Infection and transmission risks of COVID-19 in schools and their contribution to population infections in Germany: A retrospective observational study using nationwide and regional health and education agency notification data

"Empathy for children is often missing": a mixed methods analysis of a German forum on COVID-19 pandemic measures

BACKGROUND

The pandemic and its preventive measures disrupted daily routines and posed unforeseen obstacles for families. Users of public online forums chronicled these challenges by freely expressing their sentiments in unrestricted text-length formats. We explored a German COVID-19 forum to understand family perspectives and experiences of pandemic measures, particularly in terms of testing and vaccinating children. Our findings aim to inform future epidemic health policies.

METHODS

We retrieved all 11,207 entries from a COVID-19 forum during its lifespan (June 2020 - December 2021), posted during the height of the pandemic. We classified the entries into topic clusters including general pandemic situation, testing, or vaccination using state-of-the-art text embeddings and clustering algorithms. The clusters were selected based on the research's aims and analysed qualitatively using a health policy triangle framework.

RESULTS

Users generally appreciated pandemic public health safety measures for everyone's protection, yet voiced concerns about inconsistent policies and disproportional disadvantages for children compared to other societal groups, like the elderly. Non-compliers were overwhelmingly regarded with skepticism and critiqued. Users found COVID-19 (exit) strategies and information about the benefits of vaccination unclear. This created hurdles for parents and caregivers in navigating their children's school and social life. Users endorsed vaccinating children mainly for "normalising" children's lives rather than for their physical health benefits. Some users suggested prioritising teachers and early childhood educators on the vaccination eligibility list to speed up a return to "normality".

CONCLUSIONS

During pandemics, governments should prioritize addressing the societal and mental health needs of children by implementing participatory and family-oriented public health measures for schools and kindergartens. Clear communication coupled with consistent design and implementation of safety measures and regulations, would be crucial for building trust in the general population and for ensuring compliance regarding testing and vaccination. Communicating the benefits and risks of vaccinating children is of paramount importance  for informed decision-making among parents. In future epidemics, computer-aided analysis of large online qualitative data would offer valuable insights into public sentiments and concerns, enabling proactive and adaptive epidemic responses.

Implementation and effectiveness of non-pharmaceutical interventions, including mask mandates and ventilation, on SARS-CoV-2 transmission (alpha variant) in primary schools in the Netherlands

There has been a lot of discussion about the role of schools in the transmission of severe acute respiratory coronavirus 2 (SARS-CoV-2) during the coronavirus 2019 (COVID-19) pandemic, where many countries responded with school closures in 2020. Reopening of primary schools in the Netherlands in February 2021 was sustained by various non-pharmaceutical interventions (NPIs) following national recommendations. Our study attempted to assess the degree of regional implementation and effectiveness of these NPIs in South Limburg, Netherlands. We approached 150 primary schools with a structured questionnaire containing items on the implementation of NPIs, including items on ventilation. Based on our registry of cases, we determined the number of COVID-19 cases linked to each school, classifying cases by their source of transmission. We calculated a crude secondary attack rate by dividing the number of cases of within-school transmission by the total number of children and staff members. Two-sample proportion tests were performed to compare these rates between schools stratified by the presence of a ventilation system and mask mandates for staff members. A total of 69 schools responded. Most implemented NPIs were aimed at students, except for masking mandates, which preferentially targeted teachers over students (63% versus 22%). We observed lower crude secondary attack rates in schools with a ventilation system compared to schools without a ventilation system (1.2% versus 2.8%, p<0.01). Mandatory masking for staff members had no effect on the overall crude secondary attack rate (2.0% versus 2.1%, p = 0.03) but decreased the crude secondary attack rate among staff members (2.3% versus 1.7%, p<0.01). Schools varied in their implementation of NPIs, most of which targeted students. Rates of within-school transmission were higher compared to other studies, possibly due to a lack of proper ventilation. Our research may help improve guidance for primary schools in future outbreaks.

Seroprevalence of antibodies against SARS-CoV-2 in the school community in Campo Grande, state of Mato Grosso do Sul, Brazil, October 2021-November 2022

Introduction

With the reopening of schools during the coronavirus disease 2019 (COVID-19) pandemic, it was imperative to understand the role of students and education professionals in the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this paper, we determined the seroprevalence of the SARS-CoV-2 anti-nucleocapsid antibodies in the school community in Campo Grande, the capital and most populous city of the state of Mato Grosso do Sul (Brazil) and evaluated its association with sex, school level, and school type.

Materials and methods

The survey was carried out in 20 public and private schools in the urban region of Campo Grande using the TR DPP® COVID-19 immunoglobulin M/immunoglobulin G (IgM/IgG) kit from the Immunobiological Technology Institute (Bio-Manguinhos, Rio de Janeiro, Brazil). Testing was carried out in three periods: from October to December 2021; from March to July 2022; and from August to November 2022. The participants were students aged 6-17 years enrolled in primary or secondary schools and professionals of different ages and roles.

