Legionnaires’ disease outbreak: Guggenheim Museum among 31 UES buildings with cooling towers that contained illness-causing bacteria

The Guggenheim Museum, Asphalt Green’s Upper East Side campus, a Whole Foods Market and Trevor Day School are among 31 buildings whose cooling towers preliminarily tested positive for Legionella bacteria amid a Legionnaires’ disease outbreak that has sickened 46 people, city health officials said Friday.

The city Health Department released the addresses Friday evening, hours after announcing that 19 of the affected cooling towers had already been cleaned and disinfected. The remaining 12 were ordered to complete remediation by Saturday.

Officials cautioned that the preliminary PCR screening results do not establish that any of the buildings contributed to the outbreak or that live bacteria were present in their cooling towers.

The list could also grow. Laboratory testing of samples collected from 183 cooling towers remains underway, and the department said additional positive PCR results could be reported over the weekend.

The outbreak is concentrated in ZIP codes 10028, 10128 and 10075 in Carnegie Hill and Yorkville. Of the 46 people diagnosed, 22 remain hospitalized, 19 have been discharged and are recovering at home, and five were not hospitalized. No deaths have been reported, per health officials. 

Below is a map of the 31 buildings whose cooling towers preliminarily tested positive for Legionella. Green markers indicate sites where remediation is complete, while red markers show sites ordered to clean and disinfect their towers.

Locations of buildings where Legionnaires’ disease-causing bacteria was detected

The city says it detected Legionella, the bacteria that causes Legionnaires’ disease, in the cooling tower of this building at 300 East 79th St. on the Upper East Side.Photo via Google Maps

Cooling towers at 31 Upper East Side buildings have preliminarily tested positive for the bacteria that cause Legionnaires’ disease as an outbreak in Carnegie Hill and Yorkville has sickened 46 people, city health officials said Friday.

The prominent addresses on the list include the Guggenheim at 1071 Fifth Ave., Asphalt Green at 1750 York Ave. and the Whole Foods Market at 1551 Third Ave., all of which have completed remediation.

Trevor Day School’s middle and upper school at 312 E. 95th St. was among the 12 buildings ordered to finish cleaning and disinfecting its cooling tower by Saturday.

The Health Department stressed that there is no additional risk from being inside any of the listed buildings. The results involve cooling towers, which release mist into the outdoor air, rather than the buildings’ plumbing or indoor air-conditioning systems.

Residents can continue to drink tap water, bathe, shower, cook and use their air conditioners normally, officials said.

PCR tests can detect genetic material from Legionella bacteria but cannot determine whether the bacteria are alive or dead. Only live Legionella can cause illness.

The city is conducting culture testing on every cooling tower sampled to determine whether live bacteria were present when the samples were taken. Those results can take up to two weeks.

If live bacteria are found, investigators will use whole-genome sequencing to compare bacteria from the cooling towers with samples obtained from patients. That process will take additional time before officials can definitively identify the source of the outbreak.

“It’s important for us to not wait two weeks,” city Health Commissioner Dr. Alister Martin said during a Friday briefing. “That’s why you see us acting fast at this point.”
Dr. Alister Martin speaks in January after Mayor Zohran Mamdani announced his appointment as New York City health commissioner.Photo by Michael Appleton/Mayoral Photography Office

Under emergency measures adopted in response to the cluster, owners of buildings whose cooling towers receive positive PCR screening results are being ordered to clean and disinfect them immediately rather than wait for culture testing to establish whether live bacteria are present.

The Mamdani administration described the publication of the addresses and the immediate remediation orders as a more aggressive and transparent response than the city has previously used in Legionnaires’ disease investigations.

“We want to be transparent with New Yorkers about this,” Mayor Zohran Mamdani said earlier Friday at an unrelated consumer-protection briefing. “We’re looking to do it as quickly as we can.”

The Health Department identified the cluster July 2 after finding two confirmed cases in close proximity and began investigating cooling towers in Carnegie Hill and Yorkville. More than 100 city employees worked on the response over the July Fourth weekend, according to the department.

The investigation was expanded July 5 to include ZIP code 10075 after an additional case was connected to someone who lived, worked or had visited the area.

Officials warned that more cases could be confirmed even after all potentially affected cooling towers are remediated. Symptoms generally develop two to 10 days after exposure but can take as long as 14 days to appear.

Additional time can pass before a patient seeks care, is tested and has a positive result reported to the city.

“We may continue to see cases pop up,” Martin said. “If you were exposed yesterday, you might not show symptoms for quite a while if you’re still in that 10-day window.”

The Health Department is also reviewing whether the affected building owners complied with city cooling-tower testing and maintenance requirements. Officials did not say Friday whether any owners would face penalties but said noncompliance could carry serious consequences.

The 19 addresses where cooling-tower remediation has been completed are:

180 East End Ave.; 1750 York Ave.; 1660 Second Ave.; 1438 Third Ave.; 1511 Third Ave.; 1551 Third Ave.; 1071 Fifth Ave.; 1080 Fifth Ave.; 1001 Fifth Ave.; 240 E. 82nd St.; 8 E. 83rd St.; 145 E. 84th St.; 117 E. 85th St.; 125 E. 87th St.; 152 E. 87th St.; 120 E. 87th St.; 501 E. 87th St.; 168 E. 88th St.; and 160 E. 88th St.

The 12 addresses ordered to complete remediation by Saturday are:

1875 Second Ave.; 1110 Fifth Ave.; 153 E. 78th St.; 135 E. 79th St.; 300 E. 79th St.; 238 E. 81st St.; 160 E. 84th St.; 114 E. 85th St.; 401 E. 88th St.; 333 E. 91st St.; 354 E. 91st St.; and 312 E. 95th St.

The department said the list is preliminary and will be updated as laboratory testing and the investigation continue.

What is Legionnaires’ disease?

Legionnaires’ disease is a serious form of pneumonia caused by inhaling small droplets of water containing live Legionella bacteria. It is not contagious and does not spread from person to person.

Symptoms include fever, chills, muscle aches, shortness of breath and cough. People who live or work in the affected area — or who have visited it since late June — should contact a health care provider immediately if they develop flu-like symptoms, officials said.

People at increased risk include adults age 50 and older, people who smoke or vape, those with chronic lung disease and people with weakened immune systems or who take immune-suppressing medications.

People without a health care provider can call 311 or contact NYC Health + Hospitals for low- or no-cost care. Officials said masks are not recommended because the disease is not transmitted person to person and there is no evidence that masking prevents exposure to Legionella.

Asked whether the city would offer free testing to residents of the affected ZIP codes, health officials said people without providers could be connected through 311 to low- or no-cost care, but did not announce a stand-alone testing program.