The impact of levofloxacin prophylaxis on empiric intravenous antibiotic use in pediatric hematopoietic stem cell transplant recipients.

Levofloxacin prophylaxis during periods of neutropenia in pediatric hematopoietic stem cell transplant (HSCT) may reduce the number of febrile episodes and use of empiric intravenous antibiotics (EIA); however, the literature is conflicting. This retrospective review compared EIA use before and after implementation of levofloxacin prophylaxis at a children's hospital. Levofloxacin prophylaxis was associated with reduced use of certain EIA; however, did not reduce the number of positive blood cultures or clinical deteriorations. Therefore, levofloxacin prophylaxis may have implications for the stewardship of broad-spectrum intravenous antibiotics used in pediatric HSCT.

Improving inpatient paediatric de-labelling of allergies to beta-lactams: a quality improvement study.

OBJECTIVE: To evaluate the implementation of an antimicrobial stewardship programme-led inpatient beta-lactam allergy de-labelling programme using a direct oral provocation test (OPT). DESIGN: One-year quality improvement study using a before-after design. SETTING: Free-standing tertiary care paediatric hospital. PATIENTS: Patients with a reported beta-lactam allergy admitted to the paediatric medicine inpatient unit. INTERVENTIONS: Following standardised assessment and risk stratification of reported symptoms, patients with a low-risk history were offered an OPT. Beta-lactam allergy labels were removed if a reported history was considered non-allergic or after successful OPT. MAIN OUTCOME MEASURES: Removal of inappropriate beta-lactam allergy labels. RESULTS: 80 patients with 85 reported beta-lactam allergies were assessed. Median age was 8.1 years (IQR 4.8-12.9) and 34 (42%) were female. The majority (n=55, 69%) had an underlying medical condition. Amoxicillin was the most reported allergy (n=25, 29%). Reported reactions were primarily dermatological (n=65, 77%). Half of participants (n=40) were ineligible for OPT, with equal proportions due to clinical reasons or the nature of the reported reaction. Of the 40 eligible patients, 28 patients (70%) were de-labelled either by history alone (n=10) or OPT (n=18). All OPTs were successful. De-labelling allowed five additional patients (11% of those receiving antibiotics) to receive the preferred beta-lactam. Including patients who were subsequently assessed in the allergy clinic, almost half of all evaluated patients were de-labelled (n=37, 46%). CONCLUSIONS: An antimicrobial stewardship programme-led programme using a direct OPT was feasible and safe for expanding beta-lactam allergy de-labelling to paediatric patients admitted to the paediatric medicine inpatient unit.

Association of delayed adequate antimicrobial treatment and organ dysfunction in pediatric bloodstream infections.

BACKGROUND: Bloodstream infections (BSIs) are associated with significant mortality and morbidity, including multiple organ dysfunction. We explored if delayed adequate antimicrobial treatment for children with BSIs is associated with change in organ dysfunction as measured by PELOD-2 scores. METHODS: We conducted a multicenter, retrospective cohort study of critically ill children <18 years old with BSIs. The primary outcome was change in PELOD-2 score between days 1 (index blood culture) and 5. The exposure variable was delayed administration of adequate antimicrobial therapy by ≥3 h from blood culture collection. We compared PELOD-2 score changes between those who received early and delayed treatment. RESULTS: Among 202 children, the median (interquartile range) time to adequate antimicrobial therapy was 7 (0.8-20.1) hours; 124 (61%) received delayed antimicrobial therapy. Patients who received early and delayed treatment had similar baseline characteristics. There was no significant difference in PELOD-2 score changes from days 1 and 5 between groups (PELOD-2 score difference -0.07, 95% CI -0.92 to 0.79, p = 0.88). CONCLUSIONS: We did not find an association between delayed adequate antimicrobial therapy and PELOD-2 score changes between days 1 and 5 from detection of BSI. PELOD-2 score was not sensitive for clinical effects of delayed antimicrobial treatment. IMPACT: In critically ill children with bloodstream infections, there was no significant change in organ dysfunction as measured by PELOD-2 scores between patients who received adequate antimicrobial therapy within 3 h of their initial positive blood culture and those who started after 3 h. Higher PELOD-2 scores on day 1 were associated with larger differences in PELOD-2 scores between days 1 and 5 from index positive blood cultures. Further study is required to determine if PELOD-2 or alternative measures of organ dysfunction could be used as primary outcome measures in trials of antimicrobial interventions in pediatric critical care research.

