Clinical Characteristics of Pediatric Patients With COVID-19 between Omicron era vs. Pre-Omicron era

SARS-CoV-2 Disease Severity and Cycle Threshold Values in Children Infected during Pre-Delta, Delta, and Omicron Periods, Colorado, USA, 2021-2022

In adults, viral load and disease severity can differ by SARS-CoV-2 variant, patterns less understood in children. We evaluated symptomatology, cycle threshold (Ct) values, and SARS-CoV-2 variants among 2,299 pediatric SARS-CoV-2 patients (0-21 years of age) in Colorado, USA, to determine whether children infected with Delta or Omicron had different symptom severity or Ct values than during earlier variants. Children infected during the Delta and Omicron periods had lower Ct values than those infected during pre-Delta, and children <1 year of age had lower Ct values than older children. Hospitalized symptomatic children had lower Ct values than asymptomatic patients. Compared with pre-Delta, more children infected during Delta and Omicron were symptomatic (75.4% pre-Delta, 95.3% Delta, 99.5% Omicron), admitted to intensive care (18.8% pre-Delta, 39.5% Delta, 22.9% Omicron), or received oxygen support (42.0% pre-Delta, 66.3% Delta, 62.3% Omicron). Our data reinforce the need to include children, especially younger children, in pathogen surveillance efforts.

The Effect of Age and Comorbidities: Children vs. Adults in Their Response to SARS-CoV-2 Infection

While children have experienced less severe coronavirus disease (COVID-19) after SARS-CoV-2 infection than adults, the cause of this remains unclear. The objective of this study was to describe the humoral immune response to COVID-19 in child vs. adult household contacts, and to identify predictors of the response over time. In this prospective cohort study, children with a positive SARS-CoV-2 polymerase chain reaction (PCR) test (index case) were recruited along with their adult household contacts. Serum IgG antibodies against SARS-CoV-2 S1/S2 spike proteins were compared between children and adults at 6 and 12 months after infection. A total of 91 participants (37 adults and 54 children) from 36 families were enrolled. Overall, 78 (85.7%) participants were seropositive for anti-S1/S2 IgG antibody at 6 months following infection; this was higher in children than in adults (92.6% vs. 75.7%) (p = 0.05). Significant predictors of a lack of SARS-CoV-2 seropositivity were age ≥ 25 vs. < 12 years (odds ratio [OR] = 0.23, p = 0.04), presence of comorbidities (vs. none, adjusted OR = 0.23, p = 0.03), and immunosuppression (vs. immunocompetent, adjusted OR = 0.17, p = 0.02).

Nationwide epidemiology and health resource use among children with COVID-19 in Japan

BACKGROUND

The COVID-19 pandemic posed substantial challenges to healthcare systems. Understanding the responses of pediatric health services is crucial for future pandemic planning and preparedness, yet such data remains limited.

METHODS

In this retrospective cohort study, we analyzed data from administrative databases developed by Japan Medical Data Center and DeSC Healthcare Inc. The dataset comprised records of 2,612,511 children, totaling 60,224,888 person-months, from January 2020 to May 2022. Multivariate generalized estimation equations were used to examine the incidence rates of COVID-19 and associated health resource use.

RESULTS

Our analysis revealed that the incidence rates of COVID-19 gradually increased from Wave I (2.2 cases per 100,000 person-months) to Wave V (177.8cases per 100,000 person-months), with a notable elevation during Wave VI (2367.7 cases per 100,000 person-months). While nucleic acid amplification tests were primarily used during Waves I-V, the use of rapid antigen tests markedly increased in Wave VI. The hospitalization rates increased gradually from 0.2 in Wave I to 10.2 events per 100,000 person-months in Wave VI, and the case-hospitalization risk decreased from 14.9% in Wave II to 0.7% in Wave VI. Additionally, we observed decreasing trends in the use of antibiotics (Wave I, 31.8%; Wave VI, 9.0%), whereas antipyretic use rose from Wave I (56.1%) to Wave VI (86.6%).

CONCLUSIONS

Our study highlighted essential changes in the nationwide pediatric healthcare system's response to the COVID-19 pandemic. These findings provide valuable insights into the future pandemic planning and preparedness.

