TABLE 4.

Logistic regression models of associations between the presence of one or more high-level-fecal-shedding cattle in a feedlot pen and the outcomes of hide prevalence and high-level-hide-contamination prevalence analyses

ModelPen-level outcomeExplanatory variable (risk factor)OROR 95% confidence intervalP value
IaHide prevalenceFecal prevalence greater than 20%92.8-29.20.0002
IbAny high-density fecal shedder in pena14.46.5-31.8<0.0001
IcAny fecal supershedder in penb27.15.5-134.8<0.0001
IIaHigh-level hide prevalencecFecal prevalence greater than 20%19.66.9-55.5<0.0001
IIbAny high-density fecal shedder in pen17.66.5-47.8<0.0001
IIcAny fecal supershedder in pen10.25.4-19.3<0.0001
IIIaAny high-level hide cattle in penFecal prevalence greater than 20%22.94.4-119.40.0002
IIIbAny high-density fecal shedder in pen72.918.7-284.8<0.0001
IIIcAny fecal supershedder in pen176.89.5-3,3090.0005
IVaHide prevalence of >80%Fecal prevalence greater than 20%44.39.3-211.3<0.0001
IVbAny high-density fecal shedder in pen46.46.3-343.70.0003
IVcAny fecal supershedder in pen26.28.2-84.1<0.0001
VaHigh-level hide prevalence of >20%Fecal prevalence greater than 20%53.65.5-519.90.0006
VbAny high-density fecal shedder in pen50.24.9-520.70.001
VcAny fecal supershedder in pen44.86.7-302.2<0.0001
  • a A high-density fecal shedder is an animal shedding ≥200 CFU of E. coli O157:H7/g of feces.

  • b A fecal supershedder is an animal shedding >104 CFU of E. coli O157:H7/g of feces.

  • c Animals harboring E. coli O157:H7 on the hide at levels of ≥40 CFU/100 cm2.