New York City Health Department Investigating a Community Cluster of Legionnaires' Disease in Central Harlem Neighborhood (Updated 8/2/25)

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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.

https://www.nyc.gov/site/doh/about/press/pr2025/nyc-health-investigating-legionnaires-disease-in-harlem.page

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New York City Health Department Provides Update on Legionnaires' Disease Community Cluster in Central Harlem

Twenty-two New Yorkers with Legionnaires’ Disease have been identified as part of the cluster, one death has occurred

People 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 30, 2025 — The New York City Health Department today provided an update on the investigation into a community cluster of Legionnaires’ disease in the Central Harlem neighborhood (ZIP codes 10027, 10030,10035, 10037, and 10039) and bordering communities. Twenty-two people have been diagnosed with Legionnaires’ disease since July 25, 2025. One person has died.

All operable cooling towers in the investigation area have been sampled, and the Health Department has directed building owners with initial positive screening results to initiate remediation within 24 hours.

People living or working in the area with flu-like symptoms, such as cough, fever, chills, muscle aches, or difficulty breathing should contact a health care provider immediately. It is especially important for people at higher risk — including those ages 50 and older, cigarette smokers, and people with chronic lung disease or compromised immune systems — to get care if they have symptoms.

"Anyone 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. People can get Legionnaires’ disease by breathing in water vapor that contains Legionella bacteria. Legionnaires’ disease cannot be transmitted from person to person and can be treated with antibiotics. Complications from the disease are less likely the earlier treatment begins.

Legionnaires’ disease can be caused by 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.

https://www.nyc.gov/site/doh/about/p...s-cluster.page

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Last updated August 6 at 5 p.m.

Legionnaires' Disease Cluster in Central Harlem


The NYC Health Department is currently investigating a community cluster of 73 cases of Legionnaires' disease, including three deaths, in Central Harlem (ZIP codes 10027, 10030, 10035, 10037, and 10039). The risk to most people is low, but if you live or work around these ZIP codes and have flu-like symptoms, see a health care provider right away. If you do not have a health care provider, visit NYC Health + Hospitals. Symptoms include cough, fever, chills, muscle aches, and shortness of breath.

This is not an issue with any building's plumbing system. Residents in these ZIP codes can continue to drink water, bathe, shower, cook, and use your air conditioner.

• Notice to Residents in and around Central Harlem about Legionnaires' Disease (PDF, August 6)
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Read our August 4 update on the City's investigation of this cluster of cases.

Continued: https://www.nyc.gov/site/doh/health/...s-disease.page