Stepwise School Opening and an Impact on the Epidemiology of COVID-19 in the Children

Changes in Respiratory Viruses' Activity in Children During the COVID-19 Pandemic: A Systematic Review

Background/Objectives: The impact of the coronavirus disease 2019 (COVID-19) pandemic on health was significant worldwide. The measures adopted to limit the spread of the virus had an indirect effect on the epidemiology of other infectious diseases with similar mechanisms of inter-human transmission. The present literature review analyzed the scenario of pediatric acute respiratory infections in the post-lockdown period compared to the pre-pandemic and lockdown periods. The different patterns of viruses' outbreaks were evaluated according to the type of local COVID-19 restrictive measures and to the type of pathogen. Methods: Relevant scientific literature published between March 2020 and November 2024 was identified by means of electronic keyword searches in the PubMed, Scopus, and Cochrane Library databases. Results: Worldwide implementation of non-pharmacological public health interventions aimed at limiting the COVID-19 pandemic resulted in a measurable effect on the circulation of other common respiratory viruses, significantly affecting their usual seasonality. Most viruses significantly reduced their activity during the lockdown period but returned to or exceeded historical levels after discontinuation of preventive non-pharmacological measures. For many respiratory viruses, particularly respiratory syncytial virus, an off-season increase was reported. Conclusions: The non-pharmacological interventions, which effectively helped limit the COVID-19 pandemic, resulted in relevant epidemiologic changes in most common respiratory viruses. Given the different seasonality and clinical severity observed for some pathogens after lockdown, possible future off-season or more severe epidemics should be expected.

Nationwide trends in sadness, suicidal ideation, and suicide attempts among multicultural and monocultural adolescents in South Korea during the COVID-19 pandemic, 2011-2022

BACKGROUND

Researches on the mental health of Korean adolescents during COVID-19 have largely focused on those from monocultural families, but there is limited data on sadness, suicidal ideation, and suicide attempts in multicultural adolescents.

METHODS

This nationwide serial cross-sectional study included 688,708 adolescents aged 12-18 years who participated in the Korean Youth Risk Behavior Web-based Survey from 2011 to 2022. We compared and analyzed the prevalence of sadness, suicidal ideation, and suicide attempts among multicultural and monocultural adolescents. Multicultural adolescents were defined as those with at least one non-Korean parent.

RESULTS

In 2021, the prevalence of sadness among multicultural adolescents was 31.86% [95% confidence interval (CI) 30.00-33.71], suicidal ideation 17.17% (15.74-18.61), and suicide attempts 4.25% (3.51-4.99). Among monocultural adolescents, the prevalence rates were 26.09% (25.50-26.69) for sadness, 12.41% (11.97-12.85) for suicidal ideation, and 1.92% (1.76-2.67) for suicide attempts. Adolescents from multicultural backgrounds were found to have higher rates of sadness, suicidal ideation, and suicide attempts. In the general population, these rates had decreased during the pre-pandemic period but increased after the onset of the pandemic then stabilized from 2020 to 2021. Female gender, smoking, alcohol use, and low school performance emerged as significant risk factors. However, no distinct risk factors specifically linked to suicide attempts were identified. Joinpoint regression analysis results aligned with the beta slope values in the main findings, reflecting a consistent pattern across both analyses.

CONCLUSIONS

This study revealed that sadness, suicidal ideation, and suicide attempts increased during the pandemic, reversing a pre-pandemic decline. Multicultural adolescents faced these issues more than monocultural ones, underlining the need for targeted public health measures to support at-risk adolescents during pandemics.

Impact of the Early COVID-19 Pandemic on Suicide Attempts and Suicide Deaths in South Korea, 2016-2020: An Interrupted Time Series Analysis

OBJECTIVE

This study aimed to investigate the impact of coronavirus disease-2019 (COVID-19) on suicide attempts and suicide deaths in South Korea, focusing on age and sex differences.

METHODS

We analyzed the monthly number of suicide attempts and suicide deaths during pre-pandemic (January 2016-February 2020) and pandemic (March-December 2020) periods using nationally representative databases. We conducted an interrupted time series analysis and calculated the relative risk (RR) with a 95% confidence interval (CI), categorizing subjects into adolescents (<18), young adults (18-29), middle-aged (30-59), and older adults (≥60).

RESULTS

During the pandemic, the number of suicide attempts abruptly declined in adolescents (RR [95% CI] level change: 0.58 [0.45-0.75]) and older adults (RR [95% CI] level change: 0.74 [0.66-0.84]). In older males, there was a significant rebound in the suicide attempt trend (RR [95% CI] slope change: 1.03 [1.01-1.05]). The number of suicide deaths did not change among age/sex strata significantly except for older males. There was a brief decline in suicide deaths in older males, while the trend showed a following increase with marginal significance (RR [95% CI] level change: 0.76 [0.66-0.88], slope change: 1.02 [1.00-1.04]).

CONCLUSION

This study suggests the heterogeneous impact of the COVID-19 pandemic on suicide attempts and suicide deaths across age and sex strata in South Korea. These findings highlight the need for more targeted mental health interventions, given the observed trends in suicide attempts and suicide deaths during the pandemic.

The effect of silent eating during school lunchtime on COVID-19 outbreaks

Silent eating-no talking during mealtimes-has been used as a measure to reduce the spread of the COVID-19 infection because the emission of droplets during conversations has been considered a risk factor for spreading the virus. Japan implemented silent eating during school lunchtimes in May 2020, and it remained in effect until November 2022. However, concerns have been raised regarding its potential negative effects on children's well-being and educational attainment. More importantly, no study to date has examined its effectiveness in reducing the risk of COVID-19 outbreaks. This study aims to address this important knowledge gap by examining the impact of silent eating on the risk of COVID-19 outbreaks. In November 2022, the Japanese government announced that silent eating in public schools was no longer needed, which resulted in discontinuation of the measure in some schools while other schools maintained it. Taking advantage of this cancelation of the silent eating requirement as a natural experiment, we investigated whether silent eating was associated with a reduced risk of COVID-19 outbreaks. We measured the probability of class closures in public schools (the government's guidelines required class closure when more than one child was infected with COVID-19) by applying a Difference-in-Differences model with two-way fixed effects to panel data. We found no evidence that silent eating was associated with a reduced probability of class closures. Heterogeneity analysis also revealed that our findings did not vary by school characteristics. Our findings indicate that policymakers should be cautious about using silent eating at schools as a potential lever to control outbreaks of infectious diseases.

Korean adolescents' coping strategies on self-harm, ADHD, insomnia during COVID-19: text mining of social media big data

Introduction

Since the Coronavirus disease 2019 (COVID-19), public safety measures, including social distancing and school closures, have been implemented, precipitating psychological difficulties and heightened online activities for adolescents. However, studies examining the impact of the pandemic on adolescent mental health and their coping strategies in Asian countries are limited. Further, most studies have used survey measures to capture mental health challenges so far. Accordingly, this study aimed to examine the psychological challenges South Korean adolescents experienced and their coping strategies during the pandemic using the Natural Language Processing (NLP) and Text mining (TM) technique on adolescents' social media texts/posts.

Methods

The data were gathered from social media texts/posts such as online communities, Twitter, and personal blogs from January 1, 2019, to October 31, 2021. The 12,520,250 texts containing keywords related to adolescents' common psychological difficulties reported during the pandemic, including self-harm, Attention-Deficit/Hyperactivity Disorders (ADHD), and insomnia, were analyzed by TM, NLP using information extraction, co-occurrence and sentiment analysis. The monthly frequency of the keywords and their associated words was also analyzed to understand the time trend.

Results

Adolescents used the word "self-harm" in their social media texts more frequently during the second wave of COVID-19 (August to September 2020). "Friends" was the most associated word with "self-harm." While the frequency of texts with "Insomnia" stayed constant throughout the pandemic, the word "ADHD" was increasingly mentioned in social media. ADHD and insomnia were most frequently associated with ADHD medications and sleeping pills, respectively. Friends were generally associated with positive words, while parents were associated with negative words.

Conclusion

During COVID-19, Korean adolescents often expressed their psychological challenges on social media platforms. However, their coping strategies seemed less efficient to help with their difficulties, warranting strategies to support them in the prolonged pandemic era. For example, Korean adolescents shared psychological challenges such as self-harm with friends rather than their parents. They considered using medicine (e.g., sleeping pills and ADHD medication) as coping strategies for sleep and attention problems.

