Legionnaires Disease Associated with a Private-Use Hot Tub in a Vacation Rental Property - New York, October 2024-April 2025.

In mid-October 2024, the New York State Department of Health (NYSDOH) was notified of two cases of Legionnaires disease in persons who stayed at the same short-term vacation rental property and had both used the rental property's hot tub. The diagnoses were confirmed by urine antigen tests, and NYSDOH successfully isolated Legionella pneumophila serogroup 1 from the sputum of one patient. Local health department staff members collected three samples from three sinks and two samples from two showers to assess the rental property's potable water system, which was supplied by a private well. Three samples were also collected from the rental property's hot tub. Whole genome sequencing of isolates from the hot tub samples and the sputum specimen were closely related, suggesting that the hot tub was the likely source of exposure. Hot tubs create aerosols and typically maintain water temperatures of approximately 100°F-104°F (38°C-40°C). This temperature is within the most favorable range for Legionella growth and also accelerates the decay of disinfectants. Guidance from NYSDOH and CDC regarding proper operation, disinfection, and remediation of hot tubs was provided to the rental property owner. NYSDOH recommended that the owner close the hot tub until proper remediation was performed and postremediation samples without detection of any Legionella bacteria were collected by NYSDOH staff members. The rental property owner did not initially comply with NYSDOH recommendations, and a public nuisance law was used to ensure that proper measures were taken to disinfect the hot tub before use by future guests. Activities to raise awareness among short-term rental and vacation rental property owners regarding the risks associated with an improperly managed hot tub are needed to decrease the likelihood that rental property hot tubs are in a condition that is conducive to Legionella growth and reduce the risk for Legionnaires disease associated with vacation rental stays. Travelers staying in vacation rental properties should be aware that use of hot tubs might pose a risk for Legionnaires disease and exercise caution when using hot tubs, particularly those travelers with underlying medical conditions.