Severe pediatric COVID-19: a review from the clinical and immunopathophysiological perspectives

BACKGROUND

Coronavirus disease 2019 (COVID-19) tends to have mild presentations in children. However, severe and critical cases do arise in the pediatric population with debilitating systemic impacts and can be fatal at times, meriting further attention from clinicians. Meanwhile, the intricate interactions between the pathogen virulence factors and host defense mechanisms are believed to play indispensable roles in severe COVID-19 pathophysiology but remain incompletely understood.

DATA SOURCES

A comprehensive literature review was conducted for pertinent publications by reviewers independently using the PubMed, Embase, and Wanfang databases. Searched keywords included "COVID-19 in children", "severe pediatric COVID-19", and "critical illness in children with COVID-19".

RESULTS

Risks of developing severe COVID-19 in children escalate with increasing numbers of co-morbidities and an unvaccinated status. Acute respiratory distress stress and necrotizing pneumonia are prominent pulmonary manifestations, while various forms of cardiovascular and neurological involvement may also be seen. Multiple immunological processes are implicated in the host response to COVID-19 including the type I interferon and inflammasome pathways, whose dysregulation in severe and critical diseases translates into adverse clinical manifestations. Multisystem inflammatory syndrome in children (MIS-C), a potentially life-threatening immune-mediated condition chronologically associated with COVID-19 exposure, denotes another scientific and clinical conundrum that exemplifies the complexity of pediatric immunity. Despite the considerable dissimilarities between the pediatric and adult immune systems, clinical trials dedicated to children are lacking and current management recommendations are largely adapted from adult guidelines.

CONCLUSIONS

Severe pediatric COVID-19 can affect multiple organ systems. The dysregulated immune pathways in severe COVID-19 shape the disease course, epitomize the vast functional diversity of the pediatric immune system and highlight the immunophenotypical differences between children and adults. Consequently, further research may be warranted to adequately address them in pediatric-specific clinical practice guidelines.

A retrospective analysis of children with mild and asymptomatic Omicron infections under 14: A single-center study

Omicron BA.5 subvariant has been proven to be more transmissible than other Omicron subvariants. But the studies on the spread of the Omicron BA.5 subvariant in children are still limited. This study aimed to analyze the clinical features of children infected with Omicron BA.5.2 variant in the mobile cabin hospital and the influence factors of the infections. Children with mild and asymptomatic Omicron infections under 14 years old who were admitted to the mobile cabin hospital from October 30 to December 7, 2022 were retrospectively collected. A total of 741 children, 424 boys (57.2%) and 317 girls (42.8%) were enrolled, including 145 asymptomatic cases (22.7%) and 493 (77.3%) mild cases. Upper respiratory tract infection was the dominant manifestation. Fever was the most common presenting symptom (80.7%), followed by cough (52.5%). The average time to symptom disappearance was 3.76 days, and the average negative conversion time of nucleic acid was 12.3 days. Univariate analysis showed that the negative conversion time of nucleic acid differed significantly across the age groups. The multivariate analysis showed that the older the age, the longer the negative conversion time of nucleic acid. Among those with the negative conversion time of nucleic acid longer than 12 days, age was positively correlated to the negative conversion time of nucleic acid, while the number of vaccine doses received was negatively correlated to the negative conversion time of nucleic acid. Omicron infection occurred in children of any age group, with good prospect for recovery. Age and number of vaccine doses received were risk factors influencing the negative conversion time of nucleic acid.

Associations between COVID-19 Vaccination Status and Self-Reported SARS-CoV-2 Infection among 8538 Children Aged 3-17 Years during a Massive COVID-19 Outbreak after China Changed Its Zero-COVID-19 Policy: A Cross-Sectional Survey

This study aimed to investigate the associations between COVID-19 vaccination status and self-reported SARS-CoV-2 infection among children and adolescents aged 3-17 years during a massive COVID-19 outbreak after China changed its zero COVID policy. A cross-sectional online survey was conducted between 1 and 9 March 2023. Participants were the parents of children studying in kindergartens, primary schools, or secondary schools in Shenzhen. Convenient sampling was used. All kindergartens, primary schools, and secondary schools in the Longhua District of Shenzhen invited the parents of children and adolescents attending the schools. Interested parents completed an online survey. Multivariate logistic regression was fitted. Among 8538 participants, 40.9% self-reported that their children had SARS-CoV-2 infection after 7 December 2022, where 92.9% of them received two doses of the COVID-19 vaccines, and 74.6% received their second dose for more than six months. In multivariate analysis, children who received their second dose of the COVID-19 vaccination for no more than three months had a lower SARS-CoV-2 infection rate compared to unvaccinated children (<1 month: AOR: 0.17, 95% CI: 0.07, 0.44; 1-3 months: AOR: 0.54, 95% CI: 0.41, 0.75). The duration of protection conferred by the primary COVID-19 vaccination series was relatively short among children. A booster dose should be considered for children.