Impact of Nonpharmacological Interventions on Severe Acute Respiratory Infections in Children: From the National Surveillance Database

BACKGROUND

Nonpharmacological interventions (NPIs) reduce the incidence of respiratory infections. After NPIs imposed during the coronavirus disease 2019 pandemic ceased, respiratory infections gradually increased worldwide. However, few studies have been conducted on severe respiratory infections requiring hospitalization in pediatric patients. This study compares epidemiological changes in severe respiratory infections during pre-NPI, NPI, and post-NPI periods in order to evaluate the effect of that NPI on severe respiratory infections in children.

METHODS

We retrospectively studied data collected at 13 Korean sentinel sites from January 2018 to October 2022 that were lodged in the national Severe Acute Respiratory Infections (SARIs) surveillance database.

RESULTS

A total of 9,631 pediatric patients were admitted with SARIs during the pre-NPI period, 579 during the NPI period, and 1,580 during the post-NPI period. During the NPI period, the number of pediatric patients hospitalized with severe respiratory infections decreased dramatically, thus from 72.1 per 1,000 to 6.6 per 1,000. However, after NPIs ceased, the number increased to 22.8 per 1,000. During the post-NPI period, the positive test rate increased to the level noted before the pandemic.

CONCLUSION

Strict NPIs including school and daycare center closures effectively reduced severe respiratory infections requiring hospitalization of children. However, childcare was severely compromised. To prepare for future respiratory infections, there is a need to develop a social consensus on NPIs that are appropriate for children.

Effectiveness of social distancing measures and lockdowns for reducing transmission of COVID-19 in non-healthcare, community-based settings

Social distancing measures (SDMs) are community-level interventions that aim to reduce person-to-person contacts in the community. SDMs were a major part of the responses first to contain, then to mitigate, the spread of SARS-CoV-2 in the community. Common SDMs included limiting the size of gatherings, closing schools and/or workplaces, implementing work-from-home arrangements, or more stringent restrictions such as lockdowns. This systematic review summarized the evidence for the effectiveness of nine SDMs. Almost all of the studies included were observational in nature, which meant that there were intrinsic risks of bias that could have been avoided were conditions randomly assigned to study participants. There were no instances where only one form of SDM had been in place in a particular setting during the study period, making it challenging to estimate the separate effect of each intervention. The more stringent SDMs such as stay-at-home orders, restrictions on mass gatherings and closures were estimated to be most effective at reducing SARS-CoV-2 transmission. Most studies included in this review suggested that combinations of SDMs successfully slowed or even stopped SARS-CoV-2 transmission in the community. However, individual effects and optimal combinations of interventions, as well as the optimal timing for particular measures, require further investigation. This article is part of the theme issue 'The effectiveness of non-pharmaceutical interventions on the COVID-19 pandemic: the evidence'.

SARS-CoV-2 infection prevention and control measures in Belgian schools between December 2020 and June 2021 and their association with seroprevalence: a cross-sectional analysis of a prospective cohort study

BACKGROUND

To protect school-aged children from the potential consequences of a new viral infection, public health authorities recommended to implement infection prevention and control (IPC) measures in school settings. Few studies evaluated the implementation of these measures and their effect on SARS-CoV-2 infection rates among pupils and staff. The aim of this study was to describe the implementation of infection prevention and control (IPC) measures in Belgian schools and assess its relation to the prevalence of anti-SARS-CoV-2 antibodies among pupils and staff.

METHODS

We conducted a prospective cohort study in a representative sample of primary and secondary schools in Belgium between December 2020 and June 2021. The implementation of IPC measures in schools was assessed using a questionnaire. Schools were classified according to their compliance with the implementation of IPC measures as 'poor', 'moderate' or 'thorough'. Saliva samples were collected from pupils and staff to determine the SARS-CoV-2 seroprevalence. To assess the association between the strength of implementation of IPC measures and SARS-CoV-2 seroprevalence among pupils and staff, we conducted a cross-sectional analysis using the data collected in December 2020/January 2021.

RESULTS

A variety of IPC measures (ventilation, hygiene and physical distancing) was implemented by more than 60% of schools, with most attention placed on hygiene measures. In January 2021, poor implementation of IPC measures was associated with an increase in anti-SARS-CoV-2 antibody prevalence among pupils from 8.6% (95%CI: 4.5 - 16.6) to 16.7% (95%CI: 10.2 - 27.4) and staff from 11.5% (95%CI: 8.1 - 16.4) to 17.6% (95%CI: 11.5 - 27.0). This association was only statistically significant for the assessment of all IPC measures together in the population comprised of pupils and staff.

CONCLUSIONS

Belgian schools were relatively compliant with recommended IPC measures at the school level. Higher SARS-CoV-2 seroprevalence among pupils and staff was found in schools with poor implementation of IPC measures, compared to schools with thorough implementation.

TRIAL REGISTRATION

This trial is registered under the NCT04613817 ClinicalTrials.gov Identifier on November 3, 2020.

School-age vaccination, school openings and Covid-19 diffusion

This article investigates the relationship between school openings and Covid-19 diffusion when school-age vaccination becomes available. The analysis relies on a unique geo-referenced high frequency database on age of vaccination, Covid-19 cases and hospitalization indicators from the Italian region of Sicily. The study focuses on the change of Covid-19 diffusion after school opening in a homogeneous geographical territory (i.e., with the same control measures and surveillance systems, centrally coordinated by the Regional Government). The identification of causal effects derives from a comparison of the change in cases before and after school opening in the school year 2020/21, when vaccination was not available, and in 2021/22, when the vaccination campaign targeted individuals of age 12-19 and above 19. Results indicate that, while school opening determined an increase in the growth rate of Covid-19 cases in 2020/2021, this effect has been substantially reduced by school-age vaccination in 2021/2022. In particular, we find that an increase of approximately 10% in the vaccination rate of school-age population reduces the growth rate of Covid-19 cases after school opening by approximately 1%.

Using an influenza surveillance system to estimate the number of SARS-CoV-2 infections in Beijing, China, weeks 2 to 6 2023

With COVID-19 public health control measures downgraded in China in January 2023, reported COVID-19 case numbers may underestimate the true numbers after the SARS-CoV-2 Omicron wave. Using a multiplier model based on our influenza surveillance system, we estimated that the overall incidence of SARS-CoV-2 infections was 392/100,000 population in Beijing during the 5 weeks following policy adjustment. No notable change occurred after the Spring Festival in early February. The multiplier model provides an opportunity for assessing the actual COVID-19 situation.

The COVID-19 Sentinel Schools Network of Catalonia (CSSNC) project: Associated factors to prevalence and incidence of SARS-CoV-2 infection in educational settings during the 2020-2021 academic year

The Sentinel Schools project was designed to monitor and evaluate the epidemiology of COVID-19 in Catalonia, gathering evidence for health and education policies to inform the development of health protocols and public health interventions to control of SARS-CoV-2 infection in schools. The aim of this study was to estimate the prevalence and incidence of SARS-CoV-2 infections and to identify their determinants among students and staff during February to June in the academic year 2020-2021. We performed two complementary studies, a cross-sectional and a longitudinal component, using a questionnaire to collect nominal data and testing for SARS-CoV-2 detection. We describe the results and perform a univariate and multivariate analysis. The initial crude seroprevalence was 14.8% (95% CI: 13.1-16.5) and 22% (95% CI: 18.3-25.8) for students and staff respectively, and the active infection prevalence was 0.7% (95% CI: 0.3-1) and 1.1% (95% CI: 0.1-2). The overall incidence for persons at risk was 2.73 per 100 person-month and 2.89 and 2.34 per 100 person-month for students and staff, respectively. Socioeconomic, self-reported knowledge, risk perceptions and contact pattern variables were positively associated with the outcome while sanitary measure compliance was negatively associated, the same significance trend was observed in multivariate analysis. In the longitudinal component, epidemiological close contact with SARS-CoV-2 infection was a risk factor for SARS-CoV-2 infection while the highest socioeconomic status level was protective as was compliance with sanitary measures. The small number of active cases detected in these schools suggests a low transmission among children in school and the efficacy of public health measures implemented, at least in the epidemiological scenario of the study period. The major contribution of this study was to provide results and evidence that help analyze the transmission dynamic of SARS-CoV-2 and evaluate the associations between sanitary protocols implemented, and measures to avoid SARS-CoV-2 spread in schools.