Viral dynamics of the SARS-CoV-2 Omicron Variant in Paediatric Patients; A prospective cohort study.

BACKGROUND: There are limited data on the viral dynamics of SARS-CoV-2 in children. Understanding viral load changes over the course of illness and duration of viral shedding may provide insight into transmission dynamics to inform public health and infection control decisions. METHODS: We conducted a prospective cohort study of children 18 years and younger with PCR confirmed SARS-CoV-2 between February 1, 2022 and March 14, 2022. SARS-CoV-2 testing occurred on daily samples for 10 days; a subset of participants completed daily rapid antigen testing (RAT). Viral RNA trajectories were described in relation to symptom onset and resolution. The associations between both time since symptom onset/resolution and non-infectious viral load were evaluated using a Cox proportional hazards model. FINDINGS: Among 101 children aged 2 to 17 years, the median time to study-defined non-infectious viral load was 5 days post symptom onset, with 75% meeting this threshold by 7 days, and 90% by 10 days. On the day of and day after symptom resolution, 43 of 87 (49%) and 52 (60%) had met the non-infectious thresholds, respectively. Of the 50 participants completing RAT, positivity at symptom onset and on the day after symptom onset was 67% (16/24) and 75% (14/20). On the first day where the non-infectious threshold was met, 61% (n = 27/44) of participant RAT results were positive. INTERPRETATION: Children often met the study-defined non-infectiousness threshold on the day after symptom resolution. RAT tests were often negative early in the course of illness and should not be relied on to exclude infection. CLINICAL TRIALS REGISTRATION: NCT05240183.

Maternal varicella antibodies in children aged less than one year: Assessment of antibody decay.

OBJECTIVES: To investigate maternal antibody levels to varicella in infants <12 months of age in Ontario, Canada. STUDY DESIGN: In this study, we included specimens from infants <12 months of age, born at ≥37 weeks gestational age, who had sera collected at The Hospital for Sick Children (Toronto, Canada) between 2014-2016. We tested sera using a glycoprotein-based enzyme-linked immunosorbent assay (gpELISA). We measured varicella susceptibility (antibody concentration <150mIU/mL) and mean varicella antibody concentration, and assessed the probability of susceptibility and concentration between one and 11 months of age using multivariable logistic regression and Poisson regression. RESULTS: We found that 32% of 196 included specimens represented infants susceptible to varicella at one month of age, increasing to nearly 80% at three months of age. At six months of age, all infants were susceptible to varicella and the predicted mean varicella antibody concentration declined to 62 mIU/mL (95% confidence interval 40, 84), well below the threshold of protection. CONCLUSIONS: We found that varicella maternal antibody levels wane rapidly in infants, leaving most infants susceptible by four months of age. Our findings have implications for the timing of first dose of varicella-containing vaccine, infection control measures, and infant post-exposure prophylaxis recommendations.

Uptake of pertussis immunization in pregnancy and determinants of vaccination in Toronto, Canada.

INTRODUCTION: Pertussis causes significant morbidity and mortality in infants aged <6 months. Maternal pertussis vaccination during pregnancy has been recommended in Canada since 2018 to reduce these negative outcomes. In the absence of routine immunization coverage data, our objective was to evaluate uptake in Toronto, Canada. METHODS: We recruited mother-infant pairs at The Hospital for Sick Children, Toronto, between 2018 and 2020. We performed logistic regression to examine associations between demographics and self-reported pertussis vaccination. RESULTS: 76/243 mothers (31.3 %) reported receiving pertussis vaccination during their most recent pregnancy. Odds of receiving vaccination more than doubled with each 1-year increase in year of pregnancy (aOR: 2.2; 95 % CI: 1.3, 3.6; p < 0.01) and among those born in Canada as compared to those not (aOR: 2.0; 95 % CI: 1.1, 3.6; p = 0.02) CONCLUSION: Uptake of pertussis vaccination during pregnancy in Ontario has increased in recent years, however coverage remains lower than desirable.

Severe acute hepatitis of unknown etiology in a large cohort of children.

