Traces of the bacteria causing Legionnaires' disease have been detected at an East Harlem police precinct, and at least one officer has been hospitalized, officials confirmed Saturday.

The bacteria was first discovered after the Patrolman's Benevolent Association commissioned an independent test of the facility in response to a police officer's infection, which had been discovered after he was hospitalized for unrelated reasons. Nineteen of 20 samples in that initial study tested positive for Legionella bacteria.

Both the city Health Department and the NYPD's Building Maintenance Section were alerted of the case on Friday, and have since launched an investigation into the 23rd Precinct on East 102nd Street. The building's hot water has been turned off as an "interim precautionary measure," a spokesperson for the NYPD said, and prisoners are no longer being brought into the stationhouse.

The disease, a form of pneumonia, is often caused by breathing in water vapor from cooling systems or water towers that contain the bacteria. According to the NYPD, the precinct has a new cooling tower that has not yet been activated. The previous tower was shut down in 2016 as part of ongoing renovations, and is unlikely to be the cause of the infection.

"Legionnaire's disease is not contagious, officers can still work in the building but should avoid taking showers at the site until the investigation is complete," the city Health Department said in a statement. "There is no public health risk to the larger community."

The city's largest outbreak of Legionnaires occurred in the Bronx in 2015, and led to a dozen deaths. Since then, the Health Department has increased cooling tower regulations and the frequency of inspections, among other reforms. Tenants are now notified when two or more cases of Legionnaires' disease are reported at a single address in a one-year period.

Between 200 and 400 cases of the disease are reported on a yearly basis, according to the city.