ABSTRACT
Importance: Understanding the susceptibility and infectiousness of children and adolescents in comparison to adults is important to appreciate their role in the COVID-19 pandemic. Objective: To determine SARS-CoV-2 susceptibility and infectiousness of children and adolescents with adults as comparator for three variants (wild-type, Alpha, Delta) in the household setting. We aimed to identify the effects independent of vaccination. Data Sources: We searched EMBASE, PubMed and medRxiv up to January 2022. Additional studies were identified through contacting subject experts. Study Selection: Two reviewers independently identified studies providing secondary attack rates (SAR) for SARS-CoV-2 infection in children (0-9 years), adolescents (10-19 years) or both compared with adults (20 years and older) derived from household data. Data Extraction and Synthesis: Two reviewers independently performed data extraction. We assessed risk of bias of included studies using a critical appraisal checklist and a random-effects meta-analysis model to pool association estimates. Main Outcomes and Measures: Odds ratio (OR) for SARS-CoV-2 infection comparing children and adolescents with adults stratified by wild-type, Alpha, and Delta variant, respectively. Susceptibility was defined as the secondary attack rate (SAR) among susceptible household contacts irrespective of the age of the index case. Infectiousness was defined as the SAR irrespective of the age of household contacts when children/adolescents/adults were the index case. Results: Twenty-eight studies (308,857 contacts) were included in the susceptibility analysis, for Delta only one (large) study was available. Compared to adults children and adolescents were less susceptible to the wild-type and Delta variant, but equally susceptible to the Alpha variant. In the infectiousness analysis, 21 studies (201,199 index cases) were included. Compared to adults, children and adolescents were less infectious when infected with the wild-type and Delta variant. Alpha variant-related infectiousness remained unclear, 0-9 year old children were at least as infectious as adults. SAR among household contacts was highest during circulation of the Alpha variant, lowest during wild-type circulation and intermediate during Delta circulation. Conclusions and Relevance: When considering the potential role of children and adolescents, for each variant susceptibility, infectiousness, age group and overall transmissibility need to be assessed to guide public health policy.
Subject(s)
COVID-19ABSTRACT
Objective: To investigate SARS-COV-2 viral clearance and viral load kinetics in the course of infection in children aged 1-6 years in comparison with adults. Methods: Prospective cohort study of infected daycare children and staff and their close contacts in households from 11/2020-06/2021, comprising serial (self) sampling of upper respiratory tract specimen and testing for SARS-CoV-2 via PCR. Data on symptoms and exposure were used to determine the date of probable infection for each participant. We determined (a) viral clearance, and (b) viral load dynamics over time. Samples were taken from day 4-6 to day 16-18 after diagnosis of the index case in the respective daycare group (5 samples per participant). Results: We included 40 children (1-6 years) and 67 adults (18-77 years) with SARS-CoV-2 infection. Samples were available at a mean of 4.3 points of time per participant. Among the participants, the 12-day study period fell in different periods within the individual course of infection, ranging from day 5-17 to day 15-26 after assumed infection. Children reached viral clearance at a median of 20 days after assumed infection (95% CI 17-21 days, Kaplan Meier Analysis), adults at 23 days (95% CI 20-25 days, difference not significant). In both children and adults, viral load decreased over time with trajectories of the mean viral load not being statistically different between groups. Only small proportions of those tested positive had a viral load of >1 million copies/ml, which is considered the threshold for infectivity. Kaplan-Meier calculations show that from day 15 (95% CI 13-15), 50% of all participants that had a viral load no longer infectious or were negative. Conclusion: Children aged 1-6 and adults infected with SARS-CoV-2 (wild type and Alpha variant) did not differ significantly in terms of viral load kinetics and time needed to clear the virus. Therefore, containment measures are important also in the daycare settings as long as the pandemic continues.
