Plasmid genomic epidemiology of blaKPC carbapenemase-producing Enterobacterales in Canada, 2010-2021.

Carbapenems are considered last-resort antibiotics for the treatment of infections caused by multidrug-resistant Enterobacterales, but carbapenem resistance due to acquisition of carbapenemase genes is a growing threat that has been reported worldwide. Klebsiella pneumoniae carbapenemase (blaKPC) is the most common type of carbapenemase in Canada and elsewhere; it can hydrolyze penicillins, cephalosporins, aztreonam, and carbapenems and is frequently found on mobile plasmids in the Tn4401 transposon. This means that alongside clonal expansion, blaKPC can disseminate through plasmid- and transposon-mediated horizontal gene transfer. We applied whole genome sequencing to characterize the molecular epidemiology of 829 blaKPC carbapenemase-producing isolates collected by the Canadian Nosocomial Infection Surveillance Program from 2010 to 2021. Using a combination of short-read and long-read sequencing, we obtained 202 complete and circular blaKPC-encoding plasmids. Using MOB-suite, 10 major plasmid clusters were identified from this data set which represented 87% (175/202) of the Canadian blaKPC-encoding plasmids. We further estimated the genomic location of incomplete blaKPC-encoding contigs and predicted a plasmid cluster for 95% (603/635) of these. We identified different patterns of carbapenemase mobilization across Canada related to different plasmid clusters, including clonal transmission of IncF-type plasmids (108/829, 13%) in K. pneumoniae clonal complex 258 and novel repE(pEh60-7) plasmids (44/829, 5%) in Enterobacter hormaechei ST316, and horizontal transmission of IncL/M (142/829, 17%) and IncN-type plasmids (149/829, 18%) across multiple genera. Our findings highlight the diversity of blaKPC genomic loci and indicate that multiple, distinct plasmid clusters have contributed to blaKPC spread and persistence in Canada.

Characterization of Healthcare-Associated and Community-Associated Clostridioides difficile Infections among Adults, Canada, 2015-2019.

We investigated epidemiologic and molecular characteristics of healthcare-associated (HA) and community-associated (CA) Clostridioides difficile infection (CDI) among adult patients in Canadian Nosocomial Infection Surveillance Program hospitals during 2015-2019. The study encompassed 18,455 CDI cases, 13,735 (74.4%) HA and 4,720 (25.6%) CA. During 2015-2019, HA CDI rates decreased by 23.8%, whereas CA decreased by 18.8%. HA CDI was significantly associated with increased 30-day all-cause mortality as compared with CA CDI (p<0.01). Of 2,506 isolates analyzed, the most common ribotypes (RTs) were RT027, RT106, RT014, and RT020. RT027 was more often associated with CDI-attributable death than was non-RT027, regardless of acquisition type. Overall resistance C. difficile rates were similar for all drugs tested except moxifloxacin. Adult HA and CA CDI rates have declined, coinciding with changes in prevalence of RT027 and RT106. Infection prevention and control and continued national surveillance are integral to clarifying CDI epidemiology, investigation, and control.

Antimicrobial Stewardship in Bronchiolitis: A Retrospective Cohort Study of Three PICUs in Canada.

