Up to 13 cases of Measles have been confirmed across Co. Kerry, with another six also deemed as likely diagnoses.
Parents have now been advised not to bring their children to Kerry University Hospital, unless it is a serious emergency.
Co. Kerry has so far borne the brunt of the outbreak, though cases have also been detected in other parts of the country.
Measles is a highly contagious disease with an incubation period of 14 days. Humans become infectious from 4 days before the rash appears until 4 days afterwards.
Symptoms include include high fever, coughing, runny nose, and a red rash that spreads from the head down.