Can Asymptomatic or Non-Severe SARS-CoV-2 Infection Cause Medium-Term Pulmonary Sequelae in Children?

Impulse oscillometry assessment of respiratory function in pediatric patients with a history of COVID-19

OBJECTIVE

While coronavirus disease 2019 (COVID-19) is generally considered to exhibit a less severe clinical course in children than in adults, studies have demonstrated that respiratory symptoms can endure for more than 3 months following infection in at least one-third of pediatric cases. The present study evaluates the respiratory functions of children aged 3-15 years within 3-6 months of their recovery from COVID-19 using impulse oscillometry (IOS) and compares them with the values of healthy children.

METHODS

Included in this prospective cross-sectional study were 63 patients (patient group) aged 3-15 years who contracted COVID-19 between December 2021 and May 2022, as well as 57 healthy children as a control group, matched for age and sex. The demographic, clinical, and laboratory data of the patients were recorded, and respiratory function was assessed based on airway resistance (zR5, zR20, R5-20) and reactance (zX5, zX20, reactance area [AX], resonant frequency [Fres]) using an IOS device.

RESULTS

There were no significant differences in the age, weight, height, and body weight z score values of the two groups (p > .05). While the zR5 and R5-20 levels of the patient group were higher (p = .008 and p < .001, respectively) than those of the controls, the zR20, AX, and Fres values did not differ significantly between the groups (p > .05). The parameters indicating the reactance, including zX5 and zX20, were significantly lower in the patient group than in the control group (p = .028 and p < .001, respectively).

CONCLUSION

Total and peripheral airway resistances were found to be elevated in children who had recovered from COVID-19 in the preceding 3-6 months.

Pulmonary function in children post -SARS-CoV-2 infection: a systematic review and meta-analysis

OBJECTIVE

There are some concerns regarding long-term complications of COVID-19 in children. A systematic review and meta-analysis was performed evaluating the respiratory symptoms and pulmonary function, post-SARS-CoV-2 infection.

METHODS

A systematic search was performed in databases up to 30 March 2023. Studies evaluating respiratory symptoms and pulmonary function after COVID-19 infection in children were selected. The major outcomes were the frequency of respiratory symptoms and the mean of spirometry parameters. A pooled mean with 95% confidence intervals (CIs) was calculated.

RESULTS

A total of 8 articles with 386 patients were included in meta-analysis. Dyspnea, cough, exercise intolerance, and fatigue were the most common symptoms. The meta-mean of forced expiratory volume (FEV1) and forced vital capacity (FVC) was 101.72%, 95% CI= (98.72, 104.73) and 101.31%, 95% CI= (95.44, 107.18) respectively. The meta-mean of FEV1/FVC and Forced expiratory flow at 25 and 75% was 96.16%, 95% CI= (90.47, 101.85) and 105.05%, 95% CI= (101.74, 108.36) respectively. The meta-mean of diffusing capacity for carbon monoxide was 105.30%, 95%CI= (88.12, 122.49). There was no significant difference in spirometry parameters before and after bronchodilator inhalation.

CONCLUSIONS

Despite some clinical respiratory symptoms, meta-results showed no abnormality in pulmonary function in follow-up of children with SARS-CoV-2 infection. Disease severity and asthma background had not confounded this outcome.

Evaluation of Lung Ultrasonography Findings of Children With Late Respiratory System Symptoms Due to COVID-19 Infection

Owing to coronavirus disease 2019 (COVID-19), lung damage is seen as an important problem in patients after recovery. In this study, evaluation of respiratory symptoms and lung ultrasonography (LUS) findings of those who have had symptomatic and asymptomatic COVID-19 disease in children was aimed. A total of 81 patients with positive and 18 healthy children with negative COVID-19 antibodies were included to the study. The most common late presentation symptoms were cough (85.2%), shortness of breath (77.8%), and chest pain (60.5%). In LUS, 2 or less B lines, 3 or more B lines, and Z line were seen in 66.7%, 33.3%, and 9.9% of patients, respectively. There was no significant difference between control and patients in terms of these parameters (P > .05). Pleural effusion was detected in 2 patients in the late period. Respiratory system findings may develop in the late period in patients infected with COVID-19. Therefore, patients should be followed closely.

