Science Mag: School Openings can work

quote:

---

t was time, a growing chorus said, to bring children back to school.

By early June, more than 20 countries had done just that. (Some others, including Taiwan, Nicaragua, and Sweden, never closed their schools.) It was a vast, uncontrolled experiment.

Some schools imposed strict limits on contact between children, while others let them play freely. Some required masks, while others made them optional. Some closed temporarily if just one student was diagnosed with COVID-19; others stayed open even when multiple children or staff were affected, sending only ill people and direct contacts into quarantine....

When Science looked at reopening strategies from South Africa to Finland to Israel, some encouraging patterns emerged. Together, they suggest a combination of keeping student groups small and requiring masks and some social distancing helps keep schools and communities safe, and that younger children rarely spread the virus to one another or bring it home. But opening safely, experts agree, isn’t just about the adjustments a school makes. It’s also about how much virus is circulating in the community, which affects the likelihood that students and staff will bring COVID-19 into their classrooms.

“Outbreaks in schools are inevitable,” says Otto Helve, a pediatric infectious disease specialist at the Finnish Institute for Health and Welfare. “But there is good news.” So far, with some changes to schools’ daily routines, he says, the benefits of attending school seem to outweigh the risks—at least where community infection rates are low and officials are standing by to identify and isolate cases and close contacts....

Several studies have found that overall, people under age 18 are between one-third and one-half as likely as adults to contract the virus, and the risk appears lowest for the youngest children. The reason remains the subject of intense study. But the town of Crépy-en-Valois, home to 15,000 people on the northern outskirts of Paris, provides some confirmation that younger age reduces risk of infection—and transmission.

When two high school teachers developed minor respiratory symptoms in early February, no one suspected COVID-19. It was cold and flu season, and health officials still assumed the novel coronavirus was mostly confined to China. It wasn’t until 25 February, after one of their contacts was hospitalized in Paris, that the teachers realized they had been infected with SARS-CoV-2. For at least 12 days before the start of winter break on 14 February, and before France instituted precautionary measures, the virus had been spreading freely at the school.

Arnaud Fontanet, an epidemiologist at the Pasteur Institute, and his colleagues started an investigation in Crépy-en-Valois in late March to see whether they could piece together the virus’ reach in the town and its schools. In the high school, antibody testing showed that 38% of pupils, 43% of teachers, and 59% of nonteaching staff had been infected. (By then, several people associated with the school had been hospitalized with COVID-19 complications.) In six elementary schools, they found a total of three children who had caught the virus, likely from family members, and then attended school while infected. But, as far as the researchers could tell, those younger children didn’t pass the virus on to any close contacts....

“It’s still a bit speculative,” says Fontanet, who shared results from the high school on 23 April and from the elementary schools on 29 June, both on the preprint server medRxiv. But high school students “have to be very careful. They have mild disease, but they are contagious.” Children younger than 11 or 12, on the other hand, “probably don’t transmit very well. They are close to each other in schools, but that is not enough” to fuel spread. At the same time, scientists note that children have more contacts than adults, especially at school, which could offset the lower odds they will spread the pathogen.

Other outbreaks also suggest that elementary school pupils pose a smaller threat than older students. Among the worst schoolwide outbreaks was at Gymnasium Rehavia, a middle and high school in Jerusalem, where 153 students and 25 staff were infected in late May and early June. An outbreak at a New Zealand high school before that country’s shutdown infected 96 people, including students, teachers, staff, and parents. In contrast, a neighboring elementary school saw few cases.

But the picture is still blurry. Another Israeli outbreak was in an elementary school in Jaffa, with 33 students and five staff members affected. Across the globe, an elementary school classroom in Trois-Rivières, Canada, had nine of 11 students infected after one contracted the virus in the community.

Other data come from day care centers: In many countries, they stayed open for children of essential workers, and outbreaks appeared rare. Two flares in Canadian day cares—one in Toronto, and one outside of Montreal—led to temporary closures. In Texas, where overall cases have skyrocketed, at least 894 preschool staff and 441 children across 883 facilities have tested positive, according to news reports. That’s up from 210 total cases just a few weeks ago.....

---