NYC Says Source of Legionnaires’ Disease Has Been Eliminated

The New York City Health Department has reported that five people have died and seven people are currently hospitalized due to the outbreak of Legionnaires’ disease on the Upper East Side. No new cases have been reported for more than a week.

The city’s health commissioner said he believes the source of the exposure has been eliminated as a result of the city’s testing and disinfection efforts.

The health department said that 51 cooling towers in 50 buildings that have thus far come back positive in a culture test for live Legionella bacteria have all been cleaned and disinfected.

There have been 84 reported cases of Legionnaires’ disease since the first cases were identified on July 2. The affected area encompasses the neighborhoods of Carnegie Hill and Yorkville (ZIP codes 10028, 10128, and 10075).

Last week, the health department said the number of new cases appeared to be slowing and as of last night no new cases have been reported since July 15.

NYC Health Commissioner Dr. Alister F. Martin stressed that all cooling towers that tested positive for live Legionella bacteria have already undergone remediation, as were all cooling towers that previously tested positive for live or dead bacteria in the initial test.

“We believe that through our aggressive strategy of testing and remediation we have eliminated the source of exposure,” Martin said in a statement on Tuesday. “We will learn more as our investigation unfolds and look forward to updating our existing policies and procedures to preventing future clusters. Right now, we are focused on identifying the source of exposure through laboratory analyses and holding accountable anyone found out of compliance with local laws.”

The city tested the cooling towers of all 183 buildings in the affected neighborhoods, and immediately required owners of all towers with positive initial results in a PCR (polymerase chain reaction) screening to immediately drain, clean, and disinfect their cooling towers to reduce the risk of further exposure.

In addition to the PCR screening tests, a culture test that takes several days was also conducted for all sampled cooling towers. Whereas PCR tests do not distinguish between living and dead bacteria, culture tests in a lab only detect live bacteria that are capable of reproducing and spreading the disease.

The culture test confirmed that 51 cooling towers in 50 buildings had live Legionella bacteria growing at the time the water sample was collected. All 51 have been cleaned and disinfected, according to city officials.

In total, 19 cooling towers tested culture negative. The results from culture tests of other buildings are still pending.

Legionnaires outbreaks in the city are not new. Last summer, an outbreak of Legionnaires’ disease in the Central Harlem neighborhood led to at least six deaths and more than 100 diagnosed cases. The bacteria was discovered in 12 cooling towers on 10 buildings.

The site of the current outbreak, the Upper East Side, has more than three times the number of cooling towers tested during the Central Harlem investigation.

City health officials have been urging everyone in the area, especially older adults and other vulnerable communities, to seek care if they develop flu-like symptoms.

Photo: Unidentified cooling towers image for editorial purposes.