Effectiveness of COVID-19 vaccines among children and adolescents against SARS-CoV-2 variants: a meta-analysis

This systematic review and meta-analysis aimed to evaluate the effectiveness of COVID-19 vaccines among children and adolescents against SARS-CoV-2 variants. We searched PubMed, Embase, Web of Science, the Cochrane Library, and ClinicalTrials.gov for studies published on or before June 20, 2023. Studies evaluating the effectiveness of COVID-19 vaccines in children and adolescents (≤ 18 years of age) were included. Data extraction, quality assessment, and analysis were conducted following PRISMA guidelines. Ten studies were included, comprising five cohort studies (527,778 participants) and four case-control studies (1,477,422 participants). The overall vaccine effectiveness (VE) against SARS-CoV-2 variants was 68% (95% CI = 60-74%). In terms of age, the VE was higher in adolescents aged 12-18 years [69%(95% CI = 61-75%)] than in children aged 5-11 years [44%(95% CI = 1-68%)]. "Fully vaccinated" may offer greater protection than "partially vaccinated," with a VE of 71% (95%CI = 59-79%) and 66% (95%CI = 51-76%), respectively.    Conclusion: This meta-analysis presents moderate-quality evidence that the COVID-19 vaccine is effective in safeguarding children and adolescents from the SARS-CoV-2 variant. Being fully vaccinated may offer greater protection than being partially vaccinated. Nevertheless, additional high-quality controlled trials are required to verify this finding. What is Known: • The COVID-19 pandemic has led to the rapid development and deployment of vaccines worldwide. Children and adolescents are a unique population for vaccination, and the effectiveness of vaccines against SARS-CoV-2 variants in this age group is of concern. What is New: • The COVID-19 vaccine is effective in protecting children and adolescents against the SARS-CoV-2 variant. Being fully vaccinated may offer greater protection than being partially vaccinated.

The Impact of SARS-CoV-2 Infection on Symptom Control and Lung Function in Children with Asthma

Rationale: Little is known about the long-term impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection on children with asthma. Objectives: To determine whether SARS-CoV-2 infection affects symptom control and lung function in children with asthma. Methods: Using data from clinical registries and the electronic health record, we conducted a prospective case-control study of children with asthma aged 6-21 years who had (cases) or did not have (control subjects) SARS-CoV-2 infection, comparing baseline and follow-up asthma symptom control and spirometry within an ∼18-month time frame and, for cases, within 18 months of acute coronavirus disease (COVID-19). Results: A total of 171 cases had baseline and follow-up asthma symptom data, and 114 cases had baseline and follow-up spirometry measurements. There were no significant differences in asthma symptom control (P = 0.50), forced expiratory volume in 1 second (P = 0.47), forced vital capacity (P = 0.43), forced expiratory volume in 1 second/forced vital capacity (P = 0.43), or forced expiratory flow, midexpiratory phase (P = 0.62), after SARS-CoV-2 infection. Compared with control subjects (113 with symptom data and 237 with spirometry data), there were no significant differences in follow-up asthma symptom control or lung function. A similar proportion of cases and control subjects had poorer asthma symptom control (17.5% vs. 9.7%; P = 0.07) or worse lung function (29.0% vs. 32.5%; P = 0.50) at follow-up. Patients whose asthma control worsened after COVID-19 had a shorter time to follow-up (3.5 [1.5-7.5] vs. 6.1 [3.1-9.8] mo; P = 0.007) and were more likely to have presented with an asthma exacerbation during COVID-19 (46% vs. 26%; P = 0.04) than those without worse control. Conclusions: We found no significant differences in asthma symptom control or lung function in youth with asthma up to 18 months after acute COVID-19, suggesting that COVID-19 does not affect long-term asthma severity or control in the pediatric population.

