There's been a large increase in the number of mumps cases in Galway, Mayo and Roscommon this year

The HSE West says there've been 258 cases reported so far this year compared to 18 last year.

Most cases involve teenagers and young adults in the 15-24 year age group with smaller numbers occurring among younger and older people.

Dr Jennifer Martin, Public Health Doctor with HSE West says is important to remember that mumps is a preventable infection.

She says after two doses of the MMR vaccine 98% of people are fully protected against mumps.

Dr Martin says the majority of mumps cases in the West of Ireland have occurred in young adults who have received none or only one dose of MMR.