NEW HAVEN — West Nile virus, eastern equine encephalitis (EEE), Jamestown Canyon virus — all are carried by mosquitoes and the state’s mosquito trapping and testing program began June 1.

Overseen by the Connecticut Agricultural Experiment Station, trapping will occur at 108 collection sites in 87 municipalities, including Wilton, until the end of October. This includes 16 new locations that were added this year to increase coverage in high risk areas for EEE in eastern Connecticut.

“Last year, we experienced a resurgence of EEE virus activity in eastern Connecticut that resulted in four human cases with three fatalities. This was part of a region-wide increase that also affected Rhode Island, New Jersey, and Massachusetts,” said Dr. Philip Armstrong, medical entomologist at the agricultural station. “We fully expect the virus to return this year so we will be increasing our monitoring efforts in anticipation of this threat.”

“Mosquito-borne diseases such as EEE and West Nile virus infection can cause life-threatening neuro-invasive disease including encephalitis and meningitis. People should take extra precautions to avoid being bitten by mosquitoes,” said Dr. Jocelyn Mullins, state public health veterinarian.

“When you are outside enjoying the warm weather this summer, take steps to protect yourself from mosquito bites,” she cautioned. “Using insect repellent, wearing long pants and long sleeves while outside, and avoiding being outdoors during the hours of dusk and dawn are effective ways to help prevent being bitten.”

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Last season, EEE was detected in 28 communities in Connecticut with a total of 122 positive mosquito samples. In addition to the four human cases, there were also six infections in horses, all fatal. The majority of EEE virus activity occurred in Middlesex, New London, and Windham counties consistent with prior years.

EEE is the most severe mosquito-transmitted disease in the U.S. with approximately 33 percent mortality and significant brain damage in most survivors.

West Nile virus occurs every summer in the Northeast and has become the main cause of mosquito-borne illness in this region since it was first introduced into the New York City area in 1999.

The state’s mosquito traps are set every 10 days on a rotating basis and then twice a week after detection of virus. Mosquitoes are grouped (pooled) for testing according to species, collection site, and date.

Positive findings are reported to local health departments and online at https://portal.ct.gov/CAES/Mosquito-Testing/Introductory/State-of-Connecticut-Mosquito-Trapping-and-Arbovirus-Testing-Program.

For more information, visit https://portal.ct.gov/mosquito.