Seroprevalence of SARS-CoV-2 in German secondary schools from October 2020 to July 2021: a longitudinal study.

PURPOSE: To quantify the number of SARS-CoV-2 infections in students and teachers in 14 Secondary schools in eastern Saxony, Germany. Seroprevalence of SARS-CoV-2 antibodies in study population. Number of undetected cases. METHODS: Serial seroprevalence study. RESULTS: The role of educational settings in the SARS-CoV-2 Pandemic is still controversial. Seroprevalence increases from 0.8 to 5.9% from October to December when schools remained open and to 12.2% in March/April during a strict lockdown with closed schools. The ratio of undetected to detected cases decreased from 0.76 to 0.44 during the study period. CONCLUSION: During the second and third wave of the pandemic in Germany, students and teachers are not overrepresented in SARS-CoV-2 infections. The percentage of undetected cases is moderate and decreases over time. The risk of contracting SARS-CoV-2 within the household is higher than contracting it in educational settings making school closures rather ineffective in terms of pandemic control measures or individual risk reduction in children and adolescents. TRIAL REGISTRATION: DRKS00022455 (July 23rd, 2020).

Comparison of mental health outcomes in seropositive and seronegative adolescents during the COVID19 pandemic.

Post-COVID19 complications such as pediatric inflammatory multisystem syndrome (PIMS) and Long-COVID19 move increasingly into focus, potentially causing more harm in young adolescents than the acute infection. To better understand the symptoms of long-term mental health outcomes in adolescents and distinguish infection-associated symptoms from pandemic-associated symptoms, we conducted a 12 question Long-COVID19 survey. Using this survey, we compared the responses on neurocognitive, general pain and mood symptoms from seropositive and seronegative adolescents in a cross-sectional study design. Since May 2020, students grade 8-12 in fourteen secondary schools in Eastern Saxony were enrolled in the SchoolCovid19 study. Serostatus was assessed regularly in all participants. In March/April 2021, 1560 students with a median age of 15 years participated at the regular study visit after re-opening of the schools in mid-March and responded to our Long-COVID19 survey as part of this visit. 1365 (88%) students were seronegative, 188 (12%) were seropositive. Each symptom asked in the Long-COVID19 survey was present in at least 35% of the students within the last seven days before the survey. With the exception of seropositive students being less sad, there was no significant difference comparing the reported symptoms between seropositive students and seronegative students. The lack of differences comparing the reported symptoms between seropositive and seronegative students suggests that Long-COVID19 might be less common than previously thought and emphasizes on the impact of pandemic-associated symptoms regarding the well-being and mental health of young adolescents.Clinical Trial Registration: SchoolCoviDD19: Prospektive Erfassung der SARS-CoV-2 Seropositivität bei Schulkindern nach Ende der unterrichtsfreien Zeit aufgrund der Corona-Schutz-Verordnung (COVID-19), DRKS00022455, https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00022455.

Prevalence and Transmission of Severe Acute Respiratory Syndrome Coronavirus Type 2 in Childcare Facilities: A Longitudinal Study.

OBJECTIVE: To evaluate the role of childcare facilities in the transmission of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) in a longitudinal study to gain further knowledge of SARS-CoV-2 prevalence, transmission, and spread among preschool children, their parents, and their caregivers. STUDY DESIGN: Children aged 1-6 years, their parents, and their caregivers in 14 childcare facilities in Dresden, Saxony/Germany were invited to participate in the KiTaCoviDD19-study between July 2020 and January 2021. Seroprevalence of SARS-CoV-2 antibodies was assessed up to 4 times during the study period in all participating adults, and demographic characteristics, as well as epidemiologic information on personal SARS-CoV-2 history were obtained. Samples for stool virus shedding of SARS-CoV-2 were analyzed by polymerase chain reaction every 2-4 weeks in all participating children. RESULTS: In total, 318 children, 299 parents and 233 childcare workers were enrolled. By January 2021, 11% of the participating adults were found to be seropositive, whereas the percentage of children shedding SARS-CoV-2 was 6.8%. Overall, we detected 17 children with SARS-CoV-2 virus shedding in 8 different childcare facilities. In 4 facilities, there were a maximum of 3 connected cases in children. Approximately 50% of SARS-CoV-2 infections in the children could not be connected to a secondary case in our study population. CONCLUSIONS: This study does not provide evidence of relevant asymptomatic ("silent") spread of SARS-CoV-2 in childcare facilities in both low- and high-prevalence settings. Our findings add to the evidence that childcare and educational settings do not have a crucial role in driving the SARS-CoV-2 pandemic.

Kinetics and seroprevalence of SARS-CoV-2 antibodies: a comparison of 3 different assays.

Comparing seroprevalence and antibody kinetics in three different commercially available assays for SARS-CoV-2. Serostatus of COVID-19 patients was analyzed 5 months and 10 months after their infection, using three different assays: Diasorin LIAISON, Euroimmun, Abbott Diagnostics ARCHITECT. Seropositivity at baseline differed significantly depending on the assay (Diasorin 81%, Euroimmun 83%, Abbott 59%). At follow-up antibody levels detected in the Diasorin assay were stable, while there was a significant loss in seropositivity in the Euroimmun and Abbott assays. There are significant differences in SARS-CoV-2 antibody kinetics based on the specific assay used.

SARS-CoV-2 transmissions in students and teachers: seroprevalence follow-up study in a German secondary school in November and December 2020.

Objective: To quantify the number of undetected SARS-CoV-2 infections in educational settings. Design: Serial SARS-CoV-2 seroprevalence study before and during the second wave of the COVID-19 pandemic. Setting: Secondary school in Dresden, Germany. Participants: Grade 8-12 students and their teachers were invited to participate in serial blood sampling and SARS-CoV-2 IgG antibody assessment. Main outcome measure: Seroprevalence of SARS-CoV-2 antibodies in study population. Results: 247 students and 55 teachers participated in the initial study visit and 197 students and 40 teachers completed follow-up. Seroprevalence increased from 1.7% (0.3-3.3) to 6.8% (3.8-10.1) during the study period mirroring the increase of officially reported SARS-CoV-2 infections during this time. The ratio of undetected to detected SARS-CoV-2 infections ranged from 0.25 to 0.33. Conclusions: We could not find evidence of relevant silent, asymptomatic spread of SARS-CoV-2 in schools neither in a low prevalence setting nor during the second wave of the pandemic, making it unlikely that educational settings play a crucial role in driving the SARS-CoV-2 pandemic. Trial registration number: DRKS00022455.