The state of the coronavirus pandemic in the Republic of Ireland is "very urgent and high-risk", the director of the HSE has said.
Paul Reid said transmission levels of the virus were at a worrying level, adding that the worst fears from before Christmas had been realised.
The warning at an HSE briefing came ahead of a meeting of the Cabinet to discuss potential further restrictions.
The R value, the average number of people someone with coronavirus infects, has been estimated at 1.8.
"There is no doubt that most of our worst concerns that I outlined just before Christmas have been realised," Mr Reid said.
"There is an unprecedented and toxic combination of potential scenarios (which) have literally been realised and have emerged.
"That's a combination of a massively high level and rapidly growing daily cases, combined with (test) positivity levels that have not been seen in a long time, demonstrating a very dangerous level of transmission of the virus along with extreme levels of numbers of close contacts that people have had.
"Multiple factors have come together which we did fear would happen."
“Ireland is no longer in a containment phase and is once again in a mitigation phase. Given the current levels of transmission in the community, every individual should consider themselves potentially infectious."#COVID19 @CMOIreland
— Department of Health (@roinnslainte) December 30, 2020
Mr Reid made a "serious and urgent" call to the public to take immediate actions, withdraw from plans to meet with family and protect themselves by remaining at home.
Meanwhile, the HSE's lead for testing and tracing revealed a 41% rise in demand for Covid-19 testing, with 63,000 referrals in the past week.
Niamh O'Beirne said they expected to see that number double next week.
There have been 13 further deaths and 1,718 cases in the Republic, it was confirmed this afternoon.
As of 2pm, there were 455 Covid-19 positive patients in hospitals, of which 37 were in ICU. The death toll stands at 2,226.
Chief medical officer Dr Tony Holohan has urged the public to limit their contacts.
"Ireland is no longer in a containment phase and is once again in a mitigation phase," he said.
"Given the current levels of transmission in the community, every individual should consider themselves potentially infectious.
"It is essential that we all limit our contacts to our own household now, restrict our movements and do not give Covid-19 any further opportunities to spread.
"Everyone needs to stay at home other than for essential work or care.
"This is not the time to be visiting other houses."
Meanwhile, Northern Ireland has recorded the highest daily number of confirmed cases of coronavirus with 2,143 people testing positive.
Six more people have also died from coronavirus with five of those deaths occuring in the past 24 hours, according to the Department of Health.
The seven-day day infection rate per 100,000 of the population is 377.3 - up from 227 in the previous seven days.
