Paediatric inflammatory multisystem syndrome in Canada: population-based surveillance and role of SARS-CoV-2 linkage

BACKGROUND

Paediatric inflammatory multisystem syndrome (PIMS) is a rare condition temporally associated with SARS-CoV-2 infection. Using national surveillance data, we compare presenting features and outcomes among children hospitalized with PIMS by SARS-CoV-2 linkage, and identify risk factors for intensive care (ICU).

METHODS

Cases were reported to the Canadian Paediatric Surveillance Program by a network of >2800 pediatricians between March 2020 and May 2021. Patients with positive versus negative SARS-CoV-2 linkages were compared, with positive linkage defined as any positive molecular or serologic test or close contact with confirmed COVID-19. ICU risk factors were identified with multivariable modified Poisson regression.

RESULTS

We identified 406 children hospitalized with PIMS, including 49.8% with positive SARS-CoV-2 linkages, 26.1% with negative linkages, and 24.1% with unknown linkages. The median age was 5.4 years (IQR 2.5-9.8), 60% were male, and 83% had no comorbidities. Compared to cases with negative linkages, children with positive linkages experienced more cardiac involvement (58.8% vs. 37.4%; p < 0.001), gastrointestinal symptoms (88.6% vs. 63.2%; p < 0.001), and shock (60.9% vs. 16.0%; p < 0.001). Children aged ≥6 years and those with positive linkages were more likely to require ICU.

CONCLUSIONS

Although rare, 30% of PIMS hospitalizations required ICU or respiratory/hemodynamic support, particularly those with positive SARS-CoV-2 linkages.

IMPACT

We describe 406 children hospitalized with paediatric inflammatory multisystem syndrome (PIMS) using nationwide surveillance data, the largest study of PIMS in Canada to date. Our surveillance case definition of PIMS did not require a history of SARS-CoV-2 exposure, and we therefore describe associations of SARS-CoV-2 linkages on clinical features and outcomes of children with PIMS. Children with positive SARS-CoV-2 linkages were older, had more gastrointestinal and cardiac involvement, and hyperinflammatory laboratory picture. Although PIMS is rare, one-third required admission to intensive care, with the greatest risk amongst those aged ≥6 years and those with a SARS-CoV-2 linkage.

Penicillin de-labelling in vancouver, British Columbia, Canada: comparison of approaches, outcomes and future directions

BACKGROUND

Inaccurate penicillin allergy labels lead to inappropriate antibiotic prescriptions and harmful patient consequences. System-wide efforts are needed to remove incorrect penicillin allergy labels, but more health services research is required on how to best deliver these services.

METHODS

Data was extracted from five hospitals in Vancouver, British Columbia, Canada from October 2018-May 2022. The primary outcomes of this study were to outline de-labelling protocol designs, identify the roles of various healthcare professionals in de-labelling protocols and identify rates of de-labelling penicillin allergies and associated adverse events at various institutions. Our secondary outcome was to describe de-labelling rates for special populations, including pediatric, obstetric and immunocompromised subpopulations. To achieve these outcomes, participating institutions provided their de-labelling protocol designs and data on program participants. Protocols were then compared to find common themes and differences. Furthermore, adverse events were reviewed and percentages of patients de-labelled at each institution and in total were calculated.

RESULTS

Protocols demonstrated a high level of variability, including different methods of participant identification, risk-stratification and roles of providers. All protocols used oral and direct oral challenges, heavily involved pharmacists and had physician oversight. Despite the differences, of the 711 patients enrolled in all programs, 697 (98.0%) were de-labelled. There were 9 adverse events (1.3%) with oral challenges with mainly minor symptoms.

CONCLUSIONS

Our data demonstrates that de-labelling programs effectively and safely remove penicillin allergy labels, including pediatric, obstetric and immunocompromised patients. Consistent with current literature, most patients with a penicillin allergy label are not allergic. De-labelling programs could benefit from increasing clinician engagement by increasing accessibility of resources to providers, including guidance for de-labelling of special populations.

Canadian infants presenting with Brief Resolved Unexplained Events (BRUEs) and validation of clinical prediction rules for risk stratification: a protocol for a multicentre, retrospective cohort study

INTRODUCTION

Brief Resolved Unexplained Events (BRUEs) are a common presentation among infants. While most of these events are benign and self-limited, guidelines published by the American Academy of Pediatrics inaccurately identify many patients as higher-risk of a serious underlying aetiology (positive predictive value 5%). Recently, new clinical prediction rules have been derived to more accurately stratify patients. This data were however geographically limited to the USA, with no large studies to date assessing the BRUE population in a different healthcare setting. The study's aim is to describe the clinical management and outcomes of infants presenting to Canadian hospitals with BRUEs and to externally validate the BRUE clinical prediction rules in identified cases.

