New cases slow to fewer than one per day

New Legionnaires’ cases slow to fewer than one per day

The third death was announced Sunday by Dr. Alister Martin, New York City’s health commissioner, who said in a statement that the patient’s identity would not be made public. “Our hearts are with their family and friends as they mourn their loss,” Martin said.

The first death in the cluster was announced Friday. The third death brings the outbreak’s total fatalities to three in as many days.

City health officials said they have identified 74 cases of Legionnaires’ disease in the cluster. Of those, eight patients remain hospitalized, 51 have been discharged and 12 did not require hospitalization, according to city statistics.

The rate of new infections has slowed significantly, officials said. From July 10 through Friday, an average of fewer than one new case per day was recorded, compared with an average of more than eight per day between July 2 and July 8. Officials said more than a week has passed since anyone developed new symptoms, indicating no recent exposure. Emergency departments are showing no concerning trends, they added.

The sustained decline in new cases, officials said Saturday, indicates that the likely source of exposure has been eliminated.

Investigators suspect the outbreak originated from a cooling tower contaminated with Legionella bacteria, though the specific tower has not been identified. The health department tested 183 cooling-tower systems in the affected areas of Carnegie Hill and Yorkville. Initial screening detected Legionella genetic material in towers at 76 buildings, which were ordered to drain, clean and disinfect their systems. The city said all had completed the required remediation by Thursday.

Legionnaires’ disease is a form of pneumonia caused by Legionella bacteria, which grow in warm water. People who inhale water vapor containing the bacteria can develop the illness, which produces flu-like symptoms. Most people exposed to the bacteria do not become sick, but among those who do contract Legionnaires’ disease, complications can be fatal. The U.S. Centers for Disease Control and Prevention estimates that between 8,000 and 18,000 people are hospitalized with Legionnaires’ disease each year in the United States.