Follow-up evaluation of pulmonary function and computed tomography findings in chronic kidney disease patients after COVID-19 infection

Pulmonary complications are common after SARS-CoV2- infection. However, data on pulmonary sequelae of COVID-19 after recovery in dialysis patients are limited. We determined the prevalence of abnormal lung function tests and CT findings and investigate the association factors impacting pulmonary dysfunction. This prospective observational cohort study enrolled 100 patients with stage 5 chronic kidney disease (CKD) undergoing dialysis who had recovered from COVID-19 for ≥3 months. Pulmonary function test (PFT) and chest computed tomography (CT) were performed. Demographic data and laboratory results were recorded. The mean patient age was 55.15 ± 12.84 years. Twenty-one patients (21%) had severe COVID-19, requiring mechanical ventilation or oxygen supplementation. Pulmonary function tests revealed a restrictive pattern in 41% (95% confidence interval [CI], 31.73-50.78;) and an obstructive pattern in 7.29% (95% CI, 3.19-13.25) patients. The severe group showed PFT test results similar to the non-severe group, with three patients showing severe obstructive lung disease. The CT scan findings included reticulation (64%), multifocal parenchymal band (43%), ground glass opacities (32%), and bronchiectasis (28%). The median total CT score was 3 (interquartile range, 1-8.5). The CT score and PFT findings showed no association with pulmonary dysfunction extent, except in bronchiectasis. Lung function indices were associated with abnormal CT findings. Abnormal CT findings (bronchiectasis, reticulation, and ground-glass opacities) was associated with higher oxygen requirements than normal CT findings (p = 0.008, bronchiectasis; p = 0.041, reticulation; p = 0.032, ground-glass appearance). Aside from CT findings and CRP levels, no significant lung abnormalities were observed in severe and non-severe patients. Some patients had residual symptoms at follow-up. The findings indicate persistence of both radiological and physiological abnormalities in dialysis patients after COVID-19. However, the prevalence of these abnormalities was comparable to that in the normal population; few patients experienced ongoing symptoms. Follow-up observations and evaluations are warranted. Trial registration. Clinicaltrials.gov Identifier: NCT05348759.

Lung function after SARS-CoV-2 infection: A prospective cohort study in children

INTRODUCTION

Although impaired lung function after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has been described in adults, it is unclear whether lung function might be altered in children, especially among asymptomatic or mildly symptomatic patients. In this study, we report the results of lung function testing performed after SARS-CoV-2 infection in a large pediatric population.

METHODS

The study included 589 patients with previous confirmed SARS-CoV-2 infection aged 0-18 years. Both symptomatic and asymptomatic patients during acute infection were enrolled in the study. A spirometry was performed in all cooperating patients.

RESULTS

The mean age of enrolled patients was 9.6 years and the mean time from infection to enrollment was 171 days. Spirometry was performed and deemed evaluable in 433 patients. No patient had reduced forced vital capacity (FVC) and only 14 patients (3.2%) had a forced expiratory volume in the First second (FEV1) < 80%. The mean spirometry values recorded were in the normal range. There were no statistically significant differences in spirometry values between patients with respiratory symptoms during infection and those without. Similarly, there were no differences in spirometry parameters according to the time elapsed between infection and enrollment.

CONCLUSION

Lung function, according to spirometry values, does not appear to be impaired long after infection in the pediatric population. The presence of respiratory symptoms during SARS-CoV-2 infection would not represent a risk factor for impaired lung function in this cohort of patients.

The outcomes of COVID-19 pneumonia in children-clinical, radiographic, and pulmonary function assessment

OBJECTIVES

The goal of this study was to assess the pulmonary sequelae of COVID-19 pneumonia in children.

STUDY DESIGN

Children (0-18 years old) diagnosed with COVID-19 pneumonia hospitalized between March 2020 and March 2021 were included in this observational study. All children underwent follow-up visits 3 months postdischarge, and if any abnormalities were stated, a second visit after the next 3 months was scheduled. Clinical assessment included medical history, physical examination, lung ultrasound (LUS) using a standardized protocol, and pulmonary function tests (PFTs). PFTs results were compared with healthy children.

