Factory Outbreak of Escherichia coli O157:H7 Infection in Japan
1999

E. coli Outbreak in a Factory in Japan

Sample size: 3155 publication Evidence: moderate

Author Information

Author(s): Yoshiyuki Watanabe, Kotaro Ozasa, Jonathan H. Mermin, Patricia M. Griffin, Kazushige Masuda, Shinsaku Imashuku, Tadashi Sawada

Primary Institution: Kyoto Prefectural University of Medicine

Hypothesis

What caused the outbreak of E. coli O157:H7 among factory workers in Kyoto, Japan?

Conclusion

The outbreak of E. coli O157:H7 infection among factory workers was most likely caused by contaminated radish sprouts.

Supporting Evidence

  • 74 workers reported gastrointestinal symptoms in July.
  • 47 cases met the case definition, with 5 being culture-confirmed.
  • Radish sprout salad was the only food item associated with illness consumed by more than 50% of case-patients.

Takeaway

Some workers at a factory in Japan got sick from eating bad radish sprouts. The sprouts were linked to a similar outbreak at schools nearby.

Methodology

Cohort and case-control studies were conducted, and stool samples were cultured for E. coli O157:H7.

Potential Biases

Some ill workers might not have reported symptoms due to fear of repercussions.

Limitations

Recall bias may have affected the accuracy of reported food consumption.

Participant Demographics

Of the 47 case-patients, 39 (83%) were male, and the median age was 30 years.

Statistical Information

P-Value

0.04

Confidence Interval

95% CI = 1.08

Statistical Significance

p<0.05

Want to read the original?

Access the complete publication on the publisher's website

View Original Publication