Subject(s)
COVID-19ABSTRACT
Background: Whereas the majority of children under 6 years of age attend daycare centers in Germany, evidence on the role of daycare centers in the transmission of SARS-CoV-2 is scarce. Aims: This study aims to investigate the transmission risk in daycare centers among children and staff and the spread of infections to associated households. Methods: 30 daycare groups with at least one recent laboratory-confirmed SARS-CoV-2 case (child or staff) were enrolled in the study (10/2020-06/2021). Close contacts within the daycare group and households were examined over a 12-day period (repeated SARS-CoV-2 PCR tests, genetic sequencing of viruses, documentation of symptoms). Households, local health authorities and daycare staff were interviewed to gain comprehensive information on each outbreak. We determined primary cases for all daycare groups. Results: The number of secondary cases varied considerably between daycare groups. The pooled secondary attack rate (SAR) across all 30 daycare centers was 9.6%. The SAR tended to be higher in daycare centers in which the Alpha variant of the virus was detected (15.9% vs. 5.1% with evidence of wild type). The SAR in households was 53.3%. Exposed children were less likely to get infected with SARS-CoV-2 in daycare centers, compared to adults (7.7% vs. 15.5%). Conclusion: Containment measures in daycare programs are critical and become increasingly important with highly transmissible new variants to reduce SARS-CoV-2 transmission, especially to avoid spread to associated households. Virus variants may modify transmission dynamics in daycare programs.
ABSTRACT
Background: Individuals aged 70+ were most threatened by COVID-19 and most targeted by shielding recommendations. However, there is limited understanding of the situation of this high-risk population during lockdown. Methods: We derived information via a written self-completion questionnaire sent out to our population-based AugUR study participants (aged 70+, living in/near Regensburg, Germany) shortly after the lift of the curfew in spring 2020 in Bavaria, Germany. This was combined with data from previous AugUR study center visits including medical history assessment, medical exams, and bio-probing, which enabled the comparison of pre- and during-pandemic assessments in the very same individuals. Results: Among 1,850 survey participants (73–98 years; net-response 89%), 74% were at increased risk for severe COVID-19 according to medical conditions (75% extrapolated to the German population aged 70+). Despite 92% have potentially been exposed, only four reported SARS-CoV-2 infection (0.2%). COVID-19 related symptoms were reported by 23%. Regarding lifestyle changes since lockdown, we found no trend towards increased smoking or drinking alcohol, but 34% reported increased sedentary behavior and 29% refrained from medical appointments. Worse QOL was perceived by 38%. Particularly women and the more educated were susceptible to these changes. When comparing lifestyle differences between survey and previous visit, the pattern was similar. Conclusions: Our presented data will help understand the situation of this vulnerable group in the pandemic. While a majority of individuals reported no changes towards a less healthy life style, about one third would benefit from help to sustain a healthy lifestyle when accommodating future strategies.
Subject(s)
COVID-19ABSTRACT
Objectives: To gain insights into the impact of the COVID-19 pandemic on ongoing health research projects, using projects from a selected funding programme in Germany as an example. Design: Online survey Setting: Lockdowns and social distancing policies impact upon clinical and public health research in various forms, especially if unrelated to COVID-19. Research institutions have reduced onsite activities, data is often collected remotely, and during the height of the crisis, clinical researchers were partially forced to abandon their projects in favour of front-line care and crisis response. Participants: 120 investigators of health research projects across Germany, performed between 15 and 25 May 2020. Results: The response rate (78%) showed that the survey generated significant interest among investigators. 85 responses were included for analysis, and the majority of investigators (93%) reported that their projects were affected by the pandemic, with many (80%) stating that data collection was not possible as planned, and they could not carry out interventions as planned (67%). Other impacts were caused by staff being unavailable, for example through child or elder care commitments or because of COVID-19 quarantine or illness. Investigators also reported that publications were delayed or not feasible at all (56%), and some experienced problems with PhD or Masters theses (18%). The majority of investigators had mitigation strategies in place such as adjustment of data collection methods using digital tools (46%) or of project implementation in general (46%), others made changes in research design or research questions (27%). Conclusions: The COVID-19 pandemic has severely impacted upon health research projects. The main challenge is now to mitigate negative effects and to improve long-term resilience in health research. The pandemic has also acted as a driver of innovation and change, for example by accelerating the use of digital methods.