ALBANY, N.Y. (AP) — Public health officials in New York state are encouraging residents to protect themselves against West Nile Virus.

Seven human cases of the mosquito-borne illness have been discovered in New York state so far this year, with three recent cases in Nassau, Westchester and Monroe counties.

Officials at the state Health Department said Thursday that residents can prevent exposure by eliminating standing water, wearing long sleeves and pants when outdoors and using repellant.

Health officials say the virus was first found in New York state in 1999. Since 2000, 497 human cases have been reported in the state.

While most people infected with the virus show no symptoms, others can develop fever, headache, body aches and stiffness.