Symptomatic and Asymptomatic Viral Shedding in Pediatric Patients Infected With Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2): Under the Surface

Pre-admission virus detection during the COVID-19 pandemic in children with and without symptoms of infection

AIM

Pre-admission viral screening is used only in exceptional situations such as pandemics. We therefore evaluated pre-admission screening for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), respiratory syncytial virus (RSV) and influenza during the COVID-19 pandemic, comparing epidemiology and clinical features of admitted children.

METHODS

Children were screened at a paediatric emergency department from 1 March 2020 to 30 June 2022 by nasopharyngeal sampling and polymerase chain reaction kit. We retrospectively retrieved positive results from the laboratory and scrutinised charts of admitted children.

RESULTS

Out of 15 927 screened children, 522, 127 and 572 were positive and admitted with RSV, influenza A or SARS-CoV-2, respectively. Of these, 29 (5.6%), 26 (24.1%) and 245 (44.8%) were incidental findings, lacking symptoms of infection. RSV and influenza A were initially absent but re-emerged in the autumn of 2021. The rate of COVID-19 rose when the Omicron variant emerged in December 2021. The median age of children with RSV was 0.3 years, of those with influenza A 6.7 years and of those with COVID-19 1.6 years. Major complications were rare.

CONCLUSION

Frequent incidental detections of SARS-CoV-2 likely reflected widespread presence of a mild infection. Clinically, COVID-19 was like other viral respiratory infections in children.

COVID-19 vaccination rates and factors affecting vaccination in children with rheumatic disease

Objectives

This study aimed to investigate coronavirus disease 2019 (COVID-19) vaccination rates and factors affecting vaccination in children with rheumatic diseases.

Patients and methods

This multicenter cross-sectional survey-based study was conducted between July 2022 and September 2022. Four hundred seventy-four patients (256 females, 218 males; median age: 15 years; interquartile range, 13 to 16 years) were included in the patient group, and 211 healthy children (124 females, 87 males; median age: 15 years; interquartile range, 13 to 16 years) were included in the control group. A questionnaire was administered to the parents face-to-face during routine outpatient visits.

Results

Of the patients, 220 were followed up with the diagnosis of autoinflammatory disease, 174 with juvenile idiopathic arthritis, 48 with connective tissue disease, 23 with vasculitis, eight with uveitis, and one with sarcoidosis. In the study group, 256 (54%) patients and 115 (54.5%) healthy children received at least one dose of COVID-19 vaccine. Parents' concern regarding potential side effects of the vaccine was the most common reason for COVID-19 vaccination hesitancy in both groups. The median patient age, follow-up period, colchicine treatment rates, childhood vaccination and influenza vaccination rates, median parental age, parental vaccination rate, and parental education level were higher in vaccinated patients (p<0.001).

Conclusion

Parents' concerns about safety and side effects were found to be the most important factors affecting vaccination success. Identification of the underlying causes of parental vaccine hesitancy will facilitate the development of effective vaccination strategies for potential future outbreaks.

Jerusalem's CoVID-19 Experience-The Effect of Ethnicity on Disease Prevalence and Adherence to Testing

BACKGROUND

The management of the SARS-CoV-2 pandemic depends amongst other factors on disease prevalence in the general population. The gap between the true rate of infection and the detected rate of infection may vary, especially between sub-groups of the population. Identifying subpopulations with high rates of undetected infection can guide authorities to direct resource distribution in order to improve health equity.

METHODS

A cross-sectional epidemiological survey was conducted between April and July 2021 in the Pediatric Emergency Department of the Shaare Zedek Medical Center, Jerusalem, Israel. We compared three categories: unconfirmed disease (UD), positive serology test result with no history of positive PCR; confirmed disease (CD), history of a positive PCR test result, regardless of serology test result; and no disease (ND), negative serology and no history of PCR. These categories were applied to local prevailing subpopulations: ultra-orthodox Jews (UO), National Religious Jews (NRJ), secular Jews (SJ), and Muslim Arabs (MA).

RESULTS

Comparing the different subpopulations groups, MAs and UOs had the greatest rate of confirmed or unconfirmed disease. MA had the highest rate of UD and UO had the highest rate of CD. UD significantly correlated with ethnicity, with a low prevalence in NRJ and SJ. UD was also associated with larger family size and housing density defined as family size per number of rooms.

CONCLUSION

This study highlights the effect of ethnicity on disease burden. These findings should serve to heighten awareness to disease burden in weaker populations and direct a suitable prevention program to each subpopulation's needs. Early awareness and possible intervention may lower morbidity and mortality.

Analysis and interpretation of Coronavirus infection children's incidence, contributing factors, risks of complications and their relationship

OBJECTIVE

Aim: To study and investigate the incidence of Coronavirus infection in children, the course of the disease, the risks of complications and their interrelationships.

PATIENTS AND METHODS

Materials and Methods: Study included the analysis and observation of children (n=55, aged 14.36±3.62 years) with confirmed Coronerovirus infection, who were observed in the CNE ≪CMCH≫ in Uzhgorod in outpatient conditions. A study of clinical presentations, a clinical and laboratory examination followed by a mathematical analysis of the symptoms data in children with an identified Coronavirus infection and in the dynamics up to week 30 (with survey intervals in 3 weeks) from the diagnosis verification was carried out.

RESULTS

Results: A dynamic analysis of the clinical manifestation of symptoms in children with an identified Corona virus infection and within 30 weeks (with survey intervals of 3 weeks) from the beginning of the diagnosis verification was carried out. Complaints from the respiratory system were prevailed. The most long-lasting complaint was observed ≪changes in the sense of taste and smell≫ (from 35(63.6%) to 6(10.9%) up to 18 weeks inclusive. Other complaints ≪Cough, Rhinitis, Shortness of breath, Pain in the chest≫ was observed for 6 weeks. Sore throat, muscular and joint pain were persisted for 3 weeks. Fever was not identified at week 3. Illness with other viral respiratory diseases started at week 9 and was observed until week 30 (from 10(18.2%) to 19(34.5%)) with varying levels. A decrease in cases of IgM identification was observed within 6 weeks (from 55, 100% to 20, 36, 4%). On the 9th week, the presence of IgM was not established. There is also an increase in the number of cases of detection of IgG in patients with a level maximum of 6 weeks.

