The Health Service Executive has reiterated a warning to parents in the west, following an increase in the number of cases of mumps in the region in recent weeks.
Parents of students at a school in Claregalway have been notified that a number of children have developed mumps-like symptoms.
It follows an increase in the number of cases of the condition in the area, mainly among those aged between 15 and 29.
The HSE says immunisation though the MMR vaccine provides the best protection for people, and it is urging those who have not had two doses of the vaccine to seek an additional dose.
People who are uncertain if they have had two doses are also being advised to get vaccinated as soon as possible, because it can take up to 28 days for the antibodies to take effect.
Children who develop symptoms should be kept out of school for at least five days after the onset of neck swelling.
Public health officials say that children can be infectious before the onset of swelling and may have additional symptoms, such as sore throats, coughing or general malaise.
Mumps is spread by coughing and sneezing and can also be transmitted through direct contact with saliva.
It is an acute viral illness, with symptoms including fever, headache and painful, swollen salivary glands.
Mumps can also lead to complications like meningitis and can cause swollen testicles, which can lead to fertility problems in later life.