OBJECTIVES: To determine the association between the implementation of an antimicrobial stewardship program at a local PICU and to determine the association between the presence of an antimicrobial stewardship programs and antimicrobial use across three Canadian PICUs, among critically ill children with bronchiolitis. DESIGN: A multicenter retrospective cohort study. SETTING: Three Canadian PICUs over two winter seasons. INTERVENTIONS: An antimicrobial stewardship program was implemented at PICU 1 at the end of season 1. PATIENTS: Patients less than or equal to 2 years old admitted with bronchiolitis. MEASUREMENTS AND MAIN RESULTS: We used regression models with an interaction term between site (PICU 1 and PICU 2) and season (1 and 2) as the primary analysis to determine the association between implementation of an antimicrobial stewardship program at PICU 1 and 1) the proportion of antimicrobials discontinued 72 hours after hospital admission (logistic regression), 2) antimicrobial treatment duration (negative binomial regression), and 3) antimicrobial prescriptions within 48 hours of hospital admission (logistic regression). As a secondary analysis, we determined the association between having an antimicrobial stewardship program present and the aforementioned outcomes across the three PICUs. A total of 372 patients were included. During seasons 1 and 2, median age was 2.2 months (interquartile range, 1.2-6.2 mo) and 2.1 months (interquartile range, 1.3-6.8 mo), respectively. Among patients with viral bronchiolitis, implementation of an antimicrobial stewardship program at PICU 1 was associated with increased odds of discontinuing antimicrobials (odds ratio, 25.63; 95% CI, 2.86-326.29), but not with antimicrobial duration (odds ratio, 0.56; 95% CI, 0.31-1.02) or antimicrobial prescriptions (odds ratio, 0.33; 95% CI, 0.10-1.04). The presence of an antimicrobial stewardship program was similarly associated with antimicrobial discontinuation among patients with viral bronchiolitis (odds ratio, 20.79; 95% CI, 2.46-244.92), but not with antimicrobial duration (odds ratio, 0.57; 95% CI, 0.32-1.03) or antimicrobial prescriptions (odds ratio, 0.37; 95% CI, 0.12-1.11). CONCLUSIONS: Antimicrobial stewardship programs were associated with increased likelihood of discontinuing antimicrobial treatments in the PICU patients with viral bronchiolitis. However, larger studies are needed to further determine the role of an antimicrobial stewardship programs in reducing unnecessary antimicrobial use in this patient population.

Antimicrobial Prophylaxis Use in the Neonatal Intensive Care Unit: An Antimicrobial Stewardship Target That Deserves Attention!

OBJECTIVE: Previous analyses of neonatal intensive care units (NICU) antimicrobial stewardship programs have identified key contributors to overall antibiotic use, including prolonged empiric therapy >48 hours for early-onset sepsis (EOS). However, most were performed in mixed NICU settings with onsite birthing units, resulting in a high proportion of inborn patient admissions. The study aimed to describe and analyze the most common reasons for antimicrobial use in an outborn tertiary care NICU. STUDY DESIGN: This was a 10-month review of all antimicrobial doses prescribed in a 20-bed level III NICU. The primary outcome was the total days of therapy (DOT) and length of therapy (LOT) for each clinical indication. Secondary outcomes included total DOT for each antimicrobial and appropriateness of antimicrobial courses. RESULTS: Of 235 antibiotic courses and 1,899 DOT (519 DOT/1,000 patient days) prescribed in 173 infants during the study period, the most common indications were suspected EOS, followed by prophylaxis. Among the 85 DOT/1,000 patient days (PD; 38 courses) prescribed for prophylaxis, 52.5 DOT/1,000 PD (25 courses; 62%) were for surgical prophylaxis. Of 17 postoperative antibiotic courses, 15 (88.2%) were deemed to be inappropriate mostly due to a duration greater than 24 hours postoperatively (n = 13; median LOT = 3 days). CONCLUSION: Surgical prophylaxis is a common reason for antimicrobial misuse in outborn NICU. NICU-based prospective audit and feedback between neonatologists and antimicrobial stewardship teams alone may not be impactful in this setting. Partnerships with neonatologists and surgeons will be key to achieving the target of less than 24 hours of postoperative antimicrobials. KEY POINTS: · Surgical prophylaxis is a common reason for antimicrobial misuse in the NICU.. · Antimicrobial prophylaxis duration of less than 24 hours postoperatively should be encouraged.. · NICU-based prospective audit and feedback may not be impactful unless surgeons are involved..

Combined influence of practice guidelines and prospective audit and feedback stewardship on antimicrobial treatment of community-acquired pneumonia and empyema in children: 2012 to 2016.

