Increase in dairy stock linked to E.coli outbreak


Professor Alan Reilly, a former head of the Food Safety Authority, has cited the increasing numbers of dairy cattle in the country as the likely reason for a spike in the incidence of E.coli 0157 related illnesses over the past few months.

Data published by the Health Protection Surveillance Centre shows there have been 715 reported cases of illness caused by the bug since the beginning of the year, an increase of 197 cases over the same period last year.

There have been no reports of food recalls or withdrawals from the Food Safety Authority of Ireland, so the food or foods causing the outbreak have not been identified.

In the midlands and west, reported cases of illness were far higher than average at about 30/100,000 of the population. The UCD based academic described the figures as 'astronomical' compared with those for the rest of Europe. There is criticism that Alan then made a leap of equally astronomical proportions by directly linking the increased numbers of dairy cattle in Ireland with the increase in E.coli-based illnesses: “The natural reservoir of E.coli O157 is the gut of healthy cattle and sheep. We have seen a rapid expansion in in the dairy herd since the elimination of the milk quotas. More animals means more slurry to spread on land. Contamination of rural water supplies and rivers with pathogenic bacteria such as E.coli O157 results from land run-off. A study published in 2017 by the Health Service Executive, Dublin Institute of Technology and the University of Limerick clearly demonstrated the link between cattle density and contamination of private well water with cases of E.coli O157.”

Alan O'Reilly could be correct but there are flaws in his assessment. Most of the surge in E.coli outbreaks, as he identified, took place in regions where there have been minimal increases in livestock numbers. Most wells analysed this year for contamination were found to be free of E.coli 0157 bacteria. These should not be reasons for complacency. If his assumptions are correct then we need increased vigilance to protect our water supplies.