Results

During the first testing period, 162 participants were seropositive for the IgM and/or IgG anti-nucleocapsid SARS-CoV-2 antibodies, with an estimated seroprevalence of 19.6% using Bayesian multilevel regression. In the second period, 251 participants were seropositive (estimated seroprevalence, 34.6%), while in the third period, 393 participants were seroconverted (estimated seroprevalence, 56.7%). In 2022, there was an increase in the seroconversion rate compared to that in 2021. The most frequently described acute manifestations in the three periods were fever, headache, sore throat, and runny nose. In terms of the demographic profile, there was no predominance of seropositivity between the sexes, although women represented approximately 70% of the study population. There were also no differences between students and school staff.

Discussion

The results made it possible to evaluate the extent of SARS-CoV-2 transmission in the school community through immunity developed against the virus, in addition to providing information about COVID-19 symptoms in children, adolescents, and adults.

Pandemic preparedness: On the efficacy of non-pharmaceutical interventions in COVID-19 and about approaches to predict future pandemic viruses

With three major viral pandemics over the last 100 years, namely the Spanish flu, AIDS and COVID-19 each claiming many millions of lives, pandemic preparedness has become an important issue for public health. The economic, social and political consequences of the upheaval caused by such pandemics also represent a major challenge for governments with respect to sustainable development goals. The field of pandemic preparedness is vast and the current article can only address selected aspects. The article looks first backwards and addresses the question of the efficacy of non-pharmaceutical interventions (NPI) on the trajectory of the COVID-19 pandemic. The article looks then forward by asking to what extent viral candidates for future pandemics can be predicted by virome analyses from metagenome and transcriptome sequencing, by focusing on the virome from specific animal species and using ecological and epidemiological data about spillover viral infections in veterinary and human medicine. As a comprehensive overview on pandemic preparedness is beyond the capacity of a single reviewer, only selected topics will be discussed using recent key scientific publications. Since COVID-19 has not run its course, a computational program able to predict the future evolution of SARS-CoV-2 is mentioned that could assist proactive mRNA vaccine developments against possible future variants of concern. Ending the COVID-19 epidemic necessitates mucosal vaccines that can suppress the transmission of SARS-CoV-2 and therefore this article closes by discussing a promising and versatile protein nanoparticle experimental vaccine approach for inhalation that does not depend on needles nor a cold chain for distribution.

Airborne transmission risks of tuberculosis and COVID-19 in schools in South Africa, Switzerland, and Tanzania: Modeling of environmental data

The COVID-19 pandemic renewed interest in airborne transmission of respiratory infections, particularly in congregate indoor settings, such as schools. We modeled transmission risks of tuberculosis (caused by Mycobacterium tuberculosis, Mtb) and COVID-19 (caused by SARS-CoV-2) in South African, Swiss and Tanzanian secondary schools. We estimated the risks of infection with the Wells-Riley equation, expressed as the median with 2.5% and 97.5% quantiles (credible interval [CrI]), based on the ventilation rate and the duration of exposure to infectious doses (so-called quanta). We computed the air change rate (ventilation) using carbon dioxide (CO2) as a tracer gas and modeled the quanta generation rate based on reported estimates from the literature. The share of infectious students in the classroom is determined by country-specific estimates of pulmonary TB. For SARS-CoV-2, the number of infectious students was estimated based on excess mortality to mitigate the bias from country-specific reporting and testing. Average CO2 concentration (parts per million [ppm]) was 1,610 ppm in South Africa, 1,757 ppm in Switzerland, and 648 ppm in Tanzania. The annual risk of infection for Mtb was 22.1% (interquartile range [IQR] 2.7%-89.5%) in South Africa, 0.7% (IQR 0.1%-6.4%) in Switzerland, and 0.5% (IQR 0.0%-3.9%) in Tanzania. For SARS-CoV-2, the monthly risk of infection was 6.8% (IQR 0.8%-43.8%) in South Africa, 1.2% (IQR 0.1%-8.8%) in Switzerland, and 0.9% (IQR 0.1%-6.6%) in Tanzania. The differences in transmission risks primarily reflect a higher incidence of SARS-CoV-2 and particularly prevalence of TB in South Africa, but also higher air change rates due to better natural ventilation of the classrooms in Tanzania. Global comparisons of the modeled risk of infectious disease transmission in classrooms can provide high-level information for policy-making regarding appropriate infection control strategies.

Association of known SARS-CoV-2 serostatus and adherence to personal protection measures and the impact of personal protective measures on seropositivity in a population-based cross-sectional study (MuSPAD) in Germany

BACKGROUND

In 2020/2021 in Germany, several non-pharmacological interventions were introduced to lower the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We investigated to what extent knowledge of prior infection with SARS-CoV-2 or vaccination status influenced the use of personal protection measures (PPM). Further, we were interested in the effect of compliance with PPM on SARS-CoV-2 serostatus.

