19 cases have been identified in total in the East, South and Midwest of Ireland
The HSE is currently investigating an ongoing measles outbreak in different parts of Ireland.
So far 19 cases have been identified and 13 confirmed, with the remaining six deemed to be probable.
All cases have occurred in individuals under the age of 30 - most of those are in the 15-19 year age group.
It is believed that the source of infection came from a European country where measles outbreaks are occurring.
The HSE said a large proportion of those infected were unaware that they had been in contact with measles, and most had not received the MMR vaccine.
Consultant in Public Health Dr Kevin Kelleher said they were “looking to raise public awareness around the signs and symptoms of the condition and ensure that anyone with concerns addresses them immediately in order to receive a rapid diagnosis."
Symptoms of the virus include high fever, a cough, a runny nose, and a red rash that starts on the head and spreads down the body.
Dr. Kelleher stressed that “measles is highly infectious, and if cases are isolated early, the risk of transmission to vulnerable individuals decreases."
He said "the time between exposure to the virus and developing measles rash is normally 14 days. People are infectious from 4 days before rash starts until 4 days after.”
The following areas have been identified as places where those confirmed with measles have been while infectious:
In a statement issued this evening the HSE said people who are fully vaccinated with two doses of MMR vaccine are normally protected.
Those most at risk are those who are not fully vaccinated with two doses of MMR, babies, and those with weakened immune systems if exposed.
More information on the virus can be found here.