Is Lyme Disease Contagious?
Lyme disease is not contagious through casual human contact.
It is transmitted primarily through the bite of an infected blacklegged tick.
Multiple family members may become ill due to shared tick exposure — not person-to-person spread.
Lyme disease is not considered contagious. It is primarily transmitted through the bite of an infected blacklegged tick, also known as a deer tick.
Lyme disease does not spread through coughing, sneezing, kissing, sharing utensils, or casual physical contact.
For most families, the real risk comes from shared environmental exposure — such as time spent outdoors in tick-endemic areas — rather than person-to-person transmission.
How Lyme Disease Is Transmitted
Lyme disease is caused by the bacterium Borrelia burgdorferi, which is transmitted primarily through the bite of infected blacklegged ticks.
Ticks acquire the bacteria while feeding on infected animals such as mice and small mammals. The infection can then be transmitted to humans during a later blood meal.
Transmission generally requires prolonged tick attachment, though exact timing may vary depending on multiple factors.
- Lyme disease is transmitted primarily through tick bites
- It is not airborne
- It is not spread by coughing or sneezing
- It is not spread through casual contact
- Household members may still become ill because of shared tick exposure
Can Lyme Disease Spread Sexually?
Researchers have explored whether Lyme disease might spread through sexual contact, but there is currently no conclusive clinical evidence confirming sexual transmission in humans.
At this time, Lyme disease is not classified as a sexually transmitted infection.
Some couples both develop Lyme disease because they share environmental exposure to ticks, pets, wooded areas, or outdoor activities.
Can Lyme Disease Spread During Pregnancy?
Untreated Lyme disease during pregnancy has raised concerns in the medical literature because infection may potentially affect the placenta or fetus.
However, appropriate diagnosis and treatment during pregnancy are associated with improved outcomes.
Pregnant patients with suspected Lyme disease should seek medical evaluation promptly. Learn more in Lyme Disease and Pregnancy.
Can Lyme Disease Spread Through Blood Transfusion?
Transmission of Lyme disease through blood transfusion has not been clearly documented in routine clinical practice.
However, other tick-borne infections such as Babesia are known to spread through transfused blood.
Because of this concern, individuals being treated for active tick-borne illness are generally advised not to donate blood.
Why Lyme Disease Is Sometimes Misunderstood
Confusion about Lyme disease transmission often arises because multiple family members may become ill around the same time.
In many cases, this reflects shared exposure to ticks rather than person-to-person spread.
Pets may also bring ticks into the home, increasing the risk of exposure for household members.
Current evidence does not support casual person-to-person transmission of Lyme disease.
Preventing Lyme Disease
Prevention remains the best strategy for reducing Lyme disease risk.
- Perform daily tick checks after outdoor activity
- Remove attached ticks promptly
- Use insect repellents when appropriate
- Wear protective clothing in wooded or grassy areas
- Treat pets for ticks
- Avoid high-risk tick habitats when possible
For prevention strategies, see Lyme Disease Prevention Strategies.
Frequently Asked Questions
Can you catch Lyme disease from another person?
No. Lyme disease is not known to spread through casual contact, kissing, coughing, or sharing food.
Is Lyme disease sexually transmitted?
There is currently no conclusive clinical evidence proving sexual transmission of Lyme disease.
Can Lyme disease spread through pregnancy?
Untreated Lyme disease during pregnancy may pose risks, but prompt diagnosis and treatment are associated with improved outcomes.
Can multiple family members get Lyme disease?
Yes. Families sharing outdoor environments may experience similar tick exposure — reflecting shared environmental risk rather than person-to-person transmission.
Can Lyme disease spread through blood donation?
Routine transfusion-related Lyme transmission has not been clearly documented, though other tick-borne infections such as Babesia can spread through blood transfusion.
Clinical Takeaway
Lyme disease is not considered contagious through casual human contact. The infection is transmitted primarily through the bite of infected ticks.
Although questions remain about uncommon transmission scenarios, current evidence does not support routine person-to-person spread. Most cases involving multiple family members reflect shared environmental exposure rather than contagion.
Related Articles
- Lyme Disease Prevention Strategies
- Lyme Disease and Pregnancy
- Babesia and Lyme Disease
- Can You Get Lyme Disease Without a Tick Bite?
References
- Steere AC. Lyme disease. N Engl J Med. 1989;321(9):586-596.
- Wormser GP, Dattwyler RJ, Shapiro ED, et al. The clinical assessment, treatment, and prevention of Lyme disease, human granulocytic anaplasmosis, and babesiosis: clinical practice guidelines by the Infectious Diseases Society of America. Clin Infect Dis. 2006;43(9):1089-1134.
- Krause PJ. Human babesiosis. Int J Parasitol. 2019;49(2):165-174.
Dr. Daniel Cameron, MD, MPH
Lyme disease clinician with over 30 years of experience and past president of ILADS.
Symptoms • Testing • Coinfections • Recovery • Pediatric • Prevention