METHODS

Data was based on a sequential, multilocal seroprevalence study (MuSPAD), carried out in eight locations from July 2020 to August 2021. We estimated the association between a known SARS-CoV-2 serostatus (reported positive PCR test or vaccination) and self-reported PPM behavior (hand hygiene, physical distancing, wearing face mask), just as the association of PPM compliance with seropositivity against nucleocapsid (NC), receptor-binding domain (RBD), and spike protein (S) antigens. We identified relevant variables and deduced adjustment sets with directed acyclic graphs (DAG), and applied mixed logistic regression.

RESULTS

Out of the 22,297 participants (median age: 54 years, 43% male), 781 were classified as SARS-CoV-2-infected and 3,877 had a vaccinated immune response. Vaccinated individuals were less likely to keep 1.5 m distance [OR = 0.74 (95% CI: 0.57-0.97)] and only partly physically distanced [OR = 0.71 (95% CI: 0.58-0.87)]. Participants with self-reported positive PCR test had a lower chance of adhering partly to physical distancing [OR = 0.70 (95% CI: 0.50-0.99)] in comparison to the reference group. Higher odds of additionally wearing a face mask was observed in vaccinated [OR = 1.28 (95% CI: 1.08-1.51)] even if it was not obligatory. Overall, among unvaccinated participants, we found little evidence of lower odds of seropositivity given mask wearing [OR: 0.91 (95% CI: 0.71-1.16)], physical distancing [OR: 0.84 (95% CI: 0.59-1.20)] and no evidence for completely adhering to hand cleaning [OR: 0.97 (95% CI: 0.29-3.22)].

CONCLUSIONS

A known confirmed prior infection and vaccination may have the potential to influence adherence to PPM.

Atopy and Elevation of IgE, IgG3, and IgG4 May Be Risk Factors for Post COVID-19 Condition in Children and Adolescents

SARS-CoV-2 infection causes transient cardiorespiratory and neurological disorders, and severe acute illness is rare among children. Post COVID-19 condition (PCC) may cause profound, persistent phenotypes with increasing prevalence. Its manifestation and risk factors remain elusive. In this monocentric study, we hypothesized that atopy, the tendency to produce an exaggerated immunoglobulin E (IgE) immune response, is a risk factor for the manifestation of pediatric PCC. We present a patient cohort (n = 28) from an early pandemic period (2021-2022) with comprehensive evaluations of phenotypes, pulmonary function, and molecular investigations. PCC predominantly affected adolescents and presented with fatigue, dyspnea, and post-exertional malaise. Sensitizations to aeroallergens were found in 93% of cases. We observed elevated IgE levels (mean 174.2 kU/L, reference < 100 kU/L) regardless of disease severity. Concurrent Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) was found in 29% of patients that also faced challenges in school attendance. ME/CFS manifestation was significantly associated with elevated immunoglobulin G subclasses IgG3 (p < 0.05) and IgG4 (p < 0.05). A total of 57% of patients showed self-limiting disease courses with mean recovery at 12.7 months (range 5-25 months), 29% at 19.2 months (range 12-30 months), and the rest demonstrated overall improvement. These findings offer additional insights into immune dysregulation as a risk factor for pediatric PCC.

Medical education during the Covid-19 pandemic long-term experiences of German clinical medical students

INTRODUCTION

Due to the Covid-19 pandemic and the accompanying hygiene regulations, medical students in Germany faced multiple educational and personal challenges. The challenges included the cancellation and digitalisation of courses, the closing of university institutions such as libraries, a decrease in social contacts, and the risk of a Covid-19 infection. The aim of this study was to understand medical students' pandemic experiences as well as the consequences of these experiences for the students' future work as physicians.

MATERIALS AND METHODS

We performed 15 guided, one-on-one interviews with clinical medical students (third to fifth year) at the Otto-von-Guericke-University Magdeburg. Interviews were recorded, transcribed, and anonymised. We performed a qualitative content analysis in accordance with Mayring and thereby formed an inductive category system. The Consolidated Criteria for Reporting Qualitative Research (COREQ) were applied.

RESULTS

Five categories were inductively formed: "Changes in the teaching experience", "negative effects on the learning experience", "decrease in personal social contacts", "contact with covid-19", and "pandemic-associated stress increase". The participating students reported higher levels of stress due to isolation and uncertainty regarding their educational future. Furthermore, students welcomed the digitalisation of lectures, developed individual coping strategies, and voluntarily took part in the care of Covid-19 patients. Limitations to social interactions were perceived as the major restrictive factor to their educational structure, their perceived learning success and personal development.

