The Vermont Health Department will begin aerial spraying tonight between 8 and 11pm to control mosquitoes in parts of Rutland and Addison counties. Two people from the area were sickened, and one person has died from the state’s first cases of Eastern Equine Encephalitis.
Eastern Equine Encephalitis, or Triple E, is a rare and potentially fatal brain infection spread by mosquitoes. To fight the disease, the state will spray pesticides in two targeted areas, neither of which is highly populated by people. One is just north of Brandon. The other is a swampy area in nearby Whiting.
Gary Meffe is an ecologist and conservation biologist who lives in Brandon. He’s also the chair of the Brandon Leichester, Salsbury Goshen Mosquito Control District.
That part of Vermont has a lot of swampy low lands, which means lots of mosquitoes. But Meffe says this summer’s dry weather and their early efforts to spray known larvae beds meant fewer mosquitoes this year.
"We have had a very good mosquito season. The problem," says Meffe, "is there’s one mosquito that’s the culprit here and it’s had a very good year. It’s called Culiseta Melanura."
Culiseta Melanura is the rare mosquito that carries Triple E. Meffe says for some reason, their numbers were up this year.
"And it’s very difficult to control." It’s not your typical mosquito," says Meffe,"it’s larvae are hidden. We cannot treat the larvae; and the adults are at a low population level. They feed primarily on birds," says Meffe, "about 97 percent. But on rare occasions they’ll cross over and feed on mammals including humans." Adds Meffe, "It’s a difficult species to track down and treat."
The state health department believes aerial spraying will help. Erica Berl is an infectious disease epidemiologist with the Vermont Department of Health. She says the chemicals being sprayed are not harmful to mammals, but she recommends that people in the area and their pets stay indoors until thirty minutes after the spraying has finished.
"The spraying that we’re doing is really important part of trying to reduce the risk of Eastern Equine Encephalitis in those areas," says Berl. "But it’s still very important for people to protect themselves from mosquito bites and also I would also recommend that people in Vermont who own horses and alpacas lamas and emus have their animals vaccinated against it. There is a vaccine for horses that is also somewhat effective in those other species."
But says Berl unfortunately, because the infection rate among people is so rare, no vaccine exists yet for humans.
Eighty-seven-year old Richard Hollis Breen, of Brandon, died Tuesday of the illness. A Sudbury man remains hospitalized. Erica Berl says after the spraying, entomologists from the Agency of Agriculture will go out and count mosquitoes to see if numbers are down. She says depending on what they find more spraying in the area may be needed.
In addition to the two reported cases of E.E.E., State health officials confirmed an adult from Chittenden County was hospitalized with West Nile virus – which is also transmitted by infected mosquitoes. It’s the first case of West Nile reported this year in Vermont.