Legionellosis Outbreaks Linked to Two Hotels in US Virgin Islands

A CDC report published in Morbidity and Mortality Weekly Report on July 2, 2026 described two unrelated legionellosis outbreaks associated with two hotels in the US Virgin Islands between October 2024 and April 2025.

The outbreaks were identified after the US Virgin Islands Department of Health was notified in November 2024 of confirmed Legionnaires disease cases among travelers who had stayed at two different hotels on St. Croix Island. Legionnaires disease is a type of legionellosis characterized by illness with pneumonia, and the CDC report noted that infection can occur after inhalation or aspiration of water contaminated with Legionella bacteria.

Four legionellosis cases were identified across the two outbreaks. The patients were aged 53 to 73 years, and two were hospitalized. No deaths were reported. At hotel A, Legionella pneumophila was detected in 3 of 21 environmental samples, all from cold water system sources, including a showerhead, cistern, and water supply pipe. At hotel B, L. pneumophila was detected in 22 of 40 samples, including samples from sinks and showers in both cold and hot water systems.

The US Virgin Islands Department of Health required hotel A to close the implicated guest room and required hotel B to cease operations until remediation and retesting were completed. Remediation activities included plumbing and fixture replacement, hyperchlorination, evaluation of filtration, and follow-up testing. Hotel A was cleared to fully reopen after postremediation sampling indicated the water system was well controlled, and hotel B was cleared after testing no longer detected Legionella bacteria.

The report stated that the outbreaks underscore the importance of reporting legionellosis among returned travelers to support local public health investigations. The authors also noted that tropical climates can allow cold water systems to operate at temperatures favorable for Legionella growth, highlighting the importance of effective water management programs and water system disinfection.

Sources: Gallalee S, Cranford HM, Drummond A, Ekpo LL, Ellis BR, Ellis EM. Legionellosis outbreaks associated with two hotels — U.S. Virgin Islands, October 2024–April 2025. MMWR Morb Mortal Wkly Rep. 2026;75:322-326. doi:10.15585/mmwr.mm7525a2