BACKGROUND: Aminopenicillins are recommended empiric therapy for community-acquired pneumonia (CAP). The aim of the study was to assess treatment over a 5-year period after CAP guideline publication and introduction of an antimicrobial stewardship program (ASP). METHODS: Using ICD-10 discharge codes for pneumonia, children less than 18 years admitted to the Children's Hospital of Eastern Ontario January 1, 2012 and December 31, 2016 were identified. Children ≥ 2 months with consolidation were included. One day of therapy (DOT) was one or more doses of an antimicrobial given for 1 day. RESULTS: Of 1,707 patients identified, 713 met inclusion criteria. Eighteen (2.5%) had bacteria identified by culture and 79 of 265 (29.8%) had Mycoplasma pneumoniae detected. Mean DOT/1,000 patient days of aminopenicillins/penicillin (AAP) increased by 18.1% per year (95% confidence interval [CI] -0.2, 39.9%) and decreased by 37.6% per year (95% CI -56.1, -11.3%) for second- and third-generation cephalosporins in the post-ASP period. The duration of discharge antimicrobials decreased. Of 74 (10.4%) patients who had pleural fluid drained, 35 (47.3%) received more than 5 days of AAP and ≤ 5 days of second-/third-generation cephalosporins with no difference in median length of stay nor mean duration of antimicrobials. CONCLUSIONS: Implementation of CAP management guidelines followed by prospective audit and feedback stewardship was associated with a sustained decrease in the use of broad-spectrum antibiotics in childhood CAP. Use of AAP should also be strongly considered in patients with effusions (even if no pathogen is identified), as clinical outcome appears similar to patients treated with broad-spectrum antimicrobials.

Prospective audit and feedback on antibiotic use in neonatal intensive care: a retrospective cohort study.

BACKGROUND: Antimicrobial stewardship programs potentially lead to appropriate antibiotic use, yet the optimal approach for neonates is uncertain. Such a program was implemented in a tertiary care neonatal intensive care unit in October 2012. We evaluated the impact of this program on antimicrobial use and its association with clinical outcomes. METHODS: In a retrospective cohort study, we examined 1580 neonates who received antimicrobials in the 13-months before and 13-months during program implementation. Prospective audit and feedback was given 5 days a week on each patient who was receiving antibiotic. Pharmacy and microbiology data were linked to clinical data from the local Canadian Neonatal Network database. The primary outcome was days of antibiotic therapy per 1000 patient-days; secondary outcomes included mortality, necrotizing enterocolitis, and antibiotic duration for culture-positive and culture-negative late-onset sepsis. The breadth of antibiotic exposure was compared using the Antibiotic Spectrum Index. RESULTS: Overall antibiotic use decreased to 339 days of therapy per 1000 patient-days from 395 (14%, P < 0.001), without an increase in mortality. There was no difference in duration of therapy in culture-negative or culture-positive sepsis, rates of necrotizing enterocolitis, or breadth of antibiotic exposure. Fewer antibiotic starts occurred during program implementation (63% versus 59%, P < 0.001). The use of narrow-spectrum agents decreased (P < 0.001) whereas the use of cefotaxime increased (P = 0.016) during program implementation. CONCLUSIONS: Daily prospective audit and feedback was not associated with a change in antibiotic duration or clinical outcomes, however there were fewer babies started on antibiotics, suggesting that additional interventions are required to inform and sustain changes in antibiotic prescribing practices.

The evolving epidemiology of Clostridium difficile infection in Canadian hospitals during a postepidemic period (2009-2015).

BACKGROUND: The clinical and molecular epidemiology of health care-associated Clostridium difficile infection in nonepidemic settings across Canada has evolved since the first report of the virulent North American pulsed-field gel electrophoresis type 1 (NAP1) strain more than 15 years ago. The objective of this national, multicentre study was to describe the evolving epidemiology and molecular characteristics of health care-associated C. difficile infection in Canada during a post-NAP1-epidemic period, particularly patient outcomes associated with the NAP1 strain. METHODS: Adult inpatients with C. difficile infection were prospectively identified, using a standard definition, between 2009 and 2015 through the Canadian Nosocomial Infection Surveillance Program (CNISP), a network of 64 acute care hospitals. Patient demographic characteristics, severity of infection and outcomes were reviewed. Molecular testing was performed on isolates, and strain types were analyzed against outcomes and epidemiologic trends. RESULTS: Over a 7-year period, 20 623 adult patients admitted to hospital with health care-associated C. difficile infection were reported to CNISP, and microbiological data were available for 2690 patients. From 2009 to 2015, the national rate of health care-associated C. difficile infection decreased from 5.9 to 4.3 per 10 000 patient-days. NAP1 remained the dominant strain type, but infection with this strain has significantly decreased over time, followed by an increasing trend of infection with NAP4 and NAP11 strains. The NAP1 strain was significantly associated with a higher rate of death attributable to C. difficile infection compared with non-NAP1 strains (odds ratio 1.91, 95% confidence interval [CI] 1.29-2.82). Isolates were universally susceptible to metronidazole; one was nonsusceptible to vancomycin. The proportion of NAP1 strains within individual centres predicted their rates of health care-associated C. difficile infection; for every 10% increase in the proportion of NAP1 strains, the rate of health care-associated C. difficile infection increased by 3.3% (95% CI 1.7%-4.9%). INTERPRETATION: Rates of health care-associated C. difficile infection have decreased across Canada. In nonepidemic settings, NAP4 has emerged as a common strain type, but NAP1, although decreasing, continues to be the predominant circulating strain and remains significantly associated with higher attributable mortality.

