Gym linked to spread of rare disease through mist

Florida is experiencing a spike in cases of Legionnaires' disease, with a local gym identified as the source of a recent outbreak. The Orange County outbreak has resulted in 14 confirmed cases, according to the Florida Department of Health, marking the highest state-level count in a decade.

Legionnaires' disease is a severe form of pneumonia caused by Legionella bacteria. While it may be mild in healthy individuals, it can be serious or fatal for vulnerable groups. The Centers for Disease Control and Prevention (CDC) note that infection commonly occurs by inhaling mist containing the bacteria.

As a result of the gym-related outbreak, Orange Countys total cases for 2025 have reached 82, the highest in Florida. November alone saw 72 confirmed cases statewide, contributing to a total of 665 reported cases this year. The disease can also manifest as Pontiac fever, a milder infection caused by the same bacteria.

The rise in Florida reflects a broader national trend of increasing Legionnaires' disease cases, the CDC reports. Symptoms often resemble the flu initially, including high fever, headaches, and muscle aches within 210 days after exposure. Later signs can include coughing (sometimes with mucus or blood), shortness of breath, chest pain, nausea, vomiting, diarrhea, confusion, or other mental changes.

Legionella bacteria thrive in warm water and are typically spread through aerosolized droplets, such as from showers, spas, and cooling towers on buildings. Person-to-person transmission does not occur. The CDC estimates that about 90% of outbreaks are linked to preventable water system issues, including hot tubs, plumbing, and cooling systems.

Approximately 10% of infected individuals die from complications, with mortality rising to 25% for infections acquired in healthcare facilities. Older adults, smokers, and those with chronic conditions such as lung, kidney, or liver disease or weakened immune systems are at higher risk.

Legionnaires' disease has been rising across the U.S. since 2000, peaking in 2018 before declining during the COVID-19 pandemic. Cases rebounded in 2021 and continue to increase, with 8,00018,000 hospitalizations annually.

In New York City, a 2025 cluster in central Harlem linked to cooling towers caused at least seven deaths and 90 hospitalizations, highlighting the role of environmental conditions. Experts suggest climate change, with hotter and more humid weather, may contribute to increased Legionella growth in cooling systems.

Author: Chloe Ramirez