Escherichia coli O157:H7 outbreaks are most commonly linked to which animal reservoir?

Escherichia coli O157:H7 outbreaks are most commonly linked to which animal reservoir?

• A. Cattle
• B. Pigs
• C. Chickens
• D. Dogs

Answer: (A)

Escherichia coli O157:H7 outbreaks are most commonly tied to cattle because these animals can carry the organism in their intestines and shed it in feces without showing illness. This widespread shedding during slaughter and processing frequently contaminates beef, especially ground beef, which mixes bacteria from many animals. Thorough cooking and proper food handling mitigate risk, but the strongest and most consistent link for these outbreaks is cattle as the reservoir. Pigs, chickens, and dogs may harbor various strains, but they are not the primary source associated with O157:H7 outbreaks.

Escherichia coli O157:H7 outbreaks are most commonly tied to cattle because these animals can carry the organism in their intestines and shed it in feces without showing illness. This widespread shedding during slaughter and processing frequently contaminates beef, especially ground beef, which mixes bacteria from many animals. Thorough cooking and proper food handling mitigate risk, but the strongest and most consistent link for these outbreaks is cattle as the reservoir. Pigs, chickens, and dogs may harbor various strains, but they are not the primary source associated with O157:H7 outbreaks.