The Health Service Executive is facing an unprecedented surge in Covid-19 testing of children as more than 1,600 primary and secondary schools have reported positive cases since reopening.
Over the past week, some 32,000 tests were carried out on children aged up to 14 who walked in for tests or self-referred as schools deal with the fallout from further cases of the more contagious Delta variant in the wider community.
This figure does not include children who were referred for tests by GPs or as close contacts of confirmed cases.
“What we are seeing is a real surge in demand for testing for young children,” said Niamh O’Beirne, the HSE’s national lead for testing and tracing.
The proportion of those testing positive among walk-in and self-referred tests has dropped to 6 per cent from 13 per cent last week, reflecting the large numbers coming forward to be tested.
"It's not surprising for us to see a surge respiratory-like infection in the first few weeks after returning to school," said HSE chief clinical officer Colm Henry.
Pressure is growing for public health guidelines to be relaxed due to the thousands of schoolchildren who are home from school and restricting movements as close contacts.
More than 10,000 schoolchildren are estimated to be isolating at home with 632 secondary schools and 1,011 primary schools and preschool facilities contacting the HSE about cases.
Abigail Collins, HSE public health lead for schools, said Covid-19 transmission in schools was no different to what health officials saw before the summer holidays.
“It just that with very many more cases in this age group, there are very many more schools that are coming to us,” said Dr Collins.
It was “very, very early days” to identify any change in the virus in schools.
She also sought to reassure school principals encountering delays getting public health advice because the helpline closed at 4.30pm.
She said that the incubation period of the virus was four to seven days so that allows time for risk assessment to be carried out in a “slightly calmer and more orderly way”.
Sinn Féin and Labour called on the National Public Health Emergency Team (Nphet) to meet this week and consider the issue of children missing from school due to the self-isolation requirement.
Labour education spokesman Aodhán Ó Ríordáin said it was “just not sustainable” to have so many students out of school because they are close contacts of confirmed cases.
Dr Henry said health officials were “watching carefully” how the Delta variant was affecting transmission in schools and impact of the health guidance on school absences.
Nphet would meet next Thursday to consider whether to relax the 14-day isolation rule for schoolchildren deemed close contacts of cases now that more people are vaccinated, he said.
This comes as new figures reveal that about half of Covid-19 patients in hospital and intensive care are fully vaccinated against the disease.
One-sixth of deaths of people with the virus since April have been categorised as breakthrough infections of fully vaccinated individuals, according to HSE data.
More than one-quarter of intensive care admissions since July were also breakthrough infections of fully vaccinated people.
The proportion of vaccinated people requiring treatment in hospital has been increasing over recent months, as the number of vaccinated people in the wider population has risen.
Vaccination has drastically reduced infections and severe illness. However, the number of breakthrough infections has increased as the population of vaccinated people has grown.
“Vaccines were never going to be 100 per cent effective against infection; their big contribution is in preventing serious illness,” said Dr Henry.