Canadian Nosocomial Infection Surveillance Program Research Articles

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

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. 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. 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). 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.

481. Trends in SARS-CoV-2-related Pediatric Hospitalizations in the Canadian Nosocomial Infection Surveillance Program, March 2020 to December 2022

Abstract Background National surveillance can provide insights into trends in pediatric SARS-CoV-2-related hospitalizations during the pandemic and healthcare-associated infections.Figure:Proportion of all pediatric hospitalizations by age group and wave Methods From March 1, 2020, to December 31, 2022, the Canadian Nosocomial Infection Surveillance Program collected patient-level data on pediatric patients (under age 18 years) hospitalized with laboratory-confirmed SARS-CoV-2 from 9 pediatric and 25 mixed adult-pediatric hospitals. Pediatric COVID-19 vaccines became available for 12-17 years in May 2021 and for 5-11 years in November 2021. Results Of 4,878 pediatric patients, most (80.3%) were hospitalized with SARS-CoV-2 infection during the Omicron-dominant period (since Jan 2022); a higher proportion involved patients under five years of age (58.5% vs 46.9%, p &amp;lt; 0.001). Most hospitalizations pre-Omicron involved children not vaccinated against COVID-19 (92%) versus 70% during Omicron (p &amp;lt; 0.001). However, a lower proportion required intensive care during Omicron (15% vs 20%, p &amp;lt; 0.001). There was no difference in pre-existing comorbidities or mortality between periods. Overall, there were 257 healthcare-associated COVID-19 infections (HA-COVID) reported (5.4%); 89% occurred during Omicron. While there was no difference in median ages of patients with HA-COVID and community-associated COVID-19 infections (CA-COVID), 62% of patients with HA-COVID had a pre-existing comorbidity compared to 44% with CA-COVID (p &amp;lt; 0.001), and 24% remained in hospital at 30 days after HA-COVID, compared to 2.2% with CA-COVID (p &amp;lt; 0.001). Nearly 50% of patients with HA-COVID had received at least one vaccine dose, compared to 25% with CA-COVID. Conclusion During the Omicron-dominant period, a higher proportion of admitted patients with SARS-CoV-2 infection were under five years, but a lower proportion were unvaccinated and a lower proportion required intensive care and mortality was comparable between both periods. Only 5.4% of pediatric COVID-related hospitalizations were HAI, with most during Omicron. Patients with HAI were more likely to have a pre-existing comorbidity and increased hospital stay, potentially related to their underlying conditions. Disclosures All Authors: No reported disclosures

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.

Nirmatrelvir-ritonavir use among adults hospitalized with COVID-19 during the Omicron phase of the COVID-19 pandemic, Canadian Nosocomial Infection Surveillance Program.

Recent studies have demonstrated the effectiveness of nirmatrelvir-ritonavir in reducing the risk of progression to severe disease among outpatients with mild to moderate coronavirus disease 2019 (COVID-19); however, data are limited regarding the use and role of nirmatrelvir-ritonavir among hospitalized patients. This study describes the use and outcomes of nirmatrelvir-ritonavir among adults hospitalized with COVID-19 in a sentinel network of Canadian acute care hospitals during the Omicron variant phase of the pandemic. The Canadian Nosocomial Infection Surveillance Program conducts surveillance of hospitalized patients with COVID-19 in acute care hospitals across Canada. Demographic, clinical, treatment and 30-day outcome data were collected by chart review by trained infection control professionals using standardized questionnaires. From January 1 to December 31, 2022, 13% (n=490/3,731) of adult patients (18 years of age and older) hospitalized with COVID-19 in 40 acute care hospitals received nirmatrelvir-ritonavir either at admission or during hospitalization. Most inpatients who received nirmatrelvir-ritonavir, 79% of whom were fully vaccinated, had at least one pre-existing comorbidity (97%) and were of advanced age (median=79 years). Few were admitted to an intensive care unit (2.3%) and among the 490 nirmatrelvir-ritonavir treated inpatients, there were 13 (2.7%) deaths attributable to COVID-19. These findings from a large sentinel network of Canadian acute-care hospitals suggest that nirmatrelvir-ritonavir is being used to treat adult COVID-19 patients at admission who are at risk of progression to severe disease or those who acquired COVID-19 in hospital. Additional research on the efficacy and indications for nirmatrelvir-ritonavir use in hospitalized patients is warranted to inform future policies and guidelines.

