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Rare But Serious Tick-Borne Virus Investigated on Martha’s Vineyard

Inter-Island Public Health Excellence Collaborative - Joint Release from Martha's Vineyard Boards of health
Posted on: August 4, 2025 - 4:18pm
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Inter-Island Public Health Excellence Collaborative

Joint Release from Martha’s Vineyard Boards of Health

FOR IMMEDIATE RELEASE
August 4, 2025

Rare But Serious Tick-Borne Virus Investigated on Martha’s Vineyard

Martha’s Vineyard, MA — Public health officials are investigating preliminary results of a Powassan virus infection in a Martha’s Vineyard resident. The situation is being closely monitored by island’s local boards of health and shared public health staff, including Public Health Nurse and Case Investigation Coordinator Betsy VanLandingham. Aside from this pending investigation, there has been only one confirmed case of Powassan virus on the island in the past 20 years. Elsewhere in the state, three cases have been confirmed this year (CDC).

Powassan is a rare but potentially serious virus transmitted by the bite of infected Ixodes scapularis ticks—commonly known as deer ticks. Unlike other tick-borne pathogens, Powassan virus can be transmitted within 15 minutes of a tick bite. There is no specific treatment, vaccine, or cure for Powassan virus disease. Severe cases can cause brain swelling (encephalitis), confusion, seizures, and long-term neurological complications.

“The virus is present every year in a small percentage of deer ticks; fortunately, severe disease remains very rare,” said Dr. Sam Telford, Tufts University professor with longstanding research on Martha’s Vineyard. In collaboration with the Martha’s Vineyard Tick Program, directed by Patrick Roden-Reynolds, Dr. Telford’s lab has tested over 3,500 nymph deer ticks between 2021 and 2024. “Between 1 and 2% of nymph deer ticks on Martha’s Vineyard are infected. This is a similar rate to that seen elsewhere in New England. This suggests that many people who are exposed may successfully fight off the virus without ever knowing they were infected.”

Understanding the Risk

While public concern has recently focused on the increasing number of Lone Star ticks on the island, it is important to remember that deer ticks have long been established on Martha’s Vineyard and remain a major vector for disease.

“Nymph deer ticks—the second life stage of ticks—are most active on Martha’s Vineyard from May through July. Their activity coincides with when we spend most of our time outdoors and, unfortunately, when our island population grows for tourism season,” says Patrick Roden-Reynolds, Director of the Martha’s Vineyard Tick Program. “This makes nymph deer ticks the main driver of infectious diseases such as Lyme disease, babesiosis, anaplasmosis, borrelia miyamotoi, and Powassan virus. Although nymph deer tick activity typically slows in August and September, adult deer ticks become active in the fall and remain so throughout the winter and early spring whenever temperatures exceed 40°F.”

“Because Powassan virus can be transmitted so quickly—and because there is no treatment—the most effective protection is to prevent tick bites in the first place,” said Lea Hamner, contract epidemiologist for Dukes County. “With deer ticks, Lone Star ticks, and American Dog ticks all present on Martha’s Vineyard, it is possible to encounter ticks during any month of the year. Tick bite prevention needs to be a year-round habit.”

Key Facts:

  • Powassan virus is rare but serious and can cause life-threatening illness.
  • Powassan virus is carried by nymph and adult deer ticks.
  • The peak season for deer tick nymphs is May–July, but adult deer ticks are active from fall through early spring, whenever temperatures rise above 40°F.
  • The virus can be transmitted within 15 minutes of tick attachment.
  • Tick bite prevention is essential and should be practiced year-round on Martha’s Vineyard.

Top Tips to Prevent Tick Bites:

  1. Treat your clothing and gear with permethrin
    • DIY sprays last approximately 6 weeks or 6 washes. Follow label instructions.
    • Buy pre-treated clothing to get longer effectiveness; in some cases up to 70 washings.
    • Send your own clothing to InsectShield.com to get the longer effectiveness (use code MARTHASV2025 for 15% off).
  2. Dress “tick-smart”
    • Tuck pants into socks, shirts into pants.
    • Wear light-colored clothes to spot ticks more easily.
    • Leggings and snug-fitting clothing can prevent ticks from reaching the skin.
  3. Use EPA-registered tick repellents
    • Effective ingredients include: DEET, picaridin, IR3535, 2-undecanone, and oil of the lemon eucalyptus tree.
    • Use the EPA’s Find the Repellent Right for You tool to find the best option.
  4. Be ready with a tick kit
    • Stock your home, car, and bag with:
      1. Repellent – to prevent bites
      2. Sticky lint rollers – to remove unattached ticks
      3. Tweezers – to remove attached ticks
      4. Tape or baggies – to secure removed ticks
      5. Alcohol wipes – to clean the bite site
  5. Daily tick checks are a must
    • Lint roller your clothing after coming in from the outdoors to remove hitchhikers.
    • Change clothes or shower soon after being outdoors.
    • Put clothes in the dryer on high for 20 minutes to kill ticks.
    • Do full-body tick checks with a mirror—don't forget crevices.
  6. Save the tick and ID it for free
    • Submit a photo to TickSpotters for expert ID and bite risk assessment.
  7. Use the CDC Tick Bite Bot to get information on what to do after a tick bite.

 

 

Upcoming opportunities to learn more about ticks, tick-borne diseases and tick bite prevention:

Friday, August 8, 1:00PM

Virtual Tick Talk: Prevent the Bite

Free

Information and registration here: https://engagedpatrons.org/EventsExtended.cfm?SiteID=6379&EventID=566167&PK=

 

Saturday, August 16, 9am-12:30pm

Martha’s Vineyard Medical’s Tick Talk Conference

Free

Information and registration here: https://www.mvmed.org/tick-talk-2025

 

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