The New York City Department of Health and Mental Hygiene (DOHMH) is investigating a Legionnaires’ disease community cluster after 11 people were sickened with the illness in the last seven days in upper Manhattan, according to multiple news reports.
“We may continue to see additional cases,” DOHMH Commissioner Dr. Mary T. Bassett said at a community meeting at Saint Luke’s African Methodist Episcopal Church. The meeting was held to discuss the outbreak and answer questions.
The illness has affected individuals from a 20-block area in southern Washington Heights and northern Hamilton Heights. Ten of the 11 infected were hospitalized, and eight remain hospitalized. Ages of the patients have ranged from under 40 to over 80, but the majority were over the age of 50.
The illnesses are categorized as a “cluster” and not an “outbreak” because the cases are linked in space (20-block area) and time (seven-day period). If a single source is discovered to be the cause for all the illnesses, officials would then categorize it as an “outbreak.”
Cooling towers suspected
Also known as legionellosis and Legionella pneumonia, Legionnaires’ disease is a sometimes-deadly lung infection, and on average 10 percent of people infected will die. “Thankfully, there have been no fatalities, yet,” New York City Council member Mark Levine said in a news briefing about the community cluster.
Officials are “actively looking” for the source of the infection, Bassett said, and “we worry about cooling towers.” They are the suspected culprit in this cluster.
“The department has already identified all of the cooling towers that are registered with the city in this geography,” Bassett said. “And (we have) tested all of these cooling towers.”
Said Levine: “Don’t confuse this with water towers, which are in almost every building. This has nothing to do with water towers. This is cooling towers that are used in buildings with central air conditioning, that give off a water vapor, and when it’s hot out – and it’s been really hot the last couple of weeks – this bacteria thrives.”
Inspectors took water samples from 20 cooling-tower systems from buildings between 145th and 155th Streets. Preliminary testing results are expected soon; full results – using cultures, where the bacteria is grown in a laboratory – take two weeks to be completed.
The city has already treated the towers’ water, according to Dr. Demetre Daskalakis, the deputy commissioner of Disease Control.
Putting the community at ease
Officials informed the community that Legionnaires’ disease is not transmitted person-to-person.
“While most people exposed to Legionella don’t get sick, individuals ages 50 and above – especially those who smoke and have chronic lung conditions – are at a higher risk,” Bassett said in a statement. “This disease is very treatable with antibiotics. I encourage anyone with symptoms of Legionnaires’ disease to seek care early.”
Others who are more susceptible to infection include:
- heavy drinkers of alcoholic beverages
- people with compromised immune systems
- recipients of organ transplants
- people on specific drug protocols (corticosteroids, for example).
NYC’s largest outbreak killed 12 in 2015
The largest outbreak in New York City history occurred in 2015. Contaminated cooling towers were blamed for producing Legionnaires’ disease that killed 12 people and sickened more than 120 others in the South Bronx.
Every year, between 200 and 500 people are diagnosed with the disease in New York, according to city health officials. The majority of those are individual cases not associated with a cluster or outbreak.
Legionnaires’ disease is a severe type of pneumonia (lung infection). According to the Centers for Disease Control and Prevention (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.
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?
Legionnaires’ disease clusters and outbreaks have been linked to numerous sources, such as:
- cooling towers of air conditioning systems
- large plumbing systems
- water systems, such as those used in hospitals, nursing homes, and hotels
- hot-water tanks and heaters
- showers and faucets
- swimming pools
- hot tubs and whirlpools
- equipment used in physical therapy
- mist machines and hand-held sprayers
- decorative fountains.
What are the symptoms?
Legionnaires’ disease is similar to other types of pneumonia, and its symptoms can resemble those of flu, such as:
- difficulty breathing
- muscle aches
- gastrointestinal symptoms, such as nausea, vomiting, and diarrhea.