Impact of COVID-19 on healthcare-associated infections in Canadian acute-care hospitals: Interrupted time series (2018–2021)

Background: Data regarding the effects of the SARS-COV-2 (COVID-19) pandemic on healthcare-associated infections (HAIs) in Canadian acute-care hospitals are limited. We examined the impact of the COVID-19 pandemic on HAIs and antimicrobial resistant organisms in hospitals participating in the Canadian Nosocomial Infection Surveillance Program. Methods: We analyzed 13,406 HAIs including adult mixed intensive care unit (ICU) central-line–associated bloodstream infections (CLABSIs), and healthcare-associated (HA) Clostridioides difficile infection (CDI), methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infections (BSI), vancomycin-resistant Enterococcus (VRE) BSI, and carbapenemase-producing Enterobacterales (CPE) infections collected using standardized case definitions and questionnaires from 29–64 hospitals participating in the Canadian Nosocomial Infection Surveillance Program (CNISP) from January 2018 to December 2021. We used a generalized linear mixed model with quasi-Poisson distribution to assess step and slope changes in monthly HAI rates between the pre–COVID-19 pandemic period (January 1, 2018–February 29, 2020; 26 time points) and the COVID-19 pandemic period (March 1, 2020–December 31, 2021; 22 time points). Results were reported as incidence rate ratios (IRRs) with 95% confidence intervals (CIs) and adjusted for seasonality, hospital clustering, and hospital characteristics of interest. Results: In the CNISP network, 7,352 (55%) HAIs were reported in the prepandemic period and 6,054 (45%) in the pandemic period. Median age was significantly younger during the pandemic period compared to the prepandemic period among patients with HA-CDI, HA-MRSA BSI, and adult mixed ICU CLABSIs, and more than half of cases among all reported HAIs were male (range, 52%–65%). The 30-day all-cause in-hospital mortality rate did not significantly change between the prepandemic and pandemic periods for all reported HAIs and was highest among HA-VRE BSIs (34%). Modeling results indicated that the COVID-19 pandemic was associated with an immediate increase in HA-CDI and adult mixed ICU CLABSI rates whereas HA-MRSA BSI, HA-CPE and HA-VRE BSI rates immediately decreased. However, pandemic status did not have a statistically significant lasting impact on monthly rate trends for all reported HAIs after adjusting for seasonality, clustering, and hospital covariates (Fig. 1 and 2). Adjusted IRRs for all HAIs ranged from 1.00 to 1.01 (95% CI, 0.94–0.99 to 1.01–1.05).Conclusions: Although the COVID-19 pandemic placed a significant burden on the Canadian healthcare system, the immediate impact on monthly rates of HAIs in Canadian acute-care hospitals was not sustained over time. Understanding the epidemiological effects of the COVID-19 pandemic in the context of changing patient populations, and clinical and infection control practices, are essential to inform the continued management and prevention of HAIs in Canadian acute-care settings.Disclosures: None

Epidemiology of central-line–associated bloodstream infection mortality in Canadian NICUs before and after 2017

