A New Yorker has died and at least 22 others have been sickened in the Legionnaires’ disease outbreak in Harlem, city health officials said in an alarming update.

The cluster of pneumonia-like illness, initially detected on July 25, has been identified in several zip codes across Harlem, the New York City Health Department said Wednesday.

Details were not given on the person who died.

Deputy chief medical officer Dr. Toni Eyssallenne urged any New Yorkers with “flu-like symptoms” to contact their health care provider as soon as possible.

“Legionnaires’ disease can be effectively treated if diagnosed early,” Eyssallenne said.

“But New Yorkers at higher risk, like adults aged 50 and older, those who smoke or have chronic lung conditions should be especially mindful of their symptoms and seek care as soon as symptoms begin.”

Although potentially deadly if not treated in time, Legionnaires’ disease is not contagious and can be treated with antibiotics, the department said.

The disease is typically transferred through water supplies contaminated with Legionella bacteria that can appear in plumbing systems and find favorable conditions in cooling towers, whirlpool spas, hot tubs, humidifiers and condensers in large air conditioning systems.

All operable cooling towers in the area under investigation have been sampled — and the Health Department has ordered building owners with positive results to remediate the issue within 24 hours, officials said.

The areas where cases have been confirmed are in five Harlem zip codes: 10027, 10030, 10035, 10037 and 10039, along with the bordering communities, the Health Department said.