Massachusetts is one of the highest-risk states in the country for tick-borne disease. The state hosts multiple tick species carrying multiple pathogens — and 2026 has been described by health experts as shaping up to be one of the worst tick seasons on record. Here is a complete guide to the ticks found in Massachusetts, the diseases they carry, when tick activity peaks, and the prevention steps that actually reduce your risk.
This article is for educational and informational purposes only. If you have been bitten by a tick or are experiencing symptoms of tick-borne illness, contact a healthcare professional immediately.
Tick Species in Massachusetts
Four tick species are significant in Massachusetts, each with different disease risks:
| Tick | Also Known As | Diseases It Carries |
| Black-legged tick (Ixodes scapularis) | Deer tick | Lyme disease, babesiosis, anaplasmosis, Borrelia miyamotoi (hard tick relapsing fever), ehrlichiosis, deer tick virus (Powassan Type 2) |
| Woodchuck tick (Ixodes cookei) | Groundhog tick | Powassan virus (primary vector); rarely bites humans |
| American dog tick (Dermacentor variabilis) | Wood tick | Rocky Mountain spotted fever, tularemia |
| Lone star tick (Amblyomma americanum) | None common | Ehrlichiosis, STARI; can trigger alpha-gal syndrome (red meat allergy); spreading northward into southern Massachusetts |
The black-legged tick (deer tick) is by far the greatest concern for most Massachusetts residents. It is the primary vector for Lyme disease — the most common tick-borne disease in the state — and also carries babesiosis, anaplasmosis, and a related form of Powassan virus. The lone star tick is an emerging concern: climate change is driving its range northward, and it has already been documented in southern Massachusetts. A bite from the lone star tick can trigger alpha-gal syndrome, an allergy to red meat that can cause hives, gastrointestinal symptoms, and in some cases anaphylaxis.
Tick-Borne Diseases in Massachusetts
Massachusetts residents face more tick-borne disease risks than most states. The Massachusetts Department of Public Health tracks the following diseases:
Lyme Disease
Lyme disease is the most common tick-borne disease in Massachusetts and in the United States overall. It is caused by the bacteria Borrelia burgdorferi and is transmitted by the black-legged (deer) tick. For transmission to occur, the tick must typically be attached for 24 to 48 hours.
Early symptoms appear 3 to 30 days after an infected tick bite and may include an expanding rash at the bite site (the characteristic bull’s-eye or erythema migrans rash, though not always present) and flu-like symptoms including fever, fatigue, headache, and muscle and joint aches. Left untreated, Lyme bacteria can spread throughout the body and cause arthritis, neurological problems, and heart complications. Early antibiotic treatment is highly effective. Cases of Lyme disease occur throughout Massachusetts.
Powassan Virus
Powassan virus is rare but one of the most serious tick-borne diseases in the United States. Unlike Lyme disease, which requires hours of tick attachment, Powassan virus can be transmitted in as little as 15 minutes — making prompt tick removal less reliable as a prevention strategy.
Massachusetts has reported 61 cases of Powassan from 2013 to 2023, according to Mass.gov. In 2025, at least 4 Massachusetts cases were confirmed, including an infant case reported in August 2025 and a Martha’s Vineyard investigation. There is no specific treatment and no vaccine. Approximately 10% of people who develop the severe neurological form of the disease die; approximately half of survivors experience permanent neurological damage.
Most people infected with Powassan virus — an estimated 90 to 95 percent — have no symptoms or only mild flu-like illness and recover fully. The 5 to 10 percent who develop severe disease can progress rapidly to encephalitis (brain inflammation) or meningitis. Symptoms include fever, headache, vomiting, weakness, confusion, loss of coordination, speech difficulties, and seizures.
Babesiosis
Babesiosis is a parasitic infection transmitted by the deer tick that attacks red blood cells. It is caused by Babesia microti parasites. Symptoms include fever, chills, sweats, headache, body aches, loss of appetite, nausea, and fatigue. Most healthy adults experience mild illness, but it can be severe or life-threatening in people who are elderly, immunocompromised, or who do not have a spleen. Babesiosis is treated with antiparasitic medications and antibiotics. It is most common on Cape Cod, the Islands (Martha’s Vineyard and Nantucket), and in other coastal areas of southeastern Massachusetts.
Anaplasmosis
Anaplasmosis (formerly known as human granulocytic ehrlichiosis) is a bacterial infection transmitted by deer ticks. Symptoms typically begin 1 to 2 weeks after a tick bite and include fever, headache, chills, muscle aches, and occasionally nausea and vomiting. Without treatment, it can become severe. Doxycycline is an effective treatment when started promptly. Cases occur statewide.
