It took months of investigation, whole-genome sequencing, a formal public nuisance declaration, and legal pressure before the owner of a western New York vacation rental property agreed to close a hot tub that had made guests sick with Legionnaires' disease. The investigation, conducted by the New York State Department of Health (NYSDOH) and published in the CDC's Morbidity and Mortality Weekly Report (MMWR) on June 11, 2026, serves as both a window into how Legionnaires' disease investigations unfold in practice and a warning to the tens of millions of Americans booking summer vacation rentals right now.
The outbreak involved two guests who stayed at a short-term rental property in western New York in October 2024 and developed Legionnaires' disease — a severe form of pneumonia caused by Legionella pneumophila bacteria — after using the hot tub at the property. Whole-genome sequencing of bacterial isolates collected from the hot tub matched closely with isolates from one patient's sputum sample, confirming the hot tub as the probable source of infection. The hot tub was operating at a temperature of 100°F to 104°F — squarely within the range most favorable for Legionella growth — and disinfectant levels were inadequate.
