EagleTribune.com, North Andover, MA

October 8, 2013

Mosquitoes a threat until heavy frost

Sandown students kept indoors for recess

By Alex Lippa

---- — It’s rare that Timberlane Superintendent Earl Metzler hopes for colder weather in October.

“I usually enjoy warm weather, but not this year,” Metzler said.

He is hoping students at Sandown North Elementary School can enjoy recess again. The children have been stuck inside since Sept. 11, after mosquitoes at Sandown North tested positive for Eastern equine encephalitis.

“We’ve taken significant precautions,” Metzler said. “We’re extremely frustrated, but we want to make sure they are as safe as can be.”

Mosquito season lasting into October is becoming commonplace, according to Alan Eaton, an entomologist with the University of New Hampshire Cooperative Extension.

“The first frost had been coming in September through the years,” Eaton said. “But, due to climate change, we are seeing the last spring frost come earlier and the first fall frost come later.”

This year, EEE has been more prevalent in the state than West Nile virus.

Whitney Howe, vector borne surveillance coordinator with the New Hampshire Department of Health and Human Services, said 20 mosquito pools have tested positive for EEE found so far, compared to just 14 pools testing positive for WNV.

Two New Hampshire horses have tested positive for EEE this year. There have been no human cases.

There have been no reports of WNV in animals here this year, but there was one human case.

Why EEE is more prevalent this year may be up for debate.

“It’s hard to say why that is,” Eaton said. “There are different organisms which are hosts, we don’t really know until we received all the data.”

Howe said EEE increased from nine positive pools last year, while West Nile decreased after 41 positive pools last year.

“We want people to still keep in mind that there is a risk of transmission,” Howe said. “The nights have been remaining warm, so we still want people to (use) their repellants.”

Metzler said it might require two heavy frosts before Sandown children are allowed to have outdoor recess.

“We could be looking at between six to 10 weeks,” he said. “It scares us all quite a bit, but safety is our priority.”

Sandown is one town which could be more at risk, according to Eaton.

“The melanura, which is the primary mosquito vector for EEE, is found in swampy areas in Newton, Sandown, Chester and Kingston,” he said.

The last mosquito pool to test positive for either EEE or WNV was in Brentwood on Oct. 1.

“I’m feeling cautiously optimistic,” Eaton said. “Things seem to be slowing down, especially for EEE. We’re just waiting for the frost to really end it.”

Metzler said the majority of parents at Sandown North have been supportive of the decision to have indoor recess.

“They understand what’s going on,” he said. “We want them to have fun, but we don’t want to take this risk.”