OUTBREAK OF VIRAL GASTROENTERITIS DUE TO A CONTAMINATED WELL - INTERNATIONAL CONSEQUENCES

Context.-Small round-structured viruses (SRSVs) are known to cause vir al gastroenteritis, but until now have not been confirmed in the impli cated Vehicle in outbreaks. Objective.-Investigation of a gastroenteri tis outbreak. Design.-After applying epidemiologic methods to locate t he outbreak source, we conducted environmental and laboratory investig ations to elucidate the cause.Setting.-Tourists traveling by bus throu gh Alaska and the Yukon Territory of Canada. Participants.-Staff of a restaurant at a business complex implicated as the outbreak source, co nvenience sample of persons on buses that had stopped there, and bus e mployees. Main Outcome Measures.-Odds ratios (ORs) for illness associa ted with exposures. Water samples from the restaurant and stool specim ens from tourists and restaurant staff were examined by nucleic acid a mplification using reverse transcription polymerase chain reaction and sequencing of viral amplification products. Results.-The itineraries of groups of tourists manifesting vomiting or diarrhea were traced bac k to a restaurant where buses had stopped 33 to 36 hours previously, W ater consumption was associated with illness (OR, 5.3; 95% confidence interval [CI], 2.3-12.6). Eighteen of 26 employees of the business com plex were ill; although not the index case, an employee ill shortly be fore the outbreak lived in a building connected to a septic pit, which was found to contaminate the well supplying the restaurant's water, G enotype 2/P2B SRSV was identified in stool specimens of 2 tourists and 1 restaurant employee. Stools and water samples yielded identical amp lification product sequences. Conclusions.-The investigation documente d SRSVs in a vehicle epidemiologically linked to a gastroenteritis out break. The findings demonstrate the power of molecular detection and i dentification and underscore the importance of fundamental public heal th practices such as restaurant inspection, assurance of a safe water supply, and disease surveillance.