Weather keeping viruses at bay
Dry season means fewer mosquitoes
While many homeowners may be cursing the bone-dry weather that has scorched lawns across the region, Essex County's top mosquito tracker is counting this as a blessing.
The parched terrain has significantly hampered the species of mosquito that typically carries Eastern equine encephalitis, so even though the concentration of virus in the bugs is high right now, the overall population of mosquitoes is quite low, said Walter Montgomery, director of the Northeast Massachusetts Mosquito Control and Wetlands Management District.
Montgomery and other area disease trackers have been reevaluating their surveillance and battle plans this week following Monday's news that a man in Newton, N.H., just over the border from Merrimac, is New England's first confirmed human case of EEE this season.
With Merrimac and Amesbury already undergoing two rounds of spraying earlier this month, and bug counts still coming back in low numbers, Montgomery has decided against ordering another round of spraying and is taking a wait-and-see approach.
"If we had additional virus isolations, or if we saw a spike in a particular population of mosquitoes, we would spray again," Montgomery said.
The region's first EEE-bearing mosquitoes this summer were detected early this month in Newton, N.H., roughly the same time the town resident was probably infected, health officials said.
It was the discovery of that potent batch -- one infected mosquito in a tiny sampling of six, and in a species that bites humans -- that prompted the earlier spraying on both sides of the border.
"Mosquitoes typically don't respect borders, so this area is one we need to carefully monitor," said Dr. José Montero, New Hampshire's state epidemiologist.
"Maybe in this area we need to look for new strategies, but certainly this is a hot area for arboviral illnesses," Montero said.
Two years ago, Newton, N.H., resident Richard Labell lost his 20-year-old daughter, Kelly, to EEE. Last year, mosquitoes carrying the virus were detected just across the street from Labell's home.
Health officials say the latest Newton resident to be infected with the virus is expected to recover.
But Labell, 51, doesn't take any chances.
"During dawn and dusk, when I walk my dogs at 10 p.m., I don't care how hot it is -- I wear my pullover Red Sox jacket. I wear a hat and long pants," he said.
"It doesn't mean people have to panic. We just have to be vigilant in what we do, because EEE is here to stay," added Labell, Newton's former police chief. "We as people have to protect ourselves because the state and towns can only do so much."
Already this year, New Hampshire officials say they have tested 7,215 mosquito pools.
So far, just two -- one in Newton and one in Brentwood -- have come back positive for EEE.
In Massachusetts, state authorities report no human cases of EEE or West Nile virus this season. They say West Nile has been more prevalent in mosquitoes statewide this summer than EEE.
The latest sampling for communities in Essex County shows no mosquitoes with EEE, but three pools with mosquitoes carrying the West Nile virus were detected in Swampscott.
That's in addition to another West Nile-positive pool detected earlier this month in Swampscott and two others in Salem, officials said.
Kay Lazar can be reached at klazar@globe.com. 