NEWTON — Only days after a horse in Derry tested positive for Eastern equine encephalitis, the virus has been found in mosquitoes in Newton.
West Nile virus also turned up in mosquitoes trapped in nearby Raymond, according to Sarah MacGregor of Dragon Mosquito Control.
Newton is just the latest community in Southern New Hampshire to have mosquitoes test positive.
Last week, EEE turned up in a mosquito batch in Sandown and a batch collected in Hampstead tested positive for West Nile virus. EEE was previously found in mosquitoes in Londonderry, Pelham and Kingston.
“It’s breaking out everywhere,” MacGregor said of the virus. “It’s all over Rockingham County and beyond.”
That includes West Chesterfield, where a man tested positive for West Nile virus. He has since recovered.
A frost advisory issued for early yesterday didn’t bring the freeze expected to help combat virus-carrying mosquitoes. It takes two hard freezes to kill the mosquitoes, but MacGregor said she feels more confident when she sees snow in the air.
“I say unless there is snow on the ground, there is still a risk,” she said.
Dragon was to conduct emergency spraying in Sandown and Hampstead last night, Derry tonight, Raymond tomorrow night, and Newton on Friday night, MacGregor said.
“It’s a pretty busy schedule,” she said.
MacGregor said although the overall mosquito population has dwindled in the cooler weather, the mosquitoes that are still around are the species that carry deadly viruses.
She and state health department officials have said anyone going outside at dusk should wear mosquito repellent and long-sleeved clothing.
While MacGregor said the threat of EEE and West Nile is serious this year, it pales in comparison to 2005, 2007 and 2009, when numerous cases were reported.
As of Friday, the state public health lab had tested 4,263 batches of mosquitoes. Thirteen tested positive for EEE and 10 for West Nile, according to Whitney Howe, the state health department’s vector-borne disease surveillance coordinator.