As the city continues investigating a cluster of Legionnaires’ disease in the South Bronx, health officials are urging anyone who lives, works or has visited the affected area since late August to monitor for symptoms and seek medical attention if they become sick.
The Department of Health and Mental Hygiene identified nine cases connected to the cluster as of Sept. 12, with three people hospitalized, four discharged, one person who did not require hospitalization and one death.
The department has identified Legionella bacteria through preliminary testing in 10 cooling towers in the 10451 and 10456 ZIP codes, including ones at Yankee Stadium, Lincoln Hospital and Boricua College. All 10 have been ordered to undergo cleaning and disinfection by Sept. 14.
But what exactly puts people at risk — and what can residents do to protect themselves?
The Bronx Times spoke with Gregory Weston, MD, MSCR, associate hospital epidemiologist at Montefiore Medical Center, for answers.
How does Legionnaires’ disease spread?
Legionnaires’ disease is a type of pneumonia caused by Legionella bacteria, which naturally occur in water.
People can become infected when water containing live Legionella becomes aerosolized — essentially forming tiny droplets or mist that can be breathed into the lungs.
“Legionella infects people by becoming aerosolized, which means it’s able to travel into air, and then people breathe it in, and that’s how it gets introduced into the body,” Weston said.
Cooling towers can be a source of exposure because they release water mist into the outdoor air.
The Health Department said, however, that it has not yet determined whether any of the 10 cooling towers that tested positive for Legionella are the source of the South Bronx cluster.
The initial PCR tests detected Legionella bacteria DNA but cannot determine whether the bacteria are alive or dead. Culture testing, which can determine whether live Legionella bacteria were present when samples were collected, can take up to two weeks.
Is it safe to be inside buildings with affected cooling towers?
Yes, according to the Health Department.
“It’s more from being outside than from being inside,” Weston said.
Health officials said there is no additional risk from being inside any of the 10 buildings with cooling towers that tested positive for the presence of Legionella.
It is also safe to shower, drink tap water and use air conditioning in the affected areas, unless otherwise advised by health officials.
What symptoms should I be looking out for?
Symptoms typically develop two to 14 days after exposure and can include fever, cough, shortness of breath, muscle aches and general weakness or malaise. Some people with Legionnaires’ disease can also experience gastrointestinal symptoms such as diarrhea.
Some people may experience a mild illness, while others can develop severe pneumonia, according to Weston.
People experiencing shortness of breath, chest pain or significant weakness should seek medical attention.
How can I know if I have Legionnaires’ disease and not the flu or another respiratory illness?
Legionnaires’ disease can cause symptoms similar to other forms of pneumonia and respiratory infections, and it is hard to distinguish from others.
“The most important thing is for people to recognize when they’re feeling very ill, and they should seek medical attention, whether they have Legionella or influenza or whatever the respiratory infection might be,” Weston said.
For people who have been in the affected ZIP codes, the timing of symptoms can also be important. Symptoms can begin anywhere from two to 14 days after exposure.
The Health Department recommends that anyone who lives, works or has visited the affected area since late August and develops flu-like symptoms contact a health care provider immediately.
Who is most at risk?
Most people exposed to Legionella do not become sick. However, some people are at higher risk of developing Legionnaires’ disease, including adults ages 50 and older, smokers, people with chronic lung disease and people with weakened immune systems.
The Health Department also identifies people who vape and those taking medications that suppress the immune system as being at increased risk.
Weston similarly identified older people, smokers, people with emphysema or asthma or other lung disease and people with weakened immune systems as groups at higher risk.
Can a mask protect me from infection?
There is no particular evidence that wearing a mask reduces a person’s risk of developing Legionnaires’ disease in this situation, Weston said.
Instead, residents should pay close attention to how they feel and seek medical care if they become seriously ill.
What happens if you get Legionnaires’ disease?
Legionnaires’ disease can be treated with antibiotics and early treatment is important.
For relatively mild cases, Weston said treatment generally involves oral antibiotics. Patients who are hospitalized may initially receive antibiotics intravenously before switching to oral medication as they improve.
The disease can progress from a mild illness to severe pneumonia, making it important for people who become seriously ill to seek medical attention promptly.
