KEY TAKEAWAYS:

• A recent CDC report identifies the hot tub at a short-term rental property as a potential source of Legionnaires’ disease

• New York investigators identified Legionella in a rental property hot tub and found a potential connection between environmental samples and samples associated with two reported cases

• The CDC emphasizes proper maintenance and monitoring to mitigate against potential Legionella hazards for short-term rental owners

A recent Morbidity and Mortality Weekly Report from the Centers for Disease Control and Prevention (CDC) seeks to highlight potential Legionnaires’ disease hazards associated with hot tubs at short-term rentals. By way of background, the CDC estimates that approximately 15% of Legionnaires’ disease (LD) patients report staying overnight at hotels, private homes, or rental properties. Half of those patients “who reported travel and staying at a vacation rental property also reported hot tub use.” Further, approximately 10% of all those who are diagnosed with LD will die from the disease. Finally, it is notable that the CDC previously focused an MMWR report on hot tubs associated with cruise ships.

The latest MMWR outlines how the CDC worked with investigators from the New York State Department of Health (NYSDOH) and other local agencies regarding two October 2024 LD diagnoses involving two renters who had stayed at a private rental property and used a hot tub. According to the report, the NYSDOH was notified of an increased incidence of LD in one county in Western New York. Specifically, five people from the same city tested positive by urine antigen tests, with two of those family members spending several nights at a short-term rental property 40 miles south of the city.

NYSDOH investigated the rental property. The diagnoses of the two renters were confirmed by urine antigen tests and NYSDOH “isolated Legionella pneumophila serogroup 1 from the sputum of one patient.” Thereafter, environmental samples were collected from various areas of the property’s potable water system. “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.”

Finally, the NYSDOH reportedly “recommended that the owner close the hot tub until proper remediation was performed and post remediation samples without detection of any Legionella bacteria were collected by NYSDOH staff members.” The rental property owner reportedly did not initially comply with NYSDOH recommendations. As a result, a local public nuisance law was apparently used to ensure that proper measures were taken to disinfect the hot tub before use by future guests. Reportedly, the property owner subsequently hired a professional cleaner to service the hot tub weekly. A commissioner’s order was lifted in March 2025, following two successive rounds of negative sampling.

According to the recent MMWR, the CDC and NYSDOH seek to “raise awareness” about short-term rental hot tubs, which may not be subject to regulatory oversight. For hot tubs, the CDC website outlines several recommendations to mitigate against the growth of the bacteria.

First, the CDC recommends following any applicable laws for hot tub cleaning and monitoring. In addition, the CDC website provides recommendations for Vacation Rental Owners and Managers, recommending monitoring and maintaining adequate disinfectant levels, “even when the hot tub isn’t in use,” and following manufacturer recommendations for maintaining the hot tub, such as replacing the filter and water and cleaning and scrubbing the hot tub. The CDC website also suggests automatic disinfectant systems as preferable to handfeeding disinfectant.

Next, the MMWR focuses on public health department investigations. Here the MMWR recommends that, when conducting investigations, local health departments “should prioritize” sampling hot tubs as potential sources of exposure when LD cases meet the CDC outbreak definition. Further, “[p]ublic health officials should conduct on-site field visits, collect and test samples, and use all available tools, including public nuisance laws if needed, to protect public health. Regular post remediation follow-up samples should be collected to ensure long-term control. Vacation and other short-term rental property owners should be informed of the risks associated with improperly managed hot tubs, particularly for persons at increased risk for severe illness, including those with underlying medical conditions.”

Taken together, the recent MMWR underscores that hot tubs at short-term rental properties can present Legionella-related hazards when the hot tubs are not properly maintained. Short term rental property owners should follow applicable hot tub manufacturer recommendations and consider consulting professional experts regarding best practices for routine cleaning and maintaining hot tubs. When applicable, such property owners must, of course, follow all local laws and regulations.

For information about Goldberg Segalla’s Legionnaires’ disease-related defense litigation and regulatory compliance practice, please visit: https://www.goldbergsegalla.com/practices/legionnaires-disease/

If you have questions about the recent CDC report and how it impacts your business, please contact:

• Andrew J. Scholz