Effective Testing, Contact Tracing Are Essential for Schools to Open Safely During the COVID-19 Pandemic

Uncertainties persist regarding the transmission of COVID-19 among students in educational settings as schools prepare to reopen in some form.

The implementation of effective testing and contact tracing are critical when reopening schools safely during the coronavirus disease 2019 (COVID-19) pandemic, according to a study published in The Lancet Child & Adolescent Health.

With schools currently set to reopen in September in the UK and in some US school districts, the results of the study suggest that it is possible to avoid a second wave affecting schools if the reopening is supported by a broad test-trace-isolate program.

School closures have had detrimental effects on children’s mental health and wellbeing, with the potential for increasing inequality due to difficulties in access to internet or computers in lower income neighborhoods, according to the study.

Additionally, the researchers noted a lack of evidence showing that schools have a role in the transmission of COVID-19, as a majority of the data available have used modeling to predict estimates rather than real-world data from schools.

Although there remains much unknown regarding the transmission of COVID-19 in educational settings, the study points to the importance of the broader context of the potential for transmission in a school environment and the need for further research into transmission among children and teenagers.

The recent modeling study provides the first estimates on the levels of test-trace-isolate that would be needed for both schools and communities to reopen while avoiding a second wave of the pandemic.

Using workplace, community, demographic, and epidemiological data, the researchers assessed 6 different potential scenarios for schools reopening. The results of the data showed that a second wave in the UK could be avoided with testing increased to between 59% and 87% of symptomatic people, with the addition of effective contact tracing and isolation being in place.

The researchers assumed 68% of contacts could be traced and found in order for the contact tracing and isolation to be effective, 75% of individuals with symptomatic infection would have to be diagnosed and isolated if schools return full-time in September. Using a part-time rota system with half of students attending school on alternate weeks, the study authors found the number decreases to 65% of individuals with symptomatic infection.

However, the researchers found that if the levels of diagnoses and contact tracing fall below 75%, the full-time reopening of schools, combined with the gradual relaxing of the lockdown measures in the country, could result in a second wave that would peak in December 2020.

Additionally, if schools opened in a part-time rota system but the numbers of diagnoses and contact tracing dropped below 65%, the second wave would likely peak in February 2021.

In either of these scenarios, the researchers said that the second wave has the potential to result in the reproduction number rising above 1, with the resulting secondary wave of infections increasing up to 2.3 times the size of the first COVID-19 wave earlier this year.

In order to conduct the modeling study, the researchers assumed that children were as infectious as adults. However, since this assumption remains uncertain due to the lack of conclusive data available, the researchers also re-ran the model with the assumption that children and young people were 50% as infectious as adults. The researchers noted that the results remained the same with both assumptions in place.

"It's important to note that our model looked at the effects of school reopening alongside the loosening of the restrictions across society, as school reopening is likely to go hand in hand with more adults returning to work and other relaxed measures across society. Therefore, our results are reflective of a broader loosening of lockdown, rather than the effects of transmission within schools exclusively, suggesting an effective test-trace-isolate offers a feasible alternative to intermittent lockdown and school closures to control the spread of COVID-19," said lead study author Jasmina Panovska-Griffiths, PhD, a senior research fellow and lecturer at University College London and a lecturer at Oxford University, in a press release.

Additionally, the researchers noted that limitations exist for modeling studies, as the data rests on a series of assumptions. The study can also not account for the behavior of young people who are not in school and are increasing socialization outside of schools.

"Our study should not be used to keep schools shut because of a fear of a second wave but as a loud call to action to improve the infection control measures and test and trace system so we can get children back to school without interrupting their learning again for extended periods of time,” said one of the study senior authors, Chris Bonnell, PhD, a professor at the London School of Hygiene & Tropical Medicine, in a press release. “This is even more important in the context of opening up other areas of society."

REFERENCE

The Lancet Child & Adolescent Health: Effective testing and contact tracing is essential for schools to safely open during COVID-19 pandemic, two studies show. The Lancet; August 3, 2020. eurekalert.org/pub_releases/2020-08/tl-pss080320.php. Accessed August 12, 2020.