The Department of Health has recorded an additional 253 confirmed cases of Covid-19, while three further people who were diagnosed with the virus have died.
The death toll here now stands at 1,792, while the overall number of cases now stands at 32,271.
Of the cases notified today 143 are men and 108 are women, 71% are under 45 years of age.
The breakdown of today's cases is: 116 in Dublin, 22 in Kildare, 14 in Cork, 14 in Galway, 13 in Donegal, 10 in Limerick, 10 in Louth, nine in Mayo, eight in Waterford, seven in Wicklow.
The remaining 30 cases are located in Carlow, Cavan, Clare, Kilkenny, Laois, Longford, Meath, Monaghan, Offaly, Tipperary, Westmeath.
In Northern Ireland, two further coronavirus deaths have been recorded, taking the official Department of Health toll there to 575.
There are 163 new cases, from tests on 3,872 individuals, taking the cumulative total to 8,943.
There are 21 Covid-19 patients in hospital in the region, with four in ICU.
Concern over Covid-19 cases due to community transmission
Meanwhile, public health authorities are concerned about the number of Covid-19 cases detected in the last week which were as a result of community transmission, along with increased numbers of hospitalisations, the chief executive of the HSE has said.
Speaking on RTÉ's Morning Ireland programme, Paul Reid said the average number of cases per day for the last week is 246, up 39% over seven days.
He said 39% of cases emerging are from the community, not as a result of outbreaks or from close contacts.
Mr Reid also said there are now 77 people with Covid-19 in hospital, up from 23 last week.
He said ICU admissions have increased from six to 14 in the last week.
On expected #Covid19 restrictions for Dublin, HSE CEO @paulreiddublin urges people to follow public health advice. "If we keep going on the road we're going ... we're heading into a road that could get us back to the point where we have to take more restrictive actions." pic.twitter.com/FdaZ9Ss4kz— RTÉ News (@rtenews) September 18, 2020
Mr Reid said that a suite of very basic measures can make a real difference, as he called for people to reduce contacts at home and in public settings to prevent spread of the virus.
He said that we are at an important crossroads and no one wants to go backwards as he appealed to everyone to take the public health messages seriously.
Mr Reid said that the public experts have identified that spread occurs where people meet, including in pubs and restaurants.
He said that the growing number of cases of the virus are brought from the community back into the home and are highly transmissible, so places where people congregate at home and in public settings are a risk.
The HSE's chief said if six people meet, five people can get infected very quickly.
Asked how the HSE can be sure schools are not a major source of #Covid19 transmission, HSE CEO @paulreiddublin tells @MorningIreland positivity rates in tests on school children have fallen and "we're not seeing a high transmission level between children". https://t.co/kf9YPaIaqb pic.twitter.com/7j83HpazGd— RTÉ News (@rtenews) September 18, 2020
Case numbers in schools are low and testing shows that transmission rates between children and adults in schools is not a concern, Mr Reid said.
He said there has been more school children and adults coming forward with symptoms, but not testing positive.
The impact has been limited to closing a pod or a classroom if a case emerges, never a school, he said.
Mr Reid said that the first few weeks of schools reopening are challenging, but overall it has been managed really well, with the vast majority of tests returned in 24 hours.
Consultant calls on Govt to address ICU capacity
A consultant in emergency medicine at Sligo Hospital has said it is time to address the lack of critical care bed capacity in hospitals rather than seek to reassure people that there is not a problem.
Speaking on the same programme, Dr Fergal Hickey said that at the start of the pandemic every bit of capacity was used for Covid-19, along with a drop in attendances at hospital emergency departments.
This has now ended as the system returned to pre-Covid operations.
He expressed concern about the lack of critical care beds available if there is a surge in hospitalisations as a result of the Covid-19 virus.
Dr Hickey said that the 2009 Prospectus Report on Excellence in Critical Care stated there was then 289 beds in critical care.
It recommended that by 2010 that 418 beds would be required and by 2020 to have 579.
Dr Hickey said this shows that long before the pandemic the country had insufficient capacity in ICU.
There are now 281 ICU beds in the system.
Dr Hickey said that recovery areas in hospital theatres and private capacity can be used for ICU, but the reality is we are short of critical care capacity.
"We need to do something more dramatic than making small incremental improvements from time to time," said Dr Hickey.