New York City health officials confirmed five cases of Legionnaires’ disease, including one death, in a new outbreak in the South Bronx. The city’s health department launched an investigation into a community cluster in parts of Melrose and Morrisania, including ZIP codes 10451 and 10456. Sampling of cooling towers in the area has been completed, with testing ongoing at the city’s public health laboratory.

Legionnaires’ disease is a form of pneumonia caused by Legionella bacteria, which can grow in warm water systems such as cooling towers, showerheads, and hot tubs. The CDC warns that the bacteria are more likely to grow in water-filled windshield wiper fluid tanks. People can become infected by breathing in contaminated water droplets or mist. Health officials say it is safe to use air conditioners, drink tap water, and shower unless otherwise advised.

The South Bronx outbreak marks the second community cluster of Legionnaires’ disease in New York City this year, following a cluster on Manhattan’s Upper East Side in July. City officials noted that multiple community clusters have occurred in previous years, including two each in 2015, 2017, and 2018, and three in 2016. The disease was named after a 1976 outbreak in Philadelphia that affected attendees of an American Legion convention.

City health commissioner Alister F Martin stated that disease investigators have confirmed five cases and are working to identify any additional cases. "Our deepest condolences are with the loved ones of the person who has died," Martin said. He also acknowledged heightened concerns among New Yorkers following the recent Upper East Side cluster and emphasized that community health workers are canvassing the neighborhood to reach affected residents.

The health department has issued a health alert to providers, advising them to consider Legionnaires’ disease when evaluating patients with compatible symptoms. Building owners whose cooling towers test positive are directed to drain, clean, and disinfect them. Health officials have not provided details on the source of the Legionella bacteria or the specific buildings involved in the South Bronx cluster.

The full investigation into the outbreak is ongoing, and further details on the source of the bacteria and the extent of the outbreak are yet to be determined. Health officials have not ruled out the possibility of additional cases or a broader spread of the disease in the area.