Severe clinical outcome is uncommon in Clostridium difficile infection in children: a retrospective cohort study.

BACKGROUND: Clostridium difficile infection (CDI) is the most common cause of health care-associated diarrhea in children and adults. Although serious complications of CDI have been reported to be increasing in adults, this trend has not yet been demonstrated in children. The purpose of this study was to examine the features of CDI in a pediatric population, with special attention to the occurrence of CDI-related severe outcomes. METHODS: A chart review was conducted for patients with C. difficile infection detected by cytotoxin assay between August, 2008 and July, 2012. Basic demographics, mode of acquisition (nosocomial versus community), laboratory and clinical features, treatment, and outcome data were collected. Pulsed-field gel electrophoresis and polymerase chain reaction detection of toxin A (tcdA), toxin B (tcdB), binary toxin (cdtB) and tcdC genes were performed on isolates from nosocomial cases by the National Microbiology Laboratory, Winnipeg, Manitoba. RESULTS: Ninety percent of children with CDI experienced resolution of symptoms by 30 days after disease onset and 2% experienced a severe outcome. There were no cases where colectomy was performed for CDI, and only one case where CDI contributed to death. Various combinations of clinical and laboratory features were not predictive of a severe outcome. Seventy-four percent of cases were nosocomial-associated. Among all cultured strains, the NAP4 strain occurred most frequently (24%), followed by NAP1 (11%). There was no association between strain type and clinical outcome; however, relapses were significantly more frequent in NAP4-infected children. CONCLUSIONS: Severe outcomes due to CDI are uncommon in children compared to adults. Further prospective pediatric studies on CDI in community and hospital settings are required to better understand risk factors, optimal treatment and the significance of NAP4 in pediatric CDI.

Hand hygiene knowledge and practices of family caregivers in inpatient pediatrics.

Family caregivers are essential inpatient pediatric care partners, yet their handwashing knowledge and compliance are rarely studied. Through hand hygiene audits and self-administered questionnaires, we observed 9% compliance, significantly lower than self-reported practice. We suggest interventions to improve caregiver handwashing behaviors to decrease infection transmission risk to hospitalized children.

SHEA NICU white paper series: Practical approaches for the prevention of viral respiratory infections.

This white paper provides clinicians and hospital leaders with practical guidance on the prevention and control of viral respiratory infections in the neonatal intensive care unit (NICU). This document serves as a companion to Centers for Disease Control and Prevention Healthcare Infection Control Practices Advisory Committee (HICPAC)'s "Prophylaxis and Screening for Prevention of Viral Respiratory Infections in Neonatal Intensive Care Unit Patients: A Systematic Review." It provides practical, expert opinion and/or evidence-based answers to frequently asked questions about viral respiratory detection and prevention in the NICU. It was developed by a writing panel of pediatric and pathogen-specific experts who collaborated with members of the HICPAC systematic review writing panel and the SHEA Pediatric Leadership Council to identify questions that should be addressed. The document has been endorsed by SHEA, the American Hospital Association (AHA), The Joint Commission, the Pediatric Infectious Diseases Society (PIDS), the Association for Professionals in Infection Control and Epidemiology (APIC), the Infectious Diseases Society of America (IDSA), and the National Association of Neonatal Nurses (NANN).

Extracorporeal membrane oxygenation for COVID-19-associated severe acute respiratory distress syndrome in Canada: Analysis of data from the Canadian Nosocomial Infection Surveillance Program.

