New York City Health Department Investigating a Community Cluster of Legionnaires' Disease in Central Harlem Neighborhood

Legionnaires’ disease is not contagious and is treatable when caught early

Adults who have been in the affected area since late July with flu-like symptoms, fever, cough, or difficulty breathing should seek immediate medical attention

July 25, 2025 — Today, the New York City Health Department (Health Department) announced an investigation into a community cluster of Legionnaires’ disease in Central Harlem (ZIP codes 10027, 10030, 10035 and 10037) and bordering communities. Five people have been diagnosed with Legionnaires’ disease within this cluster since July 25, 2025, and results for other individuals are pending. To date, there have been no deaths associated with this cluster.

The Health Department is actively investigating these cases and is sampling and testing water from all cooling tower systems in the area of the cluster. New Yorkers with flu-like symptoms, cough, fever, or difficulty breathing should contact a health care provider immediately. People can get Legionnaires’ disease by breathing in water vapor that contains Legionella bacteria. Legionnaires’ disease is not contagious and can be treated with antibiotics when caught early.

"Any New Yorkers with flu-like symptoms should contact a health care provider as soon as possible," said Deputy Chief Medical Officer Dr. Toni Eyssallenne. "Legionnaires’ disease can be effectively treated if diagnosed early, 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."

Legionnaires’ disease is a type of pneumonia that is caused by the bacteria Legionella, which grows in warm water. Symptoms resemble other types of pneumonia and can include fever, chills, muscle aches, and cough. Most cases of Legionnaires’ disease can be traced to plumbing systems where conditions are favorable for Legionella growth, such as cooling towers, whirlpool spas, hot tubs, humidifiers, hot water tanks, and evaporative condensers of large air-conditioning systems.

Individuals only get sick by breathing in water vapor containing Legionella bacteria, and the disease is not transmitted from person to person. Individuals at higher risk include those 50 years old and older, cigarette smokers, and people with chronic lung disease or compromised immune systems. People living or working in the area who are experiencing these symptoms should seek medical attention with a primary care provider or seek urgent care.

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MEDIA CONTACT: PressOffice@health.nyc.gov