CONCLUSION

Conclusions: There is a positive effect of the CRP level on the occurrence of symptoms of cough, rhinitis, shortness of breath, chest pain, change in taste and smell, muscle and joint pain (r=0.33-0.55), with the most significant data for the symptom of pain in chest (p=0.00001). Ferritin level interactions mostly had a negative direction (r=-0.35-0.48, p=0.02-0.00001) on the development of symptoms, with the exception of rhinorrhea (r=0.48, p=0.00002) and chest pains (r=0.39, 0.003). According to multiple logistic regression analysis the chance of the symptom of a change in taste and smell increases due to an increasing in the level of Procalcitonin in 1.48 times. The chance of the symptom of shortness of breath increased due to an increasing in the Ferritin level in 1.025 times.

Comparison of Salivary Secretion, pH, and Buffer Capacity Between COVID-19 Vaccinated and Unvaccinated Child Patients Visiting Dental Clinics of University Hospitals in Riyadh City, Saudi Arabia

Objective

This study aimed to assess and compare the salivary secretion, pH, and buffer capacity between COVID-19 vaccinated and unvaccinated child patients visiting the clinics of private university dental hospitals in Riyadh, Saudi Arabia.

Methods

This is the first comparative assessment of salivary parameters between unvaccinated and COVID-19-vaccinated child patients. The study sample comprised COVID-19 unvaccinated (n = 66) and vaccinated (n = 66) pediatric dental patients aged 4-12 years seeking dental care in clinics of private university hospitals. Paraffin-stimulated saliva was collected from unvaccinated and vaccinated study participants, and the amount of saliva secreted per minute was noted. Salivary pH and buffering capacity (by 5 mmol Hydrochloric acid titration) were measured using a benchtop digital pH meter. The data obtained were compared between unvaccinated and vaccinated participants using an independent t-test.

Results

The results showed a significantly higher salivary secretion rate in unvaccinated than vaccinated study participants (0.83 ± 0.24 mL/min vs 0.67 ± 0.24 mL/min, p = 0.001). Similarly, unvaccinated subjects compared to vaccinated subjects exhibited a significantly higher pH (7.33 ± 0.39 vs 7.04 ± 0.46, p < 0.001) and buffering capacity (6.31 ± 1.55 vs 5.40 ± 1.22, p < 0.001). Moreover, unvaccinated females demonstrated a significantly higher salivary secretion (0.87 ± 0.23 vs 0.71 ± 0.25, t = 2.627, p = 0.011) and buffering capacity 6.19 ± 1.52 vs 5.34 ± 1.25, t = 2.404, p = 0.019) than vaccinated females. Similarly, unvaccinated male exhibited significantly higher salivary secretion (0.80 ± 0.25 vs 0.64 ± 0.23, t = 2.670, p = 0.009), salivary pH (7.39 ± 0.45 vs 6.94 ± 0.41, t=4.309, p<0.001) and buffering capacity (6.42 ± 1.60 vs 5.45 ± 1.21, t = 2.875, p = 0.005) than the vaccinated male subjects.

Conclusion

The vaccinated subjects showed a significantly lower mean salivary secretion, pH, and buffering capacity than unvaccinated participants. Hence, COVID-19 vaccination is likely to affect salivary parameters among pediatric patients.

Vaccine Breakthrough Infections Among Healthcare Workers in a COVID-19-Designated Tertiary Care Government Hospital in Sikkim

Introduction Since the emergence of the coronavirus disease 2019 (COVID-19) virus at the beginning of 2020, the world has gone through various waves of pandemics. The health care workers (HCWs) or the COVID warriors as they were termed were the first line of defense against the virus. They were armed with personal protective equipment and prophylactic doses of the COVID-19 vaccine. Despite these precautions, some of the HCWs still contracted the disease and a few others succumbed to it. The objective of this study was to estimate the prevalence of COVID-19 infections and vaccine breakthrough infections (BTIs) in HCWs after receiving the COVID-19 vaccine during the second wave of the pandemic. Methods This was a cross-sectional, hospital-based study conducted over a period of four months from September 2021 to December 2021 on HCWs aged 18 years and above working at the COVID-19-designated tertiary care government hospital in Sikkim. A structured coded questionnaire with no patient identifiers was used to gather details on demographics, vaccination history, breakthrough infection, and other social details. HCWs who had received at least one dose of the COVID-19 vaccine at the time of initiation of the study and were >18 years of age were included in this study. Results A total of 678 HCWs were screened, out of which 229 (33%) participants tested positive for COVID-19 and the rest of the participants (455; 67%) tested negative. COVID-19 infections and vaccine BTIs (COVID-19 infection >14 days after the second vaccination) were recorded and 137 (20%) respondents had a post-vaccination COVID-19 infection out of which 115 (18.5%) were BTI. The majority of the participants were females and of the age group of 26-35 years. The correlation of COVID-19 infections with the dose gap between vaccination, gender, age, profession, department, area posted during COVID duty, cycles of duty performed, hospitalization due to infection, influenza vaccination, and comorbidity was analyzed. Conclusion COVID-19 vaccines are disease-modifying and they decrease the severity of BTIs in HCWs. Pandemics and outbreaks cannot be predicted; therefore, it becomes very important to have healthy frontline workers who are constantly exposed to infectious agents. Monitoring of health and surveillance of infectious diseases among the HCWs should be encouraged.

Unmasking the enigma: An in-depth analysis of COVID-19 impact on the pediatric population

OBJECTIVES

COVID-19, caused by the novel coronavirus, has had a profound and wide-reaching impact on individuals of all age groups across the globe, including children. This review article aims to provide a comprehensive analysis of COVID-19 in children, covering essential topics such as epidemiology, transmission, pathogenesis, clinical features, risk factors, diagnosis, treatment, vaccination, and others. By delving into the current understanding of the disease and addressing the challenges that lie ahead, this article seeks to shed light on the unique considerations surrounding COVID-19 in children and contribute to a deeper comprehension of this global health crisis affecting our youngest population.

