What is Legionnaires’ disease? Your questions answered after 12 are hospitalized in Queens

Posted at 5:38 AM, Oct 25, 2017
and last updated 2017-10-25 06:26:24-04

FLUSHING, Queens — A community cluster of Legionnaires’ disease cases in downtown Flushing, Queens, including 12 patients as of Tuesday afternoon, is being investigated by the Health Department.

Most patients had serious underlying health conditions. Five people have been hospitalized and recovering, and seven have been discharged from the hospital. No patients have died.

Two additional cases are currently being investigated to determine whether they are part of this cluster.

News of the cluster has many people asking, what is Legionnaires’ disease, what are the symptoms and signs, and how is it treated?


Legionnaires’ disease is a treatable infection using antibiotics for pneumonia. Every year, there are between 200 and 400 cases of Legionnaires’ disease in the city.

Legionnaires’ disease is caused by the bacteria Legionella.

Most cases of Legionnaires’ disease can be traced to plumbing systems where conditions are favorable for Legionella growth, such as cooling towers, whirlpool spas, hot tubs, humidifiers, hot water tanks, and evaporative condensers of large air-conditioning systems.

Legionnaires’ disease cannot be spread from person to person. Groups at highest risk for Legionnaires’ disease include people who are middle-aged or older, especially cigarette smokers, people with chronic lung disease or weakened immune systems and people who take medicines that weaken their immune systems (immunosuppressive drugs). Those with symptoms should call their doctor and ask about testing for Legionnaires’ disease.


Symptoms include fever, cough, chills, muscle aches, headache, fatigue, loss of appetite, confusion and diarrhea. Symptoms usually appear two to 10 days after significant exposure to Legionella bacteria.

The Health Department is urging residents in the area with respiratory symptoms, such as fever, cough, chills and muscle aches, to promptly seek medical attention. The Health Department has alerted health care providers in the area about this cluster.


Legionnaires’ disease can be deadly, but is treatable with antibiotics. Most people get better with early treatment, although they may need to be hospitalized. Others have died from complications of the disease.


To raise awareness in the community, the Health Department and the Mayor’s Office are working with elected officials and sending outreach teams to transit hubs and senior centers in the area to distribute information about Legionnaires’ disease. The Health Department is also organizing a community meeting to inform residents, answer questions and address any concerns.

As of today, the Health Department has sampled all cooling towers in the investigation zone. Testing involves a two-step process that first identifies genetic evidence of the bacteria and then confirms if the bacteria are alive and able to cause disease. Positive results from the first step will enable the Health Department to identify towers that potentially have bacteria capable of making people sick.

The owners of those buildings will be ordered to immediately increase the level of biocides that kill the Legionella bacteria or to change to a new biocide and report to the Department within 24 hours. This biocide remediation will be done as a precautionary step while the second step, growing the bacteria in culture, is being done to determine the presence of the live bacteria that causes Legionnaires’ disease. It takes two weeks to allow bacteria adequate time to grow. A positive culture indicates the presence of bacteria capable of causing disease. The Department will order the owner of any building with a positive culture result to fully clean and disinfect the cooling tower.

“The Health Department is currently investigating a cluster of Legionnaires’ disease cases in the downtown Flushing area of Queens, and I urge individuals in this area with respiratory symptoms to seek medical attention right away. People over the age of 50 and people with compromised immune systems are especially at risk,” said Health Commissioner Dr. Mary T. Bassett. “As with our previous Legionnaires’ disease investigations, we are in the process of investigating the source of the cluster and are working with building owners in the area to rapidly test and clean cooling towers.”

For more information about Legionnaires’ disease, please visit the Health Department website.