Viral dynamics of SARS-CoV-2 Omicron infections in a previously low COVID-19 prevalence region: Effects of vaccination status, antiviral agents, and age.

BACKGROUND: In Taiwan, the prevalence of COVID-19 was low before April 2022. The low SARS-CoV-2 seroprevalence in the population of Taiwan provides an opportunity for comparison with fewer confounding factors than other populations globally. Cycle threshold (Ct) value is an easily accessible method for modeling SARS-CoV-2 dynamics. In this study, we used clinical samples collected from hospitalized patients to explore the Ct value dynamics of the Omicron variant infection. METHODS: From Jan 2022 to May 2022, we retrospectively included hospitalized patients tested positive by nasopharyngeal SARS-CoV-2 PCR. We categorized the test-positive subjects into different groups according to age, vaccination status, and use of antiviral agents. To investigate the nonlinear relationship between symptom onset days and Ct value, a fractional polynomial model was applied to draw a regression line. RESULTS: We collected 1718 SARS-CoV-2 viral samples from 812 individuals. The Ct values of unvaccinated individuals were lower than those of vaccinated persons from Day 4 to Day 10 after symptom onset. The Ct value increased more rapidly in those individuals with antiviral drug treatment from Day 2 to Day 7. In elderly individuals, the Ct values increased slowly from Day 5 to Day 10, and the increasing trend was unique compared with that in children and adults. CONCLUSION: Our study demonstrated the primary viral infection dynamics of the Omicron variant in hospitalized patients. Vaccination significantly affected viral dynamics, and antiviral agents modified viral dynamics irrespective of vaccination status. In elderly individuals, viral clearance is slower than that in adults and children.

Circulating pediatric respiratory pathogens in Taiwan during 2020: Dynamic change under low COVID-19 incidence.

BACKGROUND: In Taiwan, there were only 799 confirmed COVID-19 cases in 2020. The unique backdrop amidst a pandemic and promotion of nonpharmaceutical interventions generated some distinct changes in the epidemiology of common respiratory pathogens. In this study, we aimed to investigate the dynamic changes in respiratory pathogens in children during 2020. METHODS: We performed a retrospective cohort study at a tertiary hospital in southern Taiwan during 2020. Patients aged 0-18 years who visited the pediatric emergency department were enrolled. Children who presented with clinical symptoms (fever or respiratory illness) and received nasopharyngeal swabs for multiplex polymerase chain reaction (PCR) were included in our analysis. We also compared respiratory syncytial virus (RSV) trends from previous years by PCR and lateral flow immunochromatographic assays from 2017 to 2020. RESULTS: A total of 120 children were tested. The overall detection rate was 55%. With strengthened restrictions, the detection rate dropped from 70% to 30%. However, non-enveloped viruses (rhinovirus/enterovirus and adenovirus) were in constant circulation. Upon easing prevention measures, the detection rate remained above 60%, and an outbreak of an enveloped virus (RSV and parainfluenza virus) was noted. Compared with 2017-2019, the cyclical RSV epidemic was delayed, with a large surge in late 2020. CONCLUSIONS: We observed a constant circulation of non-enveloped viruses when strict nonpharmaceutical interventions were employed and a delayed surge of enveloped viruses during the easing of restrictions. Continuous surveillance and monitoring of the evolutionary dynamics of respiratory viruses is important, while easing restrictions requires balanced judgment.

Weight Gain Associated with COVID-19 Lockdown in Children and Adolescents: A Systematic Review and Meta-Analysis.

BACKGROUND: Lockdown is an effective nonpharmaceutical intervention to reduce coronavirus disease 2019 (COVID-19) transmission, but it restricts daily activity. We aimed to investigate the impact of lockdown on pediatric body weight and body mass index (BMI). METHODS: The systematic review and meta-analysis were conducted following the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) statement. Four online databases (EMBASE, Medline, the Cochrane Library and CINAHL) were searched. RESULTS: The pooled results showed that lockdown was associated with significant body weight gain (MD 2.67, 95% CI 2.12-3.23; p < 0.00001). The BMI of children with comorbidities or obesity did not change significantly. The BMI of general population was significantly higher during lockdown than before the pandemic (MD 0.94, 95% CI 0.32-1.56; p = 0.003). However, heterogeneity was high (I2 = 84%). Among changes in weight classification, increases in the rates of obesity (OR 1.23, 95% CI 1.10-1.37; p = 0.0002) and overweight (OR 1.17, 95% CI 1.06-1.29; p = 0.001) were reported. CONCLUSIONS: Our meta-analysis showed significant increases in body weight and BMI during lockdown among school-age children and adolescents. The prevalence of obesity and overweight also increased. The COVID-19 pandemic worsened the burden of childhood obesity.

Effect of obesity and body mass index on coronavirus disease 2019 severity: A systematic review and meta-analysis.

We conducted a systematic review of observational studies to examine the effects of body mass index (BMI) and obesity (BMI ≥ 30 kg/m2 ) on coronavirus disease 2019 (COVID-19). Medline, Embase, and the Cochrane Library were searched. Sixteen articles were finally included in the meta-analysis, and a random effects model was used. BMI was found to be higher in patients with severe disease than in those with mild or moderate disease (MD 1.6, 95% CI, 0.8-2.4; p = .0002) in China; however, the heterogeneity was high (I2 = 75%). Elevated BMI was associated with invasive mechanical ventilation (IMV) use (MD 4.1, 95% CI, 2.1-6.1; p < .0001) in Western countries, and this result was consistent across studies (I2 = 0%). Additionally, there were increased odds ratios of IMV use (OR 2.0, 95% CI, 1.4-2.9; p < .0001) and hospitalization (OR 1.4, 95% CI, 1.3-1.60; p < .00001) in patients with obesity. There was no substantial heterogeneity (I2 = 0%). In conclusion, obesity or high BMI increased the risk of hospitalization, severe disease and invasive mechanical ventilation in COVID-19. Physicians must be alert to these early indicators to identify critical patients.

Clinical characteristics and diagnostic challenges of pediatric COVID-19: A systematic review and meta-analysis.

BACKGROUND/PURPOSE: Current studies on pediatric coronavirus disease 2019 (COVID-19) are rare. The clinical characteristics and spectrum are still unknown. Facing this unknown and emerging pathogen, we aimed to collect current evidence about COVID-19 in children. METHODS: We performed a systematic review in PubMed and Embase to find relevant case series. Because some reports were published in Chinese journals, the journals and publications of the Chinese Medical Association related to COVID-19 were completely reviewed. A random effects model was used to pool clinical data in the meta-analysis. RESULTS: Nine case series were included. In the pooled data, most of patients (75%) had a household contact history. The disease severity was mainly mild to moderate (98%). Only 2 children (2%) received intensive care. Fever occurred in 59% of the patients, while cough in 46%. Gastrointestinal symptoms (12%) were uncommon. There are 26% children are asymptomatic. The most common radiographic finding was ground glass opacities (48%). Currently, there is no evidence of vertical transmission to neonates born to mothers with COVID-19. Compared with the most relevant virus, SARS-CoV, SARS-CoV-2 causes less severe disease. CONCLUSION: COVID-19 has distinct features in children. The disease severity is mild. Current diagnosis is based mainly on typical ground glass opacities on chest CT, epidemiological suspicion and contact tracing.