The city has reported its first cases of West Nile virus this year — and health officials are advising New Yorkers to take steps to avoid contracting it. 

Three people in Queens and one person in Manhattan have been infected with West Nile virus this summer, and the virus has been detected in mosquitos across all five boroughs, the city’s health commissioner, Dr. Ashwin Vasan, said Tuesday in an interview with NY1’s Shannan Ferry. 

Three were hospitalized with neuroinvasive disease and one was diagnosed with West Nile fever starting at the end of July, the city’s Department of Health said in a release. The agency is also investigating two possible cases in the Bronx, according to the release. 

“Every year, we do detect West Nile in all five boroughs, and every year, we do get a few cases,” Vasan said. “It’s a warning to New Yorkers to be prepared.”

The city has recorded about 17 cases each year, on average, since the West Nile virus was first detected in the five boroughs in the early 2000s, Vasan said. 

The majority of people who contract the virus, however, end up with a “very mild disease,” he said, with symptoms that include fever and malaise. 

“It’s people who have underlying health conditions, people over 60, people with chronic conditions, people with immunosuppression, those folks are at risk of a much more severe disease that affects your brain: meningitis,” he said. 

City residents can use U.S. Environmental Protection Agency-approved insect repellents, keep screens in their windows and wear long-sleeved clothing after dusk to reduce exposure to mosquitos, Vasan said. 

The Health Department is also asking New Yorkers to look for and remove standing pools of water on their properties or report them to 311 if they can’t do so themselves, he added. 

The agency tests mosquito pools at more than 1,600 locations citywide, using the data to target its anti-mosquito spraying efforts, the health commissioner said.  

“We should see more cases — we will see more cases throughout the season — but we are prepared,” he said. “And taking those steps is the best way to keep yourself safe.”