Concurrent Outbreak of Norovirus Genotype I and Enterotoxigenic Escherichia coli on a U.S. Navy Ship following a Visit to Lima, Peru
2011

Outbreak of Norovirus and E. coli on a U.S. Navy Ship

Sample size: 130 publication 10 minutes Evidence: moderate

Author Information

Author(s): Gonzaga Victor E., Ramos Mariana, Maves Ryan C., Freeman Randal, Montgomery Joel M.

Primary Institution: United States Naval Medical Research Unit Six (NAMRU-6), Lima, Peru

Hypothesis

What were the causes and factors associated with a gastrointestinal outbreak on a U.S. Navy ship following a visit to Lima, Peru?

Conclusion

The outbreak was primarily caused by Norovirus, with Enterotoxigenic E. coli also detected, and visiting a specific location in Lima was significantly associated with illness.

Supporting Evidence

  • Norovirus was identified in 82% of stool samples from symptomatic patients.
  • ETEC was detected in 73% of stool samples tested.
  • The clinical attack rate was 28.3% among the crew.
  • Visiting 'Pizza Alley' was associated with a significantly increased risk of illness.
  • Consumption of bottled water was shown to be highly protective against infection.

Takeaway

Some sailors got sick after visiting a place in Lima, Peru, and it was caused by a virus and bacteria they caught there.

Methodology

An unmatched case-control study was conducted among crew members, with data collected through questionnaires and testing of stool and emesis samples.

Potential Biases

Potential bias due to reliance on self-reported data from crew members.

Limitations

Control samples were not collected, which may have helped better define the role of ETEC in the outbreak.

Participant Demographics

Mean age of participants was 28.7 years, with 85.3% male.

Statistical Information

P-Value

0.03

Confidence Interval

1.22 to 52.73

Statistical Significance

p<0.05

Digital Object Identifier (DOI)

10.1371/journal.pone.0020822

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