Clinical features of COVID-19 in Italian outpatient children and adolescents during Parental, Delta, and Omicron waves: a prospective, observational, cohort study

Introduction

COVID-19 features changed with the Omicron variant of SARS-CoV-2 in adults. This study aims to describe COVID-19 symptoms in children and adolescents during the Parental, Delta, and Omicron eras.

Methods

A single-centre, prospective observational study was conducted on individuals aged 0-20 years attending the University Hospital of Padua (Italy) from April 2020 to December 2022. COVID-19 cases were defined by positive SARS-CoV-2 molecular detection and/or serology; patient/family symptoms and virological positivity were considered to determine the infection onset. Variables were summarized and compared using appropriate tests of descriptive statistics.

Results

A total of 509 cases [46% female, median age eight years (IQR: 4-12)] were studied. Three-hundred-eighty-seven (76%), 52 (10%), and 70 (14%) subjects experienced COVID-19 during the Parental, Delta, and Omicron waves, respectively. All subjects developed an asymptomatic/mild COVID-19. Overall, the most frequent symptoms were fever (47%) and rhinitis (21%), which showed a significant increasing incidence from the Parental to Omicron waves (p < 0.001). Conversely, diarrhea was most common during the pre-Omicron eras (p = 0.03). Stratifying symptoms according to the age group, fever, rhinitis, and skin rashes were observed more frequently among infants/toddlers; conversely, fatigue was more common in children older than five years. The duration of symptoms was similar across different SARS-CoV-2 variants of concern (VOCs); conversely, the number of symptoms varied according to the age group (p < 0.0001).

Discussion

This study showed differences in COVID-19 clinical presentation among infants, children, and adolescents and confirmed Omicron infection is more likely to be associated with upper respiratory symptoms. However, further population-based studies are needed to support these findings. In addition, active surveillance will play a crucial role in assessing the disease severity of future VOCs.

Smart Thermometer-Based Participatory Surveillance to Discern the Role of Children in Household Viral Transmission During the COVID-19 Pandemic

Importance

Children's role in spreading virus during the COVID-19 pandemic is yet to be elucidated, and measuring household transmission traditionally requires contact tracing.

Objective

To discern children's role in household viral transmission during the pandemic when enveloped viruses were at historic lows and the predominance of viral illnesses were attributed to COVID-19.

Design, Setting, and Participants

This cohort study of a voluntary US cohort tracked data from participatory surveillance using commercially available thermometers with a companion smartphone app from October 2019 to October 2022. Eligible participants were individuals with temperature measurements in households with multiple members between October 2019 and October 2022 who opted into data sharing.

Main Outcomes and Measures

Proportion of household transmissions with a pediatric index case and changes in transmissions during school breaks were assessed using app and thermometer data.

Results

A total of 862 577 individuals from 320 073 households with multiple participants (462 000 female [53.6%] and 463 368 adults [53.7%]) were included. The number of febrile episodes forecast new COVID-19 cases. Within-household transmission was inferred in 54 506 (15.4%) febrile episodes and increased from the fourth pandemic period, March to July 2021 (3263 of 32 294 [10.1%]) to the Omicron BA.1/BA.2 wave (16 516 of 94 316 [17.5%]; P < .001). Among 38 787 transmissions in 166 170 households with adults and children, a median (IQR) 70.4% (61.4%-77.6%) had a pediatric index case; proportions fluctuated weekly from 36.9% to 84.6%. A pediatric index case was 0.6 to 0.8 times less frequent during typical school breaks. The winter break decrease was from 68.4% (95% CI, 57.1%-77.8%) to 41.7% (95% CI, 34.3%-49.5%) at the end of 2020 (P < .001). At the beginning of 2022, it dropped from 80.3% (95% CI, 75.1%-84.6%) to 54.5% (95% CI, 51.3%-57.7%) (P < .001). During summer breaks, rates dropped from 81.4% (95% CI, 74.0%-87.1%) to 62.5% (95% CI, 56.3%-68.3%) by August 2021 (P = .02) and from 83.8% (95% CI, 79.2%-87.5) to 62.8% (95% CI, 57.1%-68.1%) by July 2022 (P < .001). These patterns persisted over 2 school years.