METHODS

A comprehensive literature search was conducted to gather the most recent and relevant information regarding COVID-19 in children. Multiple renowned databases, including MEDLINE, PubMed, Scopus, as well as authoritative sources such as the World Health Organization (WHO), the U.S. Food and Drug Administration (FDA), the European Medicines Agency (EMA), and the National Institutes of Health (NIH) websites and others were thoroughly searched. The search included articles, guidelines, reports, clinical trials results and expert opinions published within the past three years, ensuring the inclusion of the latest research findings on COVID-19 in children. Several relevant keywords, including "COVID-19," "SARS-CoV-2," "children," "pediatrics," and related terms were used to maximize the scope of the search and retrieve a comprehensive set of articles.

RESULTS AND CONCLUSION

Three years since the onset of the COVID-19 pandemic, our understanding of its impact on children has evolved, but many questions remain unanswered. While SAR-CoV-2 generally leads to mild illness in children, the occurrence of severe cases and the potential for long-term effects cannot be overlooked. Efforts to comprehensively study COVID-19 in children must continue to improve preventive strategies, identify high-risk populations, and ensure optimal management. By unraveling the enigma surrounding COVID-19 in children, we can strive towards safeguarding their health and well-being in the face of future global health challenges.

Post-COVID-19 effect on biochemical parameters in children: Should we take heed?

The aim of this research is to analyze the potential impact of the COVID-19 infection on the serum biochemical concentration of children 6 months after recovery from the infection. The study included 72 children with a median age of 11 years. The case group consisted of 37 children who had contracted COVID-19 6 months prior to the analysis. They reported no other pre- or post-covid chronic or systemic diseases. The control group consisted of 35 children who had no prior record of COVID-19 infection. The analysis showed a substantial variation (P = 0.026) in the mean urea values (mmol/L) between the case group (4.513 ± 0.839) and the control group (5.425 ± 1.173). However, both groups' urea levels were within the normal range of their age group. No statistical differences were found analyzing the variations between the two groups in the levels of LDH, AST, ALT, BiliT, GGT, AlbBCG2, CRP, CK, AlKP, UA, Phos, Crea2, Gluc, Ca, Na, K, Cl, TP, TC, TG, and HDL (P > 0.05). The DMFT score was substantially greater (P < 0.002) in the infected team (5.38 ± 2.841) in comparison to the non-infected group (2.6 ± 2.257). The study indicates that COVID-19 infection does not leave biochemical alterations among children who did not have pre-existing conditions. The biochemical analysis suggests that children recover better than adults from COVID-19. Furthermore, it calls for investigating non-lethal COVID-19 infection as a tool to discover underlying conditions. The DMFT score shows a correlation between COVID-19 infection and caries. However, the nature of the correlation is yet to be investigated.

Incidence of asymptomatic SARS-CoV-2 infection in children undergoing elective otolaryngologic surgery throughout the COVID-19 pandemic

Objective

Children infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are less clinically affected than adults, with most cases presenting as asymptomatic or mildly symptomatic. However, true rates of asymptomatic SARS-CoV-2 infection in children remain unclear. We sought to examine rates of SARS-CoV-2 in asymptomatic children and the role of children in transmission.

Methods

We performed a retrospective review of patients between 6 months and 17 years of age who underwent elective or semi-elective otolaryngologic surgery with physicians affiliated with Weill Cornell Medicine between May 15, 2020 and March 31, 2022. Patients were included if they received molecular assay testing for SARS-CoV-2 without SARS-CoV-2 symptoms within 5 days of scheduled surgery. SARS-CoV-2 infection status, exposure, clinical symptoms, demographic data, and insurance status were recorded.

Results

1047 patients met inclusion criteria. Thirteen positive cases (1.24%) were identified in the study population. Six cases occurred between December 2021 and February 2022 following the classification of the omicron variant as a variant of concern in November 2021. Five of the 13 cases occurred in children under 2 years of age. Seven patients were male, and five were female. Residences spanned all five boroughs of New York City and the surrounding metropolitan area.

Conclusion

Throughout the pandemic, children have had a low rate of asymptomatic disease and likely pose a low risk of transmission of SARS-CoV-2 to the general population. Our results suggest that testing of asymptomatic children is a low-yield practice that is unlikely to influence rates of SARS-CoV-2 in the general population.

Level of Evidence

3.

When do children avoid infection risks: Lessons for schools during the COVID-19 pandemic

The physical closing of schools because of COVID-19 has disrupted both student learning and family logistics. There is significant pressure for in-person learning to remain open for all children. However, as is expected with outbreaks of novel infections, vaccines and other pharmaceutical therapeutics may not be instantly available. This raises serious public health questions about the risks to children and society at large. The best protective measures for keeping young children in school focus on behaviors that limit transmission. It is therefore critical to understand how we can engage children in age-appropriate ways that will best support their ability to adhere to protocols effectively. Here, we synthesize published studies with new results to investigate the earliest ages at which children form an understanding of infection risk and when they can translate that understanding effectively to protective action.

