Non-domestic animals, particularly ruminants, are the main reservoir of the organism, which rarely causes disease in livestock. Infection occurs when humans ingest organisms originating from animal faeces, most directly by contact with grazing animals or their environments. Outbreaks have occurred following visits to farms, petting zoos and agricultural shows, but also after camping events on land previously used for animals.
Main clinical features
Although not common, infection with E.coli O157 has a range of outcomes, from asymptomatic presence or mild diarrhoea, through bloody diarrhoea and haemorrhagic colitis, to potentially fatal complications. Children and the elderly are most at risk. Whilst most illness is self-limiting, serious outcomes include haemolytic uraemic syndrome (HUS), seen mostly in children, and thrombotic thrombocytopaenic purpura (TTP), mostly seen in adults, which involves neurological complications.
Usually 7-10 days but can be up to 14 days.
Isolates of E.coli O157 and other serogroups, cultured from faeces, are voluntarily reported to HPS by diagnostic laboratories. The Scottish E.coli O157 Reference Laboratory (SERL) also reports culture positive cases, and seropositives identified from antibodies to E.coli O157 in serum.
National Outbreak of Escherichia coli O157 Phage Type 21/28 in Scotland (July-September 2016)
National Outbreak of Escherichia coli O157 Phage Type 32 in Scotland (September - October 2015)
Audit of Task Force Recommendations
National Guidance on VTEC
Scientific Poster Presentation