Conclusions and Relevance

In this cohort study using participatory surveillance to measure within-household transmission at a national scale, we discerned an important role for children in the spread of viral infection within households during the COVID-19 pandemic, heightened when schools were in session, supporting a role for school attendance in COVID-19 spread.

Hospital burden and characteristics of pediatric COVID-19 based on a multicenter collaborative retrospective study in Japan

OBJECTIVES

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant emergence preceded a wave of pediatric coronavirus disease 2019 (COVID-19) cases, putting considerable strain on hospitals across Japan. Our study evaluated the pediatric disease burden of COVID-19 in pediatric hospitals.

METHODS

This retrospective study evaluated all pediatric patients (defined as aged < 21 years) hospitalized with SARS-CoV-2 infection, or as close contacts, at four children's hospitals, between January 1 and May 31, 2022. Clinical characteristics, reasons for admission, and outcome data were analyzed.

RESULTS

In total, 492 patients (median age 3.0 years; male 58.7%) were included over the study period. Of these, 232 (47.2%) patients had at least one underlying disease. Asymptomatic and mild diseases were common during the study period (n = 451, 91.7%). Social reasons for hospitalization (including a lack of family support at home) accounted for 36.8% (n = 181) of inpatients. The median length of stay was 4.0 days. Fever was the most common symptom (n = 273, 55.5%), followed by upper respiratory (n = 77, 15.7%) and neurological (n = 60, 12.2%) symptoms. Overall, 34 (6.9%) children required invasive mechanical ventilation, 51 (10.4%) were admitted to the pediatric intensive care unit, and two (0.4%) died. COVID-19 vaccination rate was low (n =14/200, 7.0%).

CONCLUSIONS

The disease burden during the Omicron-predominant period was attributable to asymptomatic and mild infections, and some patients were hospitalized for social reasons. To maintain a medical care system for critically ill patients, each medical facility must play a role according to its function.

The Changing Trend of Paediatric Emergency Department Visits in Malaysia Following the COVID-19 Pandemic

Background The coronavirus disease 2019 (COVID-19) pandemic has impacted the emergency department (ED) due to the surge in medical demand and changes in the characteristics of paediatric visits. Additionally, the trend for paediatric ED visits has decreased globally, secondary to implementing lockdowns to stop the spread of COVID-19. We aim to study the trend and characteristics of paediatric ED visits following Malaysia's primary timeline of the COVID-19 pandemic. Methods and materials A five-year time series observational study of paediatric ED patients from two tertiary hospitals in Malaysia was conducted from March 17, 2017 (week 11 2017) to March 17, 2022 (week 12 2022). Aggregated weekly data were analysed using R statistical software version 4.2.2 (R Foundation for Statistical Computing, Vienna, Austria) against significant events during the COVID-19 pandemic to detect influential changepoints in the trend. The data collected were the number of ED visits, triage severity, visit outcomes and ED discharge diagnosis. Results Overall, 175,737 paediatric ED visits were recorded with a median age of three years and predominantly males (56.8%). A 57.57% (p<0.00) reduction in the average weekly ED visits was observed during the Movement Control Order (MCO) period. Despite the increase in the proportion of urgent (odds ratio (OR): 1.23, p<0.00) and emergent or life-threatening (OR: 1.79, p<0.00) cases, the proportion of admissions decreased. Whilst the changepoints during the MCO indicated a rise in respiratory, fever or other infectious diseases, or gastrointestinal conditions, diagnosis of complications originating from the perinatal period declined from July 19, 2021 (week 29 2021). Conclusion The incongruent change in disease severity and hospital admission reflects the potential effects of the healthcare system reform and socioeconomic impact as the pandemic evolves. Future studies on parental motivation to seek emergency medical attention may provide insight into the timing and choice of healthcare service utilisation.

