Controlling the spread of this type of E.coli is a priority for the FSA. Experts from around the globe attended a workshop in Midlothian, where priorities were agreed for research to help tackle EHEC at the main source of infection, the cattle gut. Delegates shared knowledge on the factors leading to the transmission and maintenance of infection in cattle, particularly the role of ‘supershedders’ – cattle that excrete particularly high levels of E.coli O157 in their faeces.
Supershedders are thought to play an important role in the spread of the bacteria to other cattle and the likelihood of transmission to humans via the environment or raw food. There was also discussion on intervention strategies being explored in other countries to reduce EHEC shedding by cattle and the feasibility of introducing these in the UK.
Enterohaemorrhagic E.coli (EHEC) are a group of E.coli that include verocytotoxin-producing serotypes including E.coli O157, O26 and O104. These can cause mild to severe illness, characterised by abdominal cramps, vomiting and bloody diarrhoea. EHEC infections can also lead to the serious conditions haemolytic uraemic syndrome and thrombotic thrombocytopaenic purpura. These conditions affect the blood, kidneys and, in severe cases, the central nervous system, and can even lead to death.
In the UK, EHEC infections are most commonly attributed to E.coli O157, for which there were over 1,000 cases reported in 2010. The main source for EHEC is the gut of ruminant animals, particularly cattle, which excrete or shed the bacteria in their faeces. Some cattle excrete EHEC at significantly higher levels than other animals in the herd, a phenomenon known as ‘supershedding’. Humans can become infected through direct exposure to faeces in the environment or when faecal contamination enters the water supply or food chain.
For further information on this area of research, an FSA review can be found below.