Lyme Disease and COVID-19

Quick answer

Long COVID and post-treatment Lyme disease syndrome (PTLDS) share many symptoms, including fatigue, brain fog, aches and sleep problems. Researchers now study them side by side as infection-associated chronic illnesses. There is no established evidence that COVID-19 reactivates Lyme disease. Because no single test explains these symptoms, diagnosis relies on your history, exposures and a careful evaluation.

Long COVID vs Lyme: where symptoms overlap

The table compares symptoms CDC lists for long COVID with those it describes for lingering symptoms after Lyme treatment. “Not listed” means CDC does not name that symptom in its PTLDS description, not that it never happens.

The starting illness is usually the biggest clue. Lyme often begins with an expanding rash at a tick bite in about 70 to 80% of people, or with fever, chills, headache and aches, 3 to 30 days after a bite (CDC). COVID-19 starts as a viral infection, usually confirmed with a COVID-19 test. See our guides to Lyme symptoms and PTLDS.

What research comparing them shows

Since the pandemic, scientists have paid more attention to illnesses that follow infections. Here is what published work says so far:

• Similar picture, different germs. A 2026 review in the journal Brain notes that long COVID and post-treatment Lyme both start with a known infection and share symptoms such as trouble thinking, fatigue and pain. The cause of PTLDS is unknown, though immune problems are suspected. For long COVID, researchers are studying leftover virus pieces, hidden virus, reactivation of other viruses and ongoing immune activation.
• Antimicrobials have not been the answer so far. The same review points out that prolonged antibiotics showed no lasting benefit for PTLDS, and a trial of the antiviral Paxlovid in long COVID showed no benefit. Neither has an FDA-approved treatment that targets the underlying disease, and the authors caution against unproven therapies.
• Large research programs. NIH’s RECOVER initiative studies how to understand, diagnose and treat long COVID, including clinical trials. In 2024, STAT News reported that NIH announced funding for research on neurological and psychiatric effects of infection-associated chronic illnesses, including both post-treatment Lyme and long COVID, and that NIAID was funding seven projects on persistent Lyme symptoms.
• Clinicians see the overlap. In the same STAT report, Johns Hopkins Lyme researcher John Aucott described post-treatment Lyme, long COVID and ME/CFS as looking very similar clinically.

It is still early, and no study yet explains why some people recover fully while others do not.

Can COVID-19 trigger or reactivate Lyme disease?

We did not find controlled studies showing that COVID-19 reactivates Lyme bacteria. The most relevant data come from a 2023 online survey of 889 adults with a history of Lyme disease (Cameron and McWhinney):

• Overall symptom scores were not significantly different between people who had COVID-19 and those who had not.
• About 17% of those who had COVID-19 reported long COVID, and that group had worse nerve-related symptoms.
• Overall symptom scores did not differ significantly between vaccinated and unvaccinated respondents.

The survey has real limits: answers were self-reported, people joined through word of mouth, there was no comparison group without Lyme, and it cannot show cause and effect. If you had Lyme in the past and feel worse after COVID-19, possible explanations include long COVID, a flare of existing symptoms, or something unrelated. Your provider can help sort that out.

Testing and diagnosis: telling them apart

• No test for long COVID. No lab test can show that symptoms are caused by COVID-19 (CDC).
• Lyme tests show antibodies, not active infection. Lyme antibodies can last for years after a past infection, so a positive result may reflect an old infection (IDSA). Negative antibody tests can also sometimes be false negatives (STAT, 2024).
• Exposure matters. CDC says Lyme is especially unlikely to explain lingering symptoms if a recommended test was negative or if you have not lived in or traveled to areas where Lyme is common.
• Research markers are not ready. Blood markers being studied to tell these illnesses apart are not FDA-validated for clinical use (STAT, 2024).

Help your provider by writing a timeline: tick bites or outdoor exposure, any rash, COVID-19 test dates and results, vaccinations, and when each symptom began. Our doctor visit guide and Lyme test guide can help.

Tick season during the pandemic

Ticks did not take a break during the pandemic. A CDC analysis of 2020 found that people likely encountered ticks as often as before, or more, but sought less care (McCormick and colleagues, 2021):

• Emergency department visits for tick bites dropped. In May, the rate fell from 145 per 100,000 visits in 2017 to 2019 to 89 per 100,000 in 2020.
• Lyme blood tests at one lab fell 25% from 2019 to 2020.
• In a 2020 survey, about half of people said they spent more time outdoors than in prior years.

The authors said the expected drop in reported Lyme cases likely reflected the pandemic, not a true decline. The lesson for any year: keep up tick prevention and do not delay care after a tick bite with symptoms.

For more on conditions that overlap with Lyme, visit our Lyme and other conditions hub or step 6 of our guide, living well with Lyme.

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