SARS-CoV-2 viral RNA load dynamics in the nasopharynx of infected children

Asymptomatic viruses detectable in saliva in the first year of life: a narrative review

Viral infections are common in children. Many can be asymptomatic or have delayed health consequences. In view of increasing availability of point-of-care viral detection technologies, with possible application in newborn screening, this review aimed to (1) identify potentially asymptomatic viruses detectable in infants under one year old, via saliva/nasopharyngeal swab, and (2) describe associations between viruses and long-term health conditions. We systematically searched Embase(Ovid), Medline(Ovid) and PubMed, then further searched the literature in a tiered approach. From the 143 articles included, 28 potentially asymptomatic viruses were identified. Our second search revealed associations with a range of delayed health conditions, with most related to the severity of initial symptoms. Many respiratory viruses were linked with development of recurrent wheeze or asthma. Of note, some potentially asymptomatic viruses are linked with later non-communicable diseases: adenovirus serotype 36 and obesity, Enterovirus-A71 associated Hand, Foot, Mouth Disease and Attention-Deficit Hyperactivity Disorder, Ebstein Barr Virus (EBV) and malignancy, EBV and multiple sclerosis, HHV-6 and epilepsy, HBoV-1 and lung fibrosis and Norovirus and functional gastrointestinal disorders. Our review identified many potentially asymptomatic viruses, detectable in early life with potential delayed health consequences, that could be important to screen for in the future using rapid point-of-care viral detection methods. IMPACT: Novel point-of-care viral detection technologies enable rapid detection of viruses, both old and emerging. In view of increasing capability to screen for viruses, this is the first review to explore which potentially asymptomatic viruses, that are detectable using saliva and/or nasopharyngeal swabs in infants less than one year of age, are associated with delayed adverse health conditions. Further research into detecting such viruses in early life and their delayed health outcomes may pave new ways to prevent non-communicable diseases in the future.

SARS-CoV-2 antigen rapid tests and universal screening for COVID-19 Omicron variant among hospitalized children

BACKGROUND

Clinical utility of universal antigen rapid test (ART) in the pediatric setting is unknown. We aimed to assess the performance and utility of universal ART in hospitalized children (≥5-year-old) to prevent nosocomial COVID-19 transmission.

METHODS

Cross-sectional study involving all hospitalized pediatric patients aged ≥5-year-old from 2 periods during Omicron wave. Clinical data, ART and polymerase chain reaction test results were collected.

RESULTS

A total of 444 patients were included from the 2 study periods, and 416 patients (93.7%) had concordant results between ART and polymerase chain reaction. The overall sensitivity and specificity of ART were 83.3% (95% CI: 75.2-89.3) and 97.5% (95% CI: 95.0-98.8), respectively. Negative predictive values of ART between the Omicron emergence and Omicron peak periods for a probable case group were 71.4% and 66.7%, respectively, and for a suspect case group 91.4% and 75.0%, respectively. Negative predictive values for an unlikely case group was >95% in both periods. Positive predictive value of ART was >85% for probable and suspect case groups in both periods. Seventy-five percent of patients (n = 15) who were incorrectly classified as SARS-CoV-2 negative by ART had potentially viable virus. No large nosocomial transmission clusters were detected.

CONCLUSIONS

Universal ART screening may limit nosocomial outbreaks in hospitalized children. The performance can be optimized by considering clinical symptoms, exposure and periods within COVID waves.

#Stayathome If You Have a Cold: High SARS-CoV-2 Salivary Viral Loads in Pediatric Patients with Nasopharyngeal Symptoms

The choice of the best SARS-CoV-2 detection approach is crucial to predict which children with SARS-CoV-2 are at high risk of spreading the virus in order to manage public health measures and policies. In this prospective observational study of 35 children admitted to the Pediatric Emergency Departments of two tertiary hospitals in Northern Italy who tested positive for SARS-CoV-2 by standard RT-PCR in nasopharyngeal swab (NPS), we evaluated their presenting symptoms according to their salivary viral load (SVL) determined by droplet digital PCR (ddPCR). Despite an overall low concordance between SARS-CoV-2 detected by salivary ddPCR and NPS RT-PCR (54.3%), when only patients with nasopharyngeal symptoms were analyzed, the sensitivity of ddPCR in saliva specimens increased to 71.4%, and over half of these patients had high SVL (>105 copies/mL), which was significantly more frequent than in children without nasopharyngeal symptoms (57.1% vs. 14.3%, OR = 8, CI 95% 1.28−50.03, p = 0.03). All asymptomatic children had low SVL values. Our findings support the hypothesis that children with nasopharyngeal symptoms are at higher risk of spreading SARS-CoV-2 due to their high SVL and, conversely, asymptomatic children are unlikely to spread the virus due to their low SVL, regardless of their NPS positivity.

