Table 1. Algorithm for electronic database search to find published reports on prevalence of E. coli O157 in cattle.

Search term	Boolean keywords
Descriptive term	Prevalence OR Incidence OR frequency OR occurrence OR Detection OR Identification OR Isolation OR characterization OR Investigation
Population term	Escherichia coli O157 OR E coli O157 OR O157 OR shiga toxin producing Escherichia coli O157 OR STEC O157 OR VTEC O157 OR verocytotoxin producing Escherichia coli O157 OR EHEC O157 OR Enterohaemorrhagic Escherichia coli O157 OR Enterohemorrhagic Escherichia coli O157 OR VTEC OR STEC OR EHEC OR Enterohemorragic OR Enterohaemorrhagic OR Enterohemorrhagic OR Enterohaemorragic
Outcome term	Cattle OR Bovine OR ruminant OR dairy OR Beef OR cow OR veal OR Calf OR calves OR heifer OR steer OR feedlot OR Bull OR Bullock OR yearling