Legionnaires' disease in New York City
Is Legionnaires' disease going around in New York City?
Legionnaires' disease is a serious form of pneumonia caused by Legionella bacteria. The bacteria grow in warm water systems: cooling towers, hot tubs, decorative fountains and the plumbing of large buildings. People get sick by breathing in mist or tiny droplets that contain the bacteria.
New York City has had repeated Legionnaires' clusters, most often in summer and early fall when cooling towers run hardest. The city requires building owners to register, inspect and test cooling towers, and NYC Health announces cluster investigations by neighborhood.
Know the signs
Legionnaires' disease symptoms
- Cough
- Shortness of breath
- Fever
- Muscle aches
- Headache
- Sometimes diarrhea, nausea or confusion
How it spreads
Legionnaires' disease is not spread from person to person. Exposure comes from inhaling contaminated water droplets, and symptoms typically begin two to fourteen days later. People over 50, smokers, and people with chronic lung disease or weakened immune systems are at higher risk.
The local picture
Legionnaires' in the five boroughs
HealthNarc imports the CDC's weekly provisional legionellosis counts for New York City and combines them with community reports of pneumonia-like symptoms.
During an NYC cluster investigation, the Health Department publishes the affected neighborhood and the cooling towers being tested. Check the NYC Health page linked below for current cluster notices.
What to do
Legionnaires' disease is treated with antibiotics and most people recover, but it can be severe. If you have a fever, cough and shortness of breath, especially after time in or near a neighborhood with an announced cluster, see a healthcare provider promptly and mention the possible exposure.
Where the data comes from
Sources for Legionnaires' data
The live figure above is the citywide count from the official feed HealthNarc imports (NYC Health or the CDC’s National Notifiable Diseases Surveillance System) for the latest four published weeks, compared with the four weeks before. Where no official feed exists, it falls back to community reports from the last 28 days. For exposure notices and guidance, use these sources:
In the news
Legionnaires' headlines
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Headlines link to their publishers. HealthNarc does not verify or endorse outside reporting.
Common questions
Legionnaires' in NYC: questions people ask
- Can I catch Legionnaires' disease from another person?
- No. It spreads only through inhaling contaminated water mist, not through contact with someone who is sick.
- Is the tap water safe during an NYC cluster?
- In past NYC investigations, the Health Department has said residents can continue to drink and use tap water, because the risk comes from inhaling mist from cooling towers rather than from drinking water. Always follow the current guidance NYC Health issues for a specific cluster.
- Why do NYC clusters happen in summer?
- Warm weather means cooling towers run continuously, and warm, stagnant water is where Legionella multiplies. Regular testing and disinfection of towers is how the city tries to prevent it.
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