Transmission and Profile of COVID-19 in Children in North Sumatera, Indonesia

BACKGROUND

In December 2019, a cluster of viral pneumonia cases, later identified as coronavirus disease 2019 (COVID-19), was first reported in Wuhan, China, and then continued to spread to other parts of the world. COVID-19 is thought to be more prevalent in adults than children; therefore, information about COVID-19 burden and characteristics in children is lacking.

METHODS

We gathered data on the profile and transmission in children with COVID-19 from data collected by the North Sumatera Provincial Health Office team. Data were presented as mean±SD and percentage. Statistical analysis was performed using STATA version 15.0.

RESULTS

From April to October 2020, there were 1125 confirmed COVID-19 cases in children in North Sumatera, representing approximately 8.9% of all cases. Death occurred in 0.62% of the patients, and the children who died had underlying diseases. Four major clusters of COVID-19 infection in children were found in three Islamic boarding schools and one refugee shelter.

CONCLUSION

A high number of children in North Sumatera were affected by COVID-19, and mortality was found to be higher in children with underlying diseases. Major clusters were found in places with prolonged and repeated activities in close contact, such as boarding schools and a refugee shelter.

Surveillance, contact tracing and characteristics of SARS-CoV-2 transmission in educational settings in Northern Italy, September 2020 to April 2021

BACKGROUND

The role of school contacts in the spread of the virus and the effectiveness of school closures in controlling the epidemic is still debated. We aimed to quantify the risk of transmission of SARS-CoV-2 in the school setting by type of school, characteristics of the index case and calendar period in the Province of Reggio Emilia (RE), Italy. The secondary aim was to estimate the speed of implementation of contact tracing.

METHODS

A population-based analysis of surveillance data on all COVID-19 cases occurring in RE, Italy, from 1 September 2020, to 4 April 2021, for which a school contact and/or exposure was suspected. An indicator of the delay in contact tracing was calculated as the time elapsed since the index case was determined to be positive and the date on which the swab test for classmates was scheduled (or most were scheduled).

RESULTS

Overall, 30,184 and 13,608 contacts among classmates and teachers/staff, respectively, were identified and were recommended for testing, and 43,214 (98.7%) underwent the test. Secondary transmission occurred in about 40% of the investigated classes, and the overall secondary case attack rate was 4%. This rate was slightly higher when the index case was a teacher but with almost no differences by type of school, and was stable during the study period. Speed of implementation of contact tracing increased during the study period, with the time from index case identification to testing of contacts being reduced from seven to three days. The ability to identify the possible source of infection in the index case also increased.

CONCLUSIONS

Despite the spread of the Alpha variant during the study period in RE, the secondary case attack rate remained stable from school reopening in September 2020 until the beginning of April 2021.

Analyzing the Effect of Social Distancing Policies on Traffic at Sinchon Station, South Korea, during the COVID-19 Pandemic in 2020 and 2021

The COVID-19 pandemic is recognized as one of the most serious global health problems, and many countries implemented lockdown measures to mitigate the effects of the crisis caused by this respiratory infectious disease. In this study, we investigated the relationship between social distancing policies and changes in traffic volume in Sinchon Station, South Korea. We used an official COVID-19 report provided by the Korea Disease Control and Prevention Agency (KCDA) and Seoul Metropolitan Government (SMG) to review social distancing policies, and the changes in traffic patterns before and during the COVID-19 pandemic between January 2020 and November 2021 were analyzed. Our study reveals that the changes in the overall traffic patterns from acceleration phases to deceleration phases of COVID-19 were related to the alert levels of social distancing policies implemented to tackle the situation resulting from the COVID-19 pandemic. Herein, we found that a significant decline in traffic volume took place from August to September 2020 (13.5−19.7%, weekday; 19.4−31.7%, weekend), from December 2020 to January 2021 (20.0%−26.6%, weekday; 26.8−34.0%, weekend), and from July to September 2021 (3.2−13.1%, weekday; 38.3−44.7%, weekend) when compared to the corresponding periods in 2019 (paired t-test; p < 0.001). The results of this study provide strong support for the effectiveness of Seoul’s preemptive measures, namely, the central government’s intensive social distancing campaign, in managing and reducing the impact of the pandemic situation based on the precise analysis of 10 types of facilities.

SARS-CoV-2 Circulation in the School Setting: A Systematic Review and Meta-Analysis

The contribution of children to viral spread in schools is still debated. We conducted a systematic review and meta-analysis of studies to investigate SARS-CoV-2 transmission in the school setting. Literature searches on 15 May 2021 yielded a total of 1088 publications, including screening, contact tracing, and seroprevalence studies. MOOSE guidelines were followed, and data were analyzed using random-effects models. From screening studies involving more than 120,000 subjects, we estimated 0.31% (95% confidence interval (CI) 0.05–0.81) SARS-CoV-2 point prevalence in schools. Contact tracing studies, involving a total of 112,622 contacts of children and adults, showed that onward viral transmission was limited (2.54%, 95% CI 0.76–5.31). Young index cases were found to be 74% significantly less likely than adults to favor viral spread (odds ratio (OR) 0.26, 95% CI 0.11–0.63) and less susceptible to infection (OR 0.60; 95% CI 0.25–1.47). Lastly, from seroprevalence studies, with a total of 17,879 subjects involved, we estimated that children were 43% significantly less likely than adults to test positive for antibodies (OR 0.57, 95% CI 0.49–0.68). These findings may not applied to the Omicron phase, we further planned a randomized controlled trial to verify these results.

Transmission of SARS-CoV-2 in educational settings in 2020: a review

OBJECTIVES

School closures have been used as a core non-pharmaceutical intervention (NPI) during the COVID-19 pandemic. This review aims at identifying SARS-CoV-2 transmission in educational settings during the first waves of the pandemic.

METHODS

This literature review assessed studies published between December 2019 and 1 April 2021 in Medline and Embase, which included studies that assessed educational settings from approximately January 2020 to January 2021. The inclusion criteria were based on the PCC framework (P-Population, C-Concept, C-Context). The study Population was restricted to people 1-17 years old (excluding neonatal transmission), the Concept was to assess child-to-child and child-to-adult transmission, while the Context was to assess specifically educational setting transmission.

RESULTS

Fifteen studies met inclusion criteria, ranging from daycare centres to high schools and summer camps, while eight studies assessed the re-opening of schools in the 2020-2021 school year. In principle, although there is sufficient evidence that children can both be infected by and transmit SARS-CoV-2 in school settings, the SAR remain relatively low-when NPI measures are implemented in parallel. Moreover, although the evidence was limited, there was an indication that younger children may have a lower SAR than adolescents.

CONCLUSIONS

Transmission in educational settings in 2020 was minimal-when NPI measures were implemented in parallel. However, with an upsurge of cases related to variants of concern, continuous surveillance and assessment of the evidence is warranted to ensure the maximum protection of the health of students and the educational workforce, while also minimising the numerous negative impacts that school closures may have on children.

Decreased patient visits for ankle sprain during the COVID-19 pandemic in South Korea: A nationwide retrospective study

Social distancing measures including school closure and the cancelation of sports activity were enforced during the early phase of the coronavirus disease 2019 (COVID-19) pandemic to reduce the spread of severe acute respiratory syndrome coronavirus 2 in South Korea. To assess the impact of the COVID-19 pandemic on the nationwide burden of musculoskeletal injury in 2020, we analyzed data on the number of patient visits for ankle sprain in South Korea. We collected national reimbursement data on the number of patient visits for ankle sprain between August 2010 and July 2020. To quantify the impact of the COVID-19 pandemic on the number of reductions in patient visits for ankle sprain, we developed a regression model adjusting for the annual cycle of the patient visit during 2016/17-2018/19. During the COVID-19 pandemic in South Korea, the overall number of patient visits for ankle sprain dropped by 7.9%. The number of patient visits for ankle sprain substantially reduced by 23.4% among school-aged children (6-19 years) during the COVID-19 pandemic in South Korea. Our findings suggest that the social distancing measure has had a positive impact on reducing the burden of medical usages for ankle sprain.

Transmission of SARS-CoV-2 by children and young people in households and schools: A meta-analysis of population-based and contact-tracing studies

BACKGROUND

The role of children and young people (CYP) in transmission of SARS-CoV-2 in household and educational settings remains unclear. We undertook a systematic review and meta-analysis of contact-tracing and population-based studies at low risk of bias.

