Teachers may play a larger role in the transmission of COVID-19 in schools than young students do, suggests a small new study from the Centers for Disease Control and Prevention (CDC).
In the study, the researchers investigated the transmission of COVID-19 in eight public elementary schools in Marietta, Georgia, a suburb of Atlanta, between December 1, 2020 and January 22, 2021. Overall, approximately 2,600 students and 700 staff found it attended. these six schools at the time.
During the study period, the researchers identified nine groups of COVID-19 cases involving a total of 13 educators and 32 students at six of the primary schools. (A group is defined as at least three linked cases of COVID-19.)
In four of the clusters, an educator was the ‘index patient’, or the initial case, and one student was the index patient in only one group. In the other four groups, the index patient was not determined. Eight of the nine clusters probably transferred from educators to students.
Two of the biggest clusters were the transmission of SARS-CoV-2 by the teacher-to-teacher, the virus that causes COVID-19, which probably happened during personal meetings or afternoon breaks. The infected teachers then transmitted the disease to several students. Overall, these two groups were responsible for about half (15 of 31) of the school-related cases in the study, not the index cases, the authors said.
Related: CDC issues new guidelines for reopening schools
The findings suggest that educators were ‘central’ in the COVID-19 transfer networks in schools, the authors write in their paper published in the CDC journal on Monday (February 22). Weekly report on diseases and deaths. “Initial infections among educators played a significant role in the SARS-CoV-2 transmission in school and subsequent infection chains … and emphasized the importance of preventing infections in particular among educators,” they said.
The CDC findings come a little more than a week after the agency released detailed guidelines on how US schools reopen safely.
The findings are also consistent with those of previous studies from Europe. In a study in the United Kingdom, for example, it was found that the transmission of COVID-19 by educator-to-educator was more common in schools than the transmission from student to student, and a study from Germany found that the rates of COVID-19 transfer in schools was three times higher when the index patient was a teacher compared to the case when the index case was a student.
Measures to prevent COVID-19 infection in teachers, including steps to reduce interaction between adults at school, are likely to reduce the transmission of COVID-19 in schools, the authors wrote. Indeed, they noted that the Georgia district had already made changes in the study to reduce personal interaction between educators. Vaccination of teachers can also help prevent COVID-19 spread in schools, although the authors noted that vaccination of teachers is not a requirement for reopening.
The study also found that most cases of transfer in the school COVID-19 occurred when there was ‘less than ideal physical distance’, meaning that students and teachers were very close to each other; and students did not wear face masks properly. It stresses the need to promote ‘correct mask use and physical distance where possible’ in schools, the authors wrote. Physical distance is especially important during meals, if masks are not worn, they said.
Originally published on Live Science.