Background: Extracorporeal membrane oxygenation (ECMO) for COVID-19 across Canada has not been well-described. We studied trends for patients with COVID-19-related acute respiratory distress syndrome who received ECMO. Methods: Multicentre retrospective cohort study using data from the Canadian Nosocomial Infection Surveillance Program across four different waves. Surveillance data was collected between March 2020 and June 2022. We reported data stratified by ECMO status and wave. Results: ECMO recipients comprised 299 (6.8%) of the 4,408 critically ill patients included. ECMO recipients were younger (median age 49 versus 62 years, p < 0.001), less likely to be vaccinated against COVID-19 (Wave 4 data: 5.3% versus 19%; p = 0.002), and had fewer comorbidities compared to patients who did not receive ECMO. Thirty-day all-cause mortality was similar between the ECMO and non-ECMO groups (23% versus 26%; p = 0.25). Among ECMO recipients, mortality tended to decrease across Waves 1 to 4: 48%, 31%, 18%, and 16%, respectively (p = 0.04 for trend). However, this was no longer statistically significant when removing the high mortality during Wave 1 (p = 0.15). Conclusions: Our findings suggest that critically ill patients in Canadian hospitals who received ECMO had different characteristics from those who did not receive ECMO. We also observed a trend of decreased mortality over the waves for the ECMO group. Possible explanatory factors may include potential delay in ECMO initiation during Wave 1, evolution of the virus, better understanding of COVID-19 disease and ECMO use, and new medical treatments and vaccines available in later waves. These findings may provide insight for future potential pandemics.

Historique: L'oxygénation extracorporelle en cas de COVID-19 n'est pas bien décrite au Canada. Les chercheurs ont étudié les tendances des patients ayant un syndrome respiratoire aigu lié à la COVID-19 qui ont reçu une oxygénation extracorporelle. Méthodologie: Étude de cohorte rétrospective multicentrique à l'aide de données du Programme canadien de surveillance des infections nosocomiales lors de quatre différentes vagues. Les chercheurs ont recueilli les données de surveillance de mars 2020 à juin 2022. Ils ont rendu compte des données stratifiées en fonction de l'état d'oxygénation extracorporelle et de la vague. Résultats: Les receveurs d'une oxygénation extracorporelle représentaient 299 (6,8 %) des 4 408 patients participants gravement malades. Ils étaient plus jeunes (âge médian de 49 ans par rapport à 62 ans, p<0,001), moins susceptibles d'être vaccinés contre la COVID-19 (données de la quatrième vague 4 : 5,3 % par rapport à 19 %; p=0,002) et présentaient moins d'autres maladies que les patients qui avaient reçu une oxygénation extracorporelle. La mortalité toutes causes confondues au bout de 30 jours était semblable entre le groupe sous oxygénation extracorporelle et celui sans oxygénation extracorporelle (23 % par rapport à 26 %; p=0,25). Chez les receveurs d'une oxygénation extracorporelle, la mortalité avait tendance à diminuer d'une vague à l'autre, soit de 48 %, 31 %, 18 % et 16 % entre la première et la quatrième vague, respectivement (p=0,04 par tendance). Cependant, ces résultats n'étaient plus statistiquement significatifs lorsqu'on excluait le taux de mortalité élevé observé pendant la première vague (p=0,15). Conclusions: Selon les observations des chercheurs, les patients gravement malades des hôpitaux canadiens qui avaient reçu une oxygénation extracorporelle présentaient des caractéristiques différentes de ceux qui n'en avaient pas reçu. Dans le groupe sous oxygénation extracorporelle, ils ont également observé une tendance vers une diminution de la mortalité entre les vagues. Les facteurs explicatifs possibles peuvent inclure un retard potentiel de l'initiation de l'oxygénation extracorporelle pendant la première vague, l'évolution du virus, une meilleure compréhension de la COVID-19, le recours à l'oxygénation extracorporelle, les nouveaux traitements médicaux et les vaccins offerts lors de vagues plus tardives. Ces observations pourraient donner des indications intéressantes lors de futures pandémies. Summary: COVID-19 has affected millions of people. Some patients with COVID-19 develop extremely severe disease requiring advanced critical care. Extracorporeal Membrane Oxygenation (ECMO) is an advanced potentially life-saving technique that can support patients whose lungs are unable to function properly despite using a ventilator (breathing machine). ECMO temporarily takes over lung function, essentially acting as external lungs. ECMO can allow time for the body to heal and potentially improve survival for patients with severe lung failure. The decision to use ECMO is complex and always made by a team of medical professionals who factor in the patient's overall health, medical conditions, and disease severity.We studied the trends for critically ill patients with COVID-19 who received ECMO across Canadian hospitals. We used data collected by trained health care professionals through a Canada-wide program that monitors infections in Canadian hospitals. We compared data between critically ill patients who received and did not receive ECMO, and by wave of the COVID-19 pandemic.Our data found that critically ill patients who received ECMO tended to be younger, have fewer medical conditions, and be less likely to be vaccinated against COVID-19. For patients who received ECMO, the mortality was highest in Wave 1 (48%), then Wave 2 (31%), and similar during Waves 3 and 4 (18% and 16%, respectively). Possible explanations for this trend include potential ECMO delay in Wave 1, the evolution of the virus, a better understanding of ECMO use for COVID-19 and available treatments and vaccines during later waves.In conclusion, our study highlights that critically ill patients who received ECMO in Canada had different features and traits compared to those who did not receive ECMO. As well, our study reported mortality across the waves, with possible explanations for the findings offered. These trends may be helpful in providing insight for future potential pandemics.