BACKGROUND: We evaluated the proportion, clinical features, and outcomes of previously healthy children presenting to a large Canadian quaternary pediatric center with severe acute hepatitis of unknown etiology. METHODS: All patients with serum alanine aminotransferase (ALT) > 500 U/L or aspartate aminotransferase (AST) > 500 U/L between June 1, 2018, and May 31, 2022, at The Hospital for Sick Children, were identified. Subjects with only AST > 500 U/L were excluded. Clinical characteristics, investigations, and outcomes for patients without clear etiology for ALT > 500 U/L (severe acute hepatitis of unknown etiology) for our study period and from October 1 to May 31 of each year 2018-2021 were reviewed. RESULTS: Of 977 patients with ALT/AST> 500 U/L, 720 had only ALT > 500 U/L. We excluded age below 6 months (n = 99) or above 16 years (n = 66), known pre-existing liver conditions (n = 66), and ALT > 500 U/L in already admitted patients (n = 151). Among the remaining 338 children with ALT > 500 U/L at presentation, an etiology was identified in 303 subjects. 33 (9.8%) children [median age 6.1 y (range 0.5-15.5); 61% male] were confirmed as severe acute hepatitis of unknown etiology. Twenty patients (60.6%) were tested for blood adenovirus by PCR, and 1 (5%) was positive (serotype B7). Liver tissue specimens from 18 patients revealed no evidence of viral inclusions or adenovirus. Twelve (36.3%) presented with pediatric acute liver failure, with 8 (24.2%) requiring liver transplantation. There were no deaths. Hepatitis-associated aplastic anemia occurred in 5 (15%) patients. CONCLUSIONS: Of children presenting with severe acute hepatitis to a quaternary children's hospital over a 48-month period, 9.8% had unknown etiology with no change over time. Liver transplantation remains an important treatment strategy for those presenting with pediatric acute liver failure phenotype. The frequency of cases associated with human adenovirus infection was noncontributory.

School-Based Mandatory Masking Policies and Absenteeism in Ottawa, Canada, in 2022.

This cohort study assesses the association between school-based mandatory masking policies and educational disruption in Ottawa, Canada, during the COVID-19 pandemic.

Value-Based Care for Healthy Children With First Episode of Febrile Neutropenia.

OBJECTIVES: There is a lack of guidance on the management of febrile neutropenia in otherwise healthy children, including the need for hospitalization and antibiotic administration, leading to significant practice variation in management. The aim of this initiative was to decrease the number of unnecessary hospitalizations and empirical antibiotics prescribed by 50% over a 24-month period for well-appearing, previously healthy patients older than 6 months presenting to the emergency department with a first episode of febrile neutropenia. METHODS: A multidisciplinary team of stakeholders was assembled to develop a multipronged intervention strategy using the Model for Improvement. A guideline for the management of healthy children with febrile neutropenia was created, coupled with education, targeted audit and feedback, and reminders. Statistical control process methods were used to analyze the primary outcome of the percentage of low-risk patients receiving empirical antibiotics and/or hospitalization. Balancing measures included missed serious bacterial infection, emergency department (ED) return visit, and a new hematologic diagnosis. RESULTS: Over the 44-month study period, the mean percentage of low-risk patients hospitalized and/or who received antibiotics decreased from 73.3% to 12.9%. Importantly, there were no missed serious bacterial infections, no new hematologic diagnoses after ED discharge, and only 2 ED return visits within 72 hours without adverse outcomes. CONCLUSIONS: A guideline for the standardized management of febrile neutropenia in low-risk patients increases value-based care through reduced hospitalizations and antibiotics. Education, targeted audit and feedback, and reminders supported sustainability of these improvements.

Antimicrobial use among paediatric inpatients at hospital sites within the Canadian Nosocomial Infection Surveillance Program, 2017/2018.

