Legionnaires' disease outbreak in NYC prompts cleaning of cooling towers

An outbreak of pneumonia caused by the bacteria Legionella, is spreading across the Upper East Side, officials said Tuesday, but the risk to Long Islanders remains low.

The New York City Health Department is investigating a community cluster of Legionnaires' disease in the Upper East Side neighborhoods of Carnegie Hill and Yorkville, from Central Park to the East River. As of Monday,  there were 60 patient cases. 

“In NYC we have hundreds of cases of Legionnaires every year,” city officials said. “Almost all of those hundreds of cases of Legionnaires are sporadic, meaning we don't find patterns or one source.”

Cooling towers in buildings, which extract extra heat from large buildings using water, are  the suspected sources of the infection. Water droplets or mist that contain the bacteria and is expelled from the towers can spread the illness if inhaled, officials said.

There have been 183 cooling towers sampled by the city. . Of these, 76 have been ordered to be cleaned and disinfected based on initial positive test results. 

“We are taking the most aggressive posture we have ever taken regarding a cooling tower investigation," city officials said. 

But for people who are not in areas with cooling towers, the risk is relatively small.

“People who don’t live or work in the vicinity where the outbreak is taking place are really at low risk,” Dr. Wafaa El-Sadr, a professor of epidemiology at Columbia University, said. “For the vast majority of the people who live in the city or on Long Island, the risk is very small.”

Here's what you should know about the bacteria.

What are the symptoms of Legionnaires?

“As soon as a person develops symptoms and is living near or working in a place that has a cooling tower, they should immediately go to their provider and get evaluated,” El-Sadr said. "The good news is that it’s easy to diagnose, and it’s easy to treat.”

Symptoms often start two to 10 days after contact with the bacteria. The first wave of symptoms includes a headache, muscle aches and a fever. By the second or third day, other symptoms can start, including cough, which might bring up mucus and sometimes blood, shortness of breath, chest pain, nausea, vomiting and diarrhea and confusion or other mental changes.

People visiting the city should also be aware of the contaminated areas and avoid them if possible.

“If a person is in the affected areas of the city they could contract it,” Dr. Jason Zucker, infectious disease physician at NewYork-Presbyterian/Columbia University Irving Medical Center, said. “Usually it's not just walking through, but if someone is exposed outside they can get sick."

How do people contract Legionnaires disease?

By breathing in or swallowing liquid or mist containing the bacteria. However, most healthy people exposed to the bacteria don't get sick, according to the Centers for Disease Control and Prevention.

How can the risk be decreased? 

El-Sadr does not recommend stopping any normal activities and said the risk for people in the city and on Long Island is “very low.”

“It requires very specific kinds of growing conditions,” El-Sadr said. “People should not be concerned about going into their pool or going into the water, the ocean or anything like that.”

What are the treatment options and recovery time?

Immediate treatment with antibiotics most often cures Legionnaires' disease. However, hospitalization, even for healthy people, is not uncommon and, for those with underlying conditions, the infection can be fatal, experts said.

“If someone has conditions that make Legionnaires disease more severe, like if they are older, are smokers or have heart or lung disease, then they should be more concerned,” El-Sadr said.