Temporal and spatial patterns of bovine Escherichia coli O157 prevalence and comparison of temporal changes in the patterns of phage types associated with bovine shedding and human E. coliO157 cases in Scotland between 1998-2000 and 2002-2004

Table 2 Mean pat-level prevalence of bovine E. coli O157 shedding for the SEERAD (March 1998-May 2000) and IPRAVE (February 2002-February 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

ISSN: 1471-2180