• Legionnaires' can be contracted by breathing in water vapor with Legionella bacteria
  • Four cooling towers in the area have tested positive for the said bacteria
  • The cooling towers have already been ordered to be disinfected

New York -- The number of people affected by Legionnaires' disease in the Bronx has increased, with 19 cases already identified and one death logged.

A total of 19 people have been diagnosed with Legionnaires' disease amid the ongoing community cluster of the disease in the Highbridge neighborhood in the Bronx and "bordering communities," the New York City Health Department announced in an update Wednesday. One person has died, while eight others are still hospitalized.

This is an increase from an earlier announcement on the investigation, wherein four cases were identified.

"We are saddened to hear about a death in a person who contracted Legionnaires'," Health Commissioner Dr. Ashwin Vasan said in the news release. "Health Department staff are working to ensure that buildings in the cluster area are treated and conditions remediated quickly."

Legionnaires' disease is pneumonia caused by Legionella bacteria, which can naturally be found in the environment and can grow in warm water. In an earlier notice to residents in the affected area, the agency noted that the likely source of the bacteria is a cooling tower and that it is testing all such towers in the area.

In the update, the agency confirmed that four cooling towers tested positive for Legionella pneumophila, and they have already been ordered to be disinfected. The agency is also conducting outreach in the area to help inform the residents on how they can protect themselves.

The agency stressed that Legionnaires' disease cannot be transmitted from person to person. Instead, people can get it by breathing in water vapor that's contaminated with the bacteria. It can cause symptoms that are quite similar to that of other pneumonia, and the agency is urging those who may develop symptoms such as fever, breathing difficulties and cough to contact their health care provider immediately.

While Legionnaires' disease can be treated if it's caught early, it can also be serious for some people, such as cigarette smokers, those aged 50 and above and those who have compromised immune systems.

"While most people exposed to the bacteria do not get sick, Legionnaires' disease can cause severe illness or be fatal for those at higher risk, including people pre-existing chronic health issues," Dr. Vasan said in the NYC Health Department news release. "That's why it's crucial that you seek health care as soon as you experience flu-like symptoms."

Deadly Legionnaire's Disease Found at HK Government Headquarters
Colonies of legionella in a lab dish. Reuters.