Monitoring the Viral Transmission of SARS-CoV-2 in Still Waterbodies Using a Lanthanide-Doped Carbon Nanoparticle-Based Sensor Array

The latest epidemic of extremely infectious coronavirus disease 2019 (COVID-19) has created a significant public health concern. Despite substantial efforts to contain severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) within a specific location, shortcomings in the surveillance of predominantly asymptomatic infections constrain attempts to identify the epidemiological spread of the virus. Continuous surveillance of wastewater streams, including sewage, offers opportunities to track the spread of SARS-CoV-2, which is believed to be found in fecal waste. To demonstrate the feasibility of SARS-CoV-2 detection in wastewater systems, we herein present a novel facilely constructed fluorescence sensing array based on a panel of three different lanthanide-doped carbon nanoparticles (LnCNPs). The differential fluorescence response pattern due to the counterion-ligand interactions allowed us to employ powerful pattern recognition to effectively detect SARS-CoV-2 and differentiate it from other viruses or bacteria. The sensor results were benchmarked to the gold standard RT-qPCR, and the sensor showed excellent sensitivity (1.5 copies/μL) and a short sample-to-results time of 15 min. This differential response of the sensor array was also explained from the differential mode of binding of the LnCNPs with the surface proteins of the studied bacteria and viruses. Therefore, the developed sensor array provides a cost-effective, community diagnostic tool that could be potentially used as a novel epidemiologic surveillance approach to mitigate the spread of COVID-19.

COVID-19 in Children: Where do we Stand?

From the beginning of the coronavirus disease 2019 (COVID-19) pandemic it became evident that children infected with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remain mostly asymptomatic or mildly symptomatic. We reviewed the epidemiologic and clinical features of children with SARS-CoV-2 infection. The true prevalence of asymptomatic SARS-CoV-2 infection is most likely underestimated, as asymptomatic children are less frequently tested. Serologic surveys indicate that half of children tested positive for SARS-CoV-2 report no symptoms. Anosmia/ageusia is not frequent in children but it is the strongest predictor of a positive SARS-CoV-2 test. In general, children with COVID-19 are at lower risk of hospitalization and life-threatening complications. Nevertheless, cases of severe disease or a post-infectious multisystem hyperinflammatory syndrome named multisystem inflammatory syndrome in children (MIS-C) have been described. Rarely children with severe COVID-19 develop neurologic complications. In addition, studies indicate that school closures have a limited impact on SARS-CoV-2 transmission, much less than other social distancing measures. The past months new SARS-CoV-2 variants emerged with higher transmissibility and an increased impact on morbidity and deaths. The role of children in the transmission dynamics of these variants must be elucidated. Lastly, preliminary results from COVID-19 vaccine trials indicate very good efficacy and tolerability in children. Very recently the United States Centers for Disease Control and Prevention and other public health authorities recommend vaccination of children 12 years or older to protect them but mostly to contribute to the achievement of herd immunity.

A cross-sectional investigation of SARS-CoV-2 seroprevalence and associated risk factors in children and adolescents in the United States

BACKGROUND

Pediatric SARS-CoV-2 data remain limited and seropositivity rates in children were reported as <1% early in the pandemic. Seroepidemiologic evaluation of SARS-CoV-2 in children in a major metropolitan region of the US was performed.

METHODS

Children and adolescents ≤19 years were enrolled in a cross-sectional, observational study of SARS-CoV-2 seroprevalence from July-October 2020 in Northern Virginia, US. Demographic, health, and COVID-19 exposure information was collected, and blood analyzed for SARS-CoV-2 spike protein total antibody. Risk factors associated with SARS-CoV-2 seropositivity were analyzed. Orthogonal antibody testing was performed, and samples were evaluated for responses to different antigens.

RESULTS

In 1038 children, the anti-SARS-CoV-2 total antibody positivity rate was 8.5%. After multivariate logistic regression, significant risk factors included Hispanic ethnicity, public or absent insurance, a history of COVID-19 symptoms, exposure to person with COVID-19, a household member positive for SARS-CoV-2 and multi-family or apartment dwelling without a private entrance. 66% of seropositive children had no symptoms of COVID-19. Secondary analysis included orthogonal antibody testing with assays for 1) a receptor binding domain specific antigen and 2) a nucleocapsid specific antigen had concordance rates of 80.5% and 79.3% respectively.

CONCLUSIONS

A much higher burden of SARS-CoV-2 infection, as determined by seropositivity, was found in children than previously reported; this was also higher compared to adults in the same region at a similar time. Contrary to prior reports, we determined children shoulder a significant burden of COVID-19 infection. The role of children's disease transmission must be considered in COVID-19 mitigation strategies including vaccination.

SARS-CoV-2 antibodies started to decline just four months after COVID-19 infection in a paediatric population

Aim

We evaluated the prevalence of paediatric severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infections using antibody testing and characterised antibody titres by time from exposure.

Methods

This was a single‐centre, prospective, cross‐sectional cohort study. Patients under 18 years old were eligible to participate if they attended the paediatric emergency department at the tertiary Shaare Zedek Medical Center, Jerusalem, Israel, from 18 October 2020 to 12 January 2021 and required blood tests or intravenous access. SARS‐CoV‐2 seropositivity and antibody levels were tested by a dual‐assay model.

Results

The study comprised 1138 patients (56% male) with a mean age of 4.4 years (interquartile range 1.3–11.3). Anti‐SARS‐CoV‐2 antibodies were found in 10% of the patients. Seropositivity increased with age and 41% of seropositive patients had no known exposure. Children under 6 years of age had higher initial antibody levels than older children, followed by a steeper decline. The seropositivity rate did not vary during the study, despite schools re‐opening. The findings suggest that children's immunity may start falling 4 months after the initial infection.

Conclusion

Immunity started falling after just 4 months, and re‐opening schools did not affect infection rates. These findings could aid decisions about vaccinating paediatric populations and school closures.

Multisystem inflammatory syndrome in children (MIS-C): a mini-review

Multisystem inflammatory syndrome in children (MIS-C) is a novel, life-threatening hyperinflammatory condition that develops in children a few weeks after infection with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). This disease has created a diagnostic challenge due to overlap with Kawasaki disease (KD) and KD shock syndrome. The majority of patients with MIS-C present with the involvement of at least four organ systems, and all have evidence of a marked inflammatory state. Most patients show an increase in the level of at least four inflammatory markers (C-reactive protein, neutrophil count, ferritin, procalcitonin, fibrinogen, interleukin-6, and triglycerides). Therapy is primarily with immunomodulators, suggesting that the disease is driven by post-infectious immune dysregulation. Most patients, even those with severe cardiovascular involvement, recover without sequelae. Since coronary aneurysms have been reported, echocardiographic follow-up is needed.

