The Health Protection Surveillance Centre says around 1,500 people visited their GP last week with suspected swine flu.
As of yesterday, 278 cases of the virus had been confirmed in Ireland after laboratory tests.
However, such tests are no longer being carried out following every suspected case of the illness.
Two people are in intensive care after suffering serious symptoms as a result of swine flu.
Experts say they expected an increasing number of cases to be reported in the coming weeks.