RESULTS

Forty-one patients with COVID-19 pneumonia (severe disease n = 3, mechanical ventilation, n = 0) were included in the study. Persistent symptoms were reported by seven (17.1%) children, the most common was decreased exercise tolerance (57.1%), dyspnea (42.9%), and cough (42.9%). The most prevalent abnormalities in LUS were coalescent B-lines (37%) and small subpleural consolidations (29%). The extent of LUS abnormalities was significantly greater at the first than at the second follow-up visit (p = 0.03). There were no significant differences in PFTs results neither between the study group and healthy children nor between the two follow-up visits in the study group.

CONCLUSIONS

Our study shows that children might experience long-term sequelae following COVID-19 pneumonia. In the majority of cases, these are mild and resolve over time.

Lung ultrasound in children and adolescents with long-term effects of COVID-19: Initial results

Introduction

Chronic health effects following acute COVID-19 are increasingly observed as the pandemic continues and are grouped under long COVID. Although the acute course of the COVID disease is often milder, long COVID also affects children and adolescents. As the symptoms present in Long-COVID often seem to be non-specific and not limited to organ systems, clarification of the causes and the creation of a meaningful, efficient and targeted diagnostic algorithm is urgently needed.

Methods

Therefore, in this prospective observational study, we examined 30 children with long COVID using lung ultrasound and compared the results with those of 15 lung-healthy children.

Results

In our study, no significant difference was found between the two groups in the morphological criteria of lung ultrasound of the pleura or pleural lung structures. There was no significant correlation between the lung ultrasound findings and clinical Data.

Discussion

Our findings are congruent with the current, albeit sparse, data. It is possible that the causes of persistent thoracic symptoms in long COVID might be more likely to be present in functional examinations, but not morphologically imageable. Nonspecific symptoms do not appear to be due to changes in the lung parenchyma. In conclusion, lung ultrasound alone and without baseline in acute disease is not suitable as a standard in the follow-up of long COVID patients. Further investigations on the morphological and functional changes in patient with long COVID is needed.

Prevalence and clinical presentation of long COVID in children: a systematic review

A systematic literature review was conducted up to 15th February 2022 to summarize long COVID evidence and to assess prevalence and clinical presentation in children and adolescents. Articles reporting long COVID prevalence and symptoms based on original data in the paediatric population were included. Case series quality was assessed through the JBI Critical Appraisal Checklist. For observational studies, adherence to STROBE checklist was evaluated. Twenty-two articles were included: 19 observational studies (12 cohort/7 cross-sectional) and 3 case series. Nine studies provided a control group. We found a high variability in terms of prevalence (1.6-70%). The most frequently reported symptoms were fatigue (2-87%), headache (3.5-80%), arthro-myalgias (5.4-66%), chest tightness or pain (1.4-51%), and dyspnoea (2-57.1%). Five studies reported limitations in daily function due to long COVID. Alterations at brain imaging were described in one study, transient electrocardiographic abnormalities were described in a minority of children, while most authors did not evidence long-term pulmonary sequelae. Older age, female sex, and previous long-term pathological conditions were more frequently associated with persistent symptoms.

CONCLUSION

Long COVID evidence in children is limited, heterogeneous, and based on low-quality studies. The lockdown consequences are difficult to distinguish from long COVID symptoms. High-quality studies are required: WHO definition of long COVID should be used, controlled clinical studies should be encouraged, and the impact of new variants on long COVID prevalence should be investigated to ensure an objective analysis of long COVID characteristics in children and a proper allocation of healthcare system resources.

WHAT IS KNOWN

• Children rarely develop a severe respiratory disease in the acute phase of COVID-19. • A limited number of patients develop a multisystem inflammatory condition that can lead to multiorgan failure and shock.

WHAT IS NEW

• Persistent symptoms after SARS-CoV-2 infection are reported in children and limitations in daily function due to long COVID symptoms affect school attendance. • Functional complaints of post-acute COVID are difficult to be distinguished from those due to social restrictions.

