Harlem Legionnaires’ Outbreak Multiplies, Three Now Dead

An outbreak of Legionnaires’ disease that struck Harlem in late July has spread to more people, NYC’s Department of Health said on August 4. A total of 81 people have contracted the disease, sharply up from 22 at last count. Two more people have also died, bringing the total death toll to three.

The bacterial disease, a particularly pernicious form of pneumonia that is caused by exposure to infected water vapor, has struck five separate ZIP codes–10027, 10030, 10035, 10037, and 10039–in the area. It is not contagious.

A statement shared by the city’s Acting Health Commissioner, Dr. Michelle Morse, reminded “anyone with flu-like symptoms” to “contact a healthcare provider as soon as possible.”

The disease has a mortality rate of roughly 10 percent, according to some medical professionals, which only underscores Morse’s advice. However, many healthy people who are exposed to the bacteria do not contract it, and many do not have a severe case if so. The CDC says that some segments of the population face higher systemic risk for contracting the disease, namely: men, Black people, and older adults. The Northeastern U.S. has typically been a hot zone for the disease.

Morse added that people who “smoke or have chronic lung conditions” are particularly susceptible to catching a bad case of the disease, and that it is best treated if caught early. Symptoms may include cough, fever, chills, muscle aches, or difficulty breathing.

On August 6, Mayor Eric Adams made an appearance in Harlem to talk with local residents about the disease. “If someone shakes your hand, you’re not going to get Legionnaires’,” he later told ABC7. “It is really our cooling towers that we’re looking at. We’re conducting inspections. We’re telling private business owners to do inspections as well and if we identify any Legionnaires’, they have 24 hours to rectify the situation.”

Legionnaires’ disease is caused by the Legionella bacteria, which thrives in warm water, usually within the 90-100 degree Fahrenheit range. It is predominantly found in plumbing systems such as cooling towers, humidifiers, hot-water tanks, and evaporative condensers. Hot tubs and whirlpool spas can also transmit the disease. It is not contracted from window-unit air conditioners.

As part of the August 4 update, the Health Dept. clarified that 11 cooling towers that had tested positive for the disease had since been “remediated,” or rid of the disease. It is unclear if it will mark a turning point in the latest outbreak.

Legionnaires’ disease is named after its first recorded outbreak, which struck a group of American Legion members gathered at a hotel in Philadelphia back in 1976. A total of 34 people died, out of 221 people infected. It remains the largest community-associated outbreak of Legionnaire’s in the United States.

One of the worst outbreaks on record in the five boroughs occurred in the South Bronx back in 2015, which was a particularly bad year for the disease in NYC. One infected cooling tower led to 138 cases and 16 deaths. A total of six community-associated outbreaks have occurred citywide since 2006, resulting in 213 cases and 18 deaths. The latest Harlem outbreak has yet to be added to these tallies, as it is ongoing.

Concerningly, the CDC says that Legionnaires’ disease is becoming more prevalent over the course of the 21st century, with a modest dip in the general upward trend only occurring during the height of the pandemic. The peak of reported cases occurred in 2018.