Further study is needed to create uniform diagnostic criteria, therapy, and follow-up protocols.

Development of a Rapid Viability RT-PCR (RV-RT-PCR) Method to Detect Infectious SARS-CoV-2 from Swabs

Since the rapid onset of the COVID-19 pandemic, its causative virus, Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), continues to spread and increase the number of fatalities. To expedite studies on understanding potential surface transmission of the virus and to aid environmental epidemiological investigations, we developed a rapid viability reverse transcriptase PCR (RV-RT-PCR) method that detects viable (infectious) SARS-CoV-2 from swab samples in <1 day compared to several days required by current gold-standard cell-culture-based methods. The method integrates cell-culture-based viral enrichment in a 96-well plate format with gene-specific RT-PCR-based analysis before and after sample incubation to determine the cycle threshold (C_T) difference (ΔC_T). An algorithm based on ΔC_T ≥ 6 representing ∼ 2-log or more increase in SARS-CoV-2 RNA following enrichment determines the presence of infectious virus. The RV-RT-PCR method with 2-hr viral infection and 9-hr post-infection incubation periods includes ultrafiltration to concentrate virions, resulting in detection of <50 SARS-CoV-2 virions in swab samples in 17 hours (for a batch of 12 swabs), compared to days typically required by the cell-culture based method. The SARS-CoV-2 RV-RT-PCR method may also be useful in clinical sample analysis and antiviral drug testing, and could serve as a model for developing rapid methods for other viruses of concern.

Multifaceted strategies for the control of COVID-19 outbreaks in long-term care facilities in Ontario, Canada

The novel coronavirus disease 2019 (COVID-19) has caused severe outbreaks in Canadian long-term care facilities (LTCFs). In Canada, over 80% of COVID-19 deaths during the first pandemic wave occurred in LTCFs. We sought to evaluate the effect of mitigation measures in LTCFs including frequent testing of staff, and vaccination of staff and residents. We developed an agent-based transmission model and parameterized it with disease-specific estimates, temporal sensitivity of nasopharyngeal and saliva testing, results of vaccine efficacy trials, and data from initial COVID-19 outbreaks in LTCFs in Ontario, Canada. Characteristics of staff and residents, including contact patterns, were integrated into the model with age-dependent risk of hospitalization and death. Estimates of infection and outcomes were obtained and 95% credible intervals were generated using a bias-corrected and accelerated bootstrap method. Weekly routine testing of staff with 2-day turnaround time reduced infections among residents by at least 25.9% (95% CrI: 23.3%-28.3%), compared to baseline measures of mask-wearing, symptom screening, and staff cohorting alone. A similar reduction of hospitalizations and deaths was achieved in residents. Vaccination averted 2-4 times more infections in both staff and residents as compared to routine testing, and markedly reduced hospitalizations and deaths among residents by 95.9% (95% CrI: 95.4%-96.3%) and 95.8% (95% CrI: 95.5%-96.1%), respectively, over 200 days from the start of vaccination. Vaccination could have a substantial impact on mitigating disease burden among residents, but may not eliminate the need for other measures before population-level control of COVID-19 is achieved.

Multi-generational SIR modeling: Determination of parameters, epidemiological forecasting and age-dependent vaccination policies

We use an age-dependent SIR system of equations to model the evolution of the COVID-19. Parameters that measure the amount of interaction in different locations (home, work, school, other) are approximated from in-sample data using a random optimization scheme, and indicate changes in social distancing along the course of the pandemic. That allows the estimation of the time evolution of classical and age-dependent reproduction numbers. With those parameters we predict the disease dynamics, and compare our results with out-of-sample data from the City of Rio de Janeiro. Finally, we provide a numerical investigation regarding age-based vaccination policies, shedding some light on whether is preferable to vaccinate those at most risk (the elderly) or those who spread the disease the most (the youngest). There is no clear upshot, as the results depend on the age of those immunized, contagious parameters, vaccination schedules and efficiency.

Comparaison de l’infectivité du coronavirus du syndrome respiratoire aigu sévère 2 chez les enfants et les adultes

CONTEXTE:

Le rôle des enfants dans la propagation et la transmission communautaire du coronavirus du syndrome respiratoire aigu sévère 2 (SRAS-CoV-2) est encore mal compris. Nous visons à quantifier l’infectivité du SRAS-CoV-2 d’échantillons nasopharyngés provenant d’enfants comparativement à ceux provenant d’adultes.

MÉTHODES:

Nous avons obtenu des écouvillons nasopharyngés de cas adultes et pédiatriques de la maladie à coronavirus 2019 (COVID-19) ainsi que de leurs contacts qui ont obtenu un résultat positif à la présence du SRAS-CoV-2 lors d’un test de dépistage au Manitoba entre les mois de mars et décembre 2020. Nous avons comparé la croissance virale en culture cellulaire, les valeurs de cycle seuil de test d’amplification en chaîne par polymérase couplé à une transcription inverse (RT-PCR) de l’enveloppe (E) du gène du SRAS-CoV-2 et de la dose infectieuse pour 50 % de la culture tissulaire (DICT₅₀/mL) entre les adultes et les enfants.

RÉSULTATS:

Parmi les 305 échantillons positifs à la présence du SRAS-CoV-2 validés par RT-PCR, 97 échantillons provenaient d’enfants de 10 ans et moins, 78 échantillons d’enfants de 11–17 ans et 130 échantillons d’adultes (≥ 18 ans). On a observé une croissance virale en culture dans 31 % des échantillons, dont 18 (19 %) échantillons d’enfants de 10 ans et moins, 18 (23 %) d’enfants de 11–17 ans et 57 (44 %) d’adultes (enfants c. adultes, rapport de cotes 0,45; intervalle de confiance [IC] à 95 % 0,28–0,72). Le cycle seuil était de 25,1 (IC à 95 % 17,7–31,3) chez les enfants de 10 ans et moins, 22,2 (IC à 95 % 18,3–29,0) chez les enfants de 11–17 ans et 18,7 (IC à 95 % 17,9–30,4) chez les adultes (p < 0,001). La DICT₅₀/mL médiane était considérablement plus faible chez les enfants de 11–17 ans (316, écart interquartile [EI] 178–2125) que chez les adultes (5620, EI 1171–17 800, p < 0,001). Le cycle seuil était un indicateur exact d’une culture positive chez les enfants et les adultes (aire sous la courbe de la fonction d’efficacité du récepteur, 0,87, IC à 95 % 0,81–0,93 c. 0,89, IC à 95 % 0,83–0,96, p = 0,6).

