The death toll from flu this winter has risen to six.
The flu is mainly affecting children and the over 65s, said HSE public health specialist Dr Kevin Kelleher.
He said the virus is now circulating more intensely but has not yet reached the point of widespread activity.
It has led to 29 patients being admitted to intensive care so far and has led to four outbreaks where it has spread from one person to another.
The swine flu is the main strain of virus circulating.
He said children were not among the flu fatalities so far and they also do not include any pregnant women.
Both these groups are susceptible to swine flu.
The flu is impacting on the trolley crisis which worsened this week.
It means patients who are infected have to be isolated, with less beds available to people on trolleys.