First West Nile-positive mosquitoes of the season found

WEST HAVEN » The first West Nile-positive mosquitoes of the season have been found.

The discovery kicks off the season for the illness, said Philip Armstrong, medical entomologist for the Connecticut Agricultural Experiment Station.

“This is to be expected,” Armstrong said. “We first see the virus emerge in late June or early July. So the season has really begun. We’re entering into the period where the risk increases for getting that virus.”

Last year, there was only one human case of West Nile virus, in Milford, but a total of 131 people in the state have contracted the illness since it was found here in 2000. Of them, 88 have been hospitalized for the illness and three have died.

The state began trapping mosquitoes and testing them for West Nile and other illnesses in early June. In addition to West Nile, the critters have also been tested for Eastern Equine Encephalitis, Jamestown Canyon virus and Zika virus, a disease affecting thousands of people in dozens of countries. Though more than 100 people have tested positive for Zika in Connecticut, none of them acquired it locally, and no mosquitoes tested positive for the illness last year.

The main mosquito responsible for the spread of Zika, the Aedes aegypti, is rarely found in Connecticut. However, another bloodsucker responsible for the disease, the Aedes albopictus, or Asian tiger mosquito, is becoming more common here. Armstrong said, though no mosquitoes have tested positive for Zika, the tiger mosquito is spreading fast this season, and has been found in towns all along the Interstate 95 corridor, from Stamford to West Haven and including greater Bridgeport.

“That’s a real issue, because that’s a very aggressive, biting mosquito,” Armstrong said.