The HSE is urging people who fear they or their children might have measles to call their GP before visiting the surgery.
It follows two confirmed cases of the disease in Donegal.
People who suspect they or their children may have measles is being asked not to visit their GP without first letting the doctor know about their situation.
That’s because measles would be infectious to others at the GP’s surgery.
By first calling the GP’s office, it will enable special arrangements be made for a person to visit so they can be tested and diagnosed.
The measles outbreak in Donegal has been linked to a third-level institution in Galway.
The HSE says that while the majority of children in Donegal still receive the MMR vaccine, the numbers have been dropping slightly over the past few years.
It points out that as soon as vaccination rates fall, old diseases re-emerge, hence the reason why measles outbreaks are occurring in Ireland and across Europe.
Symptoms of measles are a rash, fever, red eyes, cough or runny nose.