The disease is highly contagious.
An outbreak of measles has been reported in Westmeath.
HSE Midlands says it's been notified of four cases, and full investigative and outbreak control measures have been put in place.
It's warning people of the symptoms of the disease - which is highly contagious and can become serious.
Anyone who has not received two doses of the MMR vaccine is advised to contact their GP.
Dr. Douglas Hamilton, consultant in public health medicine in the midlands, outlines symptoms to look out for:
Gardaí Searching For Missing Man On Midlands Lake
Enterprise Minister Downplays Government's Ability To Help On Home Heating Oil
Midlands Prison Hit By Mass Overdose Incident
Offaly Man To Complete Marathon Challenge In Honour of Ashling Murphy
Recruitment Of First-Ever Professors For Ireland's Technological Universities Launched
Minister For Rural And Community Development Marks Two Official Openings And Launches In Laois
Offaly Soccer Club Granted Planning Permission For Facility Expansion
Offaly TD Warns Garda Protection For TDs Could Affect Public Access