Tick researchers found Powassan virus in these Maine towns

Stock image of a tick (Thinkstock)

STATEWIDE (BDN) -- When a Maine woman died suddenly in 2013 after a tick bite, the state went on alert against the dangerous virus that claimed her life.

Marilyn Ruth Snow, a Rockland-area artist, fell ill almost immediately after finding a tick stubbornly embedded in her shoulder that November. She died just weeks later.

(Photo of Marilyn Ruth Snow. Source: Burpee, Carpenter and Hutchins Funeral Home)

At the time, Powassan virus hadn’t been documented in Maine in nearly a decade. Much rarer than Lyme disease, but transmitted more quickly and potentially more devastating, Powassan had appeared in only 50 cases across the country over the previous decade.

Since then, two cases of Powassan have been reported in Maine, both in Cumberland County. The virus caused encephalitis, or brain swelling, but thankfully neither case was fatal.

The cases prompted Maine researchers to wonder just how many ticks crawling around the woods and fields of Maine carried the virus. Recently, they released the results of a statewide survey.

Here are the preliminary results:

  • Out of 203 pools of adult ticks, 15 tested positive for Powassan. The virus was found largely in the southern part of the state, but also in Augusta and on Swan’s Island in Hancock County.
  • Out of 21 pools of nymph ticks, two tested positive for Powassan, in Wells and Cape Elizabeth.
  • No Powassan was found east of Mount Desert Island or in northern Maine, even though researchers collected many ticks in those regions. Tick-borne infections are known to move though, as we know all too well from Lyme disease.
  • A growing population of ticks was found in eastern and western regions of Maine. While previous research has documented the presence of the deer tick in coastal areas up through southern Penobscot County, this study marked the first substantial collection of ticks from the Moosehead Lake region, the Machias area, and Somerset County.

Another interesting finding:

  • While public health campaigns often target nymphs as carriers of disease, adult ticks are just as much of a concern with Powassan. The three Maine individuals contracted Powassan during the adult tick season, in fall and early spring, and 7 percent of the adult ticks researchers collected carried the virus. So summer isn’t the only time of year to be sure to wear your bug repellent and take other tick precautions.

(Photo: A female deer tick (left) and a nymph deer tick. Courtesy of Griffin Dill, UMaine Cooperative Extension)

The Powassan virus

Powassan was first recognized in the town of Powassan, Ontario, in 1958. The virus can cause fever, headache, vomiting, weakness, confusion and seizures, and may also lead to meningitis and brain swelling, a devastating complication that kills 10 percent of those who develop it, according to the U.S. Centers for Disease Control and Prevention.

About half of those who survive the infection suffer permanent neurological symptoms such as memory problems, facial tics and blurred vision. There is no vaccine or treatment other than keeping patients comfortable and hydrated during hospitalization.

Many patients, on the other hand, experience no symptoms at all, according to the CDC.

What makes Powassan particularly troubling — in addition to the potentially debilitating symptoms — is the speed of its transmission. While a tick must be attached for 36 to 48 hours to transmit Lyme disease, according to the CDC, but debate rages on that point, Powassan has been shown to spread from tick to human in under an hour, according to the study.

Powassan occurs in two strains, depending on the tick that carries it. Sometimes known as “deer tick virus” when it’s spread by that type, Powassan also is carried by the groundhog or woodchuck tick. Researchers found some evidence that both strains are circulating in Maine, which would be a first for New England.

Hunting for ticks

Field workers collect the ticks by dragging flags made out of corduroy over leaf litter and brush.

The method researchers use to prepare the ticks for sampling is to crush them with sterile paperclips. They then batched the ticks into sample groups, or “pools,” for testing.

Their study was funded by the Maine Outdoor Heritage Fund, MMCRI, and Acadia National Park.

Avoiding ticks: Tips from the CDC

  • Choose light-colored clothing so it’s easier to spot ticks; wear long sleeves and and tuck your pants into your socks.
  • Use an EPA-approved insect repellent.
  • Check your skin and clothing for ticks and remove them promptly. Don’t miss warm, moist areas such as the ears, armpits and neck, and have someone else check your back.
  • Wash possible tick bites with soap and water and apply an antiseptic.
  • Keep your lawn mowed and tidy to remove tick habitat.
  • If you spot an embedded tick, use a tick spoon or tweezers to grasp its mouth and pull it out with steady pressure. Don’t use petroleum jelly, hot matches or nail polish remover, which can increase the risk of infection.
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