In a follow-up on the Lower Washington Heights Legionnaires’ disease cluster, New York City health officials announced the investigation is now closed.

Legionella pneumophila bacteria/CDC
Legionella pneumophila bacteria/CDC

There have been no new cases added to the cluster in the last three weeks. The likely source of the cluster has been identified. After extensive epidemiologic investigation, sampling of cooling towers, and molecular analysis of Legionella bacteria from human and cooling tower specimens, the Health Department’s Public Health Laboratory and epidemiologists have matched the Legionella strain found in the cooling tower at The Sugar Hill Project, located at 898 St. Nicholas Avenue at West 155th Street, with the strain found in six patients from the Lower Washington Heights cluster first reported on July 11.

The facility fully cooperated with the Health Department in the investigation, cleaned and disinfected its tower on July 13, and is working with the Health Department on long-term maintenance to meet the City’s cooling tower regulations.

There were 27 cases associated with the Lower Washington Heights Legionnaires’ disease cluster, including one death. Twenty-five people were hospitalized and 23 have been discharged. The remaining two people were treated as outpatients only and were never admitted.

“I am relieved that the cluster of Legionnaires’ disease in lower Washington Heights is over,” Health Commissioner Dr. Mary T. Bassett said. “After an extensive investigation, the Health Department has identified the cooling tower at the Sugar Hill Project as the most likely source of the cluster. In 2015, we worked with the City Council to create the nation’s most comprehensive cooling tower registry and regulations. During this investigation, the registry allowed the Health Department to quickly identify all cooling towers in the affected neighborhood, review their inspection records, obtain samples for rapid laboratory testing and conduct an immediate visual inspection of the tower. I am thankful to the Sugar Hill Project’s management team for their responsiveness throughout the investigation.”

Legionnaires’ disease is a type of pneumonia that is caused by certain types of the bacteria Legionella, which grows in warm water. Symptoms resemble other types of pneumonia and can include fever, chills, muscle aches, and cough. In the past, some cases of Legionnaires’ disease have been traced to plumbing systems where conditions are favorable for Legionella growth, such as cooling towers, whirlpool spas, hot tubs, humidifiers, hot water tanks, and evaporative condensers of large air-conditioning systems. An average of 200 to 500 Legionnaires’ disease cases are reported in the city every year.

Individuals only get sick by breathing in water vapor containing Legionella, and the disease is not transmitted from person to person. Individuals at higher risk include those ages 50 and above, cigarette smokers, and people with chronic lung disease or compromised immune systems.