Short and Long-Term Wellbeing of Children following SARS-CoV-2 Infection: A Systematic Review

Post-COVID conditions in children and adolescents were mostly investigated as the incidence of individual or clusters of symptoms. We aimed to describe the findings of studies assessing key outcomes related to global wellbeing and recovery in children and adolescents from a public health perspective. We searched the Cochrane COVID-19 Study Register and WHO COVID-19 Global literature on coronavirus disease database on 5 November 2021 and tracked ongoing studies published after this date. We included observational studies on children and adolescents with a follow-up greater than 12 weeks and focused on the outcomes of quality of life, recovery/duration of symptoms, school attendance and resource use/rehabilitation. We assessed their methodological quality, and we prepared a narrative synthesis of the results. We included 21 longitudinal and 4 cross-sectional studies (6 with a control group) with over 68 thousand unvaccinated children and adolescents with mostly asymptomatic or mild disease. Study limitations included convenience sampling, a poor description of their study population and heterogeneous definitions of outcomes. Quality of life was not largely affected in adolescents following COVID-19, but there might be greater impairment in young children and in those with more severe forms of the disease (4 studies). There might also be an impairment in daily activities and increased school absenteeism following COVID-19, but the findings were heterogeneous (5 studies). A total of 22 studies provided highly variable estimates based on heterogeneous definitions of overall persistence of symptoms (recovery), ranging from 0 to 67% at 8-12 weeks and 8 to 51% at 6-12 months. We found limited data on resource use and the need for rehabilitation. One controlled study indicated that the quality of life of infected children and adolescents might not substantially differ from controls. All controlled studies found a higher burden of persistent symptoms in COVID-19 cases compared with test-negative controls or cases of influenza. There is limited evidence on the short and long-term well-being of children following SARS-CoV-2 infection. High-quality longitudinal studies with control groups are needed to describe the outcomes in this population, especially in vaccinated children and those affected by new variants of the virus.

Pediatric Long-COVID: A Review of the Definition, Epidemiology, Presentation, and Pathophysiology

Although children have been largely spared the most severe consequences of acute infection with SARS-CoV-2 virus, it is estimated that up to one-quarter of the more than 14 million children diagnosed as having coronavirus disease 2019 (COVID-19) have developed persistent symptoms of fatigue, postexertional malaise, neurologic and cognitive symptoms, and other symptoms that interfere with activities of daily living for months after their initial illness. Pediatric postacute sequelae of COVID-19 (pPASC), or long-COVID, is a complex, heterogeneous, postviral condition involving multiple body systems and is likely attributable to several concurrent underlying physiologic processes, including damage from direct viral invasion, endovascular dysfunction and microthrombosis, viral persistence, and the development of autoimmunity. In this review, we explore the current state of the literature regarding definition, epidemiology, clinical presentation, and proposed pathophysiologic mechanisms of pPASC. [Pediatr Ann. 2022;51(11):e416-e420.].

Long COVID in children and adolescents

PURPOSE OF REVIEW

Although acute COVID-19 has been milder in children and young people compared with adults, there is a concern that they may suffer persistent symptoms. There is a need to define the clinical phenotype, determine those most at risk, the natural course of the condition and evaluate preventive and therapeutic strategies for both mental health and physical symptoms.

RECENT FINDINGS

More recent studies with control groups reported a lower prevalence of persistent symptoms in children and young people exposed to SARS-CoV-2. A systematic review and meta-analysis found that the frequency of the majority of reported persistent symptoms is similar in SARS-CoV-2 positive cases and controls. Children and young people infected with SARS-COV-2 had small but significant increases in persisting cognitive difficulties, headache and loss of smell. Factors associated with persisting, impairing symptoms include increased number of symptoms at the time of testing, female sex, older age, worse self-rated physical and mental health, and feelings of loneliness preinfection.

SUMMARY

This review highlights the importance of a control group in studies following SARS-CoV-2 infection, the need for case definitions and research to understand the outcomes of long COVID in children and young people.

Robustness of reported postacute health outcomes in children with SARS-CoV-2 infection: a systematic review

OBJECTIVE

To systematically assess the robustness of reported postacute SARS-CoV-2 infection health outcomes in children.

METHODS

A search on PubMed and Web of Science was conducted to identify studies published up to 22 January 2022 that reported on postacute SARS-CoV-2 infection health outcomes in children (<18 years) with follow-up of ≥2 months since detection of infection or ≥1 month since recovery from acute illness. We assessed the consideration of confounding bias and causality, as well as the risk of bias.

