A school in Co Tipperary was closed earlier this week after the HSE flagged a possible "variant of concern" following a pupil's positive test for Covid-19.
While the HSE has said it is “not aware that this strain is more dangerous,” it still wished to take “extra measures to stop it spreading further in the community”.
In a letter sent to several parents at Presentation primary school in Carrick-on-Suir, the HSE wrote that the variant identified was a "different strain" of the virus than the main one currently circulating in Ireland.
The HSE letter said: "The laboratory has advised us that they may have a 'variant of concern' which is a different strain to the main strain in Ireland at the moment.
“We are not aware that this strain is more dangerous to anyone but we wish to take extra measures to stop it spreading further in the community.
“Because of this we are asking the whole household to restrict their movements for 14 days."
‘Precautionary move’
The school suspended classes for its 300 pupils on Monday morning, with a further positive test confirmed at the school, and reopened Wednesday after getting the all-clear from the HSE.
Second class pupils as well as household members of those pupils are remaining at home and must restrict their movements for the next week.
A spokesperson for the school said that Monday's closure had been a "precautionary move" after concerns were raised by the HSE.
"The closure was to give the HSE time to assess the situation and carry out contact tracing. Siblings and close contacts are still out but the school is back open," they added.
The Department of Education has said it does not comment on individual cases and said schools generally have been supported by "enhanced public health teams" since reopening. The Department of Health did not comment on the letter.
I think the HSE needs to come out and clarify the situation facing towns like ours in future
110 Covid-19 cases were detected following the mass testing of schools in the week to March 20th, a 150 per cent increase on the previous week when there were 44 cases reported. More than 4,000 tests were carried out at 183 primary, secondary and special education schools.
Local councillor David Dunne said there was "mass hysteria" in Carrick after the Presentation's sudden closure Monday morning, with "wild rumours" of widespread closures affecting several other premises in the town.
"I think the HSE needs to come out and clarify the situation facing towns like ours in future. Blame was being spread very quickly and it was really unfair on a lot of people here. People will jump on rumours and try to blame certain groups and that will happen to more towns again," he said.
Separately, an outbreak of Covid-19 was detected at a direct provision centre in the town, Bridgewater House, following mass testing last week.