Medical chiefs have urged businesses to allow to staff to work from home to help suppress Covid-19, warning "the window for this not to be a national issue is closing".
They refused to be drawn on speculation whether further restrictions will be imposed in Cork or other counties, noting that the National Public Health Emergency Team (NPHET) meets on Thursday and that the "next three or four days" will be critical in determining what, if any, restrictions would be imposed in other counties.
The message came as Acting Chief Medical Officer Dr Ronan Glynn confirmed one further death and 429 new cases of Covid-19, including 189 in Dublin and 60 in Cork.
Any announcement on further restrictions for Cork, which has seen more than 280 cases in the last seven days, is likely to come on Friday.
Professor Philip Nolan, chair of NPHET's modelling advisory committee, said what happens in the "next three or four days" will be critical.
Dr Glynn said the entire country needs to step up efforts and avoid a "blame culture" around the virus.
He asked people to "act like it is the end of February" and urged anyone who has symptoms to get tested and restrict their movements. He said guidance around workplaces is aimed at employers as much as staff.
"We can see from mobility data does traffic volumes in Dublin when we compare it to last January are down about 20%. But in the context of level three, and in the context of the numbers that we're seeing, that is simply not enough," he said.
"And, so, I suppose that reiterating again that it really is time for every employer, for every organisation, for every sports organisation, for anything that someone is involved in, if you can reduce contacts, if there are discretionary activities that do not need to happen at this moment, then please postpone them. This is going in the wrong direction and it is becoming a national issue.
"I would liken it to a forest fire where we're seeing lots of embers, lots of small issues arising in different places around the country.
Earlier, when appearing before the Oireachtas Covid Committee, Dr Glynn had said it was "too early" to say whether the restrictions in place in Dublin had a stabilising effect on the virus in the city and county, but he said he was "optimistic" about the situation there.
The NPHET briefing was given details of a number of clusters in the west of Ireland. Dr Breda Smyth, Director of Public Health, HSE, outlined three cases which led to a large number of cases.
In one such instance, a couple aged 25-35 travelled, attended a party and went to dinner over several days. In that time, they passed the virus on to friends and restaurant staff. In total, the couple were the origin of 30 cases over just two days.
In a second case, in a small rural geographical area, a group of middle-aged people who had socialised in a pub and workplace that gave rise to 24 cases, causing clusters in three schools. Of those, 14 were linked to socialising.
In the final case, two college house parties mixing led to 21 cases. One of those attending the party met with a friend for dinner. That college student who then had the virus transmitted it to 15 of their 26 classmates. Dr Smyth said that investigations indicated that the spread had likely occurred at break times.