RESULTS

21 studies including 81 896 children reported up to 97 symptoms with follow-up periods of 2.0-11.5 months. Fifteen studies had no control group. The reported proportion of children with post-COVID syndrome was between 0% and 66.5% in children with SARS-CoV-2 infection (n=16 986) and between 2.0% and 53.3% in children without SARS-CoV-2 infection (n=64 910). Only two studies made a clear causal interpretation of an association between SARS-CoV-2 infection and the main outcome of 'post-COVID syndrome' and provided recommendations regarding prevention measures. The robustness of all 21 studies was seriously limited due to an overall critical risk of bias.

CONCLUSIONS

The robustness of reported postacute SARS-CoV-2 infection health outcomes in children is seriously limited, at least in all the published articles we could identify. None of the studies provided evidence with reasonable certainty on whether SARS-CoV-2 infection has an impact on postacute health outcomes, let alone to what extent. Children and their families urgently need much more reliable and methodologically robust evidence to address their concerns and improve care.

Pulmonary Function and Persistent Clinical Symptoms in Children and Their Parents 12 Months After Mild SARS-CoV-2 Infection

Background

Pulmonary involvement is the leading cause of morbidity and mortality after severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. Long-term impairment has been reported in adults with severe infection. However, most infections cause only mild symptoms or are even asymptomatic, especially in children. There is insufficient evidence regarding pulmonary outcome measures in mild SARS-CoV-2. The objectives of this study were to determine spirometry parameters after SARS-CoV-2 infection and correlate those with reported persisting symptoms in children, adolescents, and adults.

Methods

Data on clinical symptoms during acute infection as well as SARS-CoV-2 serology results were recorded. Twelve months after infection, spirometry was performed and information on persisting symptoms was collected using a structured questionnaire. 182 participants (108 SARS-CoV-2 positive) from 48 families were included; 53 children (< 14 years), 34 adolescents and young adults (14-25 years), and 95 adults.

Results

Spirometry values did not significantly differ between the particular subgroups of the cohort (adults, adolescents, children; infected and non-infected individuals). Adults reported more symptoms during acute infection as well more persisting fatigue (29.7% of participants), reduced physical resilience (34.4%), and dyspnea (25.0%) 12 months after infection than adolescents (fatigue 26.7%, reduced physical resilience 20%, and 0% dyspnea) and children (4%, 0%, 0%, respectively). There was no correlation between persistent subjective symptoms and spirometry results.

Discussion

Children and adolescents are less affected than adults by acute SARS-CoV-2 as well as by post-infection persistent symptoms. Spirometry was not able to demonstrate any differences between healthy individuals and participants who had suffered from mild SARS-CoV-2 12 months after the infection.

Preliminary Evidence on Pulmonary Function after Asymptomatic and Mild COVID-19 in Children

Background: While it has been described that adults can develop long-lasting deterioration in pulmonary function (PF) after coronavirus disease 19 (COVID-19), regardless of disease severity, data on the long-term pneumological impact of SARS-CoV-2 infection in children are lacking. Methods: Performing a single-center, prospective, observational study on children aged 6–18 years with a previous diagnosis of asymptomatic/mild COVID-19, we evaluated the long-term impact of mild severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in children. Results: A total of 61 subjects underwent spirometry after a mean time of 10 ± 4 months from asymptomatic or mild infection. None of the children reported any respiratory symptoms, needed any inhaled therapy, or had abnormal lung function. Conclusions: In our study, we observed that children and adolescents did not develop chronic respiratory symptoms and did not present lung function impairment after asymptomatic or mild SARS-CoV-2 infection.

The Challenge of Studying Long COVID: An Updated Review

Accurately determining the risk of long COVID is challenging. Existing studies in children and adolescents have considerable limitations and distinguishing long-term SARS-CoV-2 infection-associated symptoms from pandemic-related symptoms is difficult. Over half of individuals in this age group, irrespective of COVID-19, report physical and psychologic symptoms, highlighting the impact of the pandemic. More robust data is needed to inform policy decisions.

