NORTHBOROUGH, Mass. — It can be tempting to spend these last days of summer enjoying the great outdoors. Just watch out for mosquitoes.
The past few weeks have seen numerous reports of West Nile Virus and EEE being detected in mosquitos in the Central Massachusetts area. Westborough, in particular, has had several cases of both diseases, as have many of the surrounding towns.
Tim Deschamps, Executive Director of the Central Mass. Mosquito Control Project (CMMCP) said warmer-than-usual weather is largely responsible for this uptick in cases.
"We did see an earlier mosquito hatch in the wetlands," Deschamps said. The warmth, he added, allows mosquitoes to reproduce more rapidly and encourages the spread of the viruses they carry.
Of the two viruses, EEE is rarer and more dangerous. Its fatality rate is about 33 percent, according to the Centers for Disease Control, and those who survive can suffer significant brain damage. Children and the elderly are at particularly high risk.
On the other hand, most people who contract West Nile will experience mild symptoms or none at all, though a small percentage will suffer more severely. To read more about the symptoms of West Nile and EEE, click here.
"We're continuing to monitor the situation and respond as needed," Deschamps said.
Located in Northborough, the CMMCP works year-round to "reduce mosquito exposure to the public, and the potential for disease transmission by mosquitoes, by utilizing proven, sound mosquito control techniques," according to its mission statement. During the off-season, this typically involves clearing ditches and streams to prevent the buildup of still water that acts as a mosquito breeding ground in warm weather.
In late spring and summer, the CMMCP regularly traps mosquitos in Central Massachusetts towns and brings them to a lab in Jamaica Plain for study. Here, whether or not a mosquito is carrying a virus is only part of the equation. Certain mosquito species, Deschamps said, only bite birds, while others bite both birds and humans.
Lately, the CMMCP has been working with local health boards to coordinate spraying in high-risk areas. They use a chemical called Sumithrin, which Deschamps described as a "low-residual, synthetic copy" of the natural insecticide produced by chrysanthemum flowers. The chemical does not last longer than a few hours, and when used properly only poses minimal risks to people and the environment. The CMMCP does not require relocation during spraying; however, as some people with chemical sensitivities may wish to avoid exposure, spray schedules can be found here.
Mosquitoes tend to cease being active once the temperature drops below 50 degrees, Deschamps said. But even though fall weather is not far over the horizon, he added that it usually takes a good, hard frost to completely eliminate the threat for the season.
"We always tell people, whether or not a virus was discovered in your area, that there is some risk," Deschamps said.
"It's always a good idea to wear repellent with DEET in it," he added.
Reporter Jeff Nowak contributed to this report.