There is a mumps outbreak in the west of the country, the HSE has confirmed.
There has been an increase in the numbers of people between 15 and 29-years-old being diagnosed with the viral illness in the western region.
45 patients have been diagnosed with mumps over the past seven weeks.
Mumps can cause fever, headache, and painful swollen salivary glands.
It is spread from person to person through coughs and sneezes, and can also be transmitted through direct contact with saliva.
People diagnosed with mumps tend to be unwell for up to 10 days, but complications can include meningitis and inflammation of the testicles, which can affect fertility in men in later life.
Some patients can also experience less common complications such as inflammation of the pancreas, deafness, arthritis, and inflammation of the heart.
The HSE has said that the MMR vaccine is the best protection against mumps.
If you have not had two doses of the vaccine, or are not sure if you have had two doses, you should be vaccinated.
People diagnosed with mumps should stay away from work, college, or school for five days. Fluids, rest, and painkillers are advised for treatment.
