Hot, dry summer producing fewer cases of Lyme disease

New England’s hot summer might be helping keep the ticks that carry Lyme disease at bay.

The Northeastern states — which are some of the worst for Lyme in the U.S., posing a hazard to residents and vacationers alike — are still totaling the number of Lyme cases from the summer months, and there will likely be more in the fall. But preliminary indicators show the disease abating, and public health authorities are finding fewer deer ticks, state officials and researchers said.

In Maine, there had been a steady annual growth of Lyme cases, including a jump of 23 percent to more than 1,850 last year. But the Maine Center for Disease Control and Prevention said Lyme cases for May, June and July were below long-term averages. Those are major months for incidence of the disease.

The arachnids have more difficulty surviving in hot and dry weather, said Charles Lubelczyk, a field biologist with the Maine Medical Center Research Institute in Scarborough, Maine. Maine has had a steamy summer, with Portland experiencing the hottest August on record, and rainfall has been less than normal in many places.

“They aren’t as active as they would normally be. That may translate into less risk for some people,” Lubelczyk said. “This is also being reported in other parts of New England as well.”

It’s possible the ticks have not died, because they have the ability to hunker down and survive in less than ideal conditions, Lubelczyk said. States will have a better idea after the fall, which can also be a bad season for Lyme infections.

But this summer, communities from Connecticut to Vermont are reporting fewer ticks. New Hampshire had more than 1,800 cases last year and only about 400 at the midway point of this year.