Clinical characteristics and factors associated with severe COVID-19 in hospitalized children during the SARS-CoV-2 Omicron pandemic in Taiwan

Clinical characteristics and outcomes of children with COVID-19 in pediatric intensive care units during the Omicron wave in Taiwan

BACKGROUND

Since April 2022, the SARS-CoV-2 Omicron variant has caused a notable increase in pediatric COVID-19 cases in Taiwan. During the acute phase of infection, some children required admissions to pediatric intensive care units (PICU). This study aimed to analyze their clinical presentations and outcomes while exploring associated factors.

METHODS

Medical records were retrospectively collected from patients with COVID-19 (aged <18 years) admitted to our PICU from April 2022-March 2023. Early stage is defined as the period without adequate vaccination and treatment guidelines for children from April-June 2022, and the remaining months are referred to as late stage. Clinical characteristics and outcomes were compared between patients in early and late stages.

RESULTS

We enrolled 78 children with COVID-19, with a median length of stay (LOS) in PICU of 3 days and a 5% mortality rate. Patients admitted during the early stage had lower vaccination rates (7% vs. 50%), higher pediatric logistic organ dysfunction scores (2 vs. 0.1), and longer LOS in the PICU (6 vs. 2 days) than those admitted during the late stage. Multivariate analysis identified admission during the early stage as a risk factor for prolonged LOS (>7 days) in the PICU (odds ratio: 3.65, p = 0.047).

CONCLUSION

Without available vaccinations and suitable treatment guidelines, children with COVID-19 tended to have more severe illness and prolonged LOS in the PICU. These observations highlight the importance of vaccinations and familiarity of medical providers with adequate management of this newly-emerging infectious disease.

Seroprevalence of SARS-CoV-2 in self-reported COVID-19-free children

INTRODUCTION

COVID-19 poses risks and leads to complications for vulnerable populations, including children. Unreported cases of COVID-19 among children hinder our understanding of the true disease burden. In this study, we aimed to investigate the proportion of children who report no prior infection to SARS-CoV-2 but who nevertheless exhibit serological evidence of prior infection.

METHODS

Between November 2022 and February 2023, we recruited children and adolescents under 19 years of age who lacked a prior history of SARS-CoV-2 infection. Participants underwent SARS-CoV-2 antibody testing to assess the presence of IgG antibodies specific to nucleocapsid (N) and spike (S) proteins. Demographic and contact information were also collected.

RESULTS

Among 260 COVID-19-free children, the overall anti-N antibody positivity rate, which varied across age groups (4%-25%), was 9.2% (24/260). Contact with individuals who were positive for COVID-19, particularly the children's mothers, significantly increased the likelihood of antibody positivity. The median age of the 34 children who remained unvaccinated against COVID-19 was lower than that of the children who were vaccinated (6.5 vs. 9 years; p < 0.001). Until January 2024, the overall infection rate was 41.9% (99/236) among children who were negative for anti-N antibodies, irrespective of vaccination status or the presence of chronic disease.

CONCLUSION

We discovered previously undisclosed cases of SARS-CoV-2 infection among children. The risk of seropositivity increases substantially with household contact. Regarding children who report no prior exposure to COVID-19, clinicians must remain vigilant, as SARS-CoV-2 remains a concern.

The effectiveness of novel oral antiviral treatment for non-hospitalized high-risk patients with COVID-19 during predominance of omicron XBB subvariants

OBJECTIVES

This study investigated the association between nirmatrelvir plus ritonavir (NMV-r) or molnupiravir and the outcomes of non-hospitalized high-risk patients with COVID-19 during Omicron XBB subvariants.

METHODS

The retrospective cohort study used the TriNetX US collaborative network to identify non-hospitalized high-risk adult patients with COVID-19 between 1 February 2023, and 31 August 2023. Propensity score matching (PSM) was used to match patients receiving NMV-r or MOV (the study group) with those not receiving antivirals (the control group).

RESULTS

Using PSM, two cohorts of 17,654 patients each with balanced baseline characteristics were identified. During the follow-up period, the study group had a lower risk of all-cause hospitalization, or death (3.2% [n = 564] versus 3.8% [n = 669]; HR, 0.796; 95% confidence interval [CI], 95% CI, 0.712-0.891). Compared with the control group, the study group had a significantly lower risk of all-cause hospitalization (3.1% vs. 3.4%; HR, 0.847; 95% CI, 0.754-0.950) and mortality (0.1% vs. 0.4%; HR, 0.295; 95% CI, 0.183-0.476).

CONCLUSION

The use of novel oral antiviral including NMV-r or MOV can be associated with a lower risk of all-cause hospitalization, or death in non-hospitalized high-risk patients with COVID-19 during Omicron XBB wave.

