The first human case of West Nile in New York City was confirmed on Monday by the Health Department.

The patient, who is a Brooklyn resident, is over the age of 40 and has underlying medical conditions, according to the Health Department. He is the 318th New Yorker to be diagnosed since West Nile was found in the United States in 1999.

“This season’s first case of West Nile virus is a reminder to protect ourselves against mosquito bites,” said Health Commissioner Dr. Mary T. Bassett. “Wearing mosquito repellent when you are outdoors, getting rid of standing water, and installing window screens will reduce your risk of getting bitten. New Yorkers age 60 and older or people with weakened immune systems should be especially careful as they are more likely to become seriously ill, and in rare cases die, if infected.”

This first case of West Nile in NYC was identified about two weeks later in the season compared to previous years.

The Health Department has completed nine rounds of pesticide spraying and seven aerial larvicide treatments throughout the five boroughs to reduce the risk of West Nile and Zika viruses, the department said.

To date, no Zika virus has been found in any mosquito in New York City.

For more on the city’s mosquito control program, click here