METHODS AND ANALYSIS

This is a multicentre retrospective study, conducted within the Canadian Paediatric Inpatient Research Network (PIRN). Infants (<1 year) presenting with a BRUE at one of 11 Canadian paediatric centres between 1 January 2017 and 31 December 2021 will be included. Eligible patients will be identified using diagnostic codes.The primary outcome will be the presence of a serious underlying illness. Secondary outcomes will include BRUE recurrence and length of hospital stay. We will describe the rates of hospital admissions and whether hospitalisation was associated with an earlier diagnosis or treatment. Variation across Canadian hospitals will be assessed using intraclass correlation coefficient. To validate the newly developed clinical prediction rule, measures of goodness of fit will be evaluated. For this validation, a sample size of 1182 is required to provide a power of 80% to detect patients with a serious underlying illness with a significance level of 5%.

ETHICS AND DISSEMINATION

Ethics approval has been granted by the UBC Children's and Women's Research Board (H21-02357). The results of this study will be disseminated as peer-reviewed manuscripts and presentations at national and international conferences.

Caractéristiques des hospitalisations au Canada d’enfants ayant contracté une infection aiguë par le SRAS-CoV-2 en 2020

Contexte:

Les facteurs de risque de complications graves de l’infection par le SRAS-CoV-2 n’ont pas été bien établis chez les enfants. Nous avons voulu décrire les hospitalisations pédiatriques associées au SRAS-CoV-2 au Canada et identifier les facteurs de risque de maladie grave.

Méthodes:

Nous avons procédé à une étude prospective nationale en utilisant l’infrastructure du Programme canadien de surveillance pédiatrique (PCSP). Les hospitalisations d’enfants ayant contracté une infection par le SRAS-CoV-2 confirmée en laboratoire de microbiologie ont été rapportées du 8 avril au 31 décembre 2020 au moyen de questionnaires hebdomadaires en ligne distribués au réseau du PCSP, qui compte plus de 2800 pédiatres. Nous avons catégorisé les hospitalisations comme suit : liées à la COVID-19, infections découvertes fortuitement, ou hospitalisations pour des raisons sociales ou de contrôle des infections, et dégagé les facteurs de risque associés à la gravité de la maladie chez les patients hospitalisés.

Résultats:

Sur les 264 hospitalisations d’enfants ayant contracté le SRAS-CoV-2 au cours de la période de l’étude de 9 mois, 150 (56,8 %) ont été associées à la COVID-19 et 100 (37,9 %) étaient des cas découverts fortuitement (admission pour d’autres raisons et découverte fortuite du SRAS-CoV-2 par dépistage positif). Les nourrissons (37,3 %) et les adolescents (29,6 %) représentaient la majorité des cas. Parmi les hospitalisations liées à la COVID-19, 52 patients (34,7 %) étaient atteints d’une forme grave de la maladie, dont 42 (28,0 % des cas liés à la COVID-19) ont eu besoin d’une forme d’assistance respiratoire ou hémodynamique, et 59 (39,3 %) présentaient au moins 1 comorbidité sous-jacente. Les enfants atteints d’obésité, de maladies neurologiques chroniques ou de maladies pulmonaires chroniques, à l’exclusion de l’asthme, étaient plus susceptibles de présenter une forme grave ou critique de la COVID-19.

Interprétation:

Parmi les enfants hospitalisés au Canada chez lesquels on a diagnostiqué une infection par le SRAS-CoV-2 au début de la pandémie de COVID-19, la découverte fortuite du SRAS-CoV-2 a été fréquente. Chez les enfants hospitalisés pour une COVID-19 aiguë, l’obésité et les comorbidités neurologiques et respiratoires ont été associées à une gravité accrue.

Characteristics of children admitted to hospital with acute SARS-CoV-2 infection in Canada in 2020

Background:

Risk factors for severe outcomes of SARS-CoV-2 infection are not well established in children. We sought to describe pediatric hospital admissions associated with SARS-CoV-2 infection in Canada and identify risk factors for more severe disease.

