The Legionnaires' disease outbreak initially centered on the Upper East Side of Manhattan has now sickened 59 people, according to the city Department of Health. The bacteria responsible for the potentially deadly pneumonia has also been detected for the first time in a residential building on the Upper West Side.
Of the 59 individuals who have fallen ill, 48 have required hospitalization. No deaths have been reported in connection with this cluster, which emerged around July 2 and has affected residents of the Carnegie Hill and Yorkville neighborhoods.
Health officials confirmed that the hot-water system at The Ardsley, a high-end apartment building at 320 Central Park West, tested positive for Legionella bacteria. The building has since disinfected its water system. Mayor Zohran Mamdani stated that the presence of the bacteria in this building should not be a cause for concern, as it lacks a cooling tower, which is typically a common source of outbreaks.
The investigation into the outbreak initially focused on cooling towers in the affected area. Testing of approximately 183 cooling towers in the vicinity identified 31 buildings, including the Guggenheim Museum, that harbored the bacteria. All 31 buildings have reported completing the necessary cleaning and disinfection of their cooling towers. Records indicate that more than half of the cooling towers in the area had previously been cited by health officials for issues such as failing to perform regular monitoring and cleaning, or not submitting required Legionella test results to the Department of Health.
City officials have issued a warning advising anyone who has lived, worked, or visited the affected areas since late June to contact a healthcare provider immediately if they develop flu-like symptoms. Legionnaires' disease is a severe form of pneumonia contracted by inhaling airborne Legionella bacteria, often found in water systems. Symptoms typically include fever, cough, and shortness of breath.