12 cases of E.Coli have now been confirmed following an outbreak last week at Dun Beag creche in Dunmore.
The HSE’s multidisciplinary Outbreak Control Team says four cases have involved hospitalisation.
E.Coli VTEC can spread in a number of ways including contact with infected animals, contaminated soil, water or certain foods, and can be spread among toddlers who are not toilet trained.
The majority of cases of VTEC get better with no treatment and without hospitalisation.
However the most serious complication is Haemolytic Uraemic Syndrome or HUS which occurs in up to 10% of VTEC cases.
This can lead to anaemia and kidney failure and requires intensive medical treatment.
The number of cases of VTEC notified in Ireland each year is increasing with 927 cases confirmed in 2017.