Introduction: With the increased emergence of SARS-CoV-2 variants, the impact on schools and preschools remains a matter of debate. To ensure that schools and preschools are kept open safely, the identification of factors influencing the extent of outbreaks is of importance.Aim: To monitor dynamics of COVID-19 infections in schools and preschools and identify factors influencing the extent of outbreaks.Methods: In this prospective observational study we analyzed routine surveillance data of Mecklenburg-Western Pomerania, Germany, from calendar week (CW) 32, 2020 to CW19, 2021 regarding SARS-CoV-2 infection events in schools and preschools considering changes in infection control measures over time. A multivariate linear regression model was fitted to evaluate factors influencing the number of students, teachers and staff tested positive following index cases in schools and preschools. Due to an existing multicollinearity in the common multivariate regression model between the variables “face mask obligation for children” and “face mask obligation for adults”, two further separate regression models were set up (Multivariate Model Adults and Multivariate Model Children).Results: We observed a significant increase in secondary cases in preschools in the first quarter of 2021 (CW8 to CW15, 2021), and simultaneously a decrease in secondary cases in schools. In multivariate regression analysis, the strongest predictor of the extent of the outbreaks was the teacher/ caregiver mask obligation (B = −1.9; 95% CI: −2.9 to −1.0; p < 0.001). Furthermore, adult index cases (adult only or child+adult combinations) increased the likelihood of secondary cases (B = 1.3; 95% CI: 0.9 to 1.8; p < 0.001). The face mask obligation for children also showed a significant reduction in the number of secondary cases (B = −0.6; 95% CI: −0.9 to −0.2; p = 0.004.Conclusion: The present study indicates that outbreak events at schools and preschools are effectively contained by an obligation for adults and children to wear face masks.

Background Since the onset of the COVID-19 pandemic, children have been mentally and physically burdened, particularly due to school closures, with an associated loss of learning. Therefore, efficient testing strategies with high sensitivity are necessary to keep schools open. Apart from individual rapid antigen testing, various methods have been investigated, such as PCR-based pool-testing of nasopharyngeal swabs, gargle, or saliva samples. To date, previous validation studies have found the PCR-based saliva swab pool testing method to be an effective screening method, however, the acceptability and feasibility of a widespread implementation in the school-setting among stakeholders has not been comprehensively evaluated. Methods In this pilot study, SARS-CoV-2 saliva swab pool testing of up to 15 swabs per pool was conducted in ten primary and special schools in Mecklenburg-Western Pomerania, Germany, over a period of one month. Thereafter, parents, teachers and school principals of the participating schools as well as the participating laboratories were surveyed about the feasibility and acceptability of this method, its large-scale implementation and challenges. Data were analyzed quantitatively and qualitatively. Results During the study period, 1,630 saliva swab pools were analyzed, of which 22 tested SARS-CoV-2 positive (1.3%). A total of N = 315 participants took part in the survey. Across all groups, the saliva swab pool testing method was perceived as more child-friendly (>87%), convenient (>82%), and easier (>81%) compared to rapid antigen testing by an anterior nasal swab. Over 80% of all participants favored widespread, regular use of the saliva swab method. Conclusion In school settings in particular, a high acceptability of the test method is crucial for a successful SARS-CoV-2 surveillance strategy. All respondents clearly preferred the saliva swab method, which can be used safely without complications in children six years of age and older. Hurdles and suggestions for improvement of an area-wide implementation were outlined.

Zusammenfassung Hintergrund Die aktuelle Infektionsgefahr mit SARS-CoV-2 in Schulen wird weiterhin kontrovers diskutiert. Methodik „schugi-MV“ erfasst in strukturierten Begehungen von Schulen in Mecklenburg-Vorpommern (M-V) Daten zum Infektionsgeschehen, Hygienemanagement sowie weiteren Faktoren. Aus den Ergebnissen sollen Empfehlungen für einen sicheren Unterricht abgeleitet werden. In diesem Artikel werden Informationen zu den ersten 10, zwischen dem 18.12.2020 und 20.01.2021 besuchten Schulen vorgestellt. Ergebnisse An den besuchten Schulen lag das Verhältnis der Anzahl Indexfälle bei Erwachsenen und Kindern bei 1:1,25. Die Begehungen zeigten eine große Heterogenität der Schulen und Schulgebäude sowie der dadurch bedingten Möglichkeiten zur Umsetzung von Infektionsschutzmaßnahmen. Schlussfolgerung Basierend auf den vorliegenden, vorläufigen Ergebnissen sind Hygiene- und Infektionsschutzmaßnahmen an den Schulen in M-V nicht standardisierbar, sondern sollten Gestaltungsspielraum lassen.