New York City Upper East Side Legionnaires’ Disease Outbreak Affects 23 People

New York City health officials have identified a community outbreak of Legionnaires’ disease on the Upper East Side. The cluster was first announced on July 2 with two confirmed cases and has since risen to 23 confirmed infections, including 17 hospitalizations, with no deaths reported. Cases are concentrated in the Carnegie Hill and Yorkville neighborhoods, covering ZIP codes 10028, 10128 and 10075.

The likely source is being investigated as cooling towers in the area, which can disperse Legionella‑containing mist; officials stress the outbreak is not linked to building plumbing and that tap water, bathing, cooking and home air‑conditioning remain safe. Health Commissioner Dr. Alister Martin and Mayor Zohran Mamdani have issued alerts urging anyone who lived, worked or visited the zone since late June to monitor for flu‑like symptoms—fever, cough, shortness of breath, muscle aches—and seek medical care promptly.

High‑risk groups include people over 50, smokers, those with chronic lung disease or weakened immune systems. The city is testing all identified cooling towers (about 160, with roughly a third already examined) and will require remediation of any that test positive. Public information and remediation orders are being communicated to residents as the investigation continues.