METHODS

We searched 4 electronic databases on 28 July 2021 for contact-tracing studies and population-based studies informative about transmission of SARS-CoV-2 from 0 to 19 year olds in household or educational settings. We excluded studies at high risk of bias, including from under-ascertainment of asymptomatic infections. We undertook multilevel random effects meta-analyses of secondary attack rates (SAR: contact-tracing studies) and school infection prevalence, and used meta-regression to examine the impact of community SARS-CoV-2 incidence on school infection prevalence.

FINDINGS

4529 abstracts were reviewed, resulting in 37 included studies (16 contact-tracing; 19 population studies; 2 mixed studies). The pooled relative transmissibility of CYP compared with adults was 0.92 (0.68, 1.26) in adjusted household studies. The pooled SAR from CYP was lower (p = 0.002) in school studies 0.7% (0.2, 2.7) than household studies (7.6% (3.6, 15.9) . There was no difference in SAR from CYP to child or adult contacts. School population studies showed some evidence of clustering in classes within schools. School infection prevalence was associated with contemporary community 14-day incidence (OR 1.003 (1.001, 1.004), p<0.001).

INTERPRETATION

We found no difference in transmission of SARS-CoV-2 from CYP compared with adults within household settings. SAR were markedly lower in school compared with household settings, suggesting that household transmission is more important than school transmission in this pandemic. School infection prevalence was associated with community infection incidence, supporting hypotheses that school infections broadly reflect community infections. These findings are important for guiding policy decisions on shielding, vaccination school and operations during the pandemic.

SARS-CoV-2 transmission in schools in Korea: nationwide cohort study

OBJECTIVE

There is an urgent public need to readdress the school closure strategies. We aimed to describe the epidemiology of COVID-19 in schools and school-aged children to understand their roles in transmitting SARS-CoV-2 in Korea.

DESIGN

Retrospective cohort study.

SETTING

All schools in Korea PATIENTS: All school-aged children in Korea.

INTERVENTIONS

None (observational study).

MAIN OUTCOME MEASURES

Incidence rate, proportion of affected schools.

RESULTS

Between February and December 2020, the incidence rate was lower among school-aged children (63.2-79.8 per 100 000) compared with adults aged 19 and above (130.4 per 100 000). Household was the main route of transmission (62.3%), followed by community (21.3%) and school clusters (7.9%). Among the schools in Korea, 52% of secondary schools had COVID-19 cases, followed by 39% of primary schools and 3% of kindergartens.

CONCLUSIONS

We found that schools and school-aged children aged 7-18 years were not the main drivers of COVID-19 transmission. The major sources of transmission were households.

Transmission of SARS-CoV-2 by children: a rapid review, 30 December 2019 to 10 August 2020

BackgroundThe role of children in the transmission of SARS-CoV-2 during the early pandemic was unclear.AimWe aimed to review studies on the transmission of SARS-CoV-2 by children during the early pandemic.MethodsWe searched MEDLINE, Embase, the Cochrane Library, Europe PubMed Central and the preprint servers medRxiv and bioRxiv from 30 December 2019 to 10 August 2020. We assessed the quality of included studies using a series of questions adapted from related tools. We provide a narrative synthesis of the results.ResultsWe identified 28 studies from 17 countries. Ten of 19 studies on household and close contact transmission reported low rates of child-to-adult or child-to-child transmission. Six studies investigated transmission of SARS-CoV-2 in educational settings, with three studies reporting 183 cases from 14,003 close contacts who may have contracted COVID-19 from children index cases at their schools. Three mathematical modelling studies estimated that children were less likely to infect others than adults. All studies were of low to moderate quality.ConclusionsDuring the early pandemic, it appeared that children were not substantially contributing to household transmission of SARS-CoV-2. School-based studies indicated that transmission rates in this setting were low. Large-scale studies of transmission chains using data collected from contact tracing and serological studies detecting past evidence of infection would be needed to verify our findings.

SARS-CoV-2 infections and public health responses in schools and early childhood education and care centres in Victoria, Australia: An observational study

Background

The epidemiology of SARS-CoV-2 in children is an important consideration for control measures. To inform the safe re-opening of Victorian schools and early childhood education and care (ECEC) in late 2020, a detailed analysis of local data was undertaken.

Methods

Data on all Victorian SARS-CoV-2 confirmed cases, their close contacts, and ECEC/school events from the first case in Victoria to the end of the third school term (25/01/2020 – 18/09/2020) were analysed. We compared temporal and geographic trends in cases linked to ECEC/school events and community cases; and describe events with onward transmission by age of first case, and public health actions.

Findings

Victoria recorded 20,049 SARS-CoV-2 cases during the study period. In total, 1,691 cases and 18,423 contacts were linked to 339 events in ECEC/schools. Many (n=224, 66·1%) events had no evidence of onward transmission, and most (96·5%) involved <10 cases. Onward transmission was more common when the first case was older: when first case was aged 0-5 years, 14·1% events involved additional cases, compared to 30·5% (6-12 years), 33·3% (13-15 years), 42·9% (16-18 years), and 39·1% when the first case was an adult. ECEC/schools were closed within a median of one day (IQR 0-2) from laboratory notification of the first case.

Interpretation

Mitigation measures and rapid responses prevented most SARS-CoV-2 cases in ECEC/schools from becoming outbreaks in Victoria in 2020. As new variants emerge and vaccination coverage increases, ECEC/school mitigation strategies should be tailored to local community transmission and educational level.

Funding

The Victorian Department of Health and Human Services.

Analysis of Critical COVID-19 Cases Among Children in Korea

BACKGROUND

Coronavirus disease 2019 (COVID-19) is generally asymptomatic or mild in otherwise healthy children, however, severe cases may occur. In this study, we report the clinical characteristics of children classified as critical COVID-19 in Korea to provide further insights into risk factors and management in children.

METHODS

This study was a retrospective case series of children < 18 years of age classified as critical COVID-19. Cases were identified by the Korea Disease Control and Prevention Agency surveillance system and medical records were reviewed. Critical COVID-19 was defined as cases with severe illness requiring noninvasive (high flow nasal cannula, continuous positive airway pressure, or bilevel positive airway pressure) or invasive mechanical ventilation, extracorporeal membrane oxygenation (ECMO) or continuous renal replacement therapy (CRRT), between January 20, 2020 and October 7, 2021.

RESULTS

Among 39,146 cases diagnosed with COVID-19 in subjects < 18 years of age, eight cases (0.02%) were identified as critical COVID-19. The median age was 13 years (range 10 month-17 years) and male-to-female ratio was 1:1. Three children had underlying diseases; one child has asthma and major depressive disorder, one child had Lennox-Gastaut syndrome and one child had mental retardation and was newly diagnosed with type 2 diabetes mellitus with the diagnosis of COVID-19. Among the eight children, seven were obese (body mass index range [BMI] median 29.3, range 25.9-38.2, weight-for-length > 97% for infant) and one was overweight (BMI 21.3). All patients had fever, six patients had dyspnea or cough and other accompanied symptoms included sore throat, headache, lethargy and myalgia. Radiologic findings showed pneumonia within 1-8 days after symptom onset. Pneumonia progressed in these children for 2-6 days and was improved within 5-32 days after diagnosis. Among the eight critical cases, remdesivir was administered in six cases. Steroids were provided for all cases. Inotropics were administered in one case. Six cases were treated with noninvasive mechanical ventilator and three required mechanical ventilator. One case required ECMO due to acute respiratory distress syndrome. All cases were admitted to the intensive care unit and admission period ranged from 9-39 days. Among all critical COVID-19 cases < 18 years of age, there were no fatal cases.

CONCLUSION

To develop appropriate policies for children in the COVID-19 pandemic, it is important to monitor and assess the clinical burden in this population.

What did COVID-19 Change? The Impact of COVID-19 on Korean Parents' and Children's Daily Lives and Stress

The COVID-19 outbreak has not only posed a threat to physical health but has also changed our daily lives. This study explored how the COVID-19 pandemic affected Korean parents' and children's daily lives and stress levels. Parents' childcare time, children's screen time, the time spent for social interactions and learning, and parents' and children's stress levels before and after the pandemic were compared. The main caregivers' childcare time increased significantly during the pandemic (4.00 h/day). For children, the time spent for screen time (1.76 h) and online interactions (0.95 h) increased significantly, whereas face-to-face interaction time (4.17 h) and time spent learning (2.16 h) decreased significantly. In addition, parents' and children's stress levels increased significantly during the pandemic. Other descriptive information is provided and discussed. Our results indicate that Korean parents and children experienced significant disruption to their daily lives and increased stress during the pandemic.

