Legionnaires' Disease Cases Surge to 46 in NYC Outbreak

WHO:

ABC7 New York - New York City health officials are involved in managing the outbreak.

ABC7 New York - Mayor Zohran Mamdani is overseeing the response to the outbreak.

ABC7 New York - New York City Councilmember Julie Menin expressed concerns about the response time.

ABC News - The New York City Department of Health (NYC Health) is monitoring the situation.

WHAT:

ABC7 New York - The number of confirmed cases of Legionnaires' disease remains at 46, with hospitalizations also remaining at 22.

ABC7 New York - A list of addresses of buildings linked to the outbreak is expected to be released in the coming days.

ABC7 New York - During a previous outbreak last summer, seven people died, and more than 100 got sick with Legionnaires' disease.

Gothamist - Owners of 19 of the buildings with positive tests for Legionella bacteria have already completed the process of cleaning and disinfecting the towers.

ABC7 New York - Testing has uncovered dozens of buildings on the Upper East Side with traces of the bacteria that cause Legionnaires' disease.

ABC7 New York - A team of water treatment specialists is currently working at a building at 1511 Third Ave., which is identified as "a cooling tower of interest."

ABC7 New York - The Health Department ordered the building owner to immediately remediate, drain, clean, and disinfect the cooling tower.

ABC7 New York - A new mandatory monthly testing requirement for cooling towers is being implemented, which was first reported in May at a cooling tower in East Harlem.

ABC7 New York - The number of confirmed cases of Legionnaires' disease remains at 46, with hospitalizations also remaining at 22.

ABC7 New York - The Health Department reported that the initial PCR test at a commercial building at the corner of East 85th Street came back positive for Legionella bacteria.

ABC7 New York - A new mandatory monthly testing requirement for cooling towers is being implemented.

ABC7 New York - The number of confirmed cases of Legionnaires' disease has risen to 46.

ABC7 New York - There are currently 22 hospitalizations related to the outbreak.

ABC News - No deaths have been reported in connection with the outbreak.

ABC7 New York - Testing has identified buildings with traces of the bacteria causing Legionnaires' disease.

ABC News - NYC Health stated that all area cooling towers are being tested for the bacteria.

WHERE:

ABC7 New York - The outbreak is concentrated in three ZIP codes on the Upper East Side.

ABC7 New York - The outbreak is concentrated in the Upper East Side neighborhoods of Carnegie Hill and Yorkville, Manhattan.

ABC7 New York - A cooling tower of interest is located at 1511 Third Ave., Manhattan.

WHEN:

ABC7 New York - Testing began on July 2 after the outbreak was identified.

ABC7 New York - A list of addresses of buildings linked to the outbreak is expected to be released in the coming days.

WHY:

ABC News - NYC Health stated that there is no issue with any building's plumbing system, allowing residents to continue using tap water, bathing, and cooking.

ABC News - The likely source of the bacteria is believed to be a cooling tower in the area that sprays a mist containing the bacteria.

HOW:

BBC - The city announced its "aggressive" plan to tackle the outbreak, stating it would work to test all the water coolers in the area.

ABC7 New York - Mayor Zohran Mamdani vowed to be transparent, but the list of the "cooling towers of interest" in the affected area has not yet been released.

ABC News - Mayor Zohran Mamdani announced that his administration is implementing measures to publicly identify specific buildings suspected of being sources of Legionella bacteria.

ABC7 New York - The Health Department ordered the building owner to remediate, drain, clean, and disinfect the cooling tower.

ABC7 New York - A team of water treatment specialists is working on the cooling tower to ensure compliance with health regulations.

(UPDATED July 10, 2026 21:20 UTC)

The number of confirmed cases of Legionnaires' disease remains at 46, with 22 individuals currently hospitalized. In the coming days, a list of addresses linked to the outbreak is expected to be released, while owners of 19 buildings with positive tests for Legionella bacteria have already completed cleaning and disinfecting their facilities. The city has announced an "aggressive" plan to tackle the outbreak, which includes testing all the water coolers in the area.

(UPDATED July 10, 2026 19:23 UTC)

Testing has revealed that numerous buildings on the Upper East Side contain traces of the bacteria responsible for Legionnaires' disease, prompting a response from health officials. A team of water treatment specialists is currently addressing concerns at a cooling tower located at 1511 Third Ave., where the Health Department has ordered immediate remediation efforts. In light of this outbreak, which is concentrated in three ZIP codes, a new mandatory monthly testing requirement for cooling towers is being implemented, although the list of affected towers has yet to be disclosed by Mayor Zohran Mamdani.

(UPDATED July 10, 2026 14:52 UTC)

The number of confirmed cases of Legionnaires' disease remains at 46, with 22 individuals currently hospitalized, as reported by ABC7 New York. The Health Department has identified a positive PCR test for Legionella bacteria at a commercial building on East 85th Street, and Mayor Zohran Mamdani announced new measures to publicly identify buildings suspected of harboring the bacteria. In response to the outbreak, which is concentrated in three ZIP codes on the Upper East Side, a mandatory monthly testing requirement for cooling towers is being implemented, while NYC Health assures residents that their plumbing systems are not affected, allowing them to safely use tap water, bathe, and cook.

(UPDATED July 10, 2026 11:56 UTC)

New York City health officials are actively managing an outbreak of Legionnaires' disease that has now confirmed 46 cases, with 22 individuals currently hospitalized. Mayor Zohran Mamdani is overseeing the response, while City Councilmember Julie Menin has raised concerns about the response time, and testing has identified a cooling tower at 1511 Third Ave. as a potential source of the bacteria. The Health Department has mandated that the building owner remediate the cooling tower, and a list of addresses linked to the outbreak is expected to be released in the coming days.