tick was attached.  It often, but not always, starts as a small red area that spreads outward, clearing up in the center so it looks like a donut. Flu-like symptoms, such as fever, headache, stiff neck, sore and aching muscles and joints, fatigue and swollen glands may also occur. Even though these symptoms may go away by themselves without medical treatment, some people will get the rash again in other places on their bodies, and many will experience more serious problems.  Treatment during the early stage prevents later, more serious problems. 

Later stages (weeks to years): If untreated, people with Lyme disease can develop late-stage symptoms even if they never had a rash. The joints, nervous system and heart are most commonly affected. 

• About 60% of people with untreated Lyme disease get arthritis in their knees, elbows and/or wrists.  The arthritis can move from joint to joint and become chronic. 
• Many people who don’t get treatment develop nervous system problems.  These problems include meningitis (an inflammation of the membranes covering the brain and spinal cord), facial weakness (Bell’s palsy) or other problems with nerves of the head, and weakness or pain (or both) in the hands, arms, feet and/or legs.  These symptoms can last for months, often shifting between mild and severe. The heart also can be affected in Lyme disease, with slowing down of the heart rate and fainting.  The effect on the heart can be early or late. 

How soon do symptoms of Lyme disease appear?

Symptoms of early Lyme disease, described below, usually begin to appear from 3 to 30 days after being bitten by an infected tick.  If untreated, symptoms of late Lyme disease may occur from weeks to years after the initial infection. 

How is Lyme disease diagnosed?

Lyme disease is diagnosed through laboratory testing including molecular (PCR) and/or serologic tests.

How is Lyme disease treated?

People who are diagnosed with Lyme disease can be treated with antibiotics.  Prompt treatment during the early stage of the disease prevents later, more serious problems. 

Where does Lyme disease occur?

In the United States, Lyme disease most commonly occurs in the Northeast and mid-Atlantic regions and in the upper Midwest. In Massachusetts, Lyme disease occurs throughout the state.

Is there a seasonality (time of year) one is more likely to get Lyme disease?

Lyme disease can occur any time ticks are active.  Young ticks (nymphs) are most active during the warm weather months between May and July. Adult ticks are most active during the fall and spring but may also be out searching for a host any time that temperatures are above freezing. 

How can you prevent Lyme disease?

Prevention begins with you! Take steps to reduce your chances of being bitten by any tick. Ticks are most active during warm weather, late spring through fall. However, ticks can be out any time that temperatures are above freezing. Ticks cling to vegetation and are most numerous in brushy, wooded, or grassy habitats. When you are outside in an area likely to have ticks (e.g., brushy, wooded, or grassy places), follow these simple steps to protect yourself and your loved ones:

• Use EPA registered tick repellents.
• Products with DEET may be used on skin. Repellents containing DEET should not be used on children less than 2 months of age and should be used in concentrations no higher than 30% on older children.
• Use permethrin products on items such as clothing, shoes, bed nets and camping gear. Permethrin should not be applied to skin.
• Other repellents, such as picaridin, oil of lemon eucalyptus and IR 3535, have also been found to provide protection against ticks. More information on choosing a repellent and how to use repellents safely is included on the DPH Public Health Fact Sheet on Tick Repellents at mass.gov/DPH/Ticks.
• Wear long, light-colored pants tucked into socks or boots, and a long-sleeved shirt. This will help keep ticks away from your skin and help you spot a tick on your clothing faster.
• Stay on trails when walking or hiking, avoiding the edge habitat where ticks are likely to be.
• Talk to your veterinarian about tick control options (tick collars, repellents) for your pets.

After spending time in an area likely to have ticks, check yourself, your children, and pets for ticks. Young ticks, called nymphs, are the size of a poppy seed. Adult ticks are the size of a sesame seed. Both nymph and adult ticks can spread diseases; however, nymphs are more of a concern. They are aggressive feeders and so tiny that it can be difficult to see them on the body unless you look carefully. When doing a tick check, remember that ticks like places that are warm and moist. Always check the back of the knees, armpits, groin, scalp, back of the neck and behind the ears. If you find a tick attached to your body, remove it as soon as possible using fine-point tweezers. Do not squeeze or twist the tick’s body, instead grasp it close to your skin and pull straight out with steady pressure.

Know the symptoms of Lyme disease as described in this fact sheet.  If you have been someplace likely to have ticks and develop symptoms of any disease carried by ticks, see your health care provider right away.

Where can I get more information on Lyme disease?

• For questions about your own health, contact your health care provider.
• For questions about diseases spread by ticks, contact DPH at [phone] or online at mass.gov/DPH/Ticks. You may also contact your local Board of Health.
• Health effects of pesticides, DPH, Bureau of Climate and Environmental Health at [phone].