BACKGROUND: Antimicrobial resistance threatens the ability to successfully prevent and treat infections. While hospital benchmarks regarding antimicrobial use (AMU) have been well documented among adult populations, there is less information from among paediatric inpatients. This study presents benchmark rates of antimicrobial use (AMU) for paediatric inpatients in nine Canadian acute-care hospitals. METHODS: Acute-care hospitals participating in the Canadian Nosocomial Infection Surveillance Program submitted annual AMU data from paediatric inpatients from 2017 and 2018. All systemic antimicrobials were included. Data were available for neonatal intensive care units (NICUs), pediatric ICUs (PICUs), and non-ICU wards. Data were analyzed using days of therapy (DOT) per 1000 patient days (DOT/1000pd). RESULTS: Nine hospitals provided paediatric AMU data. Data from seven NICU and PICU wards were included. Overall AMU was 481 (95% CI 409-554) DOT/1000pd. There was high variability in AMU between hospitals. AMU was higher on PICU wards (784 DOT/1000pd) than on non-ICU (494 DOT/1000pd) or NICU wards (333 DOT/1000pd). On non-ICU wards, the antimicrobials with the highest use were cefazolin (66 DOT/1000pd), ceftriaxone (59 DOT/1000pd) and piperacillin-tazobactam (48 DOT/1000pd). On PICU wards, the antimicrobials with the highest use were ceftriaxone (115 DOT/1000pd), piperacillin-tazobactam (115 DOT/1000pd), and cefazolin (111 DOT/1000pd). On NICU wards, the antimicrobials with the highest use were ampicillin (102 DOT/1000pd), gentamicin/tobramycin (78 DOT/1000pd), and cefotaxime (38 DOT/1000pd). CONCLUSIONS: This study represents the largest collection of antimicrobial use data among hospitalized paediatric inpatients in Canada to date. In 2017/2018, overall AMU was 481 DOT/1000pd. National surveillance of AMU among paediatric inpatients is necessary for establishing benchmarks and informing antimicrobial stewardship efforts.

GloveCare: a pilot study in preparation for a cluster crossover randomized controlled trial of non-sterile glove-based care in preventing late-onset infection in the NICU.

BACKGROUND: Late-onset infections (LOI) are a major cause of morbidity and mortality among patients in the neonatal intensive care unit (NICU). Gloving after hand hygiene may be a pragmatic approach to prevent infections that arise when healthcare workers' hands transmit pathogens to neonates. OBJECTIVE: To determine the feasibility of conducting a multicenter, open-labeled randomized controlled trial (RCT) to determine whether a protocol that requires healthcare workers (HCWs) in a level 3 NICU to wear non-sterile gloves plus hand hygiene reduces the occurrence of a late-onset infection, compared to hand hygiene alone. METHODS: In this single-center pilot study, we recruited neonates admitted to the McMaster Children's Hospital NICU from June 2017 to May 2018. The NICU was randomized to begin with the standard (control) arm for 6 months (June 2017 to Dec 2017), followed by the gloving (GloveCare) arm for 6 months (Jan 2018 to July 2018), with a 2-week washout period in-between to educate healthcare workers about gloving. We measured numerous feasibility outcomes including enrollment, event rate, and compliance with hand hygiene (Moment 1: before patient contact, Moment 2: before clean procedure, Moment 3: after body fluid contact, Moment 4: after patient contact) and gloving compliance. RESULTS: We enrolled 750 neonates (390 Standard care, 360 GloveCare) and achieved 100% enrollment. We found higher hand hygiene compliance during the standard care arm compared to the GloveCare for all four moments of hand hygiene (Moment 1: 87% vs 79%, OR=1.86 (1.34, 2.59); Moment 2: OR=1.73 (1.00, 3.01); Moment 3: OR=1.11 (0.62, 1.98); Moment 4: OR=1.65 (1.27, 2.14)). We developed and validated a method to calculate glove compliance, which ranged from 48 to 85%, and was highest for moment 3 (doffing after a procedure or body fluid exposure risk). No adverse events were documented for patients or staff. DISCUSSION: Reduction in hand hygiene compliance in the GloveCare arm presents a pragmatic challenge in ascertaining the effectiveness of gloving to prevent LOI. Most LOIs were non-sterile-site infections, which is considered a less patient-important or clinically relevant outcome compared to sterile-site LOI. Ensuring efficient collection and validation of hand hygiene and gloving data is imperative. CONCLUSION: The pilot study demonstrated the feasibility of this intervention though modifications to improve hand hygiene compliance during GloveCare will be important prior to a multicenter cluster RCT to assess the efficacy of non-sterile glove-based care in preventing LOI in the NICU. TRIAL REGISTRATION: Clinicaltrials.gov, NCT03078335.

Utility of SARS-CoV-2 Genomic Sequencing for Understanding Transmission and School Outbreaks.