Clinical features and characteristics of pediatric patients with COVID-19 infection: Experiences in a Tertiary Taiwan Hospital

Coronavirus disease 2019 (COVID-19) patients have distinct clinical features in the pediatric groups. However, there is a paucity of research focused on clinical manifestation within pediatric group in Taiwan. This study is to conduct a retrospective study of the clinical features of COVID-19 in Taiwan pediatric patients. A retrospective study was conducted on pediatric patients (Aged ≤ 18 years) in a Northern Taiwan hospital from May 1st, 2021 to June 30th, 2021. Thirty-eight patients were included from emergency room. They were laboratory confirmed COVID-19 through specimens from nasopharyngeal swab by real-time reverse-transcription polymerase chain reaction (RT-PCR). Data including RT-PCR cycle threshold (Ct) values, clinical and epidemiological features were collected and analyzed. Thirty-eight patients aged from 7-month to 18-year-old were included. The median age of patients was 15-year-old. The patients had sex ratio of 23 males to 15 females. More than half patients were infected from family members. Asymptomatic patients were 47.37%. In the symptomatic patients, fever (34.21%) was the most predominant symptom. Cough, nasal obstruction and sore throat were also common. Asymptomatic children had significantly higher Ct-values than symptomatic children, and diagnosed patients with Ct-values more than 19 were associated with asymptomatic infection (P = .0084). Ct-values higher than 19 were associated with asymptomatic infection, which may be a predictor of pediatric disease severity. Our results highlight the distinct clinical manifestations and outcomes in pediatric COVID-19 patients. Compared to the adults, pediatric patients aged ≤ 18 years with COVID-19 in Taiwan mainly had mild disease.

Designing isolation guidelines for COVID-19 patients with rapid antigen tests

Appropriate isolation guidelines for COVID-19 patients are warranted. Currently, isolating for fixed time is adopted in most countries. However, given the variability in viral dynamics between patients, some patients may no longer be infectious by the end of isolation, whereas others may still be infectious. Utilizing viral test results to determine isolation length would minimize both the risk of prematurely ending isolation of infectious patients and the unnecessary individual burden of redundant isolation of noninfectious patients. In this study, we develop a data-driven computational framework to compute the population-level risk and the burden of different isolation guidelines with rapid antigen tests (i.e., lateral flow tests). Here, we show that when the detection limit is higher than the infectiousness threshold values, additional consecutive negative results are needed to ascertain infectiousness status. Further, rapid antigen tests should be designed to have lower detection limits than infectiousness threshold values to minimize the length of prolonged isolation.

Utilizing viral test results to determine isolation length would minimize both the risk of prematurely ending isolation of infectious patients and the unnecessary individual burden of redundant isolation of noninfectious patients. Here, the authors develop a framework to compute the population-level risk of different isolation guidelines with rapid antigen tests.

Saliva molecular testing bypassing RNA extraction is suitable for monitoring and diagnosing SARS-CoV-2 infection in children

Background

Adults are being vaccinated against SARS-CoV-2 worldwide, but the longitudinal protection of these vaccines is uncertain, given the ongoing appearance of SARS-CoV-2 variants. Children remain largely unvaccinated and are susceptible to infection, with studies reporting that they actively transmit the virus even when asymptomatic, thus affecting the community.

Methods

We investigated if saliva is an effective sample for detecting SARS-CoV-2 RNA and antibodies in children, and associated viral RNA levels to infectivity. For that, we used a saliva-based SARS-CoV-2 RT-qPCR test, preceded or not by RNA extraction, in 85 children aged 10 years and under, admitted to the hospital regardless of COVID-19 symptomatology. Amongst these, 29 (63.0%) presented at least one COVID-19 symptom, 46 (54.1%) were positive for SARS-CoV-2 infection, 28 (32.9%) were under the age of 1, and the mean (SD) age was 3.8 (3.4) years. Saliva samples were collected up to 48 h after a nasopharyngeal swab-RT-qPCR test.

Results

In children aged 10 years and under, the sensitivity, specificity, and accuracy of saliva-RT-qPCR tests compared to NP swab-RT-qPCR were, respectively, 84.8% (71.8%–92.4%), 100% (91.0%–100%), and 91.8% (84.0%–96.6%) with RNA extraction, and 81.8% (68.0%–90.5%), 100% (91.0%–100%), and 90.4% (82.1%–95.0%) without RNA extraction. Rescue of infectious particles from saliva was limited to CT values below 26. In addition, we found significant IgM positive responses to SARS-CoV-2 in children positive for SARS-CoV-2 by NP swab and negative by saliva compared to other groups, indicating late infection onset (>7–10 days).