Incidence and risk factors for recurrent Clostridioides difficile infection in pediatric at-risk groups in selected Pediatric Investigators Collaborative Network on Infections in Canada (PICNIC) hospitals.

OBJECTIVES: Incidence and risk factors for recurrent Clostridioides difficile infection (rCDI) are well established in adults, though data are lacking in pediatrics. We aimed to determine incidence of and risk factors for rCDI in pediatrics. METHODS: This retrospective cohort study of pediatric patients was conducted at 3 tertiary-care hospitals in Canada with laboratory-confirmed CDI between April 1, 2012, and March 31, 2017. rCDI was defined as an episode of CDI occurring 8 weeks or less from diagnostic test date of the primary episode. We used logistic regression to determine and quantify risk factors significantly associated with rCDI. RESULTS: In total, 286 patients were included in this study. The incidence proportion for rCDI was 12.9%. Among hospitalized patients, the incidence rate was estimated at 2.6 cases of rCDI per 1,000 hospital days at risk (95% confidence interval [CI], 1.7-3.9). Immunocompromised patients had higher incidence of rCDI (17.5%; P = .03) and higher odds of developing rCDI independently of antibiotic treatment given for the primary episode (odds ratio [OR], 2.31; 95% CI, 1.12-5.09). Treatment with vancomycin monotherapy did not show statistically significant protection from rCDI, independently of immunocompromised status (OR, 0.33; 95% CI, 0.05-1.15]). CONCLUSIONS: The identification of increased risk of rCDI in immunocompromised pediatric patients warrants further research into alternative therapies, prophylaxis, and prevention strategies to prevent recurrent disease burden within these groups. Treatment of the initial episode with vancomycin did not show statistically significant protection from rCDI.

Detection of SARS-CoV-2 in schools using built environment testing in Ottawa, Canada: A multi-facility prospective surveillance study.

Classroom and staffroom floor swabs across six elementary schools in Ottawa, Canada were tested for SARS-CoV-2. Environmental test positivity did not correlate with student grade groups, school-level absenteeism, pediatric COVID-19-related hospitalizations, or community SARS-CoV-2 wastewater levels. Schools in neighbourhoods with historically elevated COVID-19 burden showed a negative but non-significant association with lower swab positivity.

Corrigendum: Wastewater-based surveillance identifies start to the pediatric respiratory syncytial virus season in two cities in Ontario, Canada.

[This corrects the article DOI: 10.3389/fpubh.2023.1261165.].

A multiprovincial retrospective analysis of the incidence of myocarditis or pericarditis after mRNA vaccination compared to the incidence after SARS-CoV-2 infection.

