Nine residents of a Co Laois elder-care centre died over the bank holiday weekend, eight of whom had tested positive for the coronavirus.
They were aged between 66 and 84 years old.
The 17 remaining residents at the Maryborough Centre for Psychiatry of Old Age (which is not a nursing home), are being treated as if they are COVID-19 positive, regardless of test results or presence of symptoms.
While a number of staff are currently on sick leave, the HSE says the current staffing level is sufficient to manage the centre.
A number of elder-care settings, including nursing homes, have seen clusters of COVID-19 in recent weeks.
Amanda Phelan, Professor of Ageing and Community Nursing, at Trinity College Dublin, says the situation in nursing homes has been chaotic:
"It's been more organised in recent days, but certainly it has been chaotic and we've seen the clusters rising," she said.
"Nursing homes are a huge challenge in terms of infection control and delivering good care."
The HSE’s National Lead for Integrated Care, Dr Siobhán Ní Bhriain said that the patients at the Maryborough centre, located in St Fintan's Campus, Portlaoise, were cared for by two consultants and a palliative care support team.
Efforts were made to identify which patients had the virus and those who did not so they could be separated, she explained to RTÉ radio’s Morning Ireland.
The type of care at the centre was called "cohorting" she said, which meant there were a number of beds in one room.
If a patient was suspected of having COVID-19 they would be isolated and nursed separately, she said. This could be “very difficult” in some situations.
The Maryborough centre in Portlaoise was not a nursing home, she pointed out.