Results of a longitudinal study of the prevalence of Escherichia coli O157:H7 on cow-calf farms
American Journal of Veterinary Research , 61 , 2000

Sargeant, J.M., Gillespie, J.R., Oberst, R.D., Phebus, R.K., Hyatt, D.R., Bohra, L.K., Galland, J.C.

Objective—To describe the frequency and distribution of Escherichia coli O157:H7 in the feces and environment of cow-calf herds housed on pasture. Sample Population—Fecal and water samples for 10 cow-calf farms in Kansas. Procedure—Fecal and water samples were obtained monthly throughout a 1-year period (3,152 fecal samples from 2,058 cattle; 199 water samples). Escherichia coli O157:H7 in fecal and water samples was determined, using microbial culture. Results—Escherichia coli O157:H7 was detected in 40 of 3,152 (1.3%) fecal samples, and 40 of 2,058 (1.9%) cattle had greater than or equal to 1 sample with E coli. Fecal shedding by specific cattle was transient; none of the cattle had E coli in more than 1 sample. Significant differences were not detected in overall prevalence among farms. However, significant differences were detected in prevalence among sample collection dates. Escherichia coli O157:H7 was detected in 3 of 199 (1.5%) water samples. Conclusions and Clinical Relevance—Implementing control strategies for E coli O157:H7 at all levels of the cattle industry will decrease the risk of this organism entering the human food chain. Devising effective on-farm strategies to control E coli O157:H7 in cow-calf herds will require an understanding of the epidemiologic characteristics of this pathogen. Has a good background on history of E. coli and health issues associated with the bacteria.