394 cases have been recorded in the first ten weeks of this year.
The HSE has asked people to be aware of symptoms of norovirus, as cases of the infection have reached almost four times the level they were at this time last year.
Norovirus, also known as the winter vomiting bug, is an "easily spread" virus that causes sudden onset of vomiting and diarrhoea.
The Health Protection Surveillance Centre said a total of 394 cases have been recorded in the first ten weeks of this year.
This is nearly four times the number recorded at the same stage last year, when 109 were confirmed.
The HSE has said that young children and elderly people have been the most affected, with 50% of cases seen in those over the age of 65, and 28% of cases seen in children under five.
In addition to major symptoms such as vomiting and diarrhoea, the Executive has said people are also likely to have norovirus if they have a slight fever, headaches, painful stomach cramps and aching limbs.
It is urging people to learn how to stop the spread amid the rise in cases.
Tips to prevent the spread of the bug include frequent handwashing and thoroughly cleaning contaminated surfaces.

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