OBJECTIVE: An understanding of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) transmission in schools is important. It is often difficult, using epidemiological information alone, to determine whether cases associated with schools represent multiple introductions from the community or transmission within the school. We describe the use of whole genome sequencing (WGS) in multiple schools to investigate outbreaks of SARS-CoV-2 in the pre-Omicron period. STUDY DESIGN: School outbreaks were identified for sequencing by local public health units based on multiple cases without known epidemiological links. Cases of SARS-CoV-2 from students and staff from 4 school outbreaks in Ontario underwent WGS and phylogenetic analysis. The epidemiological clinical cohort data and genomic cluster data are described to help further characterize these outbreaks. RESULTS: A total of 132 positive SARS-CoV-2 cases among students and staff from 4 school outbreaks were identified with 65 (49%) of cases able to be sequenced with high-quality genomic data. The 4 school outbreaks consisted of 53, 37, 21 and 21 positive cases; within each outbreak there were between 8 and 28 different clinical cohorts identified. Among the sequenced cases, between 3 and 7 genetic clusters, defined as different strains, were identified in each outbreak. We found genetically different viruses within several clinical cohorts. CONCLUSIONS: WGS, together with public health investigation, is a useful tool to investigate SARS-CoV-2 transmission within schools. Its early use has the potential to better understand when transmission may have occurred, can aid in evaluating how well mitigation interventions are working and has the potential to reduce unnecessary school closures when multiple genetic clusters are identified.

A Comparison of Short Versus Long Course Intravenous Antibiotics When Treating Urinary Tract Infection in Infants <60 Days of Age.

Urinary tract infections (UTIs) are a common reason for hospitalization in infants younger than 60 days, and the optimal approach to intravenous (IV) antibiotic therapy upon UTI diagnosis in this cohort is unknown. We determined whether there was an association between IV antibiotic therapy duration (long [>3 days] vs short [≤3 days]) and treatment failure via a retrospective review of infants with confirmed UTIs receiving IV antibiotics at a tertiary referral center. A total of 403 infants were included; 39% were treated with ampicillin and cefotaxime, and 34% with ampicillin and gentamycin or tobramycin. The median IV antibiotic duration was 5 (interquartile range: 3-10) days, and 5% of patients experienced treatment failure. The treatment failure rate was similar in both short- and long-course IV antibiotic groups (P > .05), and there was no significant association between treatment duration and failure. We conclude that treatment failure for infants hospitalized with UTI is uncommon and not associated with IV antibiotic duration.

Development of Quality Indicators to Evaluate the Appropriateness of Empiric Antimicrobial Use in Pediatric Patients.

Background: Use of quality indicators is one strategy recommended to assess antimicrobial prescribing for pediatric inpatients. Objective: To achieve consensus from infectious diseases clinicians on quality indicators that characterize appropriate empiric antimicrobial use for the management of infectious syndromes in pediatric inpatients. Methods: This study was completed using the Delphi technique. The research team developed an initial list of quality indicators, informed by a literature search. A multidisciplinary group of health care providers with expertise in infectious diseases was invited to participate. The list was disseminated to this panel of experts using Opinio survey software. The experts were asked to rate the indicators on a 9-point Likert scale in relation to the following criterion: "The importance of each item in determining appropriateness considering benefit or harm at the individual or population level". Consensus was defined as at least 75% agreement and a median score of 7 or higher. Results: Twelve of 31 invited experts completed at least 1 round of the survey, and 10 completed all rounds. Consensus was achieved on 28 of 31 proposed indicators after 3 rounds. Indicators with consensus were categorized under "empiric choice" (n = 12 indicators), "dose" (n = 5), "duration" (n = 2), "administration" (n = 4), "diagnosis" (n = 2), and "documentation" (n = 3). Six of the indicators for which consensus was achieved were rephrased by the experts. Conclusions: Consensus was achieved on quality indicators to assess the appropriateness of empiric antimicrobial use in pediatric patients. Clinicians and researchers can use these consensus-based indicators to assess adherence to best practice.

