NYC health officials confirm Legionnaires' cluster in South Bronx, one death

Health department orders cooling tower testing, begins community outreach Friday

The New York City Health Department has identified a new Legionnaires’ disease cluster in the South Bronx, with five people diagnosed as of Thursday in the Melrose and Morrisania neighborhoods and one death connected to the outbreak, the agency said.

The department said in a statement that confirmatory test results for other potential cases were pending. Health Commissioner Dr. Alister Martin offered condolences to the family of the person who died. “Our deepest condolences are with their loved ones,” Martin said in a statement.

Legionnaires’ disease is a severe form of pneumonia caused by Legionella bacteria. People who inhale water vapor that contains the bacteria can develop flu-like symptoms. Most people exposed to the bacteria do not develop the disease, but complications can be fatal among those who do, according to the Health Department. The origin of the bacteria is often traced to cooling towers.

Health officials said Thursday that cooling towers in the affected area would be tested, with any that test positive for Legionella directed to undergo remediation. “Water ecologists have sampled cooling towers in the affected area,” Martin said. “Any cooling tower that tests positive will be directed to undergo full cleaning and disinfection immediately.”

Beginning Friday, the city will conduct community outreach in Melrose and Morrisania, distributing informational flyers in multiple languages, updating its website and holding town halls throughout the weekend, the city said.

Martin acknowledged public concern tied to the recent Upper East Side outbreak. “I understand that New Yorkers may have heightened concerns following the recent Upper East Side cluster,” he said. “We are taking immediate action.”

The Upper East Side cluster was declared over on July 31. It produced a total of 92 cases and seven deaths. The current South Bronx cluster is the second identified in New York City this summer.

Health officials said multiple clusters have been previously identified in the city, including two clusters each in 2015, 2017 and 2018, and three clusters in 2016.

In early August, families of victims from a 2025 Harlem Legionnaires’ disease cluster that killed seven people sued the city, alleging neglect and failures to follow its own regulations.