The insects were found in the Old Town neighborhood of Staten Island and in Douglaston and College Point in Queens, the Health Department said. No human cases have been reported this year.
"Now that West Nile virus has returned to New York City, it is important to take simple precautions to protect you and your family,” said Health Commissioner Dr. Mary Bassetti.
Mosquitoes breed in puddles of water that stand for more than four days. Bassetti said that quickly removing standing water is the best way to eliminate the insects.
Aside from getting rid of standing water, Bassetti suggested residents wear repellant and cover their arms and legs when they go out at dusk or dawn. The risk is especially high for people over 50 who are more likely to develop serious illness if they contract West Nile, Bassetti said.
The Health Department will spray larvicide from helicopters on non-residential marsh areas in Staten Island, Queens and the Bronx on Thursday, Friday and Monday from 6 a.m. to 7 p.m. at common breeding grounds for the insects, the Health Department said.
While not everybody infected with West Nile becomes sick, the virus can cause serious complications, including neurological diseases, and can also cause a minor flu-like sickness with headaches, fever, fatigue, weakness and sometimes a minor rash, the Department of Health said.
The Department of Health suggests anybody who thinks they might be infected with the virus to immediately see a doctor.