A second person has died in a legionnaires' disease outbreak in New York City, with dozens more infected. The outbreak, which has been centred on Manhattan's Upper East Side, has left nine people still hospitalised and 50 who have been discharged from hospital.
According to the New York City health department, there is 'encouraging' data suggesting that an aggressive strategy of testing, enforcement, and remediation aimed at air-conditioning systems atop many large buildings has 'stopped the source of exposure'. Those systems can release water vapor carrying the bacteria that causes legionnaires' disease, a form of pneumonia that is treatable but kills around 10% of patients.
The city's health commissioner, Dr Alister F Martin, said that every building with an initial positive test result has been directed to immediately clean and disinfect its cooling tower, and that every one has completed that work. He also reminded cooling tower operators across the city of their summertime requirement to increase use of biocides that kill the Legionalla bacteria.
Legionnaires' disease is a serious condition that is caused by the Legionalla bacteria, which can proliferate in cooling towers, hot tubs, and showerheads. People can contract the disease by inhaling tiny droplets of contaminated water, and it does not spread person to person.
In August 2025, seven people died and more than 100 were sickened during a legionnaires' disease outbreak in New York's Harlem neighborhood. The disease was named legionnaire's after a 1976 outbreak of the sickness in Philadelphia largely affected people attending a state convention of the American Legion.