Many schools worldwide have introduced measures to keep students separate in school.Credit: Lauren DeCicca / Getty
At schools in South Korea, children eat their lunch in silence, in front of plastic screens that separate them from their friends1. They wear masks unless they practice social distance in the playground. And their temperatures are checked twice every morning – first at home and again at the school gates.
This could be the new reality for the millions of children all over the world. Summer holidays are drawing to a close in the northern hemisphere, and in places such as the United States, the United Kingdom and some European countries that closed schools during the coronavirus pandemic, governments are discussing when and how to open schools. A growing number of studies show that there are ways to do this safely. The key is vigilance over hygiene and physical distance, a rapid response to public health to stop the spread of any infections and, most importantly, low levels of viral spread in the community.
“Some countries in Asia, especially South Korea, provide a good model for how schools can deliver face-to-face lessons during the pandemic,” said Zoë Hyde, an epidemiologist at the University of the West. Australia in Perth.
But researchers say that if schools are opened before the community’s transmission reaches low levels, cases will increase.
High risk environment
Schools can be high-risk places, says Young June Choe, a pediatrician and epidemiologist at Hallym University in Chuncheon, South Korea. Children are often put in poorly ventilated rooms for eight hours or longer, he says. And there is a lot of mixing, because children come from all over the area, some on public transport, and often with their parents in tow.
Earlier in the pandemic it was revealed that children may interact with the virus differently than adults. Because children had milder symptoms, it was assumed that they could be less infected. But now there is evidence that children can spread the virus to other people, especially those living in the same household2,3. Several studies show that once children are infected, they are no less infected4.
“When schools are reopened in areas with high levels of community transmission, major outbreaks are immutable and community deaths will occur as a result,” says Hyde. Evidence of this can be seen in the sporadic outbreaks and spill-overs that have already occurred, including those at a high school in Israel and a camp in the United States.
Empty community scattered
Studies in South Korea1, Europe and Australia5 show that schools can open safely when community transmission is low. Children in South Korea returned to their classrooms in mid-May when daily confirmed cases dropped to below 50 – equivalent to about one case per million people. Even with such low transmission rates, the government introduced measures to control viral spread, such as introducing opening schools, starting with secondary schools and then junior schools. At larger schools, such as those in areas where cases grew, only a fraction of students accepted. If someone tested positive, lesson went back online.
An analysis by researchers in Seoul that has not yet been peer reviewed found no sudden increase in COVID-19 cases among children aged 19 and under in the 2 months after schools reopened1. And government data reports that only 1 in 111 school-age children who tested positive got the infection at school between May and July. Most were infected by family members, as at other locations. “The takeaway message is that with the right policies, we can control the transfer to schools in a setting of low communication transmission,” says Choe. “There is no special recipe that makes Korea unique.”
A survey by the European Center for Disease Prevention and Control also found that schools that reopened in several European countries in early May have so far not been associated with a significant increase in community transmission.
The state of New South Wales (NSW) in Australia partially closed schools at the height of the state’s epidemic in March, but kept day care centers open. Kristine Macartney, director of the Australian National Center for Immunization Research and Surveillance in Sydney, and her colleagues analyzed data from schools and day care centers from January to early April. Schools remained open to the children of health care workers rather than those without alternatives.
During the study period, the state averaged 193 cases per day – 24 per million people – but 58% of the cases were in travelers returning from abroad. Macartney and colleagues found that only 25 of the 7,700 schools as day care centers reported a primary infection during their studies.5. Of those cases, only four facilities were forwarded.
Macartney points out that the results should be viewed in the context of the strong public health response. NSW maintained high levels of testing in the population, identified rapid cases and implemented contact detection, and its borders were closed, with strict enforcement of quarantines. “If the transmission in the community were to go unchecked, we are sure it would flood schools,” Macartney said, noting that in a recent case in neighboring Victoria, there were hotspots in schools. identified. “This virus will benefit from every chink in the weapons,” she says.
Renovated classrooms
In places where there is continued spread of the community, schools and camps have become sites of major outbreaks. The virus spread through mid-June through an overnight camp in the US state of Georgia. On the first day of camp, Georgia reported 993 new cases of COVID-19. Campers slept in huts in groups up to 26, did not have to wear masks, and sang and cheered every day. A full three-quarters of the 344 participants tested positive for SARS-CoV-26.
Another major outbreak was discovered in a high school in Jerusalem, Israel, 10 days after all schools reopened in mid-May. There were around 127 reported cases in the country at the beginning of May when some children started going back to school – equivalent to 15 cases per million people.
When temperatures were above 40 ° C, teens sat in air-conditioned rooms with more than 30 other classmates without masks. The outbreak affected 153 students and 25 staff members, as well as 87 siblings, parents and friends of those affected.7.
The school environment can also increase the risk of further spread of the community. In mid-March, a major school in Santiago, Chile, had a major outbreak just nine days after the country discovered its first case of COVID-19. The school had more than 30 children in a class, and had been busy holding parent-teacher meetings. Researchers detected SARS-CoV-2 antibodies in 10% of students and 17% of staff when tested about two months later8.
The outbreaks of schools in Israel and Chile suggest that large class sizes may play a part in school transmission, says Edward Goldstein, an epidemiologist infectious disease at the Harvard TH Chan School of Public Health in Boston, Massachusetts.
Schools should implement reasonable distance measures, by dividing the day into morning and afternoon breaks, for example, to reduce the number of children in a classroom, and by preventing parents and teachers from gathering at school entrances and exits, says Miguel O ‘Ryan, a researcher on infectious disease in children at the University of Chile in Santiago who is leading the study of Santiago school.
If schools reopen in areas with a high rate of community transfer, then being vigorous about masking, class size, hand washing, and testing and tracing will be important, says Katherine Auger, a pediatric researcher at Cincinnati Children’s Hospital Medical Center in Ohio.
“If we go back to schools like they used to be, then we’ll be in trouble,” she says.