INTERPRÉTATION:

Comparés aux adultes, les enfants qui ont obtenu un résultat positif à un test de dépistage du SRAS-CoV-2 à l’aide d’un écouvillon nasopharyngé étaient moins susceptibles de présenter une croissance du virus en culture et obtenaient un cycle seuil plus élevé et une concentration virale moins élevée, indiquant que les enfants ne sont pas les principaux vecteurs de la transmission du SRAS-CoV-2.

Perinatal SARS-CoV-2 Infection and Neonatal COVID-19: A 2021 Update

The coronavirus disease 2019 pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has swept across the world like an indiscriminating wildfire. Pregnant women and neonates are particularly vulnerable to this infection compared with older children and healthy young adults, with unique challenges in their management. Unfamiliarity with the consequences of this novel virus and lack of high-quality data led to considerable heterogeneity in obstetrical and neonatal management early in the pandemic. The aim of the this review is to summarize the impact of SARS-CoV-2 infection on pregnancy and childbirth and to examine care and possible outcomes for neonates with Covid-19-positive mothers. A brief review of vaccines currently approved by the United States Food and Drug Administration for emergency use and their potential effects on pregnant and lactating women in included.

Perinatal SARS-CoV-2 Infection and Neonatal COVID-19: A 2021 Update

The coronavirus disease 2019 pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has swept across the world like an indiscriminating wildfire. Pregnant women and neonates are particularly vulnerable to this infection compared with older children and healthy young adults, with unique challenges in their management. Unfamiliarity with the consequences of this novel virus and lack of high-quality data led to considerable heterogeneity in obstetrical and neonatal management early in the pandemic. The aim of the this review is to summarize the impact of SARS-CoV-2 infection on pregnancy and childbirth and to examine care and possible outcomes for neonates with Covid-19-positive mothers. A brief review of vaccines currently approved by the United States Food and Drug Administration for emergency use and their potential effects on pregnant and lactating women in included.

Infectivity of severe acute respiratory syndrome coronavirus 2 in children compared with adults

BACKGROUND:

The role of children in the transmission and community spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is unclear. We aimed to quantify the infectivity of SARS-CoV-2 in nasopharyngeal samples from children compared with adults.

METHODS:

We obtained nasopharyngeal swabs from adult and pediatric cases of coronavirus disease 2019 (COVID-19) and from their contacts who tested positive for SARS-CoV-2 in Manitoba between March and December 2020. We compared viral growth in cell culture, cycle threshold values from the reverse transcription polymerase chain reaction (RT-PCR) of the SARS-CoV-2 envelope (E) gene and the 50% tissue culture infective dose (TCID₅₀/mL) between adults and children.

RESULTS:

Among 305 samples positive for SARS-CoV-2 by RT-PCR, 97 samples were from children aged 10 years or younger, 78 were from children aged 11–17 years and 130 were from adults (≥ 18 yr). Viral growth in culture was present in 31% of samples, including 18 (19%) samples from children 10 years or younger, 18 (23%) from children aged 11–17 years and 57 (44%) from adults (children v. adults, odds ratio 0.45, 95% confidence interval [CI] 0.28–0.72). The cycle threshold was 25.1 (95% CI 17.7–31.3) in children 10 years or younger, 22.2 (95% CI 18.3–29.0) in children aged 11–17 years and 18.7 (95% CI 17.9–30.4) in adults (p < 0.001). The median TCID₅₀/mL was significantly lower in children aged 11–17 years (316, interquartile range [IQR] 178–2125) than adults (5620, IQR 1171 to 17 800, p < 0.001). Cycle threshold was an accurate predictor of positive culture in both children and adults (area under the receiver-operator curve, 0.87, 95% CI 0.81–0.93 v. 0.89, 95% CI 0.83–0.96, p = 0.6).

INTERPRETATION:

Compared with adults, children with nasopharyngeal swabs that tested positive for SARS-CoV-2 were less likely to grow virus in culture, and had higher cycle thresholds and lower viral concentrations, suggesting that children are not the main drivers of SARS-CoV-2 transmission.

Simulated Identification of Silent COVID-19 Infections Among Children and Estimated Future Infection Rates With Vaccination

Importance

A significant proportion of COVID-19 transmission occurs silently during the presymptomatic and asymptomatic stages of infection. Children, although important drivers of silent transmission, are not included in the current COVID-19 vaccination campaigns.

Objective

To estimate the benefits of identifying silent infections among children as a proxy for their vaccination.

Design, Setting, and Participants

This study used an age-structured disease transmission model, parameterized with census data and estimates from published literature, to simulate the estimated synergistic effect of interventions in reducing attack rates during the course of 1 year among a synthetic population representative of the US demographic composition. The population included 6 age groups of 0 to 4, 5 to 10, 11 to 18, 19 to 49, 50 to 64, and 65 years or older based on US census data. Data were analyzed from December 12, 2020, to February 26, 2021.

Exposures

In addition to the isolation of symptomatic cases within 24 hours of symptom onset, vaccination of adults was implemented to reach a 40% to 60% coverage during 1 year with an efficacy of 95% against symptomatic and severe COVID-19.

Main Outcomes and Measures

The combinations of proportion and speed for detecting silent infections among children that would suppress future attack rates to less than 5%.

