Current testing and contact tracing is insufficient to prevent a second wave of coronavirus after schools in the UK reopen, scientists have warned.
Increased transmission would also result from the fact that parents would not have to stay at home with their children, they say.
Researchers said getting students back to school was important – but more work was needed to control the virus.
The government said plans were in place to ensure the full reopening of schools at the start of the new school year.
“Local health officials, using the latest data, will be able to determine the best action to take to help curb the spread of the virus if cases increase,” a statement said.
Schools have been closed around the world as countries used lockdowns to control the spread of Covid-19. An estimated 1.6 billion children have not been to school.
Schools in the UK closed on March 20, except for children of key workers or vulnerable children. On June 1, they began a limited reopening for early childhood, reception, year 1 and year 6 students.
Schools are due to restart for all children in Scotland on August 11 and across the UK in early September.
But every step taken to open up society makes the spread of the coronavirus easier.
Researchers at UCL and the London School of Hygiene and Tropical Medicine used computer models to see how the virus could spread in the UK when students returned to class and their parents were no longer able to return to the UK. work or resume other activities.
The study assumes that children are less likely to catch – and therefore spread – the coronavirus and that some parents would continue to work from home.
As first reported in June, the combined effect on students and parents would be enough to trigger a second wave if there was no effective testing and traceability program.
This would occur around December 2020 and would be twice as large as the first peak, unless the government takes other action such as reimposing the lockdown.
How the test and trace works:
- People with symptoms of cough, fever, or loss of smell or taste are tested
- If they test positive for coronavirus, they self-isolate for 10 days and their household does so for 14 days
- They must inform the NHS of all people with whom they have been in close contact
- These contacts must also spend 14 days in quarantine
The success of the program depends on the quality of testing and contact tracing.
The study, now officially published in the Lancet Child and Adolescent Health, shows that a second wave could be avoided if:
- 75% of people with symptoms of Covid were found and 68% of their contacts
- 87% of people with symptoms were traced and 40% of their contacts traced
However, researchers said NHS Test and Trace in England was currently falling short.
They estimate that only 50% of contacts are traced and while it is more difficult to know the percentage of people tested, they say that also seems too low.
“It doesn’t reach the levels that we modeled. It doesn’t sound good enough to me, ”said Professor Chris Bonell of the London School of Hygiene and Tropical Medicine.
Dr Jasmina Panovska-Griffiths, UCL, added: ‘With British schools fully reopening in September, preventing a second wave will require a major ramp up of testing to test 75% of symptomatic infections – combined with the tracing 68% of their contacts and isolating symptomatic and diagnosed cases. ”
However, cases are already starting to increase and the idea of closing pubs to open schools has already been launched.
UK Government Chief Medical Adviser Professor Chris Whitty said “we are near the limit” of what we can do without causing a resurgence.
Different countries in the UK have their own contact tracing systems.
The Welsh government said its advisory group had recommended that schools open in September with 100% of pupils present, and “we should aim to trace around 80% of contacts, of which at least 35% should be traced in schools. 24 hours. “.
As of June 21, 90% of close contacts have been reached by the service, according to figures from the Welsh government.
A Scottish government said ensuring a ‘safe environment’ for education was its ‘top priority’ and the guidance set out ‘a number of specific risk mitigation measures that will need to be introduced’, including a “Enhanced surveillance program”.
In Northern Ireland, the latest figures for the week to July 29 show that 98% of contacts were successfully reached by the country’s contact tracing service.
To follow James on Twitter
- ASK MARTIN LEWIS: Answering Your Spain Travel Questions
- HOOKED: How has the lockdown affected spending habits?