By Jen Christensen, CNN
(CNN) — New York City is managing a community cluster of Legionnaires’ disease cases on the Upper East Side that officials believe is tied to bacteria found in cooling towers. Towers on 76 buildings on the Upper East Side have tested positive for the bacteria, the city’s Department of Health and Mental Hygiene said Tuesday.
Pneumonia caused by Legionella bacteria has been confirmed in 60 people this month, but no deaths have been reported.
Fifteen people are now hospitalized, and 34 people have been discharged from the hospital. Generally, about 1 in 10 people who get Legionnaires’ disease will die, according to the US Centers for Disease Control and Prevention
Cooling towers, used for refrigeration and general building cooling, expel building heat into the atmosphere by pulling outside air through warm water from a central chiller that gets sprayed over a fill material. As fans pull air through the water, a small amount evaporates, cooling the remaining water, which recirculates to take up more heat. People can get sick when they are exposed to vapor from those systems if there’s bacteria in it. Studies show that cooling towers and other warm, wet environments like hot tubs, spas and some plumbing systems are particularly vulnerable to Legionella bacteria.
New York sees hundreds of Legionnaires’ cases every year, but officials have noticed a spike in cases clustered in three particular ZIP codes: 10128, 10028 and 10075. Anyone who has been in that area in the past couple of weeks is advised to watch for symptoms such as fever, chills, fatigue, headaches, low appetite, confusion and diarrhea.
Most people who are exposed to Legionella bacteria don’t get sick at all, but vulnerable groups can include people who are over 50, who vape or smoke, or who have weakened immune systems or underlying health conditions like diabetes or lung disease. There is no vaccine or medicine to prevent it, and masks don’t seem to offer protection, the New York health department said. Treatment involves antibiotics and sometimes oxygen therapy or intensive care.
The department has tested 183 cooling towers identified as a potential source of bacteria in the affected ZIP codes and directed the owners of 76 buildings to drain, clean and disinfect those towers.
Dr. Alistair Martin, commissioner of the New York City Department of Health and Mental Hygiene, said Tuesday that owners of 57 buildings have confirmed that they’ve completed the required remediation. The remaining 19 are required to do so by Thursday.
“Seventy-six buildings we know is a significant number, but we knew that that list would be long. There’s a high concentration of cooling towers in the Upper East Side,and our initial screening tests cast a wide net,” Martin said at a news conference Tuesday. “These results are also indicative of just how common Legionella is in our built environment, and that’s why we stay vigilant.”
Public health officials noted that this particular cluster of cases is not connected to drinking water, showers or air conditioners.
Legionnaires’ disease is not contagious, and it can be managed if people are given antibiotics early in the course of the disease.
The rate of cases seems to be slowing, but more illnesses could still pop up. The incubation period is two to 14 days, so people may not know yet if they are sick.
The city says it will do additional tests to try to pinpoint exactly where the outbreak started and to distinguish between live and dead bacteria, which the initial tests can’t do. Those tests can take several weeks.