Escherichia coli O157:H7 in livestock in Japan.

The largest ever outbreak in Japan of Escherichia coli O157 infection in humans occurred in 1996. As a result, surveys were conducted later the same year to evaluate the sources and pathogenesis of this bacillus in livestock animals at the farm and in abattoirs. One of the surveys resulted in the isolation of E. coli O157 in 0.62% of cattle on randomly selected farms. Although no confirmation has been made with regard to the source of E. coli O157 infection and its pathogenicity in livestock animals, preventive measures are being applied at both farm and processing levels.