Kawasaki disease following SARS-CoV-2 infection: Stronger inflammation with no increase in cardiac complications

BACKGROUND

Herein we investigate the difference between Kawasaki disease (KD) with and without a recent history of SARS-CoV-2 infection.

METHODS

We compared the clinical characteristics of patients with KD during the SARS-CoV-2 pandemic in a single children's hospital in Korea. Fifty-two patients were enrolled and divided into group 1 (with a history of COVID-19, n = 26) and group 2 (without a history of COVID-19, n = 26) according to whether or not they contracted COVID-19 within the 8 weeks before hospitalization. Data, including clinical features and laboratory results, were analyzed and compared between groups.

RESULTS

The median age of patients was significantly higher in group 1 than in group 2 (53 months [IQR, 24-81] vs. 15 months [IQR, 6-33], p = 0.001). The incidence of cervical lymphadenopathy was significantly higher (p = 0.017), while that of BCGitis was significantly lower in group 1 (p = 0.023), and patients had a significantly longer hospital stay (5 days [IQR, 3-8] vs. 3 days [IQR, 3-4], p = 0.008). In group 1, platelet count was significantly lower (p = 0.006), and hemoglobin and ferritin levels were significantly higher (p = 0.013 and p = 0.001, respectively) on the first admission day. Following treatment with intravenous immunoglobulin (IVIG), the platelet count was significantly lower (p = 0.015), and the percentage of neutrophils and neutrophil-to-lymphocyte ratio were significantly higher in group 1 (p = 0.037 and p = 0.012). Although there was no statistical difference, patients requiring infliximab treatment due to prolonged fever was only in group 1. The incidence of cardiovascular complications did not differ between the groups.

CONCLUSIONS

Post-COVID KD showed a stronger inflammatory response than KD-alone, with no differences in cardiac complications.

Providing children with COVID-19 vaccinations is challenging due to lack of data and wide-ranging parental acceptance

AIM

Vaccines are vital to ending the COVID-19 pandemic and we reviewed the data on vaccinating children, and including them in clinical trials, as most of the activity has focused on adults.

METHODS

English and Chinese databases, including PubMed, Elsevier Scopus, Web of Science, CNKI and CQVIP were searched, along with websites such as the World Health Organization and the University of Oxford.

RESULTS

We identified 44 papers and 16 news items about vaccinating children against the virus, published from 10 February 2020 to 14 July 2021. Child vaccination has been slow and only a few countries have included children in Phase II or III clinical trials. The data on children were much more limited than on adults, but most children were asymptomatic or had mild symptoms and some deaths had been recorded. More clinical trials are needed to assess the safety and efficacy of vaccinating children, as higher vaccination levels can help to build up herd immunity. The percentage of parents willing to vaccinate their children against the virus ranged from 48.2% to 72.6%, with much lower rates for letting them participate in clinical trials.

CONCLUSION

Vaccines should be offered to children as soon as their safety and efficacy are established.

Psychometric Properties of the Stress and Anxiety to Viral Epidemics-6 Items (SAVE-6) Scale for High School Students During the COVID-19 Pandemic

OBJECTIVES

Owing to the COVID-19 pandemic, high school students have experienced a sudden change of school environment, which may result in difficulties related to mental health. The aim of this study is to estimate the reliability and validity of the Stress and Anxiety to Viral Epidemics-6 Items (SAVE-6) scale among high school students.

METHODS

A cross-sectional online survey was conducted among 300 high school students. The following scales were administered: the SAVE-6, Generalized Anxiety Disorder-7 Items (GAD-7), and Patient Health Questionnaire-9 Items (PHQ-9). Exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were conducted, and the psychometric properties of the SAVE-6 were assessed.

RESULTS

The results of the CFA indicated good model fit for the SAVE-6 scale among high school students (χ2/df = 0.485, CFI = 1.000, TLI = 1.010, RMSEA < 0.001, and SRMR = 0.029). In addition, the SAVE-6 scale demonstrated good reliability (Cronbach's alpha = 0.844, McDonald's Omega = 0.848, and split-half reliability = 0.883). The appropriate cut-off score for the SAVE-6 scale was estimated as ≥15, which corresponds to a mild level of anxiety as assessed by the GAD-7 (≥5).

CONCLUSION

The SAVE-6 scale was found to be reliable and valid, and can be used as a tool to assess the stress and anxiety of high school students during the COVID-19 pandemic.

[Children in the COVID-19 pandemic and the public health service (ÖGD) : Data and reflections from Frankfurt am Main, Germany]

BACKGROUND

The measures taken to combat the COVID-19 pandemic have severely restricted the opportunities for the development of children. This paper will discuss the reporting data of children and the public health department's activities against the background of the restrictions of school and leisure time offers as well as sports and club activities.

MATERIALS AND METHODS

Reporting data from Frankfurt am Main, Hesse, were obtained using a SURVStat query for the calendar weeks 10/2020-28/2021 and from SURVNet (until 30 June 2021). Contact persons (CP) of SARS-CoV‑2 positive persons from schools and daycare centers were screened for SARS-CoV‑2 by PCR test. These results and those of rapid antigen testing, which has been mandatory for schoolchildren since April 2021, are presented.

RESULTS

Until Easter break, the age-related seven-day incidence values per 100,000 for children 14 years of age and younger were lower than the overall incidence; it was only higher after rapid antigen-testing was mandatory for schoolchildren. Most children with SARS-CoV‑2 had no or mild symptoms; hospitalization was rarely required and no deaths occurred. Contact tracing in schools and daycare centers found no positive contacts in most cases and rarely more than two. Larger outbreaks did not occur.

CONCLUSION

SARS-CoV‑2 infections in children appear to be less frequent and much less severe than in adults. Hygiene rules and contact management have proven themselves effective during times with high incidences in the local population without mandatory rapid antigen testing - and even with a high proportion of variants of concern (alpha and delta variants) in Germany. Against this background, further restriction of school and daycare operations appears neither necessary nor appropriate.

Outbreak of SARS-CoV-2 in a Children's Nursery in the United Kingdom

BACKGROUND

Early Years' Settings (EYSs) provide childcare and education for children 0-5 years old. They remained fully open in England during the third National lockdown when other educational settings were only open for selected children. EYSs are generally considered to be low-risk settings for transmission of severe acute respiratory syndrome coronavirus 2 (SARS CoV-2).

METHODS

An observational study describing a large outbreak of SARS CoV-2 within an EYS in Cambridgeshire, United Kingdom.

RESULTS

Overall 45 cases of SARS-CoV-2 were identified; 24 adults (71% of staff members) and 21 children (25% of nursery attendees). One case was identified as the alpha variant (B.1.1.7 [VOC-20-DEC-01]). One staff member became critically unwell.

CONCLUSIONS

Transmission of SARS-CoV-2 occurred quickly, with a high attack rate; likely a consequence of a variant with enhanced transmissibility and an inability of the setting to adhere to infection control measures.

No causal effect of school closures in Japan on the spread of COVID-19 in spring 2020

Among tool kits to combat the coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2, school closures are one of the most frequent non-pharmaceutical interventions. However, school closures bring about substantial costs, such as learning loss. To date, studies have not reached a consensus about the effectiveness of these policies at mitigating community transmission, partly because they lack rigorous causal inference. Here we assess the causal effect of school closures in Japan on reducing the spread of COVID-19 in spring 2020. By matching each municipality with open schools to a municipality with closed schools that is the most similar in terms of potential confounders, we can estimate how many cases the municipality with open schools would have had if it had closed its schools. We do not find any evidence that school closures in Japan reduced the spread of COVID-19. Our null results suggest that policies on school closures should be reexamined given the potential negative consequences for children and parents.