Results

In the base-case scenarios with an effective reproduction number Re = 1.2, a targeted approach that identifies 11% of silent infections among children within 2 days and 14% within 3 days after infection would bring attack rates to less than 5% with 40% vaccination coverage of adults. If silent infections among children remained undetected, achieving the same attack rates would require an unrealistically high vaccination coverage (≥81%) of this age group, in addition to 40% vaccination coverage of adults. The estimated effect of identifying silent infections was robust in sensitivity analyses with respect to vaccine efficacy against infection and reduced susceptibility of children to infection.

Conclusions and Relevance

In this simulation modeling study of a synthetic US population, in the absence of vaccine availability for children, a targeted approach to rapidly identify silent COVID-19 infections in this age group was estimated to significantly mitigate disease burden. These findings suggest that without measures to interrupt transmission chains from silent infections, vaccination of adults is unlikely to contain the outbreaks in the near term.

Multifaceted strategies for the control of COVID-19 outbreaks in long-term care facilities in Ontario, Canada

The novel coronavirus disease 2019 (COVID-19) has caused severe outbreaks in Canadian long-term care facilities (LTCFs). In Canada, over 80% of COVID-19 deaths during the first pandemic wave occurred in LTCFs. We sought to evaluate the effect of mitigation measures in LTCFs including frequent testing of staff, and vaccination of staff and residents. We developed an agent-based transmission model and parameterized it with disease-specific estimates, temporal sensitivity of nasopharyngeal and saliva testing, results of vaccine efficacy trials, and data from initial COVID-19 outbreaks in LTCFs in Ontario, Canada. Characteristics of staff and residents, including contact patterns, were integrated into the model with age-dependent risk of hospitalization and death. Estimates of infection and outcomes were obtained and 95% credible intervals were generated using a bias-corrected and accelerated bootstrap method. Weekly routine testing of staff with 2-day turnaround time reduced infections among residents by at least 25.9% (95% CrI: 23.3% - 28.3%), compared to baseline measures of mask-wearing, symptom screening, and staff cohorting alone. A similar reduction of hospitalizations and deaths was achieved in residents. Vaccination averted 2-4 times more infections in both staff and residents as compared to routine testing, and markedly reduced hospitalizations and deaths among residents by 95.9% (95% CrI: 95.4% - 96.3%) and 95.8% (95% CrI: 95.5% - 96.1%), respectively, over 200 days from the start of vaccination. Vaccination could have a substantial impact on mitigating disease burden among residents, but may not eliminate the need for other measures before population-level control of COVID-19 is achieved.

In pursuit of the right tail for the COVID-19 incubation period

Definition of the incubation period for COVID-19 is critical for implementing quarantine and thus infection control. Whereas the classical definition relies on the time from exposure to time of first symptoms, a more practical working definition is the time from exposure to time of first live virus excretion. For COVID-19, average incubation period times commonly span 5–7 days which are generally longer than for most typical other respiratory viruses. There is considerable variability reported however for the late right-hand statistical distribution. A small but yet epidemiologically important subset of patients may have the late end of the incubation period extend beyond the 14 days that is frequently assumed. Conservative assumptions of the right tail end distribution favor safety, but pragmatic working modifications may be required to accommodate high rates of infection and/or healthcare worker exposures. Despite the advent of effective vaccines, further attention and study in these regards are warranted. It is predictable that vaccine application will be associated with continued confusion over protection and its longevity. Measures for the application of infectivity will continue to be extremely relevant.

In the long shadow of our best intentions: Model-based assessment of the consequences of school reopening during the COVID-19 pandemic

As the world grapples with the ongoing COVID-19 pandemic, a particularly thorny set of questions surrounds the reopening of primary and secondary (K-12) schools. The benefits of in-person learning are numerous, in terms of education quality, mental health, emotional well-being, equity and access to food and shelter. Early reports suggested that children might have reduced susceptibility to COVID-19, and children have been shown to experience fewer complications than older adults. Over the past few months, our understanding of COVID-19 has been further shaped by emerging data, and it is now understood that children are as susceptible to infection as adults and have a similar viral load during infection, even if asymptomatic. Based on this updated understanding of the disease, we have used epidemiological modeling to explore the feasibility and consequences of school reopening in the face of differing rates of COVID-19 prevalence and transmission. We focused our analysis on the United States, but the results are applicable to other countries as well. We demonstrate the potential for a large discrepancy between detected cases and true infections in schools due to the combination of high asymptomatic rates in children coupled with delays in seeking testing and receiving results from diagnostic tests. Our findings indicate that, regardless of the initial prevalence of the disease, and in the absence of robust surveillance testing and contact-tracing, most schools in the United States can expect to remain open for 20-60 days without the emergence of sizeable disease clusters. At this point, even if schools choose to close after outbreaks occur, COVID-19 cases will be seeded from these school clusters and amplified into the community. Thus, our findings suggest that the debate between the risks to student safety and benefits of in-person learning frames a false dual choice. Reopening schools without surveillance testing and contact tracing measures in place will lead to spread within the schools and within the communities that eventually forces a return to remote learning and leaves a trail of infection in its wake.

Surveillance of Acute SARS-CoV-2 Infections in School Children and Point-Prevalence During a Time of High Community Transmission in Switzerland

