Backwards contact tracing of those who test positive for Covid-19 will be extended from two to seven days from next week.
The extension of contact tracing will only be offered to those who are infected through community transmission, where the source of transmission is unknown, which is about 20 per cent of all cases.
The Health Service Executive’s head of contact tracing Dr Greg Martin said moving from two days to seven will identify more cases.
As the vaccination rollout continues and numbers fall, he said “we will have a mechanism where we can chase down every case”.
He said seven days was the threshold that will give greatest “bang for the buck” in terms of the resources needed to track and trace.
Dr Martin said they currently have 850 contact tracers and this is sufficient for the number of cases that are around at present.
When asked why the HSE did not roll out a seven-day contact-tracing programme earlier, Dr Martin said they were working within the resources they had.
It was piloted in early December when numbers were at 200, but abandoned when numbers started to increase so much that it was impossible to track the virus.
HSE chief executive Paul Reid said the impact of Covid-19 on the health services in the first quarter of the year was “beyond any predictions”.
The surge in cases in January and February and the lingering impact on March came at the end of a year of Covid-19 that “nobody wants to remember”, he added.
At the weekly HSE briefing he said Covid-19 figures were rising in Ireland again as they were across Europe, with a 9 per cent increase in figures over the last seven days compared to the previous seven days.
However, the number of hospitalisations at 313 on Thursday morning is down 10 per cent in a week and the number in ICUs, 75, is down 9 per cent.
Since the decision was taken last Friday to recommence the AstraZeneca vaccine, there were 2,000 doses administered last weekend and 15,500 over the last three days.
Up to Monday, 690,449 vaccines were administered with 308,899 to frontline healthcare works, 195,856 to the over-70s and 176,676 to those in long-term residential care facilities, of whom 80,760 are fully vaccinated.
Mr Reid anticipated that between 75,000 and 100,000 vaccines will be administered next week with around 100,000 doses due from AstraZeneca.
He said the second quarter of the year will see a significant ramping up in vaccinations with a million doses due in the State during April.
The programme will be rolled out with the 65 to 69-year age group, of whom there are approximately 170,000. They will be vaccinated with AstraZeneca.
Mr Reid qualified that, while a million doses are scheduled to arrive in the State every month in the next quarter, “it is not fixed and confirmed” and the “vast majority” of AstraZeneca deliveries have been wrong.
The first Johnson & Johnson vaccines are due to arrive in the State in the second half of April.
This will be followed by a “huge scaling up” in May when the general population begins to be vaccinated, he stated.
“We hope in quarter two we can build the foundation for a society that we all want to go back to. We can look forward in a way that gives us much better hope. Everybody wants to see hope back in society,” he said.
HSE chief clinical officer Dr Colm Henry said the five-day average at present is 574 cases. He said it could be stated with “absolute predictability” that numbers in hospitals and ICUs will increase as a result of the increase in numbers.
He warned it was too soon for the vaccination programme to have an impact on hospital numbers.
Dr Henry said it was clear that schools are not having a significant impact on children.
Just 2.8 per cent of children have contracted Covid-19, but the disruption to their schooling has been almost universal, he said.
He stated that it was regrettable that schools had to close in January because Covid-19 numbers had got out of control.