New York City Department of Health and Mental Hygiene (DOHMH) officials met with tenants of the Co-Op City complex last week to inform them that no new cases of Legionnaires’ disease have been found and the risk of contracting the disease is very low, according to a story posted on

The community meeting comes weeks after the residents were alerted that a cluster of three Legionnaires’ cases had been confirmed at Co-Op City’s Building 11 within the past 12 months, including the death of an elderly tenant.

The three cases occurred in Building 11, which is actually three smaller, connected buildings at the complex, which share a water supply. They do not, however, have a cooling tower, which is a common breeding ground for Legionella bacteria, the bacteria that causes Legionnaires’ disease.

The first case was reported last year, while two others have occurred within the past 60 days. Had the illnesses occurred within a six-month period, health officials would categorize it as an “outbreak” instead of a cluster.

The notification took place as part of the DOHMH’s public notification protocol for Legionnaires’ disease, which requires management to notify tenants when there are two or more cases reported at a single building in a 12-month period.

Riverbay Corporation, Co-Op City’s property management company, installed a copper-silver ionization system last week to proactively disinfect the water supply. Copper-silver ionization is a disinfection process, primarily used to control Legionella. The technology is recognized by the World Health Organization (WHO) and the Environmental Protection Agency (EPA) to control Legionella within potable water distribution systems found in hospitals, hotels and other large facilities.

No information was released by health officials or the management company regarding the results of the water testing performed in late April. Results typically take 2-3 weeks to become available.

Residents, visitors to, and employees of Co-Op City who have recently suffered from or are currently suffering from pneumonia- or flu-like symptoms should seek immediate medical attention from their primary health-care provider. They should also contact the DOHMH to report the illness.

Co-Op City, located in the Baychester section of the borough, is the largest cooperative housing development in the world. It has 15,372 apartments in 35 high-rise buildings and seven townhouse groups with approximately 50,000 residents. It is situated at the intersection of I-95 and the Hutchinson River Parkway and is part of Bronx Community District 10.

The three buildings in Co-Op City are located at 100, 120, and 140 Carver Loop in zip code 10475 in the north Bronx.

Congressmen concerned

Robert R. Redfield, director of the Centers for Disease Control and Prevention (CDC), wrote to Congressmen Eliot Engel recently that the DOHMH is heading up the investigation into the Legionnaires’ cases at Co-Op City. They’re “checking the internal plumbing of the building affected, and out of an abundance of caution sampling the building’s internal water supply,” Redfield wrote.

Congressmen Eliot Engel
Congressmen Eliot Engel

“An abundance of caution is the only way to handle something like this,” Congressman Engel wrote on his website, “so I am encouraged to hear that’s the track being taken with this very serious issue.

“Though the CDC has made clear that DOHMH is carrying out the investigation, they have assured me that they are in close communication with the city, and stand ready to assist if needed,” he added. “I will remain in contact with officials at both the federal and local level to ensure this is handled quickly and appropriately.”

Redfield’s reply was in response to an April 26 letter from Engel, which requested the CDC’s assistance. “I am extremely alarmed by these cases and ask that the Centers for Disease Control and Prevention work with the New York City Department of Health and Mental Hygiene to investigate the cause of these cases without delay,” Engel wrote.

Legionnaires’ timeline

In 2012 and 2013, two residents in Building 27 of Co-Op City were sickened with Legionnaires’, which they were believed to have contracted through contaminated shower heads. Tenants did not learn of those illnesses until early 2014, angering many residents. Officials of Riverbay Corp., Co-Op City’s management company, said testing did not find Legionella, which is why residents were never told.

Between December 2014 and January 2015, there were eight cases of Legionnaires’ disease at Co-Op City. Those illnesses were linked to a cooling tower infected with Legionella bacteria. Riverbay paid a chemical treatment company $200,000 to disinfect that water with chlorine and clean the tower to eliminate Legionella from the system.

Legionnaires’ 101

Legionnaires’ disease – also called legionellosis and Legionella pneumonia – is a severe type of pneumonia (lung infection). According to the CDC, an estimated 25,000 cases of pneumonia due to Legionella bacteria (Legionella pneumophila) occur yearly in the U.S. Only 5,000 cases are reported, however, because of its nonspecific signs and symptoms.

Ten percent of people who become infected with Legionnaires’ disease will die from the infection.

Legionella bacteria are contracted by inhaling microscopic water droplets, usually in the form of mist or vapor. The bacteria, which grow best in warm water, are found primarily in human-made environments.

Where do Legionella live?
Outbreaks have been linked to a number of sources, such as:

  • large plumbing systems
  • showers and faucets
  • hot-water tanks and heaters
  • swimming pools
  • hot tubs and whirlpools
  • decorative fountains
  • mist machines and hand-held sprayers
  • equipment used in physical therapy
  • water systems, such as those used in hospitals, nursing homes, and hotels
  • the cooling towers of air conditioning systems.

Who is most at risk?
Anyone can become ill from Legionella, but those most susceptible to infection include:

  • people 50 years of age or older
  • smokers, current and former
  • heavy drinkers of alcoholic beverages
  • people with chronic lung disease
  • people with compromised immune systems
  • recipients of organ transplants
  • individuals who are on specific drug protocols (corticosteroids, to name one).

Legionnaires’ symptoms
Legionnaires’ disease is similar to other types of pneumonia. Symptoms can even resemble those of flu, which is why it often goes under-reported. Symptoms include:

  • cough
  • shortness of breath
  • fever
  • muscle aches
  • headaches
  • gastrointestinal symptoms, such as nausea, vomiting, and diarrhea.