Borrelia miyamotoi (Hard Tick Relapsing Fever)
Borrelia miyamotoi is a bacterium related to Lyme disease bacteria, transmitted by the deer tick. It was first identified in Japan in 1995. Onset and symptoms are similar to Lyme disease — fever, chills, headache, and muscle aches — but unlike Lyme disease, it typically does not cause the characteristic bull’s-eye rash. It is treated with the same antibiotics used for Lyme disease. Considered rare but found throughout Massachusetts wherever deer ticks are present.
Ehrlichiosis
Ehrlichiosis is caused by bacteria transmitted by the lone star tick (and to a lesser extent the deer tick). Symptoms include fever, headache, chills, muscle aches, and occasionally rash. Doxycycline is effective treatment when started early. The increasing presence of the lone star tick in southern Massachusetts makes this disease a growing concern for the state.
Rocky Mountain Spotted Fever
Rocky Mountain Spotted Fever (RMSF) is a serious bacterial infection transmitted by the American dog tick. Despite its name, RMSF cases occur throughout the eastern United States. Symptoms include fever, headache, rash, and if untreated, potentially life-threatening illness. Cases are less common in Massachusetts than Lyme disease but do occur. Prompt antibiotic treatment is essential.
When Are Ticks Most Active in Massachusetts?
Tick-borne diseases are year-round in Massachusetts, not just a summer phenomenon. The Massachusetts Department of Public Health tracks two distinct activity peaks:
- Peak 1: March/April through August — the primary and most intense tick season. Nymph deer ticks (the immature stage most likely to transmit disease, because they are tiny and hard to detect) are most active from May through July
- Peak 2: October through November — adult ticks become active again in fall. Adult deer ticks remain active through winter whenever temperatures are above freezing (above approximately 40°F), which in Massachusetts can be most of the winter in mild years
- Most tick-borne disease cases are diagnosed in June through August, corresponding to the nymph activity period
The most dangerous tick stage for disease transmission in terms of risk per encounter is the nymph. Nymphs are roughly the size of a poppy seed — small enough to be missed on a body check — and they are most active during the warm months when people are most active outdoors. As Patrick Roden-Reynolds, Director of the Martha’s Vineyard Tick Program, noted in August 2025: nymph deer tick activity ‘coincides with when we spend most of our time outdoors and… when our island population grows for tourism season.’
Powassan Virus Cases in Massachusetts: 2024 and 2025
Nationally, approximately 239 Powassan disease cases were reported over the past 10 years. Massachusetts accounts for a significant share: 61 confirmed cases between 2013 and 2023, according to Massachusetts DPH.
In 2025, Massachusetts saw notable Powassan activity. A Massachusetts infant was reported in August 2025 as a suspected Powassan case — covered by Spectrum News 1 Massachusetts. Barnstable County public health officials confirmed they were investigating a Powassan case on Martha’s Vineyard in August 2025, with 3 other confirmed Massachusetts cases that year.
The CDC notes that Powassan virus cases are increasing nationally. With 2026 shaping up as an intense tick season, Massachusetts DPH’s tick surveillance data (updated June 8, 2026) is tracking the developing picture. Residents should monitor the Mass.gov monthly tick-borne disease surveillance reports for current case data.
Tick Prevention in Massachusetts
Prevention is the most effective strategy against tick-borne disease — particularly for Powassan virus, which has no treatment and can transmit so quickly that even prompt tick removal may not prevent infection.
Personal Protection
- Use EPA-registered insect repellents: Products containing DEET, picaridin, IR3535, or oil of lemon eucalyptus are effective against ticks. Apply to exposed skin and clothing according to label directions
- Treat clothing with permethrin: Permethrin-treated clothing kills ticks on contact. Pre-treated clothing is available or clothing can be treated at home (lasts approximately 6 washes) or sent to a service like InsectShield (lasts up to 70 washes). Permethrin should only be applied to clothing, not skin
- Wear protective clothing: Tuck pants into socks and shirts into pants when in tick-infested areas. Light-colored clothing makes ticks easier to spot before they reach the skin
- Shower within 2 hours of being outdoors: Showering washes off unattached ticks and provides an opportunity to do a tick check
- Perform a full body tick check: After outdoor activity, check all areas carefully — especially the scalp, behind ears, armpits, belly button, groin, and backs of knees. Use a mirror or ask someone to help check hard-to-see areas
Yard and Habitat Management
- Keep grass mowed short and remove leaf litter around the yard — ticks thrive in moist, shaded areas
- Create a barrier of wood chips or gravel between lawn and wooded areas to reduce tick migration
- Remove wildlife attractions (bird feeders, brush piles) that may bring deer and other tick hosts into your yard
- Consider acaricide (tick pesticide) treatments in high-risk areas — contact your local mosquito and pest control district for guidance
How to Remove a Tick
If you find an attached tick, prompt and correct removal reduces the chance of disease transmission. The Massachusetts DPH and CDC recommend:
- Use fine-tipped tweezers — grasp the tick as close to the skin as possible
- Pull upward with steady, even pressure — do not twist or jerk the tick, as this can cause mouth parts to break off and remain in the skin
- Do not squeeze the tick’s body — this can force fluids into the bite wound
- After removal, clean the bite area with rubbing alcohol or soap and water
- Dispose of the tick by placing it in alcohol, putting it in a sealed bag, or flushing it down the toilet — do not crush it with your fingers
- Do not use petroleum jelly, fingernail polish remover, or heat to remove a tick — these methods are ineffective and can increase disease transmission risk
Note the date you removed the tick. Monitor the bite area and your health for the following weeks. The incubation period for most tick-borne diseases is 1 to 4 weeks after the bite. Contact your healthcare provider if you develop a rash, fever, headache, fatigue, or muscle aches after a tick bite.
