• Posted August 12, 2025

Update: NYC Legionnaires’ Outbreak Grows to 90 Cases; 3 Deaths Reported

A Legionnaires’ disease outbreak in Central Harlem has now sickened 90 people and caused three deaths, New York City health officials said Tuesday.

The update comes just a few days after the city’s health department proposed new rules for the testing of building cooling towers, suspected origin of the outbreak.

Cooling towers are large rooftop devices that release mist into the air to help cool buildings. But if the water inside the tower becomes too warm or isn't disinfected properly, bacteria called Legionella can grow. People can get sick when they inhale this contaminated mist.

A Department of Health spokesperson told CNN that the proposed rules “were in development well before the Legionnaires’ cluster in Central Harlem.”

Under current city law, building owners must register and maintain their cooling towers, which are regularly inspected, CNN said. 

The new proposal would set strict timelines for testing, require analysis of samples by state-certified labs and impose fines for noncompliance. 

Financial penalties have not been specified. Right now, failing to follow maintenance rules can bring fines of $500 to $2,000.

Still, enforcement could be difficult. Inspections have dropped sharply, city data shows, with fewer than half as many in 2024 compared to 2017, when the city began tracking numbers, according to Gothamist, a non-profit newsroom affiliated with WNYC public radio.

The cluster was announced July 25. Health officials say all working cooling towers in the affected area have been tested, and those with Legionella have been cleaned. 

Legionnaires’ disease is a type of pneumonia, the U.S. Centers for Disease Control and Prevention (CDC) says.

Symptoms can include: Cough, fever, headaches, muscles aches and shortness of breath.

The infection can be treated with antibiotics. Left untreated, it may lead to serious complications like lung failure or death.

Each year, around 6,000 cases are reported in the U.S., the Occupational Safety and Health Administration (OSHA) says. Health officials suspect the true number is higher, however, because it can be hard to tell Legionnaires’ apart from other types of pneumonia.

More information

The Mayo Clinic has more on symptoms and causes of Legionnaires' disease.

SOURCE: CNN, Aug. 11, 2025