NEW YORK (CBSNewYork) – A deadly mosquito-borne virus that has already killed several people this year has now been detected in New York.

According to health officials in both Rockland County and Long Island, local mosquitoes have tested positive for Eastern Equine Encephalitis.

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Rockland County Executive Ed Day and County Health Commissioner Dr. Patricia Schnabel Ruppert made the disturbing revelation on Friday.

“The infected mosquitoes were collected from a trap in the Town of Orangetown on Sept. 17,” Rockland officials said in a statement.

On Long Island, EEE was found in the Suffolk County town of Manorville on Sept. 18.

“We don’t want people to be alarmed but rather informed,” said Suffolk Health Commissioner Dr. James Tomarken.

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“We will be treating the Manorville area for mosquitoes this weekend, and we encourage residents to take precautions to avoid being bitten by mosquitoes.”

Authorities say there have not been any human cases of EEE reported to this point in either New York community.

Suffolk County officials will be out spraying against mosquitoes in the Manorville and Calverton areas on Saturday from 7 p.m. until midnight.

(Credit: Suffolk County Department of Public Works)

EEE is rare and serious illness transmitted to humans by a mosquito bite and had already killed at least at least eight people in the U.S. in 2019.

The CDC says, on average, just seven people contract EEE in the U.S. each year. More than two dozen have been infected in 2019, including multiple cases in New Jersey and Connecticut.

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The CDC adds that a third of patients infected with EEE die from the brain-infecting virus and there is no human vaccine against the virus.