Vero cytotoxin-producing Escherichia coli, particularly serogroup O157, associated with human infections in England and Wales: 1992-4.

Investigations were performed by the Laboratory of Enteric Pathogens on Vero cytotoxin-producing Escherichia coli (VTEC) in England and Wales from 1992-4. Bacterial isolates, faeces and sera obtained from patients with diarrhoea, bloody diarrhoea and haemolytic uraemic syndrome were examined. Using serotyping, Vero cytotoxin gene probing and serodiagnostic tests for E. coli O157, evidence of infection was detected in 543, 434 and 491 individuals in 1992, 1993 and 1994 respectively; VTEC of serogroup O157 were isolated from 470, 385 and 411 cases. The O157 VTEC strains belonged to at least 19 different phage types (PT) although 84% belonged to PT2, PT49, PT8, PT1 or PT4. Antibodies to E. coli O157 lipopolysaccharide were detected in 13% of the cases. The average annual rate of infection with O157 VTEC was 0.83/100000 and 12% of the 1458 individuals with evidence of infection with VTEC or E. coli O157 developed haemolytic uraemic syndrome. There were at least 18 general outbreaks and many family outbreaks.