THE NUMBER of Scots pupils testing positive for coronavirus increased over ten-fold over just six weeks after they returned to school in August, the Herald can reveal.

New figures reveal that in the week in October before the half-term holiday, there were 409 school pupils testing positive for Covid-19 running at a rate of around 54 per 100,000 pupils. Nearly two in three were in secondary schools.

That has soared from at the start of the new term, when there were as few as 38 Covid-positive pupils - a rate of five per 100,000.

And the Herald can reveal that since then, Covid-related illness cases amongst pupils have since doubled again.

The figure come as unions have warned that teachers could refuse to attend schools if they feel that their environment is unsafe.

The rise in Covid cases amongst school pupils comes despite the fact the number of pupils actually tested for Covid slumped from 27,994 in the week starting on August 24, to just 4,449 before the October holiday.

The highest positive test rates are seen among S5-6 pupils in October where they reached 129 per 100,000.

Scotland's largest teachers union EIS has said teachers could carry out a "safety strike" if schools remain open full time. It has said school closures should be in the mix, and are surveying members on the effectiveness of Covid safety measures and on their willingness or otherwise to support ‘safety strikes’ should they be necessary.

Unions agree that blended or part-time learning - where education is a mix of being at home and in the classroom - should be on the table.

The Glasgow branch of the public service union UNISON called on the Scottish Government to "drop" it's attempt to keep schools and early years establishments fully open as more than two million people in 11 local authority areas - including Glasgow - are placed within Scotland's toughest Covid restrictions today (Friday).

READ MORE: Teachers 'being told to keep self-isolation numbers low'

The Level Four rules will see the closure of non-essential shops, pubs, restaurants and gyms.

HeraldScotland:

They will be imposed in East Dunbartonshire, East Renfrewshire, Glasgow, Renfrewshire and West Dunbartonshire.

North and South Lanarkshire, East and South Ayrshire, Stirling and West Lothian will also move to Level Four.

Brian Smith, Glasgow UNISON branch secretary said if workers believe that the current health and safety measures in their workplace are inadequate several courses of action are open, including in "extreme circumstances" refusing to attend schools under Section 44 of the Health and Safety Act. The union could also institute a collective grievance and report councils to the Health and Safety Executive.

He said: "The branch firmly believes that schools and early years establishments should not be fully operational during Level Four.

"We oppose the Scottish Government's position of attempting to maintain current service arrangements.

"There needs to be fewer staff and pupils attending schools and early years establishments."

EIS general secretary Larry Flanagan said: "The EIS is strongly of the view that at Level 4 both blended and remote learning have to be actively considered as part of the operational arrangements, both in terms of ensuring schools are Covid secure and also as a contribution to making Level 4 an effective intervention.

"Level 4 is an indication of high levels of community infection which clearly impacts on schools as much as anywhere. We already have schools suffering severe disruption because of infection levels and self-isolation requirements; blended or remote leaning could bring stronger coherence to the education offer to pupils, over the short period of time which Level 4 is due to apply for. "We will be calling on local authorities to engage in meaningful discussions around how Level 4 is managed within schools."

But an expert scientific report commissioned by the Scottish Government has backed the government’s decision to keep schools open through the Covid-19 crisis.

READ MORE: Teachers say Scots school closures should be on the cards as Level 4 lockdown is imposed in 11 council areas

The paper, from the Covid-19 Advisory Sub-Group on Education and Children’s Issues, which examined the risks posed by the virus to pupils and staff, and the benefits to children and young people of schools remaining open, states the rate of coronavirus-related sickness among pupils is low across the country.

It asserted there was no direct evidence that transmission of the virus within schools plays a significant role in driving rates of infection among children.

Separate Scottish Government data shows that the number of pupils not in school for Covid-related reasons has doubled since the before the half-term break, reaching 30,028 on 11 November - about 4% of the school population. The vast majority of those pupils are self-isolating rather than showing Covid symptoms.

It emerged that half of one Scots secondary school is off after a total of 16 tested positive for coronavirus.

More than 400 pupils are self-isolating following an outbreak of coronavirus at Auchmuty High School in Glenrothes, Fife.

Head teacher, Alan Pithie said in a message that ten pupils and six staff members had tested positive for the virus.

John Swinney on Wednesday defended the decision to keep schools open in areas which are being moved to the toughest levels of lockdown restrictions. The deputy first minister said keeping schools open was "absolutely central" to the well-being of children and young people.

According to the Scottish Government over 0.2% of pupils tested positive for coronavirus in the first nine weeks of the school term restarting in Scotland.

Nicola Sturgeon said their findings reinforced her view the benefits of reopening schools outweigh the risks of increasing transmission rates.

She said on Wednesday: "While we will continue to listen carefully to all concerns, these findings do reinforce our view that at this time, the benefits young people gain from being in school outweigh the overall impact of schools on transmission rates."

The advisory sub-group paper – published to provide the evidence base for keeping schools open – says that there continued to be “strong evidence that children and younger people are much less susceptible to severe clinical Covid-19 disease than older people” and that there is “no current direct evidence that transmission within schools plays a significant contributory role in driving increased rates of infection among children”.

And it said that the prevalence of infection only began to increase in school-aged children in Scotland in mid-September and that coincided with an increase in community prevalence across all ages.

It says it is difficult to separate the risk from infection as a result of behaviour outside school and from in-school contacts.

It said that “there is clear evidence that time out of school has a detrimental effect on children and young people’s wellbeing, including impacts on developmental and mental health harms”.

New data also shows that on November 10, there were 748 children off school due to Covid-19-related illness, which includes those with symptoms but had not yet tested positive. That's nearly double the numbers who were off before the schools' half-term break in early October.

A Scottish Government spokesman said: “Being in school is in the best interests of children and our priority remains to ensure schools are safe, open and welcoming. We have put in place robust measures developed with input from the Education Recovery Group, which includes local authority and union representatives, to help us to protect our school community.

“The Health and Safety Executive has provided very positive feedback on the way schools are implementing the guidance. We are keeping this, and scientific evidence under review, so where there is a need to take further action, we will work with teachers, parents, trades unions, local authorities and young people’s representatives to do so.

“There is no current direct evidence that transmission within schools plays a significant contributory role in driving increased rates of infection among children..."

Neither the Scottish Government or Public Health Scotland were able to show they were aware of the number of pupils who had tested postive for Covid in November.

The Scottish Government were first asked if they had the numbers a fortnight ago. They were only able to be detail how many had Covid-related illness - which includes many who have symptoms but not necessarily the virus.

A spokesman said "the separation" into the number of Covid positive pupils "is not available to us" and eventually referred us to Public Health Scotland.

Public Health Scotland were unable to update.