Studies of the presence of verocytotoxic Escherichia coli O157 in bovine faeces submitted for diagnostic purposes in England and Wales and on beef carcases in abattoirs in the United Kingdom.

A survey of beef carcases in abattoirs in the UK was carried out in order to estimate the prevalence of contamination with verocytotoxin-producing Escherichia coli (VTEC) serogroup O157. Contamination with verocytotoxin-producing E. coli (VTEC) O157 was confirmed in 0.47% of the 4067 (95% confidence limits 0.22-1.00%) of neck muscle samples. A significant tendency for carcases present in the same abattoir on the same day to have similar results was found, thus suggesting cross contamination. VTEC O157 was found in 0.83% of 6495 bovine faeces samples routinely submitted for diagnostic purposes to Veterinary Investigation Centres in England and Wales. Of the samples from cattle less than 6 months old, 3.7% of 68 samples from animals without gastrointestinal disease were positive for E. coli O157, in contrast to 0.75% of 2321 samples from cases of gastrointestinal disease. No association with season or herd type (beef or dairy) was found.