Volume 18, Number 3—March 2012
Research
Pathogenic Potential to Humans of Bovine Escherichia coli O26, Scotland
, Tracy Rosser, Lesley J. Allison, Emily Courcier, Judith Evans, Iain J. McKendrick, Michael C. Pearce, Ian Handel, Alfredo Caprioli, Helge Karch, Mary F. Hanson, Kevin G.J. Pollock, Mary E. Locking, Mark E.J. Woolhouse, Louise Matthews, J. Chris Low, and David L. GallyTable 3
Farm-level and fecal pat–level prevalence of Escherichia coli O26, Scotland*
| E. coli O26 status | Farms, n = 338 |
Fecal pats, n = 6,086 |
|||||
|---|---|---|---|---|---|---|---|
| No. positive | Observed prevalence | Adjusted prevalence (95% CI) | No. positive | Observed prevalence | Adjusted prevalence (95% CI) | ||
| E. coli O26* | 68 | 0.20 | 0.22 (0.18–0.27) | 249 | 0.041 | 0.046 (0.031–0.062) | |
| stx+ E. coli O26 | 38 | 0.11 | 0.12 (0.09–0.16) | 122 | 0.020 | 0.020 (0.012–0.029) | |
| stx1 + stx2 + E. coli O26 | 13 | 0.04 | 0.06 (0.031–0.09) | 97 | 0.016 | 0.004 (0.001–0.008) | |
| stx1 + stx2 + eae + E. coli O26 | 12 | 0.04 | 0.05 (0.03–0.09) | 24 | 0.004 | 0.004 (0.001–0.007) | |
*Minor differences in the farm-level prevalence estimates for E. coli O26 between Pearce et al. (21) and this study resulted from use of different statistical models. Pearce et al. (21) aimed to provide national prevalence estimates; thus, weighted estimates of mean prevalence were generated that accounted for the fractions of the national herd found in different Animal Health Districts (AHDs). By contrast, we reported the mean of the sample collected in a stratified fashion across the AHDs. Because there were only relatively small differences in mean prevalence in the different AHDs, the effect on the 2 means is negligible and the effect on the standard errors relatively small.