Methods:

We conducted a national prospective study using the infrastructure of the Canadian Paediatric Surveillance Program (CPSP). Cases involving children who were admitted to hospital with microbiologically confirmed SARS-CoV-2 infection were reported from Apr. 8 to Dec. 31 2020, through weekly online questionnaires distributed to the CPSP network of more than 2800 pediatricians. We categorized hospital admissions as related to COVID-19, incidental, or for social or infection control reasons and determined risk factors for disease severity in hospital.

Results:

Among 264 hospital admissions involving children with SARS-CoV-2 infection during the 9-month study period, 150 (56.8%) admissions were related to COVID-19 and 100 (37.9%) were incidental infections (admissions for other reasons and found to be positive for SARS-CoV-2 on screening). Infants (37.3%) and adolescents (29.6%) represented most cases. Among hospital admissions related to COVID-19, 52 (34.7%) had critical disease, 42 (28.0%) of whom required any form of respiratory or hemodynamic support, and 59 (39.3%) had at least 1 underlying comorbidity. Children with obesity, chronic neurologic conditions or chronic lung disease other than asthma were more likely to have severe or critical COVID-19.

Interpretation:

Among children who were admitted to hospital with SARS-CoV-2 infection in Canada during the early COVID-19 pandemic period, incidental SARS-CoV-2 infection was common. In children admitted with acute COVID-19, obesity and neurologic and respiratory comorbidities were associated with more severe disease.

Non-invasive assessment of aortic stiffness and blood pressure in young Turner syndrome patients

Background Females with Turner syndrome (TS) carry an elevated risk of aortic dissection. The objective of the study was to assess the biophysical properties of the aorta and ambulatory blood pressure (BP) in females with TS and compare these findings to those in healthy female age-matched controls. Methods This was a prospective cohort study including subjects aged 8-25 years. Utilizing two-dimensional (2D) echocardiography and Doppler, proximal aortic dimensions were measured and biophysical properties of the aorta were calculated including pulse wave velocity (PWV), arterial pressure-strain elastic modulus and stiffness index. Resting BP was measured and ambulatory blood pressure monitoring (ABPM) was performed. Results Of 23 TS patients and 46 controls (median age 16.3 years), aortic annulus, sinus of Valsalva and sinotubular (ST) junction diameters, as well as left ventricular (LV) mass, were significantly greater in TS patients compared with controls when scaled for height2.7, but not for body surface area (BSA), although ascending aorta diameter was greater when scaled for both. Median PWV was faster in TS patients compared to controls (451 vs. 360 cm/s) while arterial pressure-strain elastic modulus and stiffness index were similar. Resting BP was abnormal in seven out of 22 patients and ABPM was abnormal in 16 out of 21 patients. Conclusions Young patients with TS had dilated proximal aortas when scaled for height2.7 and stiffer aortas when compared with healthy female age-matched controls. Moreover, resting BP underdiagnosed pre-hypertension and hypertension compared to ABPM. These findings are consistent with the presence of a primary aortopathy in TS.

Third-generation cephalosporin-resistant urinary tract infections in children presenting to the paediatric emergency department

Background

The incidence of antibiotic-resistant urinary tract infections (UTIs) in children is increasing. The purpose of this study was to describe the incidence, clinical characteristics, and risk factors for third-generation cephalosporin-resistant UTIs presenting to the paediatric emergency department (ED).

Methods

This was a retrospective cohort study conducted at British Columbia Children's Hospital. Children aged 0 to 18 years old presenting to the ED between July 1, 2013 and June 30, 2014 and were found to have UTI due to Enterobacteriaceae and Pseudomonas species were included. Patient demographics, clinical features, laboratory findings, and outcomes were compared using standard statistical analyses. Risk factors for resistant UTIs were analyzed using multiple logistic regression analysis.

Results

There were 294 eligible patients. The median age was 27.4 months. A third-generation cephalosporin-resistant organism was identified in 36 patients (12%). Patients with resistant UTI had lower rates of appropriate empiric antibiotic therapy (25% versus 95.3%, P<0.05), higher rates of hospitalization (38.9% versus 21.3%, P<0.05), higher rates of undergoing a voiding cystourethrogram (19.4% versus 5.0%, P<0.05), and higher rates of UTI recurrence within 30 days (13.9% versus 4.7%, P<0.05). In multivariate analysis, recent hospitalization (odds ratio [OR] 4.3, confidence interval [CI] 1.2 to 16) and antibiotic therapy (OR 3.5, CI 1.5 to 8.5) within the previous 30 days were risk factors for resistant UTI.

Conclusions

Third-generation cephalosporin-resistant organisms account for a significant proportion of community-acquired paediatric UTIs. Recent hospitalization and antibiotic use are associated with increased risk of resistant UTI.

