Monitoring Legionnaires' Disease in the Bronx

The New York City Department of Health and Mental Hygiene is investigating an outbreak of Legionnaires’ disease in the South Bronx.

September 04, 2015

While Legionnaires’ disease is not transmitted person-to-person, and no members of the Columbia Community have reported illness, the University is closely monitoring the situation. According to the Department of Health, the outbreak has not affected the city’s drinking or bathing water; it is safe for building residents to drink and bathe with tap water. It is also safe to use home air-conditioning units and to be in air-conditioned environments.

After several cooling towers in the South Bronx tested positive for Legionella, the bacteria that causes this disease, the city's Health Commissioner issued an order to all owners of buildings with water-recirculating cooling towers across New York City to inspect and disinfect cooling towers.

Cooling towers that Columbia University owns and manages are regularly monitored under an established precautionary maintenance program. Columbia is also complying with the commissioner’s order and performing extra inspections of our cooling towers.

About Legionnaires’ Disease

Legionnaires’ disease (or Legionellosis) is a type of pneumonia. It is caused by a type of bacteria (Legionella) that grows in warm water.  The disease is not contagious and is not spread person to person.  People only get sick by breathing in water vapor containing the bacteria (for example, by inhaling contaminated mist from faucets, showers, whirlpools or cooling towers). People who are sick with Legionnaire's cannot make others sick.

According to the NYC Department of Health, groups at high risk 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).  

If you feel ill and have a compelling reason to suspect Legionnaires’, such as having spent time in one of the affected buildings in the Bronx, please consult with your healthcare provider. Particularly if you have a medical condition that affects your breathing, like emphysema, or if you are a smoker, ask your doctor about testing for Legionnaires’ disease.

  • Students at Morningside may call Columbia Health at (212) 854-2284.
  • Students at CUMC may call the Student Health Service at  (212) 305-3400.
  • Faculty and staff should contact their healthcare provider directly.

For additional information about Legionnaires’ disease and the outbreak in the Bronx, please visit the NYC Department of Health website at:

As the situation changes, we will continue to update the Columbia Preparedness website,, and the Columbia homepage, The Columbia University Medical Center homepage,, will also be updated.