Outbreak of Viral Gastroenteritis Due to a Contaminated Well International Consequences Michael Beller, MD, MPH; Andrea Ellis, DVM, MSc; Spencer H. Lee, PhD; Michael A. Drebot, PhD; Sue Anne Jenkerson, MSN, FNP; Elizabeth Funk, MD, MPH; Mark D. Sobsey, PhD; Otto D. Simmons III, MSPH; Stephan S. Monroe, PhD; Tamie Ando, PhD; Jacqueline Noel; Martin Petric, PhD; John P. Middaugh, MD; John S. Spika, MD Context.\p=m-\Small round-structured viruses (SRSVs) are known to cause viral gastroenteritis, but until now have not been confirmed in the implicated vehicle in outbreaks. Objective.\p=m-\Investigation of a gastroenteritis outbreak. Design.\p=m-\After applying epidemiologic methods to locate the outbreak source, we conducted environmental and laboratory investigations to elucidate the cause. Setting.\p=m-\Tourists traveling by bus through Alaska and the Yukon Territory of Canada. Participants.\p=m-\Staff of a restaurant at a business complex implicated as the outbreak source, convenience sample of persons on buses that had stopped there, and bus employees. Main Outcome Measures.\p=m-\Odds ratios (ORs) for illness associated with ex- posures. Water samples from the restaurant and stool specimens from tourists and restaurant staff were examined by nucleic acid amplification using reverse transcription polymerase chain reaction and sequencing of viral amplification prod- ucts. Results.\p=m-\The itineraries of groups of tourists manifesting vomiting or diarrhea were traced back to a restaurant where buses had stopped 33 to 36 hours previ- ously. Water consumption was associated with illness (OR, 5.3; 95% confidence interval [CI], 2.3-12.6). Eighteen of 26 employees of the business complex were ill; although not the index case, an employee ill shortly before the outbreak lived in a building connected to a septic pit, which was found to contaminate the well supply- ing the restaurant's water. Genotype 2/P2B SRSV was identified in stool specimens of 2 tourists and 1 restaurant employee. Stools and water samples yielded identi- cal amplification product sequences. Conclusions.\p=m-\The investigation documented SRSVs in a vehicle epidemio- logically linked to a gastroenteritis outbreak. The findings demonstrate the power of molecular detection and identification and underscore the importance of funda- mental public health practices such as restaurant inspection, assurance of a safe water supply, and disease surveillance. JAMA. 1997;278:563-568 SMALL ROUND-structured viruses (SRSVs), also called Norwalk-like vi¬ ruses, are human enteric viruses in the family Caliciviridae.1 These viruses have not been cultivated in vitro, do not have a practical animal model in which they can be propagated, and are shed in rela¬ tively low numbers for only a short time during human illness.2 Nevertheless, SRSVs have been established as the ma¬ jor cause of viral gastroenteritis among adults worldwide.1·3 Outbreaks due to per¬ son-to-person4"6 or common-source trans¬ mission by foodhandlers,5·7"12 and con¬ sumption of contaminated oysters,13"18 ice,19·20 and celery21 have occurred. Wa¬ terborne outbreaks involving commu¬ nity water systems22·23 and contami¬ nated wells2426 have been reported. Transmission via aerosolized vomitus may be possible.6·27"30 Although epidemio¬ logie and laboratory investigations of SRSV outbreaks have been thorough, none has identified SRSVs in the incrimi¬ nated vehicle. We investigated a gastro¬ enteritis outbreak in tourists traveling by tour bus between the United States and Canada, which provided an oppor¬ tunity to develop novel laboratory meth¬ ods not previously used to study SRSVs. METHODS Background The outbreak was reported to the Alaska Division of Public Health after a Fairbanks, Alaska, hotel operator rec¬ ognized that ill bus passengers were staying at the hotel. Ill bus passengers were also identified in hotels in Skagway and Valdez, Alaska; the investigation subsequently implicated a restaurant in the Yukon Territory of Canada in a small community on the Alaska Highway. The restaurant, which catered largely to From the Division of Public Health, Alaska De- partment of Health and Social Services, Anchorage (Drs Beller, Funk, Middaugh, and Ms Jenkerson); Bureau of Disease Surveillance and Field Epidemi- ology, Laboratory Centre for Disease Control, Ot- tawa, Ontario (Dr Ellis); National Centre for Entero- viruses, Halifax, Nova Scotia (Drs Lee and Drebot); Division of Viral and Rickettsial Diseases, National Center for Infectious Diseases, US Centers for Dis- ease Control and Prevention, Atlanta, Ga (Drs Mon- roe, Ando, and Ms Noel); Department of Environ-$ mental Sciences and Engineering, School of Public Health, University of North Carolina, Chapel Hill (Dr Sobsey and Mr Simmons); Virology Laboratory, Department of Microbiology, Hospital for Sick Chil- dren, Toronto, Ontario (Dr Petric); Bureau of Infec- tious Disease, Laboratory Centre for Disease Con- trol, Ottawa, Ontario (Dr Spika). Dr Ellis is now with the Bureau of Infectious Disease, Laboratory Cen- tre for Disease Control, Ottawa, Ontario. Reprints: Michael Beller, MD, MPH, Division of Public Health, Alaska Department of Health and Social Ser- vices, PO Box 240249, Anchorage, AK 99524 (e-mail: mikeb@health.state.ak.us). by guest on December 3, 2009 www.jama.com Downloaded from