Current Management of Focal Atrial Tachycardia in Children

Background—

Focal atrial tachycardia (FAT) is an uncommon cause of supraventricular tachycardia in children. Incessant FAT can lead to tachycardia-induced cardiomyopathy. There is limited information regarding the clinical course and management of FAT. This study characterizes current management strategies for FAT in children including the prevalence of spontaneous resolution and the role of catheter ablation.

Methods and Results—

This is a retrospective chart review of pediatric patients with FAT managed between January 2000 and November 2010 at 10 pediatric centers. There were 249 patients with a median age at diagnosis of 7.2 (95% confidence interval, 5.8–10.4) years. Cardiomyopathy was observed in 28%. Resolution of FAT occurred in 89%, including spontaneous resolution without catheter ablation in 34%. Antiarrhythmic medications were used for initial therapy in 154 patients with control of FAT in 72%. Among first-line medications, β-blockers were the most common (53%) and effective (42%). Catheter ablation was successful in 80% of patients. FAT recurrence was less common with electroanatomic mapping compared with conventional mapping techniques (16% versus 35%; P =0.02). Patients were followed for a median of 2.1 (95% confidence interval, 1.8–2.6) years.

Conclusions—

FAT is managed successfully in most children. Current approaches are variable. Many patients have control of FAT with medications; however, catheter ablation is used for most patients. Spontaneous resolution is common for young children, emphasizing the role for delayed ablation in this group. Ablation is successful for all ages. Lower recurrence occurs when electroanatomic mapping techniques are used.

Huge calcified aneurysm of the sinus of Valsalva

Aneurysms of the sinus of Valsalva often remain undiagnosed until they rupture. A 61-year-old man had a huge, heavily calcified unruptured aneurysm, originating from the right sinus of Valsalva, detected incidentally on a chest radiograph taken for the diagnosis of cardiomegaly. Two-dimensional echocardiography revealed pericardial effusion with a huge calcified mass compressing the right ventricular outflow tract. The Doppler color-flow echocardiogram showed blood flow from the aortic root into the aneurysm. A chest computed tomographic scan revealed a large thrombosed aneurysm originating from the aortic root and measuring 10x10 cm. After pericardiocentesis, cardiac catheterization was performed, which showed that the right ventricular systolic pressure had elevated to 80 mmHg. Aortic root aortography demonstrated a huge unruptured calcified aneurysm in the sinus of Valsalva arising from the right coronary sinus. The patient underwent surgical correction to prevent aneurysmal rupture and to relieve the right ventricular outflow obstruction.

Applications of phthalimide photochemistry to macrocyclic polyether, polythioether, and polyamide synthesis

Irradiation of phthalimides which contain N-linked omega-trimethylsilylmethyl-substituted polyether, polythioether, and polysulfonamide chains results in efficient production of the corresponding macrocyclic polyether, polythioether, and polysulfonamide products. These photocyclization reactions follow sequential single electron transfer (SET)-desilylation pathways. Only in the cases of phthalimides, bearing mixed ether-thioether N-substituents, do these excited-state cyclization reactions proceed with lower degrees of regioselectivity. This is a result of competitive desilylation and alpha-to-sulfur deprotonation reactions of the zwitterionic diradical intermediates formed by initial SET.

Clinical characteristics of unexplained sudden cardiac death in Korea

In Western countries, sudden cardiac death (SCD) is closely related to coronary artery disease, but in Korea the clinical characteristics of SCD are not well determined. Over a 4-year period (June 1995 to May 1999), 186 cases of SCD, ranging in age from 16 to 75 years, were admitted to the Chonnam National University Hospital. In 82 (44.1%) of these, neither symptoms nor evidence of structural heart disease was found and so their clinical characteristics were investigated. There were 66 (80.5%) men and 16 (19.5%) women (male/female ratio = 4.1:1). The mean age was 50 +/- 14 years: 19 (23.2%) were in their 40s, 21 (25.6%) in their 50s, and 17 (20.7%) in their 60s. The time of circulatory collapse witnessed in 68 cases of SCD showed 2 peaks: between midnight and 03.00h (n=16, 23.5%) and between 09.00h and midday (n=15, 22.1%). Unexplained SCD occurred at home in 48 (64.9%) cases and on the street in 12 (16.2%); it occurred during normal daily routine activity in 23 (39.6%) and during sleep in 15 (25.9%). Thirty-three patients (40.2%) experienced various prodromal symptoms, including chest discomfort (n=13, 15.9%) and dyspnea (n=8, 9.8%). The electrocardiogram taken on arrival recorded asystole in 65 (79.3%) and ventricular fibrillation in 17 (20.7%). Idiopathic ventricular fibrillation was diagnosed in 14 (10 men, 4 women; 45 +/- 11 years) of 21 patients who recovered spontaneous circulation. Five (6.1%) patients were discharged alive, and an implantable cardioverter-defibrillator was implanted in 2. Unexplained SCD is common in Korea and develops predominantly in middle-aged males around midnight or in the late morning usually with no prodromal symptoms (59.8%). Idiopathic ventricular fibrillation is thought to be one of the important causes.

