SARS-CoV-2 infection and transmission in school settings during the second wave in Berlin, Germany: a cross-sectional study

BackgroundSchool attendance during the SARS-CoV-2 pandemic is intensely debated. Modelling studies suggest that school closures contribute to community transmission reduction. However, data among school-attending students and staff are scarce. In November 2020, we examined SARS-CoV-2 infections and seroreactivity in 24 randomly selected school classes and connected households in Berlin, Germany. MethodsStudents and school staff were examined, oro-nasopharyngeal swabs and blood samples collected, and SARS-CoV-2 infection and IgG antibodies detected by RT-PCR and ELISA. Household members performed self-swabs. Individual and institutional infection prevention and control measures were assessed. Classes with SARS-CoV-2 infection and connected household members were re-tested after one week. Findings1119 participants were examined, including 177 primary and 175 secondary school students, 142 staff, and 625 household members. Participants reported mainly cold symptoms (19{middle dot}4%). SARS-CoV-2 infection occurred in eight of 24 classes affecting each 1-2 individuals. Infection prevalence was 2{middle dot}7% (95%CI; 1{middle dot}2-5{middle dot}0%; 9/338), 1{middle dot}4% (0{middle dot}2-5{middle dot}1%; 2/140), and 2{middle dot}3% (1{middle dot}3-3{middle dot}8%; 14/611) among students, staff and household members, respectively, including quarantined persons. Six of nine infected students were asymptomatic. Prevalence increased with inconsistent facemask use in school, way to school on foot, and case-contacts outside school. IgG antibodies were detected in 2{middle dot}0% (0{middle dot}8-4{middle dot}1%; 7/347), 1{middle dot}4% (0{middle dot}2-5{middle dot}0%; 2/141) and 1{middle dot}4% (0{middle dot}6-2{middle dot}7%; 8/576), respectively. For three of nine households with infection(s) detected at cross-sectional assessment, origin in school seemed possible. After one week, no school-related, secondary infections appeared in affected classes; the attack rate in connected households was 1{middle dot}1%. InterpretationThese data suggest that school attendance under preventive measures is feasible, provided their rigorous implementation. In balancing threats and benefits of open versus closed schools during the pandemic, parents and society need to consider possible spill-overs into their households. Deeper insight is needed into the infection risks due to being a schoolchild as compared to attending school. FundingSenate of Berlin.

SARS-CoV-2 infection, risk perception, behaviour, and preventive measures at schools in Berlin, Germany, during the early post-lockdown phase: A cross-sectional study

BackgroundBriefly before the first peak of the COVID-19 pandemic in Berlin, Germany, schools closed in mid-March 2020 for six weeks. Following re-opening, schools gradually resumed operation at a reduced level for nine weeks preceding the summer holidays. AimDuring this phase, we conducted a situational assessment in schools among students and teachers as to infection status, symptoms, affective, behavioural, educational issues, and preventive measures. MethodsAt twenty-four randomly selected primary and secondary schools, one class each was examined. Oro-nasopharyngeal swabs and capillary blood samples were collected to assess SARS-CoV-2 infection (PCR) and specific IgG (ELISA), respectively. Medical history, household and schooling characteristics, leisure time activities, fear of infection, risk perception, hand hygiene, physical distancing, and facemask wearing were assessed. ResultsAmong 535 participants (385 students, 150 staff), one teenager was SARS-CoV-2 infected (0.2%), and seven individuals exhibited specific IgG (1.3%); 16% reported symptoms upon examination, and 48% in the preceding 14 days. Compared to before the pandemic, the proportion of leisure time spent as screen-time increased, and the majority of primary school students reported reduced physical activity. Fear of infection and risk perception were relatively low, but acceptance of adapted health behaviours was high. Governmental preventive measures were adequately implemented, with primary schools performing better than secondary schools. ConclusionIn this phase of rare infection and low seroreactivity, individual and school-level infection prevention and control measures were largely adhered to. Nevertheless, vigilance, continued and proactive preventive measures, and well-rehearsed reaction options are essential to cope with increasing pandemic activity.

SARS-CoV-2 infections in kindergartens and associated households at the start of the second wave in Berlin, Germany - a cross sectional study

ObjectivesThe comparatively large proportion of asymptomatic SARS-CoV-2 infections in the youngest children opens up the possibility that kindergartens represent reservoirs of infection. However, actual surveys in kindergartens beyond individual outbreaks are rare. At the beginning of the second pandemic wave in Berlin, Germany, i.e., end of September 2020, we screened SARS-CoV-2 infections among kindergarten children, staff and connected household members. MethodsTwelve kindergartens were randomly selected in the Berlin metropolitan area, and a total of 720 participants were recruited (155 pre-school children, 78 staff, 487 household members). Participants were briefly examined and interviewed, and SARS-CoV-2 infections and anti-SARS-Cov-2 IgG antibodies were assessed. ResultsSigns and symptoms, largely resembling common cold, were present in 24.2% of children and 28.9% of staff. However, no SARS-CoV-2 infection was detected among 701 PCR-tested individuals, and only one childcare worker showed IgG seroreactivity (0.15%; 1/672). ConclusionsAgainst a backdrop of increased pandemic activity in the community, this cross-sectional study does not suggest that kindergartens are silent transmission reservoirs. Nevertheless, at increasing pandemic activity, reinforced precautionary measures and repeated routine testing appears advisable.