NEW YORK − Health officials identified another fatality in New York City’s largest Legionnaires’ disease outbreak in years.

On Aug. 28, the city Department of Health and Mental Hygiene announced a seventh death in the ongoing community cluster in central Harlem, in upper Manhattan, suspected to be caused by local water cooling towers that are harboring bacteria. Dr. Michelle Morse, the acting city health commissioner, said on X that the person identified as a Legionnaires' victim died of the bacterial disease before mid-August.

Officials have identified 114 confirmed cases since late July in the city’s largest outbreak of Legionnaires' disease in a decade. Six people are currently hospitalized and newly diagnosed cases have continued to decline since early August, city data shows.

The outbreak of the disease, a severe form of pneumonia caused by the Legionella bacteria, is believed to have spread from mist released by cooling towers used to regulate temperature inside buildings.

While Legionella is naturally found in freshwater, it grows in warm or hot water, according to the Centers for Disease Control and Prevention. Without proper maintenance, cooling towers and other water systems can emit mist containing bacteria, which people in the neighborhood breathe in. CDC estimates around nine in 10 outbreaks were caused by preventable problems with effective water management, including for hot tubs, plumbing systems and cooling towers.

Officials have worked to remediate a dozen cooling towers of large buildings that tested positive for the bacteria in five Harlem ZIP codes (10027, 10030, 10035, 10037 and 10039). The 12 cooling towers on 10 buildings include a city-run hospital, a health center, a condo and a City College of New York building, according to Mayor Eric Adams' office.

Legionnaires’ disease doesn’t spread from person to person. It also doesn’t spread from cool air that comes from air conditioning units, which are common in New York apartments, nor does it spread from drinking water.

On Aug. 20, construction workers filed a lawsuit in state court against a construction company for contracting the disease while working in Harlem. Lawyers for the workers say the company was negligent and city officials failed to provide proper oversight.

In 2015, New York City experienced its largest outbreak, with 138 cases and 16 deaths from Legionnaires' disease, linked to a single cooling tower in the South Bronx, just across the Harlem River from the Harlem neighborhood where the current outbreak is concentrated.

What are Legionnaires' disease symptoms?

People typically develop symptoms after two days of being exposed to the bacteria, and it can take as long as two weeks, the city health department said. Most people exposed to the bacteria don’t develop Legionnaires’ disease, and city officials say the risk is low.

People who contract the disease experience flu-like symptoms, including fever, chills, muscle aches and a cough, according to the CDC. They can also have headaches, fatigue, loss of appetite, confusion and diarrhea.

People ages 50 and older are at higher risk, as well as smokers, people with chronic lung disease or weakened immune systems caused by a health issue or a medication.

In severe forms, Legionnaires’ disease can cause lung failure and death. About 1 in 10 people who get sick die from the disease, according to the CDC.

However, Legionnaires’ disease is easily treatable with antibiotics if identified early. People with symptoms should seek medical care as soon as possible, health officials said.

Hotter, more humid temperatures in a warming climate make Legionnaires’ disease a growing health concern in industrialized countries, as USA TODAY reported. Cases have increased in recent years, according to CDC data.

Contributing: Andrea Riquier and N'dea Yancey-Bragg of USA TODAY

Eduardo Cuevas is a reporter for USA TODAY based in New York City. Reach him by email at emcuevas1@usatoday.com or on Signal at emcuevas.01.

This article originally appeared on USA TODAY: Another person dies in NYC's largest Legionnaires' disease outbreak in a decade

Reporting by Eduardo Cuevas, USA TODAY / USA TODAY

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