Surveillance of Outbreaks of SARS-CoV-2 Infections at School in the Veneto Region: Methods and Results of the Public Health Response during the Second and Third Waves of the Pandemic between January and June 2021

During the COVID-19 pandemic, many countries adopted various non-pharmacological interventions to contain the number of infections. The most often used policy was school closures. We describe the strategy adopted by the Veneto Regional Authority to contain transmission in school settings. This included a detailed school surveillance system, strict contact tracing, and maintaining school attendance with self-monitoring for symptoms whenever possible. All analyzed COVID-19 cases among children, adolescents (0–19 years old), and school staff were registered using a web-based application between 4 January 2021 and 13 June 2021. During the study period, 6272 episodes of infection in schools were identified; 87% were linked to a student index case and 13% to school staff; 69% generated no secondary cases; 24% generated one or two; and only 7% caused more than two. Our data may help to clarify the role of school closures, providing useful input for decisions in the months to come. Good practice in public health management needs tools that provide a real-time interpretation of phenomena like COVID-19 outbreaks. The proposed measures should be easy to adopt and accessible to policymakers.

Impact of School Closures on the Proportion of Children in the COVID-19 Pandemic: An Example from the Winter Lockdown in Germany

BACKGROUND

In addition to widely used basic hygiene measures in school, school closures are applied to contain SARS-CoV-2 spread, although the effect on the pandemic is unclear. We proposed a simple approach to disentangle the effect of school closures from other lockdown measures on the pandemic course based on publicly available data in Germany.

METHODS

We used data on the number of SARS-CoV-2 cases from the onset of the pandemic to 14th April 2021. We compared the proportion of children (5-14 years old) in all cases prior to the lockdown measures, including school closure, to that during a ten-week lockdown in Germany. The total number of paediatric cases occurring during lockdown was compared to the number expected in absence of school closures. The latter was calculated based on the actual weekly number of all cases and the pre-lockdown proportion of paediatric cases.

RESULTS

The proportion of children in all cases was 2.3 percentage points lower at the nadir than the proportion before the lockdown. The estimated total number of paediatric cases prevented by school closures was estimated at 13,246 amounting to 24% of the expected cases in absence of school closures.

CONCLUSION

School closure during the winter lockdown reduced the number of expected SARS-CoV-2 cases in children in absence of school closures. The contribution of these prevented cases to the total population incidence is small. These data might provide the basis to model the effect of school closures in addition to basic hygiene measures on the course of the COVID-19 pandemic.

Spatial distribution of SARS-CoV-2 infection in schools, South Korea

Identification of geographical areas with high burden of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission in schools using spatial analyses has become an important tool to guide targeted interventions in educational setting. In this study, we aimed to explore the spatial distribution and determinants of coronavirus disease 2019 (COVID-19) among students aged 3-18 years in South Korea. We analysed the nationwide epidemiological data on laboratory-confirmed COVID-19 cases in schools and in the communities between January 2020 and October 2021 in South Korea. To explore the spatial distribution, the global Moran's I and Getis-Ord's G using incidence rates among the districts of aged 3-18 years and 30-59 years. Spatial regression analysis was performed to find sociodemographic predictors of the COVID-19 attack rate in schools and in the communities. The global spatial correlation estimated by Moran's I was 0.647 for the community population and 0.350 for the student population, suggesting that the students were spatially less correlated than the community-level outbreak of SARS-CoV-2. In schools, attack rate of adults aged 30-59 years in the community was associated with increased risk of transmission (P < 0.0001). Number of students per class (in kindergartens, primary schools, middle schools and high schools) did not show significant association with the school transmission of SARS-CoV-2. In South Korea, COVID-19 in students had spatial variations across the country. Statistically significant high hotspots of SARS-CoV-2 transmission among students were found in the capital area, with dense population level and high COVID-19 burden among adults aged 30-59 years. Our finding suggests that controlling community-level burden of COVID-19 can help in preventing SARS-CoV-2 infection in school-aged children.

COVID-19 in Early Life: Infants and Children Are Affected Too

Compared with adults, children are less likely infected with SARS-CoV-2 and are often asymptomatic when infected. However, infection in children can lead to severe disease. The pandemic affects the lives of all children, especially those with lower socioeconomic status. This review highlights the physiological impacts of COVID-19 in early life.

Lessons learnt during the COVID-19 pandemic: Why Australian schools should be prioritised to stay open

In 2020, school and early childhood educational centre (ECEC) closures affected over 1.5 billion school-aged children globally as part of the COVID-19 pandemic response. Attendance at school and access to ECEC is critical to a child's learning, well-being and health. School closures increase inequities by disproportionately affecting vulnerable children. Here, we summarise the role of children and adolescents in Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) transmission and that of schools and ECECs in community transmission and describe the Australian experience. In Australia, most SARS-CoV-2 cases in schools were solitary (77% in NSW and 67% in Victoria); of those that did progress to an outbreak, >90% involved fewer than 10 cases. Australian and global experience has demonstrated that SARS-CoV-2 is predominantly introduced into schools and ECECs during periods of heightened community transmission. Implementation of public health mitigation strategies, including effective testing, tracing and isolation of contacts, means schools and ECECs can be safe, not drivers of transmission. Schools and ECEC are essential services and so they should be prioritised to stay open for face-to-face learning. This is particularly critical as we continue to manage the next phase of the COVID-19 pandemic.

Risk of infection and transmission of SARS-CoV-2 among children and adolescents in households, communities and educational settings: A systematic review and meta-analysis

BACKGROUND

There is uncertainty with respect to SARS-CoV-2 transmission in children (0-19 years) with controversy on effectiveness of school-closures in controlling the pandemic. It is of equal importance to evaluate the risk of transmission in children who are often asymptomatic or mildly symptomatic carriers that may incidentally transmit SARS-CoV-2 in different settings. We conducted this review to assess transmission and risks for SARS-CoV-2 in children (by age-groups or grades) in community and educational-settings compared to adults.

METHODS

Data for the review were retrieved from PubMed, EMBASE, Cochrane Library, WHO COVID-19 Database, China National Knowledge Infrastructure (CNKI) Database, WanFang Database, Latin American and Caribbean Health Sciences Literature (LILACS), Google Scholar, and preprints from medRixv and bioRixv) covering a timeline from December 1, 2019 to April 1, 2021. Population-screening, contact-tracing and cohort studies reporting prevalence and transmission of SARS-CoV-2 in children were included. Data were extracted according to PRISMA guidelines. Meta-analyses were performed using Review Manager 5.3.

RESULTS

Ninety studies were included. Compared to adults, children showed comparable national (risk ratio (RR) = 0.87, 95% confidence interval (CI) = 0.71-1.060 and subnational (RR = 0.81, 95% CI = 0.66-1.01) prevalence in population-screening studies, and lower odds of infection in community/household contact-tracing studies (odds ratio (OR) = 0.62, 95% CI = 0.46-0.84). On disaggregation, adolescents observed comparable risk (OR = 1.22, 95% CI = 0.74-2.04) with adults. In educational-settings, children attending daycare/preschools (OR = 0.53, 95% CI = 0.38-0.72) were observed to be at lower-risk when compared to adults, with odds of infection among primary (OR = 0.85, 95% CI = 0.55-1.31) and high-schoolers (OR = 1.30, 95% CI = 0.71-2.38) comparable to adults. Overall, children and adolescents had lower odds of infection in educational-settings compared to community and household clusters.

CONCLUSIONS

Children (<10 years) showed lower susceptibility to COVID-19 compared to adults, whereas adolescents in communities and high-schoolers had comparable risk. Risks of infection among children in educational-settings was lower than in communities. Evidence from school-based studies demonstrate it is largely safe for children (<10 years) to be at schools, however older children (10-19 years) might facilitate transmission. Despite this evidence, studies focusing on the effectiveness of mitigation measures in educational settings are urgently needed to support both public health and educational policy-making for school reopening.

Respiratory syncytial virus and influenza epidemics disappearance in Korea during the 2020-2021 season of COVID-19

OBJECTIVES

We investigated whether non-pharmaceutical interventions (NPIs) reduce winter-prevalent respiratory viral infections represented by a respiratory syncytial virus (RSV) and influenza virus (IFV) during the winter in Korea.

METHODS

The Korean Influenza and Respiratory Virus Monitoring System database was used. From January 2016 through January 2021, the weekly positivity of respiratory viruses and the weekly number of hospitalizations with acute respiratory infections were collected. The NPI period was defined as February 2020-January 2021. We analyzed whether hospitalization and sample positivity by respiratory viruses changed after NPIs. Bayesian structural time-series models and Poisson analyses were used. Data from other countries/regions reporting positive rates of RSV and IFV were also investigated.

