A consultant in infectious diseases has said there are many more positive COVID-19 cases in the community than figures suggest.
Dr Eoghan De Barra was speaking after a record 16,428 new cases were confirmed here yesterday.
There has also been a rise in new admissions to hospital of COVID patients, at levels not seen since January.
Dr De Barra is a consultant in infectious diseases at Beaumont Hospital and a senior lecturer at the Royal College of Surgeons in Ireland.
He says the true scale of infections isn't known.
"The testing system is completely full at the moment, I think we all know many people who've been up till midnight trying to get PCR slots.
"The system can't cope, and we don't have an idea of demand - at least the HSE doesn't release [to] us how many clicks they're actually getting to try to get slots.
"The 50% positivity rate is a vast over-estimate probably because of the number of people who are doing a follow-up on a lateral flow - an antigen test that was positive.
"So there are probably many, many more infections out there that either can't get a test, are not going to bother getting a follow on test, or indeed have such minimal symptoms that they're not going to get [a test]."
Dr De Barra says it's likely people have the virus, but are unaware.
"We know on - I think - the 16th of December in London, one in 20 people in London was positive... so there are many more positive cases.
"So I think I'd echo Tony Holohan's comment that the likelihood is, if you're going to meet up with some people today some of them are positive - likely unbeknownst to themselves."