Contexte: L'utilisation d'indicateurs de qualité est l'une des stratégies recommandées pour évaluer la prescription d'antimicrobiens aux patients pédiatriques hospitalisés. Objectif: Parvenir à un consensus, entre les cliniciens des maladies infectieuses, portant sur les indicateurs de qualité qui caractérisent l'utilisation empirique appropriée des antimicrobiens pour la prise en charge des syndromes infectieux chez les patients pédiatriques hospitalisés. Méthodes: Cette étude a été réalisée à l'aide de la technique Delphi. L'équipe de recherche a dressé une liste initiale d'indicateurs de qualité éclairée par une recherche documentaire. Un groupe multidisciplinaire de prestataires de soins de santé ayant une expertise dans le domaine des maladies infectieuses a été invité à participer. La liste a été diffusée à ce panel d'experts à l'aide du logiciel d'enquête Opinio. Les experts ont été invités à noter les indicateurs sur une échelle de Likert de 9 points par rapport au critère suivant : « L'importance de chaque élément pour déterminer la pertinence compte tenu du bienfait ou du dommage à l'échelle individuelle ou de la population ¼. Le consensus était défini comme « Un accord d'au moins 75 % et un score médian d'au moins 7 ¼. Résultats: Douze des 31 experts invités ont terminé au moins 1 cycle de l'enquête et 10 les ont tous terminés. Un consensus a été atteint pour 28 des 31 indicateurs proposés après 3 cycles. Les indicateurs qui ont atteint le consensus ont été classés en « choix empirique ¼ (n = 12 indicateurs), « dose ¼ (n = 5), « durée ¼ (n = 2), « administration ¼ (n = 4), « diagnostic ¼ (n = 2) et « documentation ¼ (n = 3). Six indicateurs faisant consensus ont été reformulés par les experts. Conclusions: Un consensus a été atteint pour les indicateurs de qualité visant à évaluer l'utilisation empirique appropriée des antimicrobiens chez les patients pédiatriques. Les cliniciens et les chercheurs peuvent utiliser ces indicateurs basés sur le consensus pour évaluer le respect des meilleures pratiques.

Multinational consensus antimicrobial stewardship recommendations for children managed in hospital settings.

Children are entitled to receive antibiotic therapy that is based on evidence and best practice, but might be overlooked in hospital programmes designed to achieve antimicrobial stewardship [AMS]. This failure to include children could be because children make up small proportion of patients in most hospitals, and are cared for by specialised paediatric staff. We reviewed the evidence and consulted experts in three global regions to develop ten recommendations for good-practice in hospital AMS programmes for children. We performed a review of scientific research, published between Jan 1, 2007, and Oct 17, 2019, concerning AMS, and formed a multinational expert group comprising members from the USA, Canada, the UK, Belgium, Switzerland, Australia, and Aotearoa New Zealand to develop the recommendations. These recommendations aim to help health-care workers who care for children in these regions to deliver best-practice care. We surveyed health-care workers with expertise in antibiotic therapy for children across these regions, and found that the recommendations were considered both very important and generally feasible. These recommendations should be implemented in hospitals to improve antibiotic therapy for children and to stimulate research into future improvements in care.

Trends in Clostridioides difficile infection rates in Canadian hospitals during the coronavirus disease 2019 (COVID-19) pandemic.

The coronavirus disease 2019 (COVID-19) pandemic has placed significant burden on healthcare systems. We compared Clostridioides difficile infection (CDI) epidemiology before and during the pandemic across 71 hospitals participating in the Canadian Nosocomial Infection Surveillance Program. Using an interrupted time series analysis, we showed that CDI rates significantly increased during the COVID-19 pandemic.

SARS-CoV-2 vaccine acceptance among caregivers of children younger than five years of age: A cross-sectional survey in Toronto.

Background: Despite severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine approval in Canada for children six months to five years old, vaccine acceptance for this age group remains low compared with other age groups. This study aimed to assess vaccine acceptance among caregivers of children younger than five years old and to identify factors associated with SARS-CoV-2 vaccine hesitancy in Toronto. Methods: A multi-language self-administered survey was sent to caregivers of children attending 660 Toronto schools and two community health centres between April 5 to July 4, 2022. Data on socio-demographic characteristics, acceptance of routine childhood and influenza vaccines and current SARS-CoV-2 vaccine status for parents and older siblings were collected. Results: A total of 253 caregivers of children younger than five years old answered the survey. Although 234 (94%) of the responding caregivers were fully vaccinated against SARS-CoV-2 and more than 90% had their children older than five years receiving one dose of the vaccine, only 148 (59%) had intentions to vaccinate their child younger than five years old. Conclusion: These findings highlight the importance of interventions to increase vaccine confidence among caregivers of children aged younger than five years old.

