150, 0.335) 0.262 (0.177, 0.367) 0.637    Autumn 0.262 (0.173, 0.375) 0.231 (0.154, 0.330) 0.648    Winter 0.149 (0.094, 0.229) 0.130 (0.082, 0.199) 0.674 By animal health district          Highland 0.153 (0.096, 0.234) 0.198

(0.130, 0.289) 0.396    North East 0.248 (0.163, 0.359) 0.199 (0.130, 0.290) 0.442    Central 0.249 (0.164, 0.359) 0.204 (0.134, 0.296) 0.480    South West 0.189 (0.121, 0.283) 0.261 (0.177, 0.366) 0.257    South East 0.189 (0.166, 0.364) 0.231 (0.168, 0.354) 0.374    Islands 0.171 (0.108, 0.259) 0.111 (0.070, 0.172) 0.197 By phage type          PT2 0.033 (0.002, 0.352) 0.017 (0.008, 0.034) 0.857    PT8 0.011 (0.006, 0.020) 0.019 (0.01, 0037) 0.278 Selleck Cobimetinib    PT21/28 0.135 (0.067, 0.252) 0.124 (0.066, 0.219) 0.865

   PT32 0.031 (0.0021, 0.378) 0.060 (0.019, 0.176) 0.779 Table 2 Mean pat-level prevalence of bovine E. coli O157 shedding for the Selleckchem BIBF 1120 SEERAD (March 1998-May 2000) and IPRAVE (February 2002-February Pritelivir cell line 2004) surveys. Category Mean Prevalence (Lower, Upper 95% Confidence Limits) P-value   SEERAD IPRAVE   All categories 0.089 (0.075, 0.105) 0.040 (0.028, 0.053) <0.001 By season          Spring 0.104 (0.084, 0.126) 0.044 (0.024,0.0 66) <0.001    Summer 0.084 (0.053, 0.118) 0.039 (0.022, 0.058) 0.018    Autumn 0.085 (0.061, 0.110) 0.045 (0.024, 0.069) 0.016    Winter 0.074 (0.035, 0.107) 0.030 (0.011, 0.054) 0.045 By animal health district          Highland 0.094 (0.044, 0.170) 0.023 (0.008,0.045) 0.034    North East 0.114 (0.075, 0.161) 0.024 (0.005, 0.050) <0.001    Central 0.093 (0.068, 0.118) 0.033 (0.011, 0.058) <0.001    South West 0.051 (0.030, 0.073) 0.068 (0.026, 0.133) 0.550    South East 0.106 (0.074, 0.139) 0.054 (0.022, 0.091) 0.030    Islands 0.064 (0.028, 0.108) 0.042 (0.013, 0.077) 0.396 By phage type          PT2 0.013 (0.008, 0.019) 0.004 (0.001, 0.007) 0.007    PT8 0.004 (0.001, 0.007) 0.004 (0.000, 0.009) 0.821    PT21/28 0.052 (0.039, 0.067) 0.019 (0.012, 0.028) <0.001    PT32 0.010 (0.006, 0.014) 0.007 (0.003, 0.011) 0.262 In the majority of farms sampled in both surveys, no shedding animals were detected. The distribution of the prevalence on E. coli O157 positive farms is shown in Figure 2 for both

the SEERAD and IPRAVE surveys. The distribution of prevalence for the two studies was different (Kolmogorov-Smirnov two-sample Megestrol Acetate test: exact P < 0.001). The median prevalence of shedding animals was statistically significantly lower (Wilcoxon-Mann-Whitney test: exact P < 0.001) in the IPRAVE compared with the SEERAD survey (SEERAD: 0.25 (95%CI: 0.20-0.33); IPRAVE: 0.11 (95%CI: 0.09-0.14). Figure 2 Distribution of prevalence of E. coli serogroup O157 on positive farms.