Conclusions

Saliva is a suitable sample type for diagnosing children aged 10 years and under, including infants aged <1 year, even bypassing RNA extraction methods. Importantly, the detected viral RNA levels were significantly above the infectivity threshold in several samples. Further investigation is required to correlate SARS-CoV-2 RNA levels to viral transmission.

Dynamics of Reverse Transcription-Polymerase Chain Reaction and Serologic Test Results in Children with SARS-CoV-2 Infection

OBJECTIVES

To determine the time to reverse transcription-polymerase chain reaction (RT-PCR) negativity after the first positive RT-PCR test, factors associated with longer time to RT-PCR negativity, proportion of children seroconverting after proven severe acute respiratory syndrome coronavirus 2 infection, and factors associated with the lack of seroconversion.

STUDY DESIGN

The Epidemiological Study of Coronavirus in Children of the Spanish Society of Pediatrics is a multicenter study conducted in Spanish children to assess the characteristics of coronavirus disease 2019. In a subset of patients, 3 serial RT-PCR tests on nasopharyngeal swab specimens were performed after the first RT-PCR test, and immunoglobulin G serology for severe acute respiratory syndrome coronavirus 2 antibodies was performed in the acute and follow-up (<14 and ≥14 days after diagnosis) phase.

RESULTS

In total, 324 patients were included in the study. The median time to RT-PCR negativity was 17 days (IQR, 8-29 days), and 35% of patients remained positive more than 4 weeks after the first RT-PCR test. The probability of RT-PCR negativity did not differ across groups defined by sex, disease severity, immunosuppressive drugs, or clinical phenotype. Globally, 24% of children failed to seroconvert after infection. Seroconversion was associated with hospitalization, persistence of RT-PCR positivity, and days of fever.

CONCLUSIONS

Time to RT-PCR negativity was long, regardless of the severity of symptoms or other patient features. This finding should be considered when interpreting RT-PCR results in a child with symptoms, especially those with mild symptoms. Seroprevalence and postimmunization studies should consider that 11 in 4 infected children fail to seroconvert.

Designing isolation guidelines for COVID-19 patients utilizing rapid antigen tests: a simulation study using viral dynamics models

Appropriate isolation guidelines for COVID-19 patients are warranted. Currently, isolating for fixed time is adapted in most countries. However, given the variability in viral dynamics between patients, some patients may no longer be infectious by the end of isolation (thus they are redundantly isolated), whereas others may still be infectious. Utilizing viral test results to determine ending isolation would minimize both the risk of ending isolation of infectious patients and the burden due to redundant isolation of noninfectious patients. In our previous study, we proposed a computational framework using SARS-CoV-2 viral dynamics models to compute the risk and the burden of different isolation guidelines with PCR tests. In this study, we extend the computational framework to design isolation guidelines for COVID-19 patients utilizing rapid antigen tests. Time interval of tests and number of consecutive negative tests to minimize the risk and the burden of isolation were explored. Furthermore, the approach was extended for asymptomatic cases. We found the guideline should be designed considering various factors: the infectiousness threshold values, the detection limit of antigen tests, symptom presence, and an acceptable level of releasing infectious patients. Especially, when detection limit is higher than the infectiousness threshold values, more consecutive negative results are needed to ascertain loss of infectiousness. To control the risk of releasing of infectious individuals under certain levels, rapid antigen tests should be designed to have lower detection limits than infectiousness threshold values to minimize the length of prolonged isolation, and the length of prolonged isolation increases when the detection limit is higher than the infectiousness threshold values, even though the guidelines are optimized for given conditions.

Preoperative SARS-CoV-2 Screening Fails to Detect Viral Particles Prior to Airway Surgery

Objectives/Hypothesis

Children have higher rates of asymptomatic SARS‐CoV‐2 infections or milder courses of infection, and their carrier status may potentially impact viral transmission to those providing them care. The aim of this study is to compare the existing COVID‐19 preoperative screening protocols to the detection of SARS‐CoV‐2 viral particles in surgical samples.

Study Design

Cross‐sectional study.

Methods

We conducted a prospective study with consecutive convenience sampling of children undergoing adenoidectomy between January and April 2021. Total nucleic acid was extracted from adenoid tissue and real‐time reverse transcription‐polymerase chain reaction was conducted to test for the presence of SARS‐CoV‐2 viral particles. Univariate logistic regression was used to summarize the effect size of variables of interest on the odds of having SARS‐CoV‐2 positive adenoid tissue.

Results

Forty adenoid samples were collected and 11 (27.5%) had a positive SARS‐CoV‐2 reverse transcriptase‐polymerase chain reaction. Patients with positive adenoids were older (11.8 vs. 7.9 years, odds ratio: 1.3, P = .01) and more likely to have had a positive nasopharyngeal swab in the previous 90 days (4/11 or 36% vs. 0).

