How is Lyme disease spread to humans?
Lyme disease is spread to humans through the bite of an infected deer tick.
- A tick must be attached for at least 24 hours to spread Lyme disease to a person. It is important to remove ticks as soon as they are found to prevent illness.
- Most humans are infected by immature ticks, called nymphs.
- Nymphs are very small, about the size of a poppy seed. They are difficult to see, and most people may not feel their bite. This makes them harder to remove promptly.
- Nymphs are most active during the spring and early summer.
- Adult ticks also spread Lyme disease.
- Adults are much larger than nymphs, and are more likely to be found and removed before the bacteria are spread to the person.
- Adult ticks are most active during the cooler months.
- Ticks can attach to any part of the body but are often found in hard-to-see areas, such as:
- Behind the knees
- In and around the ears
- Inside the belly button
Lyme disease is preventable and treatable. Visit our Tick Bite Prevention page to learn how to prevent tick bites, and how to properly remove a tick if you are bitten.
What are the signs and symptoms of Lyme disease?
BE ALERT FOR FEVER OR RASH. Even if you do not remember being bitten by a tick, a fever or rash may be the first sign of Lyme disease. Contact your health care provider right away if you have either of these symptoms.
Early symptoms can show up three to 30 days after being bitten by an infected tick.
Early signs and symptoms include:
- Circular reddish rash, also known as erythema migrans (EM) rash
- Occurs in about 70 to 80 percent of cases.
- Expands in size over a period of days or weeks.
- May clear in the center as it gets bigger, giving it a "bull's-eye" appearance.
- NOTE: A small bump or redness at the tick bite site is common, and usually goes away in one to two days. This is not a sign of Lyme disease.
- Fever, sweats, chills
- Stiff neck
- Muscle and/or joint pain
Later symptoms can show up weeks to months after being bitten by an infected tick.
If left untreated, Lyme disease can affect other body systems. Later signs and symptoms include:
- Arthritis (joint swelling)
- Meningitis (brain and spinal cord swelling)
- Facial palsy (droop on one or both sides of the face)
- Heart abnormalities
- Nerve pain
- Shooting pains, numbness, or tingling in the hands or feet
How is Lyme disease treated?
Most people treated with oral antibiotics during the early stages of Lyme disease recover completely. It is important to get treatment as soon as possible after symptoms start. Antibiotics commonly used for oral treatment include doxycycline, cefuroxime axetil, or amoxicillin. The following table shows the current treatment recommendations from CDC for early stage Lyme disease in adults and children.
Treatment for Early Lyme Disease
If treatment is delayed, the bacteria can spread to the joints, heart, and nervous system and have long-term effects. Lyme disease can be difficult to treat in later stages, and severe cases may require intravenous treatment. Some people may have symptoms that will not go away or return even after appropriate antibiotic treatment, a condition called post-treatment Lyme disease syndrome (PTLDS).
- Lyme Disease Fact Sheet, P-42070 (Multiple Languages): Educational fact sheet for the general public on Lyme disease covering signs and symptoms, treatment, and prevention.
- Lyme Disease Risk in Wisconsin, P-01752 (PDF): Educational flyer describing the risk posed by Lyme disease in Wisconsin.
- Tickborne Diseases Risk in Wisconsin, P-01751 (PDF): Educational flyer describing the risk posed by illnesses spread by ticks in Wisconsin.
- Protecting Your Family From Mosquitoes and Ticks, P-02080 (PDF): A fact sheet with simple steps you can take to protect yourself from ticks.
- Lyme Disease Frequently Asked Questions (FAQ): FAQ about Lyme disease transmission, diagnosis, testing, treatment, and more.
- Lyme Disease Educational Materials: Communications tools for Lyme disease prevention. Many items are available for order.
- Post-Treatment Lyme Disease Syndrome (PTLDS): Information on PTLDS and dangers of long-term or alternative treatments.
- Wisconsin Ticks and Tick-Borne Diseases: Information on ticks and diseases they spread from our partners at the University of Wisconsin-Madison Medical Entomology Laboratory.
- Lyme Disease: Information on Lyme disease from our partners at the Minnesota Department of Health.
- Midwest Center of Excellence for Vector-Borne Disease Ticks: Information on ticks found in the Midwest, tick surveillance resources, and tick biology and development.
Lyme disease is preventable and treatable. Visit our Tick Bite Prevention page to learn how to protect yourself from Lyme disease and other illnesses spread by ticks.
Questions about illnesses spread by ticks? Contact us!
Phone: 608-267-9003 | Fax: 608-261-4976