A Prolonged Outbreak of Human Adenovirus A31 (HAdV-A31) Infection on a Pediatric Hematopoietic Stem Cell Transplantation Ward with Whole Genome Sequencing Evidence of International Linkages.

A surge in hematopoietic stem cell transplantation (HSCT) human adenovirus A31 (HAdV-A31) infections was initially observed in late 2014/2015 at SickKids (SK) Hospital, Toronto, Canada. In response, enhanced laboratory monitoring for all adenovirus infections was conducted. Positive samples underwent genotyping, viral culture, and, in selected cases, whole-genome sequencing (WGS). HAdV-A31 specimens/DNA obtained from four international pediatric HSCT centers also underwent WGS. During the SK outbreak period (27 October 2014 to 31 October 2018), 17/20 HAdV-A31 isolates formed a distinct clade with 0 to 8 mutations between the closest neighbors. Surveillance before and after the outbreak detected six additional HAdV-A31 HSCT cases; three of the four sequenced cases clustered within the outbreak clade. Two SK outbreak isolates were identical to sequences from two patients in an outbreak in England. Three SK non-outbreak sequences also had high sequence similarity to strains from three international centers. Environmental PCR testing of the HSCT ward showed significant adenovirus contamination. Despite intense infection control efforts, we observed re-occurrence of infection with the outbreak strain. Severe but nonfatal infection was observed more commonly with HAdV-A31 compared to other genotypes, except HAdV-C1. Our findings strongly implicate nosocomial spread of HAdV-A31 over 10 years on a HSCT unit and demonstrate the value of WGS in defining and mapping the outbreak. Close linkages among strains in different countries suggest international dissemination, though the mechanism is undetermined. This large, extended outbreak emphasizes the pre-eminent role of HAdV-A31 in causing intractable pediatric HSCT outbreaks of severe illness worldwide.

Effect of Wearing a Face Mask on Hand-to-Face Contact by Children in a Simulated School Environment: The Back-to-School COVID-19 Simulation Randomized Clinical Trial.

Importance: Wearing a face mask in school can reduce SARS-CoV-2 transmission but it may also lead to increased hand-to-face contact, which in turn could increase infection risk through self-inoculation. Objective: To evaluate the effect of wearing a face mask on hand-to-face contact by children while at school. Design, Setting, and Participants: This prospective randomized clinical trial randomized students from junior kindergarten to grade 12 at 2 schools in Toronto, Ontario, Canada, during August 2020 in a 1:1 ratio to either a mask or control class during a 2-day school simulation. Classes were video recorded from 4 angles to accurately capture outcomes. Interventions: Participants in the mask arm were instructed to bring their own mask and wear it at all times. Students assigned to control classes were not required to mask at any time (grade 4 and lower) or in the classroom where physical distancing could be maintained (grade 5 and up). Main Outcomes and Measures: The primary outcome was the number of hand-to-face contacts per student per hour on day 2 of the simulation. Secondary outcomes included hand-to-mucosa contacts and hand-to-nonmucosa contacts. A mixed Poisson regression model was used to derive rate ratios (RRs), adjusted for age and sex with a random intercept for class with bootstrapped 95% CIs. Results: A total of 174 students underwent randomization and 171 students (mask group, 50.6% male; control group, 52.4% male) attended school on day 2. The rate of hand-to-face contacts did not differ significantly between the mask and the control groups (88.2 vs 88.7 events per student per hour; RR, 1.00; 95% CI, 0.78-1.28; P = >.99). When compared with the control group, the rate of hand-to-mucosa contacts was significantly lower in the mask group (RR, 0.12; 95% CI, 0.07-0.21), while the rate of hand-to-nonmucosa contacts was higher (RR, 1.40; 95% CI, 1.08-1.82). Conclusions and Relevance: In this clinical trial of simulated school attendance, hand-to-face contacts did not differ among students required to wear face masks vs students not required to wear face masks; however, hand-to-mucosa contracts were lower in the face mask group. This suggests that mask wearing is unlikely to increase infection risk through self-inoculation. Trial Registration: ClinicalTrials.gov Identifier: NCT04531254.