Mosquitoes in York County have tested positive for West Nile virus and Mainers should take steps to avoid being bitten by mosquitoes, the Maine Center for Disease Control and Prevention said.

The positive test is the first direct confirmation this year that the disease is being carried by mosquitoes in Maine. The disease spreads in U.S. mosquito populations each summer, but does not often reach Maine. The last time a mosquito in Maine tested positive for West Nile was September 2015, state data show.

State health officials announced this week that a person from Cumberland County was diagnosed with the virus, but the CDC said they believed that person – and unidentified adult – probably contracted the disease while outside the state.

Maine’s Health and Environmental Testing Laboratory this week confirmed the presence of West Nile virus in a group of mosquitoes collected Aug. 21 in Kittery, the CDC said. The state collects a sampling of as many as 50 mosquitoes – known a mosquito pool – and tests for the disease. One mosquito pool tested positive.

“West Nile is widespread throughout the United States right now,” said state epidemiologist Dr. Siiri Bennett. “Mainers should take extra precautions against being bitten.”

Four cases of West Nile virus have been confirmed this season in Massachusetts and another case was confirmed in Connecticut.


The adult in Cumberland County who tested positive for West Nile became ill in early August while on a cross-country road trip and was hospitalized. It is the state’s first human case of West Nile virus since 2015.

Mosquitoes pick up West Nile virus and Eastern Equine Encephalitis when they bite infected birds. While most people infected with the mosquito-borne virus show no symptoms, others can develop fever, headache, body aches and stiffness.

Officials say the best ways to avoid mosquito bites are to get rid of standing water and to wear insect repellent. They also recommend people vaccinate horses against both West Nile virus and Eastern Equine Encephalitis virus.

Gillian Graham can be contacted at 791-6315 or at:

Twitter: grahamgillian

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