Background: Switzerland had one of the highest incidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in Europe during the second wave. Schools were open as in most of Europe with specific preventive measures in place. However, the frequency and transmission of acute unrecognized, asymptomatic or oligosymptomatic infections in schools during this time of high community transmission is unknown. Thereof, our aim was to pilot a surveillance system that detects acute SARS-CoV-2 infections in schools and possible transmission within classes. Methods: Fourteen out of the randomly selected sample of the Ciao Corona cohort study participated between December 1 and 11, a time when incidence rate for SARS-CoV-2 infections was high for the canton of Zurich. We determined point-prevalence of acute SARS-CoV-2 infections of school children attending primary and secondary school. A buccal swab for polymerase chain reaction (PCR) and a rapid diagnostic test (RDT) to detect SARS-CoV-2 were taken twice 1 week apart (T1 and T2) in a cohort of children from randomly selected classes. A questionnaire assessed demographics and symptoms compatible with a SARS-CoV-2 infection during the past 5 days. Results: Out of 1,299 invited children, 641 (49%) 6- to 16-year-old children and 66 teachers from 14 schools and 67 classes participated in at least one of two testings. None of the teachers but one child had a positive PCR at T1, corresponding to a point-prevalence in children of 0.2% (95% CI 0.0-1.1%), and no positive PCR was detected at T2. The child with positive PCR at T1 was negative on the RDT at T1 and both tests were negative at T2. There were 7 (0.6%) false positive RDTs in children and 2 (1.7%) false positive RDTs in teachers at T1 or T2 among 5 schools (overall prevalence 0.7%). All 9 initially positive RDTs were negative in a new buccal sample taken 2 h to 2 days later, also confirmed by PCR. Thirty-five percent of children and 8% of teachers reported mild symptoms during the 5 days prior to testing. Conclusion: In a setting of high incidence of SARS-CoV-2 infections, unrecognized virus spread within schools was very low. Schools appear to be safe with the protective measures in place (e.g., clearly symptomatic children have to stay at home, prompt contact tracing with individual and class-level quarantine, and structured infection prevention measures in school). Specificity of the RDT was within the lower boundary of performance and needs further evaluation for its use in schools. Given the low point prevalence even in a setting of very high incidence, a targeted test, track, isolate and quarantine (TTIQ) strategy for symptomatic children and school personnel adapted to school settings is likely more suitable approach than surveillance on entire classes and schools. Clinical Trial Registration: https://clinicaltrials.gov/ct2/show/NCT04448717, ClinicalTrials.gov NCT04448717.

Simulated identification of silent COVID-19 infections among children and estimated future infection rates with vaccination

IMPORTANCE

A significant proportion of COVID-19 transmission occurs silently during the pre-symptomatic and asymptomatic stages of infection. Children, while being important drivers of silent transmission, are not included in the current COVID-19 vaccination campaigns.

OBJECTIVE

To investigate the benefits of identifying silent infections among children as a proxy for their vaccination.

DESIGN

This study used an age-structured disease transmission model, parameterized with census data and estimates from published literature, to simulate the synergistic effect of interventions in reducing attack rates over the course of one year.

SETTING

A synthetic population representative of the United States (US) demographics.

PARTICIPANTS

Six age groups of 0-4, 5-10, 11-18, 19-49, 50-64, 65+ years based on US census data.

INTERVENTIONS

In addition to the isolation of symptomatic cases within 24 hours of symptom onset, vaccination of adults was implemented to reach a 40%-60% coverage over the course of one year with an efficacy of 95% against symptomatic and severe COVID-19.

MAIN OUTCOMES AND MEASURES

The combinations of proportion and speed for detecting silent infections among children which would suppress future attack rates below 5%.

RESULTS

In the base-case scenarios with an effective reproduction number R e = 1.2, a targeted approach that identifies 11% and 14% of silent infections among children within 2 or 3 days post-infection, respectively, would bring attack rates under 5% with 40% vaccination coverage of adults. If silent infections among children remained undetected, achieving the same attack rates would require an unrealistically high vaccination coverage (at least 81%) of this age group, in addition to 40% vaccination coverage of adults. The effect of identifying silent infections was robust in sensitivity analyses with respect to vaccine efficacy against infection and reduced susceptibility of children to infection.

CONCLUSIONS AND RELEVANCE

In this simulation modeling study of a synthetic US population, in the absence of vaccine availability for children, a targeted approach to rapidly identify silent COVID-19 infections in this age group was estimated to significantly mitigate disease burden. Without measures to interrupt transmission chains from silent infections, vaccination of adults is unlikely to contain the outbreaks in the near term.

No Spread of SARS-CoV-2 From Infected Symptomatic Children to Parents: A Prospective Cohort Study in a Controlled Hospital Setting

Introduction: The transmission rates severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from children to adults are unclear due to a lack of controlled conditions. Materials and Methods: We investigated the occurrence of SARS-CoV-2 transmission among 12 discordant child-parent pairs in our ward. In each hospital isolation room, caregivers and children lived in close contact during the entire hospitalization period. Results: A total of 136 swab-positive children (mean age, 3.6 ± 4.9 median age, 1; IQR 0-6.2, range 0.1-17) attended by their caregivers were hospitalized. Of those, 12/136 (8.8%, mean age, 6.1 ± 5.3 median age, 4.5) were attended by caregivers who were swab and serology negative at admission despite previous close contact with positive children at home. Three children were completely dependent on their mothers, one of whom was being breastfed. The mean duration of overall exposure to the index case was 20.5 ± 8.2 days. Conclusion: None of the infected children transmitted SARS-CoV-2 infection to their caregivers, raising the hypothesis of a cluster of resistant mothers or of limited transmission from children to adults despite prolonged exposure and close contact. These data might provide reassurance regarding school openings and offer the chance of investigating SARS-CoV-2 variants in the future under the same quasi-experimental conditions.

Deployment of a Smart Handwashing Station in a School Setting During the COVID-19 Pandemic: Field Study

Background

Hand hygiene is one of the most effective ways to remove germs, prevent the spread of infectious pathogens, and avoid getting sick. Since the COVID-19 pandemic began, health authorities have been advocating good hand hygiene practices.

Objective

The primary aim of this study is to field test a prototype smart handwashing station deployed in a school setting during the COVID-19 pandemic.

Methods

We deployed a smart handwashing station and examined key technological considerations including connectivity, security, and data management systems, as well as the health and safety of users.

Results

The smart handwashing station was deployed for 10 days in a school setting in Australia during the COVID-19 pandemic. The smart handwashing station’s electrical components remained operational during field testing and underwent robust cleaning protocols each day. The handwashing station was used 1138 times during the field test and there was no COVID-19 transmission at the school during the testing.

Conclusions

This study demonstrates that a personalized feedback approach using technology can successfully be implemented at a school and can provide a platform to improve hand hygiene among school-aged children.