In 1982 scientists discovered a mutation whereby genetic material from a Shigella bacterium (which causes dysentery) merged spontaneously with a harmless strain of E.coli. A new deadly food borne germ, E.coli 0157, had emerged. It is the most common member of a family of microbes known as VTEC. These organisms pose a serious risk as the number required to cause illness is very low. They can survive gastric juices in the human stomach and pass to the gut where they grow and produce highly poisonous "verotoxins". The incidence of E.coli 0157 in Ireland at 2.1 per 100,000 population is high compared to other European countries. Significantly, the rate is rising, whereas in Britain, which has seen some of the worst outbreaks, it is declining.
Livestock are the reservoir of most E.coli 0157, but contamination of other foods can occur. It has been found in milk, fruit, vegetables and water. The very young, the very old, the immuno-suppressed are most susceptible. Children risk kidney failure. Symptoms include bloody diarrhoea, severe cramps and bruising.
