NEW YORK – Four people have died and more than two dozen others have been sickened in an outbreak of Legionnaires' disease centered in the Harlem neighborhood of Manhattan, city health officials confirmed late Friday. An urgent investigation has traced the source of the severe pneumonia-like illness to contaminated cooling towers on ten buildings within the affected area.

The New York City Department of Health and Mental Hygiene (DOHMH) is leading the response, working to identify all potential sources and prevent further infections. The department has ordered the immediate disinfection of the implicated cooling towers and is conducting widespread testing in the 2-mile radius surrounding the initial cluster of cases.

Health Officials Scramble to Contain Spread

According to a statement from Health Commissioner Dr. Aris Thorne, the city has confirmed 28 cases of Legionnaires' disease in this outbreak, with all patients requiring hospitalization. The four individuals who died were over the age of 50 and had underlying health conditions, which are significant risk factors for severe complications from the disease.

"Our hearts go out to the families of those who have passed," Dr. Thorne stated in a press briefing on Saturday morning. "Our top priority is the health and safety of all New Yorkers. We have identified the likely sources and are taking aggressive, immediate action to remediate them. The risk to the general public is low, and I want to be clear that the city's drinking water is safe."

Health officials are actively conducting outreach in the community, urging residents with symptoms such as fever, cough, chills, and muscle aches to seek immediate medical attention. Early diagnosis and treatment with antibiotics are critical for a successful recovery.

What is Legionnaires' Disease?

Legionnaires' disease is a serious type of pneumonia caused by the bacterium Legionella. It is not spread from person to person. Instead, infection occurs when individuals inhale microscopic water droplets (aerosol or mist) containing the bacteria.

Legionella thrives in warm, freshwater environments. In urban settings, it is commonly found in large, complex water systems that are not properly maintained, including:

• Cooling towers used in air conditioning systems for large buildings.
• Hot tubs and whirlpools.
• Decorative fountains.
• Hot water tanks and heaters.

Symptoms typically appear two to 14 days after exposure. While most healthy people exposed to Legionella do not get sick, individuals who are over 50, current or former smokers, or have chronic lung disease or weakened immune systems are at a much higher risk.

A Recurring Challenge for New York City

This recent outbreak echoes previous incidents in the city, most notably a major outbreak in the South Bronx in 2015 that killed 12 people and infected more than 120. That event prompted the passage of stringent local laws requiring building owners to register, regularly inspect, and disinfect their cooling towers to prevent bacterial growth.

The current investigation in Harlem will likely examine whether the owners of the 10 identified buildings were in compliance with these regulations. Officials have not yet released the specific addresses of the buildings but have assured the public that the cooling towers are no longer a threat.

As the DOHMH continues its epidemiological investigation, residents are advised to remain vigilant. The department has emphasized that standard home and office air conditioning units, which do not use water to cool the air, are not a risk for Legionella growth.