NEW YORK / RankWire.AI / – Preliminary testing detected Legionella DNA in a cooling tower at Yankee Stadium as New York City investigates a Legionnaires’ disease cluster in the South Bronx. The city had confirmed 11 cases by Tuesday night, including one death. Three people remained hospitalized. The New York City Health Department identified 10 cooling towers with positive preliminary PCR results across ZIP codes 10451 and 10456, which cover parts of Melrose and Morrisania.
City health officials sampled 24 cooling towers while investigating the cluster. Ten produced positive PCR results, including the tower at Yankee Stadium at 1 E. 161st St. PCR testing can detect genetic material from Legionella bacteria. However, it cannot determine whether the bacteria are alive. Only live Legionella bacteria can cause illness, and additional laboratory culture testing is underway to help determine whether viable bacteria were present in the sampled towers.
The New York Yankees said no confirmed cases in the current cluster have been associated with Yankee Stadium. The team said its cooling towers were installed in 2024 and undergo regular water quality testing. A Legionella test conducted Aug. 20 returned a negative result, according to the Yankees. The club also conducted weekly water quality and bacteriological indicator testing on Aug. 26, Sept. 2 and Sept. 9 before the city collected its PCR sample on Sept. 11.
Cooling towers cleaned after positive preliminary tests
The New York City Health Department ordered all 10 cooling towers with positive PCR results to undergo full cleaning and disinfection. Officials required remediation to be completed by Sept. 14. Health Commissioner Alister Martin said Tuesday that all towers with concerning positive results had been cleaned and disinfected. The Yankees said the cooling tower at Yankee Stadium was drained, cleaned and disinfected on Sept. 13 after the city informed the organization of its preliminary result.
Legionnaires’ disease is a type of pneumonia caused by Legionella bacteria. People usually become infected after breathing small water droplets containing the bacteria. The disease generally does not spread from person to person. Symptoms can include fever, cough and difficulty breathing. City officials advised people who have lived, worked or visited the affected South Bronx area since late August to contact a health care provider if they develop flu-like symptoms.
City continues South Bronx Legionnaires investigation
Health officials said eight of the 10 towers with positive preliminary results complied with the city’s 31-day Legionella testing requirement. Two locations had not provided the required testing information when the city announced its findings. The investigation covers cooling towers in the affected South Bronx neighborhoods, including sites at Yankee Stadium and other properties. Officials continue to use laboratory testing and epidemiological information to determine the source of exposure connected with the confirmed illnesses.
The Health Department said residents in ZIP codes 10451 and 10456 can continue drinking tap water, showering and using air conditioners unless officials issue different guidance. The department also said being inside buildings connected to the 10 cooling towers does not create additional risk. The Yankees said city health officials have not asked the team to postpone games at Yankee Stadium. Health officials continue monitoring confirmed cases while laboratory work proceeds on samples collected during the South Bronx investigation.