RESULTS

Compared with the pre-NPI period, the positive rates of RSV and IFV decreased significantly to 19% and 6%, and 23% and 6% of the predicted value. Also, hospitalization significantly decreased to 9% and 8%, and 10% and 5% of the predicted value. The positive rates of IFV in 14 countries during the NPI period were almost 0, whereas sporadic outbreaks of RSV occurred in some countries.

CONCLUSIONS

No RSV and IFV winter epidemics were observed during the 2020-2021 season in Korea.

SARS-CoV-2 transmission in kindergarten to grade 12 schools in the Vancouver Coastal Health region: a descriptive epidemiologic study

BACKGROUND

There is an urgent need to assess the role of schools in the spread of SARS-CoV-2 in Canada to inform public health measures. We describe the epidemiology of SARS-CoV-2 infection among students and staff in the Vancouver Coastal Health (VCH) region in the first 3 months of the 2020/2021 academic year, and examine the extent of transmission in schools.

METHODS

This descriptive epidemiologic study using contact tracing data included individuals aged 5 years and older with SARS-CoV-2 infection, reported between Sept. 10 and Dec. 18, 2020, who worked in or attended kindergarten to grade 12 (K-12) schools in person in the VCH region. We described case and cluster characteristics and reported the number of school-based transmissions.

RESULTS

During the study period, 699 cases of SARS-CoV-2 infection were reported (55 cases per 10 000 VCH school population). Among cases in VCH resident staff and students, 52.5% (354/674) were linked to a household case or cluster; less than 1.5% (< 10) of infected individuals were hospitalized and none died. Out of 699 cases present at school, 26 clusters with school-based transmission resulted in 55 secondary cases. Staff members accounted for 53.8% of index cases (14/26) while making up 14.3% of the school population (17 742/123 647). Among clusters, 88.5% (23) had fewer than 4 secondary cases.

INTERPRETATION

In our population during the study period, there were no deaths and severe disease was rare; furthermore, school-based SARS-CoV-2 transmissions were uncommon and clusters were small. Our results, which relate primarily to symptomatic disease, support the growing body of evidence that schools likely did not play a major role in SARS-CoV-2 spread in 2020.

SARS-CoV-2 transmission in kindergarten to grade 12 schools in the Vancouver Coastal Health region: a descriptive epidemiologic study

BACKGROUND

There is an urgent need to assess the role of schools in the spread of SARS-CoV-2 in Canada to inform public health measures. We describe the epidemiology of SARS-CoV-2 infection among students and staff in the Vancouver Coastal Health (VCH) region in the first 3 months of the 2020/2021 academic year, and examine the extent of transmission in schools.

METHODS

This descriptive epidemiologic study using contact tracing data included individuals aged 5 years and older with SARS-CoV-2 infection, reported between Sept. 10 and Dec. 18, 2020, who worked in or attended kindergarten to grade 12 (K-12) schools in person in the VCH region. We described case and cluster characteristics and reported the number of school-based transmissions.

RESULTS

During the study period, 699 cases of SARS-CoV-2 infection were reported (55 cases per 10 000 VCH school population). Among cases in VCH resident staff and students, 52.5% (354/674) were linked to a household case or cluster; less than 1.5% (< 10) of infected individuals were hospitalized and none died. Out of 699 cases present at school, 26 clusters with school-based transmission resulted in 55 secondary cases. Staff members accounted for 53.8% of index cases (14/26) while making up 14.3% of the school population (17 742/123 647). Among clusters, 88.5% (23) had fewer than 4 secondary cases.

INTERPRETATION

In our population during the study period, there were no deaths and severe disease was rare; furthermore, school-based SARS-CoV-2 transmissions were uncommon and clusters were small. Our results, which relate primarily to symptomatic disease, support the growing body of evidence that schools likely did not play a major role in SARS-CoV-2 spread in 2020.

School closures during the coronavirus disease 2019 outbreak

School closures during the coronavirus disease 2019 (COVID-19) pandemic have been outlined in studies from different disciplines, including economics, sociology, mathematical modeling, epidemiology, and public health. In this review, we discuss the implications of school closures in the context of the current COVID-19 pandemic. Modeling studies of the effects of school closures, largely derived from the pandemic influenza model, on severe acute respiratory syndrome coronavirus 2 produced conflicting results. Earlier studies assessed the risk of school reopening by modeling transmission across schools and communities; however, it remains unclear whether the risk is due to increased transmission in adults or children. The empirical findings of the impact of school closures on COVID-19 outbreaks suggest no clear effect, likely because of heterogeneity in community infection pressure, differences in school closure strategies, or the use of multiple interventions. The benefits of school closings are unclear and not readily quantifiable; however, they must be weighed against the potential high social costs, which can also negatively affect the health of this generation.

COVID-19 in childhood: Transmission, clinical presentation, complications and risk factors

Children less than 18 years of age account for an estimated 2%-5% of reported severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cases globally. Lower prevalence of coronavirus disease 2019 (COVID-19) among children, in addition to higher numbers of mild and asymptomatic cases, continues to provide challenges in determining appropriate prevention and treatment courses. Here, we summarize the current evidence on the transmission, clinical presentation, complications and risk factors in regard to SARS-CoV-2 in children, and highlight crucial gaps in knowledge going forward. Based on current evidence, children are rarely the primary source of secondary transmission in the household or in child care and school settings and are more likely to contract the virus from an adult household member. Higher transmission rates are observed in older children (10-19 years old) compared with younger children ( <10 years old). While increasing incidence of COVID-19 in neonates raises the suspicion of vertical transmission, it is unlikely that breast milk is a vehicle for transmission from mother to infant. The vast majority of clinical cases of COVID-19 in children are mild, but there are rare cases that have developed complications such as multisystem inflammatory syndrome in children, which often presents with severe cardiac symptoms requiring intensive care. Childhood obesity is associated with a higher risk of infection and a more severe clinical presentation. Although immediate mortality rates among children are low, long-term respiratory, and developmental implications of the disease remain unknown in this young and vulnerable population.

Pediatric Endocrinology of Post-Pandemic Era

The COVID-19 pandemic has brought about significant changes in the global health and medical environment. In order to prevent viral transmission, governments implemented strong social distancing, even lockdowns. The closure of schools has reduced physical activity among children and adolescents. Children, especially those with chronic diseases, are often reluctant to visit or even give up visiting hospitals, resulting in delayed diagnosis or missing the right timing for treatment. New guidelines are needed for the management of patients with endocrine diseases such as diabetes or thyroid disease, as well as children with chronic diseases who need regular clinical monitoring. Therefore, it is necessary to analyze the previous research on pediatric endocrinology reported during COVID-19, guide the direction for future research, and establish guidelines to care for pediatric patients with endocrine diseases in the post-pandemic era.

Clinical Characteristics and Transmission of COVID-19 in Children and Youths During 3 Waves of Outbreaks in Hong Kong

IMPORTANCE

Schools were closed intermittently across Hong Kong to control the COVID-19 outbreak, which led to significant physical and psychosocial problems among children and youths.

OBJECTIVE

To compare the clinical characteristics and sources of infection among children and youths with COVID-19 during the 3 waves of outbreaks in Hong Kong in 2020.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study involved children and youths aged 18 years or younger with COVID-19 in the 3 waves of outbreaks from January 23 through December 2, 2020. Data were analyzed from December 2020 through January 2021.

MAIN OUTCOMES AND MEASURES

Demographic characteristics, travel and contact histories, lengths of hospital stay, and symptoms were captured through the central electronic database. Individuals who were infected without recent international travel were defined as having domestic infections.

RESULTS

Among 397 children and youths confirmed with COVID-19 infections, the mean (SD) age was 9.95 (5.34) years, 220 individuals (55.4%) were male, and 154 individuals (38.8%) were asymptomatic. There were significantly more individuals who were infected without symptoms in the second wave (59 of 118 individuals [50.0%]) and third wave (94 of 265 individuals [35.5%]) than in the first wave (1 of 14 individuals [7.1%]) (P = .001). Significantly fewer individuals who were infected in the second and third waves, compared with the first wave, had fever (first wave: 10 individuals [71.4%]; second wave: 22 individuals [18.5%]; third wave: 98 individuals [37.0%]; P < .001) or cough (first wave: 6 individuals [42.9%]; second wave: 15 individuals [12.7%]; third wave: 52 individuals [19.6%]; P = .02). Among all individuals, 394 individuals (99.2%) had mild illness. One patient developed chilblains (ie, COVID toes), 1 patient developed multisystem inflammatory syndrome in children, and 1 patient developed post-COVID-19 autoimmune hemolytic anemia. In all 3 waves, 204 patients with COVID-19 (51.4%) had domestic infections. Among these individuals, 186 (91.2%) reported having a contact history with another individual with COVID-19, of which most (183 individuals [90.0%]) were family members. In the third wave, 18 individuals with domestic infections had unknown contact histories. Three schoolmates were confirmed with COVID-19 on the same day and were reported to be close contacts.