Conclusion

These data are the first report on the presence of SARS‐CoV‐2 particles in pediatric adenoidectomy specimens, with a high percentage of patients showing evidence of viral particles within the adenoid. This finding calls in to question the utility of preoperative COVID screening protocols which have yet to be rigorously validated in asymptomatic patients and have the potential to delay patients' surgical care.

Level of Evidence

3 Laryngoscope, 132:1665–1667, 2022

Upper respiratory tract SARS-CoV-2 RNA loads in symptomatic and asymptomatic children and adults

OBJECTIVES

Studies comparing SARS-CoV-2 RNA load in the upper respiratory tract (URT) between children and adults, either presenting with COVID-19 or asymptomatic have yielded inconsistent results. Here, we conducted a retrospective, single center study to address this issue.

PATIENTS AND METHODS

1,184 consecutive subjects (256 children and 928 adults) testing positive for SARS-COV-2 RNA in nasopharyngeal exudates (NP), of whom 424 (121 children and 303 adults) had COVID-19 and 760 (135 children and 625 adults) were asymptomatic close contacts of COVID-19 patients. SARS-CoV-2 RNA testing was carried out using the TaqPath COVID-19 Combo Kit (Thermo Fisher Scientific, MS, USA). The AMPLIRUN® TOTAL SARS-CoV-2 RNA Control (Vircell SA, Granada, Spain) was used for estimating SARS-CoV-2 RNA loads (in copies/mL). SARS-CoV-2 RNA loads at the time of laboratory diagnosis (single specimen/patient) were used for comparison purposes.

RESULTS

Median initial SARS-COV-2 RNA load was lower (P=0.094) in children (6.98 log₁₀ copies/ml; range, 3.0-11.7) than in adults (7.14 log₁₀ copies/ml; range, 2.2.-13.4) with COVID-19. As for asymptomatic individuals, median SARS-CoV-2 RNA load was comparable (P=0.97) in children (6.20 log₁₀ copies/ml; range, 1.8-11.6) and adults (6.48 log₁₀ copies/ml; range, 1.9-11.8). Children with COVID-19 symptoms displayed SARS-CoV-2 RNA loads (6.98 log₁₀ copies/ml; range, 3.0-11.7) comparable to their asymptomatic counterparts (6.20 log₁₀ copies/ml; range, 1.8-11.6) (P=0.61). Meanwhile in adults, median SARS-CoV-2 RNA load was significantly higher in symptomatic (7.14 log₁₀ copies/ml; range, 2.2.-13.4) than in asymptomatic subjects (6.48 log₁₀ copies/ml; range, 1.9-11.8) (P=<0.001). Overall, a faster URT SARS-CoV-2 RNA clearance rate was observed in children than in adults.

CONCLUSIONS

Based on viral load data at the time of diagnosis, our results suggested that SARS-CoV-2 infected children, with or without COVID-19, may display NP viral loads of comparable magnitude to that found in their adult counterparts; However, children may have shorter viral shedding as compared to adults.

Pediatric Airway Management in Times of COVID-19-a Review of the Evidence and Controversies

Purpose of Review

This review summarizes and provides a comprehensive narrative synthesis of the current evidence on pediatric airway management during the COVID-19 pandemic.

Recent Findings

The safe care of children undergoing airway management is a primary concern for pediatric anesthesiologists. The COVID-19 pandemic has brought challenges related to airway management and the use of personal protective equipment, aerosol barriers, and the need for simulation and intubation teams. The risk of COVID-19 transmission to the health care worker may be lower in children due to the smaller volume of aerosol dispersal. The implementation of vaccinations may further reduce the risk to health care workers. Evidence demonstrating the impact of COVID-19 on airway outcomes in children is necessary to inform their care.

Summary

This review shows that pediatric airway management can be a safe procedure for both the patient and provider in the right setting. The use of appropriate personal protective equipment, particularly focusing on protection from aerosolized particles, is paramount to reduce infection risk. However, there are opportunities for future research.

8806 Russian patients demonstrate T cell count as better marker of COVID-19 clinical course severity than SARS-CoV-2 viral load

The article presents a comparative analysis of SARS-CoV-2 viral load (VL), T lymphocyte count and respiratory index PaO₂:FiO₂ ratio as prospective markers of COVID-19 course severity and prognosis. 8806 patients and asymptomatic carriers were investigated in time interval 15 March–19 December 2020. T cell count demonstrated better applicability as a marker of aggravating COVID-19 clinical course and unfavourable disease prognosis than SARS-CoV-2 VL or PaO₂:FiO₂ ratio taken alone. Using T cell count in clinical practice may provide an opportunity of early prediction of deteriorating a patient’s state.