Risk assessment of communicable respiratory diseases transmission based on social contact networks: a primary school contact data survey conducted with portable high-precision devices.

backgroundDuring the 2020 COVID-19 pandemic, class suspension and school closures, as non-pharmacological interventions, effectively curbed on-campus communicable diseases transmission by minimizing contact. Targeted temporary measures taken for high-risk groups and activities, such as suspending a certain group activity and isolating students with symptoms at home, can significantly reduce transmission without the need for a complete suspension. However, there is currently a lack of in-depth analysis of teacher and student contact behavior. The aim is to assess the risk of communicable respiratory diseases transmission among different populations and activities in primary school.

methodsWe utilized Ultra-Wideband (UWB) wearable devices - a wireless positioning technology enabling centimeter-level proximity detection to record 143,328 close contacts among 292 teachers and students in a primary school throughout the day. By converting data into a network matrix, we constructed a dynamic contact network for the corresponding analysis and calculated network indicators. We also analyzed the contact patterns and distribution of contagion risk among different groups and activity types of contacts.

resultsNetwork analysis reveals that among the top 10% of individuals in terms of closeness centrality and eigenvector centrality, the proportion of younger students was the highest. Additionally,the duration of single contact was longer among younger students. High-risk contacts predominantly occurred during classes, after-school service, large recess activity and lunch break. The risk of contact was highest among teachers and students of the same grade, with an average contact duration of 57.46 and 56.17 min, while inter-grade durations were only 4.15 and 1.17 min. Moreover, same-grade teachers and students had higher proportion of medium-high risk and above interactions. Inter-grade contacts primarily occurred among students (38.99% medium-high-risk interactions), with 90.45% concentrated during morning self-study and after-school services.

conclusionsThe identification of high-risk contact activities and populations on campus provides important quantitative parameters for targeted intervention particular during the early stage of outbreak.