The chief medical officer says too many people are testing positive for Covid-19, and then failing to isolate themselves.
Dr Tony Holohan's comments followed the confirmation of 939 more cases of the virus in the Republic yesterday, and three more deaths.
There were 262 cases in Dublin, 96 in Cork and 61 in Meath -- which is now second only to Co Cavan for its ratio of cases to population in the last fortnight.
There were 51 new confirmed cases in Donegal.
Professor Anthony Staines of DCU outlines where these outbreaks are coming from: