The epidemiology, detection and control ofEscherichia coli O157

Abstract

Numbers of cases of human infections caused by Escherichia coli O157 have increased over the last decade in many countries. As well as the typical symptoms of gastrointestinal illness, the organism can cause more life-threatening diseases such as haemorrhagic colitis and haemolytic uraemic syndrome (HUS). Although the incidence remains relatively low compared with the other foodborne pathogens such as Campylobacter and Salmonella, the mortality rate associated with infection is much higher. Cattle are thought to be the main environmental source of this organism, and most cases have been associated with consumption of beef and beef products. However, other food vehicles have been identified, such as apple cider and raw or unpasteurised milk and milk products. Cross-contamination has been shown to be an important factor in outbreaks, which, together with the fact that the infectious dose is low (as few as 10 cells), means that robust hygienic procedures are essential at all stages of the food chain to reduce risk of infection. Person-to-person spread is a common source of illness, and several laboratory-acquired cases have also occurred. Efficient detection, isolation and confirmation techniques are required to establish the reservoirs of this organism in the environment and its spread into, and within, the food chain. This article reviews the epidemiology of E coli O157 and discusses detection and preventative methods, both developed and developing. © 1999 Society of Chemical Industry