Transmission of SARS-CoV-2 in a primary school setting with and without public health measures using real-world contact data: A modelling study

Abstract

Background Stringent public health measures have been shown to influence the transmission of SARS-CoV-2 within school environments. We investigated the potential transmission of SARS-CoV-2 in a primary school setting with and without public health measures, using fine-grained physical positioning traces captured before the COVID-19 pandemic. Methods Approximately 172.63 million position data from 98 students and six teachers from an open-plan primary school were used to predict a potential transmission of SARS-CoV-2 in primary school settings. We first estimated the daily average number of contacts of students and teachers with an infected individual during the incubation period. We then used the Reed-Frost model to estimate the probability of transmission per contact for the SARS-CoV-2 Alpha (B.1.1.7), Delta (B.1.617.2), and Omicron variant (B.1.1.529). Finally, we built a binomial distribution model to estimate the probability of onward transmission in schools with and without public health measures, including face masks and physical distancing. Results An infectious student would have 49.1 (95% confidence interval (CI) = 46.1-52.1) contacts with their peers and 2.00 (95% CI = 1.82-2.18) contacts with teachers per day. An infectious teacher would have 47.6 (95% CI = 45.1-50.0) contacts with students and 1.70 (95% CI = 1.48-1.92) contacts with their colleague teachers per day. While the probability of onward SARS-CoV-2 transmission was relatively low for the Alpha and Delta variants, the risk increased for the Omicron variant, especially in the absence of public health measures. Onward teacher-to-student transmission (88.9%, 95% CI = 88.6%-89.1%) and teacher-to-teacher SARS-CoV-2 transmission (98.4%, 95% CI = 98.5%-98.6%) were significantly higher for the Omicron variant without public health measures in place. Conclusions Our findings illustrate that, despite a lower frequency of close contacts, teacher-to-teacher close contacts demonstrated a higher risk of transmission per contact of SARS-CoV-2 compared to student-to-student close contacts. This was especially significant with the Omicron variant, with onward transmission more likely occurring from teacher index cases than student index cases. Public health measures (eg, face masks and physical distance) seem essential in reducing the risk of onward transmission within school environments.

COVID-19 monitoring of school personnel through molecular salivary test and dried blood spot analysis

“…Among these subjects, only one participant reported to be infected at school. Yan et al [ 46 ] demonstrated that, during the highly transmissible Omicron wave, risk of infection in teacher-to-teacher contact was higher compared to student-to-student or student-to/from-teacher contact.…”

“…In our experience the school setting was characterised by a low risk for SARS-CoV-2 infection, since only one subject reported being infected at school. Several studies conducted in primary and secondary schools reported a low incidence of cases, monitoring both students and school personnel [ 17 , 46 , 48 , 49 ]. Macartney et al [ 50 ] observed few cases and secondary infection rates among pupils and school personnel in a population of 8.1 million Australians.…”

A dynamic causal modeling of the second outbreak of COVID-19 in Italy

“…The same study concludes that uncontrolled transmission of SARS-CoV-2 in schools could spread transmission to other areas and increase the burden of contact tracing. In short, there is a growing body of literature and data (see also Yan et al 2022) showing that schools are a privileged environment for transmission and amplification of viral circulation, identifying schools as a major driver in the onward spread of infection. Therefore, it does not seem unreasonable that the mass of infections in September 2020 was strongly influenced by the reopening of schools.…”

COVID-19 Prevention Strategies for Victoria Students within Educational Facilities: An AI-Based Modelling Study

“…Secondly, there are currently 13 SARS-CoV-2 variants in circulation, including Alpha, Beta, Delta, Gamma, and Omicron. Researchers have proven that the Delta and Omicron have increased infection rates and transmissibility [ 28 , 29 ]. Therefore, the one-off training method is not ideal for creating training and test sets for the COVID-19 infection simulation.…”