COVID-19 RT-qPCR-based screening in Austrian schools and incidences in the general population: a Bayesian spatiotemporal analysis

Abstract

In 2021, the emergence of highly transmissible COVID-19 variants of concern increased susceptibility among younger populations. Despite this risk, face-to-face education remained essential for societal functioning and children's well-being, prompting the Austrian government to implement a nationwide screening program in educational institutions. This study explores the impact of this program on COVID-19 transmission by examining the relationship between incidence rates and factors such as age, vaccination coverage, and RT-qPCR positivity rates among school-aged children across Austrian districts, using a Bayesian spatiotemporal discrete model. Our findings highlight significant effects of vaccination and positivity rates on COVID-19 incidence, with variations in their influence across different age groups and locations. These results underscore the importance of monitoring these variables, particularly when active screening programs are in place.

Keywords: Austria; COVID-19; RT-qPCR; School; Screening; Spatiotemporal analysis.

Fig. 1

Border of districts and federal states in Austria from September 13, 2021, to January 2, 2022

Fig. 2

Posterior predictive check based on PIT histogram for the initial model among school children in Austria, from September 13, 2021, to January 2, 2022

Fig. 3

Effect of age, vaccination coverage, and positivity rate on predicted COVID-19 incidence among school children in Austria, from September 13, 2021, to January 2, 2022. Green color indicates high vaccination coverage ($\ge 50\%$) in the corresponding age group and yellow color indicates low vaccination coverage ($<50\%$). The y-axis range varies across age groups for clarity of the visualization. PI = predicted interval

Fig. 4

Posterior COVID-19 incidence rate (IR) per 1,000 children at the district level in Austria, from September 13, 2021, to January 2, 2022. The border of each federal state is indicated with black lines. The federal state of Vienna, excluded from the analysis, is marked with black fill

Fig. 5

Exceedance probability at the district level in Austria, from September 13, 2021, to January 2, 2022. IR = incidence rate per 1,000 children. The border of each federal state is indicated with black lines. The federal state of Vienna, excluded from the analysis, is marked with black fill

Fig. 6

Percentage of cold spots and hot spots in each federal state of Austria from September 13, 2021, to January 2, 2022. The holiday period in Burgenland, Upper Austria, Styria, and Vorarlberg is marked with red dashed lines. The holiday period in Carinthia, Lower Austria, Salzburg, and Tyrol is marked with black dashed lines