An outbreak of measles has been confirmed in north Dublin, striking both children and adults, the HSE has warned.
It is advising people who think they have measles to stay at home and to contact their GP for advice.
"This is a community outbreak of measles affecting adults and children," doctors said, adding: "There have been five cases since the start of February."
Measles is a highly infectious illness and spreads very easily. There has already been an outbreak reported in Donegal this year.
All individuals should be aware of their measles immunity status before travel (either immune from infection or being vaccinated with the correct number of doses for their age) and seek MMR vaccination (if appropriate) to ensure protection against measles while away.
Measles cases in Europe mainly occur in unvaccinated populations in both adults and children.
Large outbreaks with fatalities are ongoing in countries that had previously eliminated or interrupted transmission of measles.
The European Centre for Disease Prevention and Control (ECDC) monitors the measles outbreaks in the EU/EEA and publishes regular updates on measles cases and outbreaks.
Symptoms of measles include high fever, cough, runny nose and red eyes, and the infected person can have a red rash that starts on the head and spreads down the body - this normally starts a few days after onset of illness. The rash consists of flat red or brown blotches, which can flow into each other.
It lasts about four to seven days, while vomiting, diarrhoea and stomach pain may also happen.
All children should get the MMR vaccine when they are aged 12 months.
If any child aged over 12 months has missed this vaccine they should get it now from their GP.
Children aged six-11 months, travelling to other countries and regions where measles outbreaks are reported, are recommended the MMR vaccine.
A dose given before 12 months of age does not replace the dose that would normally be given at 12 months of age.
All children should get a second dose of MMR vaccine when they are four to five years old or in Junior Infants at school.
If any child in Senior Infants or older has missed this vaccine they should get it now from their GP.