Basic pandemic safety limits are spreading in schools

Can schools safely remain open even though the COVID-19 pandemic continues largely unchecked? So far, the data has been mixed. Studies of the spread in schools seem to suggest that they are not a major source of infections. But when countries that closed their schools as part of a pandemic set of restrictions were compared to those that did not, those that closed their schools had a lower overall infection rate. Thus, the results of the opening of schools seem a little mixed.

Yesterday, the CDC released a detailed examination of the spread of SARS-CoV-2 within a single school system in rural Wisconsin. Although the findings are from a time before new strains were more easily spread, they do show that some of the measures set out in the guidelines on how to safely reopen schools are working. As a result of these precautions, infections at school have decreased by 37 percent compared to infections in the community as a whole, and very few infections have occurred at school. But it also raises an obvious question: if these metrics work, why aren’t we all using them?

Appropriate warnings

The study began at the end of August 2020 and continued until the end of November. He focused on schools in Wood County, Wisconsin, and tracked the infections that have taken place among his teachers and staff, as well as comparing these with the spread of the pandemic in the county as a whole. Overall, 4,876 students and 654 staff were included in the data.

Schools have taken many of the steps experts advised before the start of the school year. Each student was given multiple face masks when they started, and the use of the mask was mandatory throughout the period. Compliance with this rule, based on surveys of teachers, was consistently above 90%. (The report notes, however, that not all teachers returned these reports, so data may be missing in classrooms with lower compliance.)

Aside from the masks, schools have reduced class sizes, to 20 students or less. And these groups of students were kept together throughout the day, rather than mingling throughout the day. All students who showed symptoms of COVID-19 were sent home for self-isolation, and all their siblings were similarly barred from attending school. The report does not contain any information on whether changes to the classrooms – increased separation of students or improved ventilation – were also included in the package of precautions taken. But overall, these policies are in line with the recommendations of health authorities for safe schooling.

Out of control

And the schools have been put to the test. As in most of the rest of the United States, COVID-19 cases in the county exploded in the fall. At times, Wood County had a 40% positivity rate, meaning that four out of 10 tests for SARS-CoV-2 produced a positive result. This is taken as an indication that there are many more positive cases at the same time that have not been detected.

Overall, the number of cases among students and staff was significantly lower than in the surrounding community. The rate in surrounding towns during the period was nearly 5,500 cases per 100,000 population. In contrast, students and staff had a rate of 3,450 cases per 100,000 people. This translates to 191 cases in total: 133 among students and 58 among staff.

Contact tracing indicates that only seven of those cases were detected by transmission at school, all of which involved student-to-student spread. These seven cases involved dissemination among students in the same class group. In fact, three of them occurred within the same class group. The lack of distribution between class groups is a reassuring validation of this strategy.

The biggest limitation of the analysis is that the testing capacity was clearly not sufficient to track the spread of infections during this study period. There is a very good chance that some asymptomatic cases were missed from school during this time, which could influence the conclusions of the contact tracing portion of the experiment. As such, the seven cases attributed to school spread should be considered a lower bound.

There are several ways to look at this data. The first are the most obvious: it is not impossible to eliminate the risks during an uncontrollable pandemic. But, with proper precautions, it is possible to limit the risk to students and severely limit the chances of getting new infections at school.

But the key message is that it is impossible to separate students from the community as a whole. While infections among students were on the decline compared to the population as a whole, a significant number of students ended up with SARS-CoV-2, and most of these infections occurred through interactions that took place. took place outside the school system. This raises the obvious question of whether the population as a whole would have benefited from adopting more of the practices used by schools.

As more infectious strains become more widespread and vaccine distribution struggles to progress, it is critical that we take all that can be done to limit the spread in the meantime.