Spread of Legionnaires’ Disease Linked to Outdated Building Regulations

The New York City Health Department confirmed 108 cases of Legionnaires’ disease, five deaths, and 14 current hospitalizations as of Aug. 18. This is nearly double the number of cases reported in New York at the end of July.

Legionnaires’ disease is a bacterial lung infection, or pneumonia, caused by the bacteria Legionella pneumophila, which grows in warm water. Legionnaires’ disease causes flu-like symptoms and is treatable with antibiotics. However, if left untreated, it can result in shock and multi-organ failure. Complications from the disease are less likely the earlier treatment begins.

The update comes days after NYC’s Health Department proposed new regulations for the testing of cooling towers, which they suspect are linked to the outbreak.

Cooling towers are rooftop devices that release mist into the air as they cool large buildings. If the water inside becomes too warm, stagnant, or isn’t properly disinfected, Legionella bacteria can grow and infect people who inhale the mist.

Under New York City law, building owners are responsible for registering and maintaining their cooling towers, which are routinely inspected for compliance. The new proposal would set specific time periods for testing and require tests to be conducted by state-certified labs. It also details monetary penalties for noncompliance, though the posted documents didn’t specify amounts. Currently, building owners who fail to follow routine maintenance rules face fines of US$500 to $2,000.

The proposed changes to testing and fines, however, may come with the challenge of enforcement; city data shows that the city conducted a record low number of inspections in 2024, which was less than half the inspections of 2017, when the city first recorded inspection numbers.