The reproduction number of the COVID-19 virus is now between 1.3 and 1.7 in Ireland and case numbers are "growing exponentially", NPHET has warned.

According to Prof Philip Nolan, chair of NPHET's Irish Epidemiological Modelling Advisory Group, case numbers are likely to double every 10 to 14 days "if everyone of us does not immediately act to break chains of transmission of the virus".

"I am more concerned than I have been at any point since late April. If we do not interrupt transmission now and bring the R-number back to below one, modelling shows that we could have 500-1,000 cases per day by October 16, 50-60% of which would be in Dublin," Prof Nolan explained.

While major concern has been expressed about the number of cases in Dublin in recent weeks, the acting chief medical officer, Dr Ronan Glynn, emphasised that the current situation "has deteriorated both in Dublin and nationally over the past week".

"Along with Dublin, we have seen particularly concerning trends in Louth, Waterford and Donegal. It is now absolutely essential that people action public health advice and act as if they, or those close to them, are potentially infectious," he commented.

As of Wednesday, there were 73 patients in hospital with COVID-19, with nine of these admitted in the previous 24 hours. Fourteen patients with the virus are in ICU.

"We are seeing a sharp increase in the rate of admissions of COVID-19 patients into our acute hospitals. We know that without a reversal of these trends, admissions can escalate rapidly to the point where our healthcare facilities will be under unsustainable pressure," warned Dr Colm Henry, chief clinical officer of the HSE.

On a more positive note, this exponential growth of cases has not been found in children, despite the reopening of schools in recent weeks.

"While we have been conducting a large number of tests on children thanks to the vigilance of parents around symptoms and contacting GPs with concerns, we have not witnessed a disproportionate rise in the number of confirmed cases in children," noted Dr Mary Favier, COVID-19 advisor to the Irish College of General Practitioners.

A further 254 cases of the virus were confirmed on Wednesday, bringing the total number of cases to 31,799. Three more deaths were also confirmed, brining the total number of deaths to 1,788.

The country's five-level plan to deal with the virus, which was published this week, can be viewed here.