Machine learning versus multivariate logistic regression for predicting severe COVID-19 in hospitalized children with Omicron variant infection

With the emergence of the Omicron variant, the number of pediatric Coronavirus Disease 2019 (COVID-19) cases requiring hospitalization and developing severe or critical illness has significantly increased. Machine learning and multivariate logistic regression analysis were used to predict risk factors and develop prognostic models for severe COVID-19 in hospitalized children with the Omicron variant in this study. Of the 544 hospitalized children including 243 and 301 in the mild and severe groups, respectively. Fever (92.3%) was the most common symptom, followed by cough (79.4%), convulsions (36.8%), and vomiting (23.2%). The multivariate logistic regression analysis showed that age (1-3 years old, odds ratio (OR): 3.193, 95% confidence interval (CI): 1.778-5.733], comorbidity (OR: 1.993, 95% CI:1.154-3.443), cough (OR: 0.409, 95% CI:0.236-0.709), and baseline neutrophil-to-lymphocyte ratio (OR: 1.108, 95% CI: 1.023-1.200), lactate dehydrogenase (OR: 1.993, 95% CI: 1.154-3.443), blood urea nitrogen (OR: 1.002, 95% CI: 1.000-1.003) and total bilirubin (OR: 1.178, 95% CI: 1.005-3.381) were independent risk factors for severe COVID-19. The area under the curve (AUC) of the prediction models constructed by multivariate logistic regression analysis and machine learning (RandomForest + TomekLinks) were 0.7770 and 0.8590, respectively. The top 10 most important variables of random forest variables were selected to build a prediction model, with an AUC of 0.8210. Compared with multivariate logistic regression, machine learning models could more accurately predict severe COVID-19 in children with Omicron variant infection.

Association between nirmatrelvir plus ritonavir and the outcomes of non-hospitalized obese patients with COVID-19

OBJECTIVE

To investigate the association between nirmatrelvir plus ritonavir (NMV-r) and the outcomes of non-hospitalized obese patients with coronavirus disease 2019 (COVID-19).

METHODS

This retrospective cohort study used the TriNetX research network to identify non-hospitalized obese adult patients with COVID-19 between 1 January 2022 and 30 June 2023. Propensity score matching was used to match patients receiving NMV-r (NMV-r group) with those not receiving NMV-r (control group). The primary outcome was the compositive outcome of all-cause emergency department (ED) visits, hospitalization or death during the 30-day follow-up period.

RESULTS

Using propensity score matching methods, two cohorts of 30,969 patients each with balanced baseline characteristics were identified. During the follow-up period, the NMV-r group had a lower risk of all-cause ED visits, hospitalization or death [4.80% (n=1489) vs 5.50% (n=1705); hazard ratio (HR) 0.900, 95% confidence interval (CI) 0.839-0.965]. Compared with the control group, the NMV-r group had a lower risk of all-cause ED visits (HR 0.812, 95% CI 0.740-0.891) and all-cause mortality (HR 0.089, 95% CI 0.027-0.288). The lower risk in the NMV-r group compared with the control group was observed consistently in most subgroup analyses according to body mass index (30.0-34.9 kg/m2: HR 0.68, 95% CI 0.55-0.82; 35.0-39.9 kg/m2: HR 0.67, 95% CI 0.52-0.87), age (4-64 years: HR 0.83, 95% CI 0.75-0.92; ≥65 years: HR 0.88, 95% CI 0.79-0.98), sex (men: HR 0.69, 95% CI 0.60-0.79; women: HR 0.69, 95% CI 0.63-0.76) and vaccination status (unvaccinated: HR 0.75, 95% CI 0.70-0.81).

CONCLUSION

NMV-r is associated with reduced risk of all-cause ED visits, hospitalization and death for non-hospitalized obese patients with COVID-19. Accordingly, these findings support the use of NMV-r in obese patients.

Clinical effectiveness of nirmatrelvir plus ritonavir in the treatment of COVID-19 in patients with cirrhosis

OBJECTIVES

This retrospective cohort study assessed the clinical effectiveness of nirmatrelvirplus ritonavir (NMV-r) in treating COVID-19 in patients with liver cirrhosis(LC).

METHODS

The data of non-hospitalized adult patients with LC who had COVID-19 were selected from the TriNetX platform for the period between 1 March 20201 March 2020, and 31 December 202231 December 2022. Propensity score matching was used to match patients receiving NMV-r (theNMV-r group) with those not receiving NMV-r (the control group). Hazard ratios(HRs) along with 95% confidence intervals (CIs) for the primary outcome - a composite of all-cause hospitalization or mortality during the 30-day follow-up period - were calculated and compared.

RESULTS

Two cohorts of 2,369 patients each with balanced baseline characteristics were identified.During the follow-up period, the NMV-r group had a lower risk of all-cause hospitalization or mortality (HR, 0.642;95% CI, 0.503-0.819) than did the control group.NMV-r was also associated with a reduced risk of individual all-cause hospitalization (HR 0.681, 95% CI 0.530-0.876])and all-cause mortality (HR, 0.270; 95% CI,0.129-0.562). This association was consistently observed in the subgroups of age, sex, vaccination status, and LC severity.

CONCLUSIONS

NMV-r can reduce all-cause hospitalization and mortality among patients with LC who have COVID-19.