CONCLUSIONS AND RELEVANCE

This cross-sectional study found that nearly all children and youths with COVID-19 in Hong Kong had mild illness. These findings suggest that household transmission was the main source of infection for children and youths with domestic infections and that the risk of being infected at school was small.

Shifting patterns of respiratory virus activity following social distancing measures for COVID-19 in South Korea

BACKGROUND

We hypothesized that nationwide social distancing and other preventive measures for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were associated with reduced detection of other respiratory viruses in South Korea.

METHODS

We analyzed national surveillance data to compare incidence of respiratory viruses during 2016-2019 vs. 2020. Results of multiplex reverse transcriptase-polymerase chain reaction assays for eight respiratory viruses were included: adenovirus (ADV), parainfluenza virus (PIV), respiratory syncytial virus (RSV), influenza virus (IFV), human coronavirus (HCoV; non-SARS-CoV-2), human rhinovirus (HRV), human bocavirus (HBoV), and human metapneumovirus (HMPV).

RESULTS

During 2016-2019, rates of detection of respiratory viruses were relatively stable: ADV, 3.7%-9.2%; PIV, 1.4%-17.0%; RSV, 0.3%-15.3%; IFV, 0.4%-35.6%; HCoV, 1.5%-8.4%; HRV, 7.0%-25.1%; HBoV, 0.6%-6.3%; and HMPV, 0.7%-14.5%. Following implementation of social distancing in February 2020, rates of detection of enveloped viruses (HCoV, HMPV, IFV, PIV and RSV) were significantly reduced by up to 100%. However, non-enveloped viruses (ADV, HRV and HBoV) persisted throughout 2020, and HRV rates in hospitalized patients significantly increased.

CONCLUSIONS

After implementation of social distancing for SARS-CoV-2 in South Korea, rates of detection of enveloped respiratory viruses decreased significantly, whereas non-enveloped viruses persisted, suggesting that enhanced infection prevention strategies are required to mitigate spread of these viruses.

[Impact of COVID-19s alarm states in the care of pediatric patients in Primary Care in a health area in northern Spain]

Objetivo

La pandemia por SARS-CoV-2 ha supuesto un cambio global en el modelo asistencial, potenciando la asistencia telemática, especialmente a nivel de Atención Primaria (AP). El objetivo de nuestro estudio es describir el impacto que han tenido los dos estados de alarma decretados en España en la asistencia de la población infantil a nivel de AP.

Material y métodos

Estudio observacional retrospectivo. Se analizaron las consultas de AP correspondientes a pacientes pediátricos (<14 años) de un área sanitaria del norte de España y de un Centro de Salud perteneciente a esa área, durante el primer y segundo estados de alarma, y se compararon con sus períodos homólogos del 2019.

Resultados

Durante el primer estado de alarma en que se estableció confinamiento domiciliario y cierre de los colegios, se objetivó un gran descenso de las consultas pediátricas en los centros de salud (758 vs. 1.381 en 2019), a expensas principalmente de revisiones de salud y enfermedades infecciosas. Dicha disminución no se observó en el segundo estado de alarma (1.375 vs. 1.233 en 2019). En ambos aumentó de forma significativa el porcentaje de consultas telefónicas.

Conclusiones

La implantación de los estados de alarma ha supuesto un descenso de la demanda asistencial, sobre todo durante la primera ola, que podría deberse al temor de las familias a acudir al centro de salud y la disminución de la transmisibilidad de los virus debido al confinamiento domiciliario, asimismo ha supuesto un aumento de la atención telemática secundaria a la necesidad de reorganización de la asistencia sanitaria.

Implications of the school-household network structure on SARS-CoV-2 transmission under school reopening strategies in England

In early 2020 many countries closed schools to mitigate the spread of SARS-CoV-2. Since then, governments have sought to relax the closures, engendering a need to understand associated risks. Using address records, we construct a network of schools in England connected through pupils who share households. We evaluate the risk of transmission between schools under different reopening scenarios. We show that whilst reopening select year-groups causes low risk of large-scale transmission, reopening secondary schools could result in outbreaks affecting up to 2.5 million households if unmitigated, highlighting the importance of careful monitoring and within-school infection control to avoid further school closures or other restrictions.

Many countries have closed schools as part of their COVID-19 response. Here, the authors model SARS-CoV-2 transmission on a network of schools and households in England, and find that risk of transmission between schools is lower if primary schools are open than if secondary schools are open.

[Children and COVID-19-Data from mandatory reporting and results of contact person testing in daycare centers and schools in Frankfurt am Main, Germany, August-December 2020]

BACKGROUND

In face of the coronavirus disease 2019 (COVID-19) pandemic, the question that children are also drivers of this pandemic and that groups, classes, or the entire facility should be closed when severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) occurs in schools or daycare centers is always implied. These questions were investigated using the mandatory reporting data in Frankfurt am Main and the extensive testing of contact persons (CP) in schools and daycare centers after the occurrence of an index case.

METHOD

The reporting data were taken from SurvStat. The index cases from daycare centers and schools were isolated and the CPs were offered PCR testing for SARS-CoV‑2 on a voluntary basis, regardless of whether symptoms suggestive of SARS-CoV‑2 had occurred or not. Deep nasal/pharyngeal swabs were collected by paramedics on behalf of the public health department of the city of Frankfurt am Main, Germany, and tested according to established standards at two accredited institutes.

RESULTS

From March to 31 December 2020, 22,715 COVID-19 cases were reported in Frankfurt, including 1588 (7.6%) SARS-CoV‑2 detections in children 14 years and younger. Thus, approximately half as many SARS-CoV‑2 detections were reported in children up to 14 years of age than would have corresponded to their proportion in the population. In autumn 2020, the increase in incidence in children over the weeks followed the increase in incidence in the general population, the age-related incidence of children remained below the incidence in the general population.From week 35 to week 52, index cases were reported from 143 daycare centers and 75 schools. As a result, 7915 CPs were tested. In daycare centers, SARS-CoV‑2 was detected in 4.5% of adult CPs and 2.5% of child CPs and in schools SARS-CoV‑2 was detected in 0.9% of adult CPs and 2.5% of student CPs tested. On average, less than 1 CP tested positive per index case. The rate of positive findings increased with increasing incidence in the overall population. No major outbreak occurred.

DISCUSSION

Regarding the level and timing of age-related incidences among children in Frankfurt am Main, there was no evidence that children were the drivers of the pandemic. Only a small percentage of the examined CPs in schools and daycare centers tested positive for SARS-CoV‑2. In the absence of evidence of intense transmission in the facilities, CP attendance can/should continue under hygiene conditions and there is no need to close entire groups, classes, or even facilities.

Preparing for the Coronavirus Disease (COVID-19) Vaccination: Evidence, Plans, and Implications

The formation of herd immunity through vaccination is a key point in overcoming the coronavirus disease 2019 (COVID-19) pandemic. To acquire herd immunity, a high vaccination rate is required, which is necessary to instill confidence in the public regarding the effectiveness and safety of the vaccine. In the real-world setting, thorough preparation of components, such as priority setting, vaccine delivery, logistics, and side-effect monitoring is necessary to overcome vaccine hesitancy. Each country prioritizes vaccination since healthcare workers, nursing facility residents, and the elderly population, and similar trends are found between countries. Vaccination is performed at large centers and medical institutions operated by the country, and variations are dependent on the environment of each country. The transport of mRNA vaccines is a challenging task, and to this end, each government is striving for safe distribution. In addition, each authority operates a surveillance system to monitor the safety of vaccines, and Korea needs to produce evidence for monitoring effects and side effects with expertise. Even after the acquisition of herd immunity, COVID-19 is highly likely to remain an endemic infectious disease, and a higher immunity level may be required because of variants of the virus. If the spread of variants of concern continues, a booster vaccination may be required. Therefore, non-pharmaceutical interventions, such as social distancing, wearing a mask, and epidemiological investigation should be maintained.