Community transmission of Covid-19 is the biggest concern facing the National Public Health Emergency Team, according to Professor Philip Nolan.
Speaking on RTÉ's This Week programme, the Chairman of NPHET's Epidemiological Modelling Advisory Group said he is "quite concerned" by the jump in Covid-19 cases in recent weeks.
Prof Nolan said the focus needs to be on the figure from the last 14 days. He said there has been a three-fold increase when you compare the last fortnight with the previous period.
He said there have been "explosive outbreaks" in certain counties, and said it is not uncommon to have 'superspreader' events.