Bat tests positive for rabies

Bat found in ‘Mink Meadows area’ home is first animal ever to test positive on the Vineyard.

Pictured here is a little brown bat, though a big brown bat is Vineyard's most common bat. — Courtesy BiodiversityWorks

Updated Feb. 26

A bat found in a Tisbury home was sent to a the state public health laboratory where it tested positive for rabies, according to the Tisbury board of health.

In a press release issued Monday, Tisbury health officials said the results were returned on Feb. 21. “Although bats are known to carry rabies and pose a risk to human and animal health, this is the first time a rabid bat has been documented on Martha’s Vineyard since testing began in 1985,” the release states.

Tisbury health agent Maura Valley told The Times Tuesday the bat was found dead in a home in the “Mink Meadows area.” The homeowners do not want to be identified, she said. She verified the rabid bat constituted “the first positive result on the Vineyard.”

Rabies is a serious viral disease that can be spread through the saliva of an infected animal by a bite or scratch, or if the saliva gets into a person’s eyes, nose, or mouth, the release states. Rabies is 100 percent preventable if an exposed person receives prompt rabies prophylaxis. However, it is fatal if treatment is not initiated in a timely manner. Almost all human cases of rabies acquired in the U.S. since 1990 have been due to a bat strain of the virus.

The health department is warning that anyone who has had any direct contact with a bat should consider themselves exposed to rabies unless they can be sure a bite or scratch did not occur. “The teeth and claws of bats are so small that a bite or scratch may leave only a very small mark, and the wound may not bleed or hurt,” the release states. “This means that under certain conditions, a person may not realize that an exposure has occurred. These conditions include: a sleeping person awaking to find a bat in the room; or an adult witnessing a bat in the room with a previously unattended child, mentally disabled person, or intoxicated person. Pets found in a room with a bat may also have been exposed.”

For animals exposed to a bat, a veterinarian should be consulted.

Anyone exposed to a bat is encouraged to contact the DPH Division of Epidemiology and Immunization at 617-983-6800 (available 24 hours) to discuss the situation.

According to MDPH, out of 889 bats tested for rabies in 2018 from across the state, 26 were positive, the release states. On average, about 3 percent of bats tested for rabies are positive. This positive test is a reminder that although the incidence of rabies in bats is extremely low, bats, like any mammal, can carry rabies.

BiodiversityWorks biologist Liz Baldwin, who studies bats infected with white nose fungus on the Vineyard, told The Times the rabies discovery isn’t as big a deal as it may seem. “It certainly doesn’t mean there hasn’t been a bat that’s flown over before with rabies,” she said.

Baldwin said the pathogen won’t sweep through the Vineyard bat population, which she described as primarily composed of big brown bats. She identified the rabies-positive bat as a big brown bat. The Vineyard also sees red bats in the summer, and has a modest population of long-eared bats and little brown bats, both of which have been thinned out by white nose fungus, she said.

Other Vineyard mammals like raccoons might contract rabies if they were to eat a rabid bat, she said.

Because she and her colleagues regularly handle bats, Baldwin said, “we’re all vaccinated.”

She and her colleagues also receive annual titer tests, an antibody analysis to measure vaccination strength.

If anyone at Biodiversity Works were to be bitten, they would receive a rabies booster, she said.

What you should know
The board of health offers the following preventative measures:

  • Teach children to never approach animals they don’t know — even if they appear friendly.
  • Report any animal that behaves oddly to your local animal control official.
  • Enjoy wild animals from a distance. Do not keep wild animals as pets. This is against the law in Massachusetts.
  • Make sure your pets are vaccinated against rabies. By law, all dogs, cats, and ferrets must be regularly vaccinated against rabies.
  • Keep your chimney capped and repair holes in attics, cellars, and porches to help keep wild animals like bats out of your home.

What you should do if you think you’ve been exposed to rabies:
If you are bitten or scratched by a bat:

  • Wash the wound with soap and water right away for 10 minutes.
  • Call your doctor or MDPH. They can help you determine if you need to be treated for rabies exposure.
  • If the bat can be safely captured, call your local board of health to have the bat submitted for rabies testing.

What you should do if you think your pet has been exposed to rabies:

  • If your pet has direct contact with a bat or is found in the same room with a bat, call your veterinarian to help you determine if the animal needs medical attention.
  • In some cases, it may be necessary to confine your animal and watch it to see if it develops signs of rabies. Your local animal inspector or animal control officer can help you determine if this is necessary.

Please read the following important information: 1.) Capturing a bat. 2.) What to do if a bat is in your home. 3.) Bat inspection in homes.

For more information on rabies prevention, contact the MDPH Division of Epidemiology and Immunization at 617-983-6800, visit the MDPH website at, or contact your local board of health at the following numbers:

Aquinnah board of health, 508-645-2309
Chilmark board of health, 508-645-2105
Edgartown board of health, 508-627-6120
Oak Bluffs board of health, 508-693-3554
Tisbury board of health, 508-696-4290
West Tisbury board of health, 508-696-0105

Updated to provide more details. -Ed.