Pulmonary Function and Long-Term Respiratory Symptoms in Children and Adolescents After COVID-19

Background

Persistent respiratory symptoms after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in adults are frequent, and there can be long-term impairment of pulmonary function. To date, only preliminary evidence is available on persistent respiratory sequelae of SARS-CoV-2 in children and adolescents. Our objective was to examine the long-term effects of symptomatic and asymptomatic SARS-CoV-2 infections on pulmonary function in this age group in a single-center, controlled, prospective study.

Methods

Participants with serological or polymerase chain reaction-based evidence of SARS-CoV-2 infection were recruited from a population-based study of seroconversion rates. Multiple-breath washout (MBW), body plethysmography, and diffusion capacity testing were performed for children and adolescents. Participants were interviewed about their symptoms during the acute phase of infection and long-lasting symptoms. Cases were compared with SARS-CoV-2 seronegative controls from the same population-based study with and without history of respiratory infection within 6 months prior to assessment. Primary endpoints were differences in pulmonary function, including diffusion capacity and MBW, between participants with and without evidence of SARS-CoV-2 infection. Secondary endpoints included correlation between lung function and long-lasting symptoms as well as disease severity.

Findings

In total, 73 seropositive children and adolescents (5-18 years) were recruited after an average of 2.6 months (range 0.4-6.0) following SARS-CoV-2 infection. Among 19 patients (27.1%) who complained of persistent or newly emerged symptoms since SARS-CoV-2, 8 (11.4%) reported respiratory symptoms. No significant differences were detected in frequency of abnormal pulmonary function when comparing cases with 45 controls, including 14 (31.1%) with a history of previous infection (SARS-CoV-2: 12, 16.4%; controls: 12, 27.7%; odds ratio 0.54, 95% confidence interval 0.22-1.34). Only two patients with persistent respiratory symptoms showed abnormal pulmonary function. Multivariate analysis revealed reduced forced vital capacity (p = 0.012) in patients with severe SARS-CoV-2 infection.

Interpretation

Pulmonary function is rarely impaired in children and adolescents after SARS-CoV-2 infection, except from those with severe infection, and did not differ between SARS-CoV-2 and other previous infections, suggesting that SARS-CoV-2 is not more likely to cause pulmonary sequelae than other infections. The discrepancy between persisting respiratory symptoms and normal pulmonary function suggests a different underlying pathology such as dysfunctional breathing.

Inflammatory Markers, Pulmonary Function, and Clinical Symptoms in Acute COVID-19 Among Non-Hospitalized Adolescents and Young Adults

Summary

Mild, subacute COVID-19 in young people show inflammatory enhancement, but normal pulmonary function. Inflammatory markers are associated with age and male sex, whereas clinical symptoms are associated with age and female sex, but not with objective disease markers.

Background

Coronavirus Disease 2019 (COVID-19) is widespread among adolescents and young adults across the globe. The present study aimed to compare inflammatory markers, pulmonary function and clinical symptoms across non-hospitalized, 12 – 25 years old COVID-19 cases and non-COVID-19 controls, and to investigate associations between inflammatory markers, clinical symptoms, pulmonary function and background variables in the COVID-19 group.

Methods

The present paper presents baseline data from an ongoing longitudinal observational cohort study (Long-Term Effects of COVID-19 in Adolescents, LoTECA, ClinicalTrials ID: NCT04686734). A total of 31 plasma cytokines and complement activation products were assayed by multiplex and ELISA methodologies. Pulmonary function and clinical symptoms were investigated by spirometry and questionnaires, respectively.

Results

A total of 405 COVID-19 cases and 111 non-COVID-19 controls were included. The COVID-19 group had significantly higher plasma levels of IL-1β, IL-4, IL-7, IL-8, IL-12, TNF, IP-10, eotaxin, GM-CSF, bFGF, complement TCC and C3bc, and significantly lower levels of IL-13 and MIP-1α, as compared to controls. Spirometry did not detect any significant differences across the groups. IL-4, IL-7, TNF and eotaxin were negatively associated with female sex; eotaxin and IL-4 were positively associated with age. Clinical symptoms were positively associated with female sex and age, but not with objective disease markers.

