Covid-19 infections and outbreaks were “uncommon” in English schools after they reopened in June, according to a Public Health England report.
A study released by the health agency on Sunday found there were 67 individual cases, four “co-primary” cases and 30 outbreaks of Covid-19 in schools during June.
Co-primary cases were defined as two or more confirmed cases with a common epidemiological link diagnosed at the same time, while outbreaks were defined as two or more epidemiologically linked cases where subsequent cases were diagnosed within 14 days.
The 67 single cases were made up of 30 students and 37 staff. A total of 121 cases were linked to the outbreaks – 30 in children and 91 in staff. More than a million children attended school in the month.
No children were admitted to hospital. One teacher was admitted to intensive care for respiratory support.
Over the same period, 25,470 cases were recorded in England overall, PHE said.
Its report said: “Staff members need to be more vigilant for exposure outside the school setting to protect themselves, their families and the educational settings.”
It said there was a strong correlation between the regional incidence of Covid-19 and the number of outbreaks in educational settings, which “emphasises the importance of controlling community transmission”.
The potential for spread means school closures may be necessary as part of lockdown in regions with increasing community transmission, but these “should probably be considered only in extremis”, it added.
The analysis, conducted by researchers from St George’s University and the London School of Hygiene and Tropical Medicine, found children were more likely to acquire the virus at home rather than at school.
“What we found essentially was that there was a very low risk [of transmission] among children and staff at the time,” Dr Shamez Ladhani, one of the report’s authors, told Sky News.
“But you have to understand that these were circumstances where we had just come out of the lockdown and there were very small school numbers that were open at the time with very small classes.”
He said most children who got Covid got it at home, often from parents who were key workers, and “most of the infection and transmission in schools is driven by staff”.
The UK’s chief medical officers have said children are more at risk of long-term harm if they do not attend school than if they return to the classroom despite coronavirus.
In a joint statement, the advisers said children had an “exceptionally low risk of dying” from Covid-19.