More than 40,000 people are waiting to be tested for coronavirus.
The HSE says they're beginning to work through the backlog.
50 test centres across the country open in the next couple of days.
785 people have tested positive for Covid-19 in the country - including 147 healthcare workers.
The operations officer with the HSE Anne O'Connor says they are working to get through the backlog.
She said "...from last weekend, was the build-up of people who had contacted GPs in advance of having the health systems secured.
"That coupled with the establishment of the testing sites meant that we do have a demand."
Ms O'Connor said that the Department hopes the new testing sites will help reduce the waiting list.
She said: "We now will have a higher number of testing sites this week than we had planned at all, so that will help in terms of reducing that backlog.