Conclusions

Among non-hospitalized adolescents and young adults with COVID-19 there was significant alterations of plasma inflammatory markers in the subacute stage of the infection. Still, pulmonary function was normal. Clinical symptoms were independent of inflammatory and pulmonary function markers, but positively associated with age and female sex.

Therapeutic Strategies for COVID-19 Lung Disease in Children

The novel Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection has milder presentation in children than in adults, mostly requiring only supportive therapy. The immunopathogenic course of COVID-19 can be divided in two distinct but overlapping phases: the first triggered by the virus itself and the second one by the host immune response (cytokine storm). Respiratory failure or systemic involvement as Multisystem Inflammatory Syndrome in Children (MIS-C) requiring intensive care are described only in a small portion of infected children. Less severe lung injury in children could be explained by qualitative and quantitative differences in age-related immune response. Evidence on the best therapeutic approach for COVID-19 lung disease in children is lacking. Currently, the approach is mainly conservative and based on supportive therapy. However, in hospitalized children with critical illness and worsening lung function, antiviral therapy with remdesivir and immunomodulant treatment could be considered the "therapeutic pillars."

Pulmonary function tests in the follow-up of children with COVID-19

The SARS-CoV-2 virus has infected more than 235 million people since it was accepted as a pandemic in March 2020. Although a milder disease is seen in the pediatric age group, the extent of lung damage and its long-term effects are still unknown. In this study, persistent respiratory symptoms and pulmonary function tests were investigated in children with COVID-19. Fifty children with a confirmed diagnosis of COVID-19 were included in the study. Patients were evaluated for ongoing respiratory symptoms and pulmonary function tests 3 months after infection. Patients with and without persistent symptoms were compared in terms of demographic, clinical, laboratory, and radiological characteristics and also disease severity. Three months after infection, persistent respiratory symptoms were found to be present in 28% of patients; cough, chest pain and tightness, dyspnea, and exertional dyspnea were the most common symptoms. Three patients had an obstructive deficit, and one had a restrictive deficit. Four patients had impaired diffusing capacity of the lungs for carbon monoxide (DLCO). A significant decrease in FEV1/FVC and an increase in lung clearance index were found in the patients with persistent respiratory symptoms. Persistent respiratory symptoms were present in 50% of patients who had severe disease and 12.5% with non-severe disease. DLCO was also significantly lower in the severe disease group.   Conclusions: Our study suggests that the persistence of respiratory symptoms is not related to the severity of acute COVID-19 in children. The inflammatory process due to COVID-19 may continue regardless of its severity, and consequently, peripheral airways may be affected. What is Known: • As compared with adults, children with COVID-19 exhibit a milder disease course and lower mortality rates. However, due to the lack of follow-up studies on children, the long-term effects of their contracting the disease are unknown. What is New: • Although COVID-19 has been thought to have a milder course in children, respiratory system symptoms persist in approximately 30% of patients 3 months after infection. The persistent respiratory symptoms suggest that the inflammatory process due to COVID-19 may continue in some children, even if the clinical findings at admission are not severe, and that the peripheral airways may be affected accordingly.

How Common is Long COVID in Children and Adolescents?

In children, the risk of coronavirus disease (COVID) being severe is low. However, the risk of persistent symptoms following infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is uncertain in this age group, and the features of "long COVID" are poorly characterized. We reviewed the 14 studies to date that have reported persistent symptoms following COVID in children and adolescents. Almost all the studies have major limitations, including the lack of a clear case definition, variable follow-up times, inclusion of children without confirmation of SARS-CoV-2 infection, reliance on self- or parent-reported symptoms without clinical assessment, nonresponse and other biases, and the absence of a control group. Of the 5 studies which included children and adolescents without SARS-CoV-2 infection as controls, 2 did not find persistent symptoms to be more prevalent in children and adolescents with evidence of SARS-CoV-2 infection. This highlights that long-term SARS-CoV-2 infection-associated symptoms are difficult to distinguish from pandemic-associated symptoms.