Objective: To compare myocarditis/pericarditis risk after COVID-19 mRNA vaccination versus SARS-CoV-2 infection, and to assess if myocarditis/pericarditis risk varies by vaccine dosing interval. Methods: In this retrospective cohort study, we used linked databases in Quebec, Ontario, and British Columbia between January 26, 2020, and September 9, 2021. We included individuals aged 12 or above who received an mRNA vaccine as the second dose or were SARS-CoV-2-positive by RT-PCR. The outcome was hospitalization/emergency department visit for myocarditis/pericarditis within 21 days of exposure. We calculated age- and sex-stratified incidence ratios (IRs) of myocarditis/pericarditis following mRNA vaccination versus SARS-CoV-2 infection. We also calculated myocarditis/pericarditis incidence by vaccine type, homologous/heterologous schedule, and dosing interval. We pooled province-specific estimates using meta-analysis. Results: Following 18,860,817 mRNA vaccinations and 860,335 SARS-CoV-2 infections, we observed 686 and 160 myocarditis/pericarditis cases, respectively. Myocarditis/pericarditis incidence was lower after vaccination than infection (IR [BNT162b2/SARS-CoV-2], 0.14; 95%CI, 0.07-0.29; IR [mRNA-1273/SARS-CoV-2], 0.28; 95%CI, 0.20-0.39). Within the vaccinated cohort, myocarditis/pericarditis incidence was lower with longer dosing intervals; IR (56 or more days/15-30 days) was 0.28 (95%CI, 0.19-0.41) for BNT162b2 and 0.26 (95%CI, 0.18-0.38) for mRNA-1273. Conclusion: Myocarditis/pericarditis risk was lower after mRNA vaccination than SARS-CoV-2 infection, and with longer intervals between primary vaccine doses.

Effects of school-level and area-level socio-economic factors on elementary school student COVID-19 infections: a population-based observational study.

OBJECTIVES: To estimate the variability of the cumulative incidence of SARS-CoV-2 infections among elementary school students attributable to individual schools and/or their geographic areas, and to ascertain whether socio-economic characteristics of school populations and/or geographic areas may be predictive of this variability. DESIGN: Population-based observational study of SARS-CoV-2 infections among elementary school children. SETTING: 3994 publicly funded elementary schools in 491 forward sortation areas (designated geographic unit based on first three characters of Canadian postal code), Ontario, Canada, September 2020 to April 2021. PARTICIPANTS: All students attending publicly funded elementary schools with a positive molecular test for SARS-CoV-2 reported by the Ontario Ministry of Education. MAIN OUTCOME MEASURES: Cumulative incidence of laboratory-confirmed elementary school student SARS-CoV-2 infections in Ontario, 2020-21 school year. RESULTS: A multilevel modelling approach was used to estimate the effects of socio-economic factors at the school and area levels on the cumulative incidence of elementary school student SARS-CoV-2 infections. At the school level (level 1), the proportion of the student body from low-income households was positively associated with cumulative incidence (ß=0.083, p<0.001). At the area level (level 2), all dimensions of marginalisation were significantly related to cumulative incidence. Ethnic concentration (ß=0.454, p<0.001), residential instability (ß=0.356, p<0.001) and material deprivation (ß=0.212, p<0.001) were positively related, while dependency (ß=-0.204, p<0.001) was negatively related. Area-related marginalisation variables explained 57.6% of area variability in cumulative incidence. School-related variables explained 1.2% of school variability in cumulative incidence. CONCLUSIONS: The socio-economic characteristics of the geographic area of schools were more important in accounting for the cumulative incidence of SARS-CoV-2 elementary school student infections than individual school characteristics. Schools in marginalised areas should be prioritised for infection prevention measures and education continuity and recovery plans.

Perspective: the potential of wastewater-based surveillance as an economically feasible game changer in reducing the global burden of pediatric respiratory syncytial virus infection.

Respiratory syncytial virus (RSV) is the leading viral cause of childhood bronchiolitis and pneumonia causing over 3 million hospitalizations and 100,000 deaths in children under 5 years of age annually. Wastewater-based surveillance (WBS) has proven an effective early warning system for high-consequence pathogens, including SARS-CoV-2, polio, mpox, and influenza, but has yet to be fully leveraged for RSV surveillance. A model predicated on the Canadian province of Ontario demonstrates that implementation of a WBS system can potentially result in significant cost savings and clinical benefits when guiding an RSV preventive program with a long-acting monoclonal antibody. A network of integrated WBS initiatives offers the opportunity to help minimize the devastating global burden of RSV in children by optimizing the timing of preventive measures and we strongly advocate that its benefits continue to be explored.

Epidemiology of Primary and Recurrent Healthcare-Associated and Community-Associated Pediatric Clostridioides difficile Infection in Canada, 2015-2020.

Clostridioides difficile infection (CDI) among children remains a concerning cause of morbidity in hospital settings. We present epidemiological and molecular trends in healthcare- and community-associated CDI among children in Canadian inpatient and outpatient settings, including those who experienced recurrent infections.