More than 5,000 coronavirus tests were carried out on children here in one weekend - as it emerged positive cases have been reported in more than 60 schools across Northern Ireland.
he Stormont Education Committee heard yesterday that up until Tuesday, 88 positive cases have occurred in 64 schools among pupils or staff in the first two weeks of term.
Stark warnings have been issued of the inevitability that the number of cases will keep rising.
Chief Medical Officer Michael McBride said he will be issuing a letter to parents along with further guidance soon in a bid to alleviate their fears and concerns.
He said that during the weekend of August 30 there were more than 5,000 tests carried out on children in Northern Ireland - the overwhelming majority negative.
Dr McBride said it was inevitable that with the return of schools we will see colds and other viruses starting to re-emerge and "not every child needs tested" for coronavirus.
"They only need tested if they have one or more of the recognised symptoms of Covid; a new continuous cough, a fever, a loss of taste or smell. As a parent myself I do understand the concerns of parents. Do not take an appointment to be tested that might be genuinely needed by someone with symptoms."
Yesterday the Department of Education stressed that it was important to remember that only 64 out of our 1,300 schools, which teach more than 300,000 pupils, were affected.
Among those raising serious concerns was Justin McCamphill from teaching union NASUWT who said cases were only going to grow in schools.
He said: "We had warned about this and we said in August the department should have stuck to its original guidance which would have kept social distancing in schools and we are now seeing the out-workings of the abandonment of the social distancing policy."
Mr McCamphill said the situation was having a "major impact" on the mental health and wellbeing of staff.
"We also have staff themselves who have been asked to isolate who are finding it extremely difficult to get tests," he continued.
"Staff have told us when they go online there are no tests available in Northern Ireland and that is causing issues for schools as staff are out while waiting on tests to take place."
In addition he said one area that needs attention is that of substitute teachers brought in to cover sickness. He said: "One of the big unanswered questions is what happens when substitute teachers go from school to school - are they going to be a vector of transmission?
"We think there needs to be a scheme in place that can provide extra substitute teachers on a permanent basis to all schools for the duration of this pandemic so they have flexibility and they are not putting health and wellbeing at risk by having substitute teachers moving from one school to another."
Mr Camphill said it's important that official guidance is followed in all schools.
"We do hear reports that in some schools recommendations around, say, wearing facemasks in corridors aren't being followed," he said. "In many schools they are taking the term 'strongly recommended' to mean you can do it if you want."
In response, a Department of Education spokesperson said: "Substitute teachers should follow the New School Day advice and guidance as well as any other protocols put in place at the school they are working in to safeguard their own safety and that of the pupils and other teaching and support staff."
On the issue of school closures, the Education Authority said it was working with the Department of Education "to identify how we effectively collate, record and publish data centrally moving forward".