E. coli Outbreak Linked to Alfalfa Sprouts
Author Information
Author(s): Thomas Breuer, Denise H. Benkel, Roger L. Shapiro, William N. Hall, Mary M. Winnett, Mary Jean Linn, Jakob Neimann, Timothy J. Barrett, Stephen Dietrich, Frances P. Downes, Denise M. Toney, James L. Pearson, Henry Rolka, Laureance Slutsker, Patricia M. Griffin, Investigation Team
Primary Institution: Centers for Disease Control and Prevention
Hypothesis
Is alfalfa sprouts a new vehicle for E. coli O157:H7 infection in humans?
Conclusion
The outbreak was linked to alfalfa sprouts grown from contaminated seeds, highlighting the need for improved food safety measures.
Supporting Evidence
- E. coli O157:H7 isolates from patients in Michigan and Virginia had indistinguishable PFGE patterns.
- Alfalfa sprouts were the only food item significantly associated with illness in both states.
- Trace-back investigations linked the outbreak to a specific lot of contaminated seeds from Idaho.
- The outbreak ended after the implicated sprouts were removed from sale.
- PFGE subtyping was crucial in linking isolated infections to a common source.
Takeaway
Some people got sick from eating alfalfa sprouts that were grown from bad seeds. This shows we need to be careful about what we eat.
Methodology
Case-control studies were conducted in Michigan and Virginia to investigate exposures associated with E. coli O157:H7 infection.
Potential Biases
Potential bias in selecting controls and reliance on telephone interviews for data collection.
Limitations
The study relied on self-reported food consumption, which may be subject to recall bias.
Participant Demographics
Patients included 68% females with a median age of 31 years in Michigan and similar demographics in Virginia.
Statistical Information
P-Value
p<0.05
Confidence Interval
95% CI 5-558
Statistical Significance
p<0.05
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