Protecting families from contaminated food and water
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Protecting families from contaminated food and water
Posted in Legionella,Legionnaire's disease,Our Blog,Outbreaks & Recalls on July 14, 2026
The Upper East Side Legionnaires’ disease outbreak has been linked to buildings’ cooling towers, but what is the connection between Legionnaires’ disease and cooling towers?
This Legionnaires’ outbreak is growing every day, despite work toward remediation efforts. In this case, Legionella is not contaminating the water supply. Experts say it is linked to cooling towers.
How do Legionella bacteria get in these cooling towers on top of buildings and why does that complicate the situation in densely populated areas like the Upper East Side? If you work or live in the area, do you know what symptoms to look out for and what you should do if you get sick?
Follow along as we explain those topics and more. But first, let’s take a look at the current outbreak statistics!
As of July 13, there have been at least 60 total cases of Legionnaires’ disease connected to Upper East Side Zip codes. Only 11 people did not require hospitalization. So far, 34 people have been discharged. At least 15 people are currently hospitalized.
No deaths have been reported.
The last illness was reported on July 12, 2026. So, we may see more cases added to the total. It can take a few weeks between a patient feeling sick to getting medical care and for the results to return positive.
We have said that this outbreak involves a connection between Legionnaires’ disease and cooling towers. But where does Legionnaires’ disease come from?
Legionnaires’ disease is caused by inhaling microscopic Legionella bacteria suspended in aerosolized water droplets. Essentially water mist. Inhaling this mist can move these waterborne bacteria into your lungs where they can cause infection.
Legionella bacteria are naturally occurring in certain water systems. Places like lates, streams, and rivers. It is when these germs find their way in human-made systems that things get dangerous.
Certain human-made water systems are better suited for growing and spreading harmful Legionella bacteria. But anything that generates a mist or spray can spread bacteria. Fixtures like hot tubs, decorative fountains and water features, and even shower heads and sink faucets. These germs love warm water. So, things like hot tubs, hot water tanks and heaters, and cooling towers (like those used in large buildings’ air-cooling systems or industrial processes). Large, complex plumbing systems, especially those under construction or with dead legs, are especially vulnerable to Legionella growth.
Cooling towers are the most common sources of Legionnaires’ disease outbreaks.
But what is the connection between Legionnaires’ disease and cooling towers?
To understand how Legionella bacteria get into cooling towers, you have to first understand how cooling towers work.
Cooling towers are a thermodynamics marvel used by large buildings in their air conditioning systems. They transfer heat from hot water and make it cold water. A fan blows over the cold water and enters the building as “conditioned air.” As the water absorbs more heat, it goes back to the heat transfer area of the apparatus. Over and over again.
While this is a simplified explanation, I’m sure you get the point.
So, how does Legionella enter the equation?
This isn’t entirely a closed system. There are air intake areas and there are places that hot air gets dispersed into the atmosphere. If a small amount of Legionella bacteria enters the system (either from another nearby cooling tower, a body of water, or small contamination in the water supply, it can grow to infectious numbers within the unit.
Over a short period of time, the bacteria can even form a biofilm. A complex structure that protects itself from decontamination.
In places like the Upper East Side of New York City, buildings are tightly packed together. With a lot of people in a small geographical area, this type of vertical landscape along roads is expected.
However, this proximity situation can lead to cross-contamination from one building’s system to another. Which means one building contaminated with Legionella bacteria can easily spread to several buildings with Legionella bacteria.
Which is likely why at least 31 buildings in the Upper East Side neighborhoods of Carnegie Hill and Yorkville have tested positive for Legionella DNA in cooling tower water samples.
Routine decontamination required by local health authorities should prevent small amounts of contamination from growing to infectious problems.
Among the expected requirements of decontamination protocols, the CDC has additional suggestions to reduce the risk associated with Legionnaires’ disease and cooling towers.
Things like using high-efficiency drift eliminators to contain mist. Placement considerations, like positioning cooling towers at least 25 feet from building air intakes to reduce the risk of the cooling tower’s drift plume from being pulled into the ventilation system. Things like avoiding stagnation by recirculating water during intermittent operation and automating the water treatment system to prevent lapses in safety protocols.
Most people with Legionnaire’s disease experience pneumonia-like symptoms. Which is why many cases go undiagnosed. Only specialized laboratory tests can determine if you have Legionnaires’ disease. It is important to notify your healthcare provider of your potential exposure risk if you begin experiencing symptoms.
So, what types of symptoms are common?
Common symptoms include:
Other Symptoms may include:
Most people begin feeling sick between two and 14 days after exposure. However, it can take longer for symptoms to appear in some cases.
If you have pneumonia-like symptoms and recently worked, stayed, or visited the Upper East Side, you may have Legionnaires’ disease. Seek medical attention right away, as prompt diagnosis often leads to better outcomes.
Reporting your illness can also help the outbreak investigation. Understanding exposure periods and locations of interest can paint a more thorough picture for outbreak investigators. Your cooperation may help narrow or expand the scope of the outbreak investigation.
It is also a good idea to get advice from an experienced Legionnaires’ disease lawyer.
Medical bills, lost work, and other burdens associated with Legionnaires’ disease add up. Who is responsible for those expenses?
If you wish to pursue a legal claim for financial compensation, The Lange Law Firm, PLLC has a Legionnaires’ disease lawyer that can help.
Call (833) 330-3663 or send us an email for a free, no obligation consultation.
By: Heather Van Tassell (contributing writer, non-lawyer)