Irish rates of E. coli are ten times higher than European averages.
Data from the Health Protection Surveillance Centre shows that there have been 715 reported cases of illness from E.coli since the start of the year.
Symptoms include bloody diarrhoea, vomiting and stomach cramps.
In more serious cases and if left untreated it can cause fatalities, though none have been reported during this outbreak.
Alan Reilly, Adjunct Professor at the Institute of Food and Health in UCD says warmer temperatures make it easier for bugs to live:
"When you're looking at outbreaks over the year - you see peaks during the summer and those peaks are down to the good weather, the bugs will grow quicker at warmer temperatures."