CDC Describes Legionnaires' Outbreaks at Two Hotels in the Virgin Islands

Separate outbreaks of Legionnaires’ disease at two hotels in the U.S. Virgin Islands in 2024 illustrate the need to tailor guidance for controlling Legionella to warmer climates, according to the latest issue of CDC’s Morbidity and Mortality Weekly Report. The outbreaks affected four people, two of whom were hospitalized. All four recovered.

The first two patients were traveling companions who stayed in the same hotel room for nine days in late October 2024. One of these patients was hospitalized upon his return to the U.S. Sampling conducted by the U.S. Virgin Islands Department of Health found Legionella pneumophila in a showerhead as well as the hotel cistern and the water supply pipe. All three positive samples came from the cold water system, which had water temperatures ranging from 80 F to 87 F, in the range that promotes Legionella. Statistical analysis of the sampling results indicated uncontrolled bacterial growth. VIDOH required the hotel to close the room where the two patients had stayed while the property conducted remediation. In February 2025, after sampling confirmed that the water system was well controlled, VIDOH allowed the hotel to reopen the room.

A woman who stayed at a different hotel from Oct. 31 through Nov. 9, 2024, was hospitalized with severe sepsis, bilateral pneumonia, and acute respiratory failure upon returning to the U.S. She and a family member who traveled with her were both confirmed to have contracted Legionnaires’ disease. The family member recovered following treatment with antibiotics. Samples from six sinks and four showers at the hotel tested positive for L. pneumophila. The samples were taken from both cold and hot water sources with temperatures ranging from 82 F to 118 F. Again, statistical analysis indicated uncontrolled growth of Legionella. VIDOH closed the entire hotel until April 2025, when sampling detected no Legionella.

The two unrelated outbreaks suggest that tropical climates can contribute to proliferation of Legionella, the report states. At the first hotel, warm water temperatures were in the range that promote Legionella growth, from 77 F to 113 F, but bacteria were found only in cold water. The report suggests that hot water temperatures at the second hotel, where Legionella were present in both cold and hot water, did not reach sufficiently high temperatures to suppress growth. 

At both hotels, water was supplied by municipal sources, private water trucks, and cisterns. “Cisterns pose challenges for cleaning, monitoring, and disinfectant dosing and risk recontamination from open connections,” the report notes. “Ongoing improvements in maintenance and disinfection recommendations for these systems are needed.”

For more information, read the MMWR report.