Legionnaires’ Disease Outbreak on the Upper East Side: A Simple Guide for Everyone

What’s Going On? (The Outbreak)

Imagine tiny invisible germs called bacteria living in water. Right now, on the Upper East Side of New York City, some of these germs (called Legionella) have made 46 people sick with a disease called Legionnaires’.

Here is what we know so far, straight from city health officials on Friday:

• The sickness is happening mostly in neighborhoods called Carnegie Hill and Yorkville (ZIP codes 10028, 10128, and 10075).
• The city is testing water from 183 cooling towers, and more early test results might be announced over the weekend.
• Out of the 46 people who got sick:
  • 22 are still in the hospital.
  • 19 went home and are getting better.
  • 5 did not need to go to the hospital at all.
  • Thankfully, no one has died.

Which Buildings Are Affected?

So far, 31 buildings got a preliminary (early) positive test for the germ’s traces in their cooling towers. Some famous places on the list include:

• The Guggenheim Museum (1071 Fifth Ave.)
• Asphalt Green (1750 York Ave.)
• Whole Foods Market (1551 Third Ave.)
• Trevor Day School (312 E. 95th St.)

Important Point: The city released a map with green markers for buildings that are already cleaned, and red markers for buildings that still need cleaning. The list of buildings is preliminary and will be updated as the investigation continues!

Buildings That Finished Cleaning (19 Places)

• 180 East End Ave.
• 1750 York Ave.
• 1660 Second Ave.
• 1438 Third Ave.
• 1511 Third Ave.
• 1551 Third Ave.
• 1071 Fifth Ave.
• 1080 Fifth Ave.
• 1001 Fifth Ave.
• 240 E. 82nd St.
• 8 E. 83rd St.
• 145 E. 84th St.
• 117 E. 85th St.
• 125 E. 87th St.
• 152 E. 87th St.
• 120 E. 87th St.
• 501 E. 87th St.
• 168 E. 88th St.
• 160 E. 88th St.

Buildings Ordered to Clean by Saturday (12 Places)

• 1875 Second Ave.
• 1110 Fifth Ave.
• 153 E. 78th St.
• 135 E. 79th St.
• 300 E. 79th St.
• 238 E. 81st St.
• 160 E. 84th St.
• 114 E. 85th St.
• 401 E. 88th St.
• 333 E. 91st St.
• 354 E. 91st St.
• 312 E. 95th St. (This is Trevor Day School!)

What Are Cooling Towers and Should You Worry?

Cooling towers are big machines on the outside of buildings that help keep them cool. They sometimes spray a fine mist into the outdoor air.

Important Point: You are not in extra danger just by being inside these buildings! The possible germs are in the outdoor mist machines, not in the building’s drinking water pipes or indoor air conditioners. You can keep drinking tap water, bathing, showering, cooking, and using your home AC like normal.

How the City is Handling It (The Investigation)

The city is acting super fast. Here is the step-by-step of what happened:

1. July 2: The city found two sick people living close to each other and started checking cooling towers in Carnegie Hill and Yorkville.
2. July 4 Weekend: Over 100 city workers helped investigate.
3. July 5: They expanded the search to ZIP code 10075 after another case was linked to the area.
4. Friday: They announced 19 towers were already cleaned, and 12 must be cleaned by Saturday.

The early test used is called a "PCR test."

Important Point: A PCR test is like finding a tiny piece of a germ’s DNA. It tells us the germ was there, but it cannot tell us if the germ is still alive or if it actually caused the sickness. Only live germs can make you sick!

To be sure, the city is doing a "culture test" (which catches live germs) on every tower. This takes up to two weeks. If they find live germs, they will do "whole-genome sequencing" (like reading the germ’s full instruction manual) to compare the water germs to the sick people’s germs and find the exact source.

City Health Commissioner Dr. Alister Martin said: “It’s important for us to not wait two weeks. That’s why you see us acting fast at this point.” Under new emergency rules, building owners must clean immediately instead of waiting for slow tests. Mayor Zohran Mamdani said the city wants to be “transparent with New Yorkers” and act quickly, calling this a more aggressive approach than past outbreaks.

Because symptoms can take 2 to 10 days (up to 14 days) to show up after breathing the mist, more people might get diagnosed even after cleaning is done. The city is also checking if building owners followed maintenance rules, and penalties could happen for not complying.

What Is Legionnaires’ Disease? (ELI5)

Legionnaires’ disease is a serious lung sickness (like a bad pneumonia) that happens when someone breathes in tiny water droplets (mist) from outside that contain live Legionella germs.

• It is NOT contagious: You cannot catch it from hugging or being near a sick person.
• Symptoms: Fever, chills, muscle aches, shortness of breath, and cough.
• Higher risk groups: Adults 50+, smokers/vapers, people with lung problems, and those with weak immune systems or who take immune-suppressing medicines.

What Should You Do If You Feel Sick?

If you live, work, or visited the affected areas (since late June) and feel flu-like symptoms:

1. Contact a doctor or healthcare provider right away.
2. No provider? Call 311 or contact NYC Health + Hospitals for low- or no-cost care. (The city did not announce a separate free testing program, but 311 will connect you to help).
3. Don’t wear a mask for this: Officials say masks are not recommended because the sickness doesn’t spread person-to-person, and there is no proof masks stop the water mist germs.

Summary

To wrap it up simply: 31 buildings on the Upper East Side found possible germ traces in their outdoor cooling mist machines. 46 people are sick, but no one has died. The city cleaned 19 towers and ordered 12 more cleaned by Saturday. Early tests don’t prove live germs were there, but the city is cleaning anyway to keep everyone safe. You can use water and AC normally, but if you feel sick and were in the area, call a doctor or 311!

FAQ

1. Can I get sick just by walking into the Guggenheim or Whole Foods?
No! Health officials say there is no extra risk from being inside the buildings. The possible germs are only in the outdoor cooling towers, not inside the building’s air or water taps.

2. Should I boil my tap water or stop showering?
Absolutely not. The city says it is perfectly safe to drink tap water, bathe, shower, and cook as usual.

3. Why did the city clean the towers if the test didn’t prove live germs were there?
The early test (PCR) finds germ DNA, but takes two weeks to confirm if they are alive. The city decided not to wait and cleaned immediately to protect people faster under emergency measures.

4. How do I know if I have Legionnaires’ disease vs. just a cold?
If you have fever, chills, cough, muscle aches, or trouble breathing and were in the UES area since late June, call a doctor. Only a medical test can be sure.

5. Will the building owners get in trouble?
The city is checking if owners followed maintenance rules. They didn’t announce penalties on Friday, but said not following rules could have serious consequences.