It says outbreaks in households are the main factor - there have been almost a thousand in the last week alone.
The reproduction rate of the virus has risen slightly and is now estimated at between 0.7 and 0.9.
HSE chief executive Paul Reid says they're monitoring some areas of particular concern:
"The trend we are seeing has stalled. And that's been the biggest factor, but a similar trend what we see in all year - high transmission levels in private households with some community transmissions," he said.
"We are saying marginal increases in our serial testing and nursing homes, schools not particularly, meat plants again a marginal increase, but they are early warning indicators for us".
