Legionnaires' Disease Outbreak Linked to a Decorative Fountain
Author Information
Author(s): O'Loughlin Rosalyn E, Kightlinger Lon, Werpy Matthew C, Brown Ellen, Stevens Valerie, Hepper Clark, Keane Tim, Benson Robert F, Fields Barry S, Moore Matthew R
Primary Institution: Centers for Disease Control and Prevention
Hypothesis
What is the source of the Legionnaires' disease outbreak in Rapid City, South Dakota?
Conclusion
The outbreak was traced to a decorative fountain in Restaurant A, which was removed to halt transmission.
Supporting Evidence
- Six of 11 case-patients reported eating in Restaurant A versus 0 controls.
- Legionella was isolated from 24 of 43 cooling towers tested.
- The outbreak strain was found only in the decorative fountain in Restaurant A.
- Case-patients were significantly more likely to have passed through areas with cooling towers positive for Legionella.
- Legionella pneumophila serogroup 1 was isolated from four clinical specimens.
- All case-patients and controls were residents of Rapid City.
Takeaway
A small fountain in a restaurant made people sick with Legionnaires' disease, and when it was taken away, no more people got sick.
Methodology
A case-control study was conducted with 13 case-patients and 52 matched controls, along with environmental sampling.
Potential Biases
Potential bias due to media attention influencing case-patient reporting.
Limitations
Recall bias may have affected case-patient responses, and controls were not re-interviewed after the source was identified.
Participant Demographics
All case-patients were white, older than 50 years, and residents of Rapid City.
Statistical Information
P-Value
32.7
Confidence Interval
95% CI 4.7-∞
Statistical Significance
p<0.05
Digital Object Identifier (DOI)
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