An outbreak of mumps has seen 45 cases reported for the first three weeks of January, compared with just one case during the same period last year.
The outbreak, mainly among students, was first detected last October and by the end of the year, the incidence had increased 10-fold.
Britain has seen a 14-fold increase in suspected cases in the past year - its highest level in 15 years.
Some health professionals are now asking if consideration should be given to providing a mumps vaccination for all teenagers, once they reach 18.
In the third week of January, there were five outbreaks in the Health Service Executive southern area and four in the west. there were three in the mid-west and two in the north-west.
The 18-24 year old population has been worst affected, according to Dr Suzanne Cotter, public health specialist with the Health Protection Surveillance Centre.
She said many had either received no vaccine as children, or just one instead of two.
The measles, mumps and rubella vaccine was introduced in 1988, but many of those now contracting mumps were born too early to have received it as babies. They may also have been born too late to have secured immunity through exposure to the wild mumps virus in the general population.
The MMR vaccine is given after the baby reaches one year, while a second dose is administered to four to five year-olds. Dr Cotter said the uptake among children in Ireland remained below the target of 95 per cent required to prevent the spread of mumps.
She added that students in mumps-affected colleges had been targeted for MMR vaccination and this was being taken up. It was too early to say if a blanket vaccination should be introduced. "There are a lot of issues to be considered," she said - how would the vaccine be given, who would administer it and where would it be administered?
Dr Niall Ó Cléirigh of the Irish College of General Practitioners said the increase in mumps cases was "fairly significant". "I've seen one case myself and it's the first I've seen in years," he said.
He highlighted other factors, including media sensationalising of alleged links between the MMR vaccine and autism. Young children who were not vaccinated were now at risk of contracting the disease from older teenagers. Immigration from countries which did not have an immunisation programme was also a factor.
Dr Ó Cléirigh said the medicine was now entering new territories with the MMR vaccine. People who had been vaccinated in their early years were now teenagers and the question of the waning immunisation effect was arising, he said. Revaccinating of young adults might need to be considered.
The Health Protection Surveillance Centre has called on all parents to ensure that their children receive two doses of MMR as part of the routine childhood immunisation programme.