Tick-Borne Disease Symptoms: When to See a Doctor
Seek medical care promptly if you develop any of the following after a known or suspected tick bite:
- A rash — especially a red, expanding rash around the bite site (Lyme disease bull’s-eye rash), though not all Lyme cases produce this rash
- Fever, chills, or sweats
- Severe headache
- Muscle or joint aches
- Fatigue that is unusual or severe
- Nausea, vomiting, or loss of appetite
- Confusion, difficulty with speech or coordination, or seizures (seek emergency care immediately — these may indicate Powassan virus encephalitis or meningitis)
Tell your doctor about the tick bite and where you think you may have been exposed. Early antibiotic treatment is highly effective for Lyme disease, anaplasmosis, ehrlichiosis, and other bacterial tick-borne diseases. Powassan virus has no specific treatment — supportive care is the only option — making prevention the critical strategy.
Frequently Asked Questions
What tick diseases are in Massachusetts?
Massachusetts residents face risk from Lyme disease, babesiosis, anaplasmosis, Borrelia miyamotoi (hard tick relapsing fever), ehrlichiosis, Powassan virus, Rocky Mountain spotted fever, and alpha-gal syndrome (red meat allergy from lone star tick bites). Lyme disease is by far the most common. Powassan virus is rare but serious, with no treatment available.
How many Powassan virus cases has Massachusetts had?
Massachusetts reported 61 confirmed cases of Powassan virus from 2013 to 2023, according to the Massachusetts Department of Public Health. In 2025, at least 4 cases were reported, including cases on Martha’s Vineyard and an infant case in August 2025. For current case counts, the Massachusetts DPH maintains monthly surveillance reports at mass.gov.
When is tick season in Massachusetts?
Tick-borne diseases are year-round in Massachusetts. There are two activity peaks: March/April through August (primary peak, with nymph deer ticks most active May–July), and October–November (adult tick activity). Adult deer ticks remain active in winter whenever temperatures exceed 40°F. Most tick-borne disease diagnoses occur in June through August.
How fast can Powassan virus transmit?
Powassan virus can be transmitted in as little as 15 minutes of tick attachment — compared to 24 to 48 hours required for Lyme disease transmission. This makes prompt tick removal less reliable as a Powassan prevention strategy, which is why tick avoidance and repellent use are especially important for this disease.
What is the new tick spreading into Massachusetts?
The lone star tick (Amblyomma americanum) is spreading northward into southern Massachusetts due to climate change. It carries ehrlichiosis and STARI, and can cause alpha-gal syndrome — a red meat allergy that can range from hives and stomach problems to anaphylaxis. It has already been documented in southern Massachusetts.
Final Thoughts
Massachusetts has a genuine, year-round tick problem — not just a summer inconvenience. The combination of Lyme disease (very common), babesiosis and anaplasmosis (moderately common, particularly on Cape Cod and the Islands), and Powassan virus (rare but severe and with no treatment) makes tick prevention a serious health priority for anyone who spends time outdoors in the state. The 15-minute transmission window for Powassan means that the standard Lyme disease advice — check for ticks, remove promptly — is not sufficient protection against everything Massachusetts ticks carry. Repellent use, permethrin-treated clothing, and habitat management are the most effective tools available. Monitor the Massachusetts DPH’s monthly tick-borne disease surveillance page for current case counts as the 2026 season develops.
This article is for educational and informational purposes only. Consult a healthcare professional for medical advice, diagnosis, or treatment related to tick bites or tick-borne illness.