There has been a spike in the number of cases of mumps among school students in Sligo and South Donegal.
Since the start of this year, 175 cases of the infection have been reported in Sligo, Leitrim and Donegal.
The HSE says anyone who develops mumps should stay at home for the five days after onset of the disease to prevent spreading the infection to others.
Symptoms of mumps include fever, headache, tiredness and swollen and tender salivary glands.
Public Health Registrar Dr Laura Heavey has this advice for students.