Natural course of acute COVID-19 among healthy children in a tertiary hospital

BACKGROUND

Previous studies have reported the clinical and epidemiological characteristics of children with coronavirus disease 2019 (COVID-19) in a cross-sectional fashion; however, the natural course of each symptom based on a daily basis during the acute phase has not yet been clarified. This retrospective study aimed to describe the natural course of COVID-19 in children according to dominant variants.

METHODS

We conducted our study on symptomatic children with COVID-19 who were hospitalized at the National Center for Child Health and Development, in Japan. We excluded patients who were observed for less than 9 days and those with underlying disease, COVID-19 vaccination, coinfection, complications, or therapeutic intervention. We collected the data on each participant's age at admission, sex, medical history, observation period, hospitalization period, SARS-CoV-2 test results, and 10 daily symptoms in the first 9 days from the illness onset.

RESULTS

Eventually, 115 children were included in this study. The prevalence of fever during the omicron era declined more rapidly over time than that during the pre-omicron era. The prevalence of cough and rhinorrhea did not decline during the observation period, and these clinical manifestations were more common during the pre-omicron era at any point. The prevalence of dysgeusia and/or dysosmia steadily increased over time in the pre-omicron era. This study demonstrated that the prevalence of some symptoms differed not only at the onset but also over time during the acute phase.

CONCLUSION

Details of the natural clinical course of children with COVID-19 help primary care physicians to manage these patients.

Bacterial coinfections in hospitalized children with COVID-19 during the SARS-CoV-2 Omicron BA.2 variant pandemic in Taiwan

Background

Bacterial coinfections have been widely recognized in adults with coronavirus disease 2019 (COVID-19). However, bacterial coinfections in hospitalized children with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have not been sufficiently researched. This study aimed to determine the clinical presentations and risk factors for bacterial coinfections of pediatric inpatients during the SARS-CoV-2 Omicron BA.2 variant pandemic.

Methods

This retrospective, observational study included patients younger than 18 years of age who were hospitalized for COVID-19 confirmed by polymerase chain reaction (PCR) or antigen rapid tests during the SARS-CoV-2 Omicron BA.2 variant pandemic. Data and outcomes of these patients with or without bacterial coinfections were compared.

Results

During this study period, 161 children with confirmed COVID-19 were hospitalized. Twenty-four had bacterial coinfections. The most frequently reported concurrent diagnosis was bacterial enteritis, followed by lower respiratory tract infections. Children with bacterial coinfections had higher white blood cell (WBC) counts and PCR cycle threshold values. The bacterial coinfection group comprised a relatively greater proportion of patients who required high-flow nasal cannula oxygen and remdesivir. The length of stay in the hospital and that in the intensive care unit were longer for children with COVID-19 with bacterial coinfections. Mortality was not observed in either group. Abdominal pain, diarrhea, and comorbidity with neurologic illnesses were risk factors for bacterial coinfections with COVID-19.

Conclusion

This study provides clinicians with reference points for the detection of COVID-19 in children and its possible association with bacterial infections. Children with COVID-19 and neurologic diseases who present with abdominal pain or diarrhea are at risk of bacterial coinfections. Prolonged fever duration and higher PCR test cycle threshold values, WBC levels, and high-sensitivity C-reactive protein (hsCRP) levels may indicate bacterial coinfections in children with COVID-19.

Omicron targets upper airways in pediatrics, elderly and unvaccinated population

Omicron, a severe acute respiratory syndrome coronavirus-2 variant, has spread around the globe, causing dramatic increases in infection rates. Viral mutant antigens were responsible for the strong infectivity, fast replication, and high reinfection rates reported from all ages. Omicron causes clinical symptoms mostly related to the upper respiratory tract with minimal symptoms from the lower respiratory tract besides an urgent presentation of cases that resembled a fatal illness, epiglottitis. Not to mention the long coronavirus disease 2019, which rises exponentially in the Omicrons era. Apparently, the disease has a less aggressive course than earlier variants with lower death rates; however, the infection is not trivial. Severe infection was raised among pediatrics, unvaccinated, and the elderly. Complete vaccine protection is urgently needed to protect the most vulnerable community members. Additionally, self-protective strategies such as wearing a mask and safe social distancing cannot be omitted.