CONCLUSION

This study identified social restrictions as well as didactic and academic structural challenges as relevant factors contributing to perceived stress and fear for medical students during the Covid-19 pandemic, especially as regards their learning experience. Students' acceptance of digitalised learning may enable regular interaction with university peers and may facilitate a structured educational life. However, the implementation of digital resources could not provide a sufficient substitute for in-person courses.

SARS-CoV-2 transmission with and without mask wearing or air cleaners in schools in Switzerland: A modeling study of epidemiological, environmental, and molecular data

BACKGROUND

Growing evidence suggests an important contribution of airborne transmission to the overall spread of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), in particular via smaller particles called aerosols. However, the contribution of school children to SARS-CoV-2 transmission remains uncertain. The aim of this study was to assess transmission of airborne respiratory infections and the association with infection control measures in schools using a multiple-measurement approach.

METHODS AND FINDINGS

We collected epidemiological (cases of Coronavirus Disease 2019 (COVID-19)), environmental (CO2, aerosol and particle concentrations), and molecular data (bioaerosol and saliva samples) over 7 weeks from January to March 2022 (Omicron wave) in 2 secondary schools (n = 90, average 18 students/classroom) in Switzerland. We analyzed changes in environmental and molecular characteristics between different study conditions (no intervention, mask wearing, air cleaners). Analyses of environmental changes were adjusted for different ventilation, the number of students in class, school and weekday effects. We modeled disease transmission using a semi-mechanistic Bayesian hierarchical model, adjusting for absent students and community transmission. Molecular analysis of saliva (21/262 positive) and airborne samples (10/130) detected SARS-CoV-2 throughout the study (weekly average viral concentration 0.6 copies/L) and occasionally other respiratory viruses. Overall daily average CO2 levels were 1,064 ± 232 ppm (± standard deviation). Daily average aerosol number concentrations without interventions were 177 ± 109 1/cm3 and decreased by 69% (95% CrI 42% to 86%) with mask mandates and 39% (95% CrI 4% to 69%) with air cleaners. Compared to no intervention, the transmission risk was lower with mask mandates (adjusted odds ratio 0.19, 95% CrI 0.09 to 0.38) and comparable with air cleaners (1.00, 95% CrI 0.15 to 6.51). Study limitations include possible confounding by period as the number of susceptible students declined over time. Furthermore, airborne detection of pathogens document exposure but not necessarily transmission.

CONCLUSIONS

Molecular detection of airborne and human SARS-CoV-2 indicated sustained transmission in schools. Mask mandates were associated with greater reductions in aerosol concentrations than air cleaners and with lower transmission. Our multiple-measurement approach could be used to continuously monitor transmission risk of respiratory infections and the effectiveness of infection control measures in schools and other congregate settings.

When schools were open for in-person teaching during the COVID-19 pandemic - the nordic experience on control measures and transmission in schools during the delta wave

BACKGROUND

Extensive measures to control spread of SARS-CoV-2 have led to limited access to education for millions of children and adolescents during the COVID-19 pandemic. Education and access to schools is vital for children and adolescents' learning, health, and wellbeing. Based on high vaccine uptake and low incidence levels, the Nordic countries (Denmark, Finland, Iceland, Norway and Sweden) decided to start the academic year 2021/22 with schools open for in-person teaching and moderate mitigation measures. We describe trends in SARS-CoV-2 infections and vaccination coverage among students during the first 12 weeks of the fall semester.

METHODS

In this multinational, retrospective, observational study, we have used surveillance and registry data from each of the Nordic countries to describe vaccine uptake (≥12 years), infection incidence (whole population) and transmission of SARS-CoV-2 among students. The study period, week 30 to 41 (Jul 26th - Oct 17th), represents the autumn semester from immediately before school started until fall break. In addition, we collected information on mitigation measures applied by the respective countries.

RESULTS

There were slight variations between the countries regarding existing infection prevention and control (IPC) measures, testing strategies and vaccination start-up among adolescents. All countries had high vaccine uptake in the adult population, while uptake varied more in the younger age groups. Incidence in the school-aged population differed between countries and seemed to be influenced by both vaccine uptake and test activity. Infection clusters among school-aged children were described for Denmark and Norway, and the number of clusters per week reflected the incidence trend of the country. Most events consisted of only 1-2 cases. Larger clusters appeared more frequently in the higher grades in Norway and in lower grades in Denmark.

CONCLUSION

Data from the Nordic countries indicate that vaccination of adults and adolescents, in addition to mitigation measures, enabled full in-person learning. As SARS-CoV-2 infection does not represent a severe medical risk for most children as previously thought, measures targeting this group should be carefully adjusted and kept at a minimum. Our data add to the evidence on incidence and transmission of SARS-CoV-2 among students in schools open for in-person teaching, and may be valuable for decision makers worldwide.