Successful management of intractable coronary spasm with a coronary stent

Although the long-term survival of patients suffering from coronary spasm is usually excellent, serious complications can develop, such as disabling pain, myocardial infarction, ventricular tachyarrhythmias, atrioventricular block and sudden cardiac death. A 40-year-old man who had intractable chest pain from coronary artery spasm suffered ventricular fibrillation and an acute anterior myocardial infarction upon first admission. The patient underwent a coronary angiogram, which revealed a spontaneous focal spasm at the proximal left anterior descending coronary artery (LAD). He was treated by the combination of nitrate and calcium channel blocker, but continued to complain of severe chest pain despite intensive medical therapy and he had to be treated in the emergency room 5 times during an 8-month follow-up period. An ergonovine coronary angiogram was performed and an intracoronary ultrasound examination, which revealed a focal spasm at the same site of the proximal LAD with a small amount of localized eccentric atheromatous plaque. A coronary artery stent was placed in the proximal LAD and his symptoms resolved. A follow-up coronary angiogram was performed 3 years after stenting and the stent remained patent without any in-stent restenosis or spasm.

Initial and late results of Freedom coronary stent

OBJECTIVES

Initial and late results after implantation of Freedom stents, a balloon expandable stainless steel coil stents were evaluated.

METHODS

From Jun. 1996 to Nov. 1997, we implanted 123 Freedom stents in 122 lesions in 117 patients and performed follow-up coronary angiograms at 7.0 +/- 3.6 months after stents placement. Clinical courses after stenting and follow-up coronary angiographic findings were evaluated. Comparison of clinical, angiographic, and procedural factors according to the presence or absence of restenosis was performed.

RESULTS

In 117 patients who underwent stents implantation, major complications were not observed. Follow-up coronary angiograms were performed in 47 stents in 41 patients (35%). Among 47 stents, angiographic significant restenosis (percent diameter stenosis > 50%) was observed in 13 (28%). Mean age in 41 patients was 59 +/- 9 years, with 27 male patients (66%). Indications for stents implantation were de novo lesions in 18 (38%), suboptimal results after PTCA in 18 (38%), bail-out lesions in 4 (9%) and restenotic lesions in 7 (15%). Lesion types by AHA/ACC classification were A in 1 (1%), B1 in 10 (21%), B2 in 17 (36%), and C in 19 (40%). Average lesion length was 13.7 +/- 9.0 mm, stent diameter 3.0 +/- 0.3 mm, and stent length 24.6 +/- 9.0 mm. There were no significant differences of the clinical, angiographic, and procedural characteristics according to the presence or absence of restenosis.

CONCLUSION

Freedom coronary stents implantation is safely performed in various morphology of coronary lesions and no significant predictive factors on restenosis in follow-up coronary angiogram were observed.

Co-cultivation of conjunctival epithelial cells and Chlamydia trachomatis: electron microscopic findings

This study used primary culture of rabbit conjunctival epithelial cells to investigate the infection process of chlamydia. The epithelial cells isolated from conjunctiva of rabbit were initially cultured for three weeks. After attaining confluence they were infected with Chlamydia trachomatis (C. trachomatis) serotype D, and after co-cultivation for 24, 48, and 96 hours, electron microscopic study was performed. An inclusion body, a characteristic finding of chlamydial infection, was observed in the vicinity of the nucleus after 24 hours of co-cultivation. It contained a large number of elementary and reticulate bodies and their intermediate forms. Infectious particles known as elementary bodies were noted in the inclusion as 20 to 30 microns sized round bodies with an electron dense core. Reticulate bodies were also noted; they too were round but somewhat pleomorphic and larger than elementary bodies. Some reticulate bodies multiplied actively by means of binary fission. In this study, we observed the characteristic changes of C. trachomatis-infected cells; this in-vitro system might provide a suitable model for the study of some aspects of the pathogenesis of ocular chlamydia infection.