NYC launches emergency response after almost 50 infected with disease outbreak

Nearly 50 people have been sickened in a Legionnaires’ disease outbreak in New York City as officials ordered emergency action at dozens of buildings in a bid to stop the deadly bacteria spreading.

Health officials say at least 46 people have been diagnosed with Legionnaires’ disease as part of an outbreak centred on the Upper East Side, with 22 patients remaining in hospital, 19 discharged and five recovering without requiring hospital treatment. No deaths have been reported.

In an unprecedented move, New York City has published a preliminary list of 31 buildings whose cooling towers tested positive for the presence of Legionella bacteria during initial screening.

Building owners have been ordered to immediately clean and disinfect their cooling towers while investigators work to identify the source of the outbreak.

Officials stressed the buildings have not been confirmed as the source of the infections.

Initial PCR tests can detect the presence of Legionella bacteria but cannot determine whether the bacteria are alive. Further culture testing, which takes up to two weeks, will establish whether live bacteria capable of causing illness were present.

The city says additional buildings could be added to the list as more test results become available over the weekend.

Mayor Zohran Mamdani has ordered what officials described as a faster and more transparent response, including publishing the addresses of affected buildings and requiring immediate remediation rather than waiting for confirmatory laboratory results.

Health officials are urging anyone who has lived, worked or visited the affected Upper East Side neighbourhoods since late June and develops flu-like symptoms to seek medical advice immediately.

Legionnaires’ disease is a serious form of pneumonia caused by Legionella bacteria, which are spread by inhaling tiny droplets of contaminated water. The illness is not spread from person to person.

Authorities have reassured residents that it remains safe to drink tap water, shower and use air conditioners in the affected areas, adding there is no increased risk from simply being inside any of the buildings identified during the investigation.