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Legionnaires' Disease

Legionnaires' Disease Cluster in Central Harlem

The NYC Health Department is currently investigating a community cluster of Legionnaires' disease in Central Harlem (ZIP codes 10027, 10030, 10035, 10037, and 10039).

The risk to most people in these ZIP codes is low. If you live or work in the area and have flu-like symptoms, see a health care provider right away. Symptoms include cough, fever, chills, muscle aches, and shortness of breath. If you do not have a health care provider, visit NYC Health + Hospitals or call 311 or 844-NYC-4NYC (844-692-4692).

As of August 11, there are:

  • 90 confirmed cases
  • 3 deaths
  • 17 currently hospitalized

People usually develop symptoms 2 to 10 days after exposure, though it can be as long as two weeks.

The Health Department has sampled and tested water from cooling towers in the investigation zone. Any cooling towers with initial positive results for Legionella bacteria have completed the treatment required by the Health Department. We are continuing to monitor and let buildings know if additional treatment is needed.

A building plumbing system is separate from a cooling tower system. This community outbreak is not related to a building’s hot or cold water supply. Residents in these ZIP codes can continue to drink water, bathe, shower, cook, and use their air conditioner.

Legionnaires’ disease is not spread from person to person. You cannot get Legionnaires’ disease from someone who is sick.

Read our August 4 update on the City's investigation of this cluster of cases.

Last updated August 11 at 4:30 p.m.


Legionnaires’ disease is a type of pneumonia. It is caused by bacteria (Legionella) that grow in warm water. Legionnaires’ disease causes flu-like symptoms, and complications from the disease can be fatal.

People who inhale mist that contains Legionella bacteria can get sick.

Most people who are exposed to the bacteria do not develop Legionnaires’ disease, and it is not contagious — you cannot get it from someone else. You cannot get Legionnaires’ disease by drinking the water. The bacteria that causes Legionnaires’ disease does not spread through cooled air from air conditioners.

You are at an increased risk for Legionnaires’ disease if you:

  • Are 50 years old or older
  • Smoke
  • Have a chronic lung disease
  • Have a weakened immune system
  • Take medicines that weaken your immune system

When there are multiple people in a neighborhood with Legionnaires’ disease (community cluster), common sources of exposure are cooling towers, hot tubs, and spray fountains.

At other times, when there are multiple people with Legionnaire’s disease who live in the same building (building cluster), the exposure is typically related to a building’s plumbing system — most often the hot water system. When this happens, a building’s residents can be exposed through water mist when they shower.

When there are two or more confirmed cases of Legionnaires’ disease within a 12-month period associated with the same building with a shared hot water system, the Health Department will conduct a building evaluation.

Symptoms

Legionnaires’ disease symptoms include fever, chills, muscle aches, and cough. People may also have headaches, fatigue, loss of appetite, confusion or diarrhea.

If you have these symptoms, seek medical attention. It is especially important for people at increased risk for Legionnaire's disease to seek care right away. Tell your health care provider you are worried about Legionnaires’ disease.

Prevention

There is no vaccine or medicine that can prevent Legionnaires’ disease. The best way to prevent it is through the proper maintenance of water systems where Legionella may grow.

In NYC, building owners are required to register cooling towers. This allows the Health Department to quickly investigate when we are notified of clusters of Legionnaires’ disease cases. Building owners also need to routinely test the water in the cooling tower for the presence of Legionella and do routine checks of their system as required by NYC cooling tower regulations. They also need to routinely test the water for the presence of Legionella. You can look up results of Health Department inspections of cooling tower systems by building address or building identification number (BIN).

The Health Department investigates clusters of Legionnaires’ disease cases to find the source of the contamination in order to prevent other people from getting sick.

Additional Resources

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