NYC Health Department Investigating Community Cluster of Legionnaires’ Disease on the Upper East Side

Two People on the Upper East Side Diagnosed With Legionnaires’ Disease, a Type of Pneumonia Caused by Breathing Water Vapor Containing Legionella Bacteria in the Outside Air

Adults With Flu-Like Symptoms, Fever, Cough, or Difficulty Breathing Who Have Been in the Affected Area Since Late June Should Seek Immediate Medical Attention

July 2, 2026 — Today, the NYC Health Department has launched an investigation into a likely community cluster of Legionnaires’ disease in the Upper East Side neighborhoods of Carnegie Hill and Yorkville (ZIP codes 10028 and 10128). As of July 2, two people have been diagnosed with Legionnaires’ disease in the affected area, and confirmatory results for other potential cases are currently pending. To date, there are no deaths associated with this cluster. Any New Yorkers who currently live or work in this area or people who have visited the area since late June and are experiencing flu-like symptoms, such as fever, cough, or difficulty breathing should contact a health care provider immediately.

The NYC Health Department is actively investigating this Legionnaires’ disease cluster by sampling and testing water from all cooling tower systems in the area. Past community clusters have been caused by Legionella bacteria spreading through the air from the mist produced by cooling towers. Building owners with any cooling towers that test positive for the presence of Legionella bacteria will be directed to conduct full remediation.

A Health Alert is going out to health care providers, advising them to consider Legionnaire’s disease for people presenting with compatible symptoms and community outreach will be conducted in the area beginning over the weekend.

“As of now, we have two confirmed cases of Legionnaires’ disease, and are working to rapidly confirm any other cases in the area. The Health Department has identified this cluster early and is launching an investigation to reduce the risk of additional cases. Any New Yorkers with flu-like symptoms who live, work, or visited the affected area since late June should contact a health care provider as soon as possible,” said NYC Health Commissioner Dr. Alister Martin. “Legionnaires’ disease is deadly but can be effectively treated if diagnosed early. New Yorkers at higher risk, including anyone who is 50 and older, those who smoke, or people with 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 only get sick by breathing in water vapor containing Legionella bacteria. Symptoms resemble other types of pneumonia and can include fever, chills, muscle aches, and cough. Legionnaires’ disease is not contagious and can be treated with antibiotics when caught early. With warm weather this weekend, the NYC Health Department wants to remind New Yorkers that it is safe to use air conditioners, cooling centers, and all city facilities in this neighborhood. It is also safe to shower, and drink tap water. Mist from a cooling tower blows outside and does not affect the internal air conditioning, window air conditioning units, or plumbing system. 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