Background: The Canadian Nosocomial Infection Surveillance Program (CNISP) observed increased mortality among neonatal intensive care unit (NICU) patients with central-line–associated bloodstream infection (CLABSI) starting in 2017. In this study, we compared NICU patients with CLABSIs before and after 2017, and quantified the impact of epidemiological factors on 30-day survival. Methods: We included 1,276 NICU patients from 8–16 participating CNISP hospitals from the pre-2017 period (2009–2016) and the post-2017 period (2017–2022) using standardized definitions and questionnaires. We used Cox regression modeling to assess the impact of age at date of positive culture, sex, birthweight, CLABSI microorganism, region of the country, and surveillance period (before 2017 vs after 2017) on time to 30-day all-cause mortality from date of positive culture. Gestational age was not available for this analysis. We reported model outputs as hazard ratios with 95% CIs. Results: In total, 769 (60%) NICU CLABSIs were reported in the pre-2017 period and 507 (40%) in the post-2017 period. The 30-day all-cause mortality rate was 8% (n = 100 of 1,276) overall, and significantly higher after 2017 (12%, n = 61 of 507) than before 2017 (5%, n = 39 of 769) (P &lt; .001).During the post-2017 period, cases were significantly younger: 16 days (IQR, 9–33) versus 21 days (IQR, 11–49) (P = .002). Median days from ICU admission to infection were shorter: 14 (IQR, 8–31) versus 19 (IQR, 10–41) (P &lt; .001). More gram-negative CLABSIs were identified (29% vs 24%; P = .040) and fewer gram-positive CLABSIs were identified (64% vs 72%; P = .006) compared to the pre-2017 period. Mortality was higher in CLABSIs caused by gram-negative bacteria (15%, n = 50 of 328) than gram-positive bacteria (4.4%, n = 39 of 877) (P &lt; .001), and mortality was higher in neonates with birthweight &lt;1,000 g (11%, n = 71 of 673) compared to those weighing ≥1,000 g (5%, n = 28 of 560) (P &lt; .001).Adjusting for all other factors, survival modeling indicated that NICU CLABSIs identified in the post-2017 period had 2.12 (95% CI, 1.23–3.66) times the hazard ratio of 30-day all-cause mortality compared to those before 2017 (P &lt; .006). Those identified with a gram-positive bacterium had a 0.28 hazard ratio (95% CI, 0.12–0.65) of 30-day mortality compared to those with a gram-negative bacterium or fungus (P = .003). In the fully adjusted model, age, sex, and birthweight were not significantly associated with NICU CLABSI survival. Conclusions: NICU patients with CLABSIs had significantly higher all-cause mortality between 2017–2022 compared to 2009–2016, and those who acquired gram-positive–associated CLABSIs had improved survival compared to other organisms. Further work is needed to identify and understand factors driving the increased mortality among NICU CLABSI patients from 2017–2022.Disclosures: None

Healthcare-associated infections and antimicrobial resistance in Canadian acute care hospitals, 2017-2021.

Healthcare-associated infections (HAIs) and antimicrobial resistance (AMR) continue to contribute to excess morbidity and mortality among Canadians. This report describes epidemiologic and laboratory characteristics and trends of HAIs and AMR from 2017 to 2021 (Candida auris 2012-2021) using surveillance and laboratory data submitted by hospitals to the Canadian Nosocomial Infection Surveillance Program (CNISP) and by provincial laboratories to the National Microbiology Laboratory (NML). Data collected from 88 Canadian sentinel acute care hospitals between January 1, 2017, and December 31, 2021, for Clostridioides difficile infections (CDI), carbapenemase-producing Enterobacterales (CPE), methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infections (BSIs) and vancomycin-resistant Enterococcus (VRE) BSIs. Candida auris (C. auris) surveillance was initiated in 2019 by CNISP and in 2012 by the NML. Case counts, rates, outcomes, molecular characterization and antimicrobial resistance profiles are presented. From 2017 to 2021, increased rates per 10,000 patient days were observed for MRSA BSIs (35%; 0.84-1.13), VRE BSIs (43%; 0.23-0.33) and CPE infections (166%, 0.03-0.08). CDI rates decreased 11% (5.68-5.05). Thirty-one C. auris isolates were identified in Canada from 2012 to 2021, with the majority from Western Canada (68%). From 2017 to 2021, the incidence of MRSA and VRE BSIs, and CPE infections increased in Canadian acute care hospitals participating in a national sentinel network (CNISP) while CDI decreased. Few C. auris isolates were identified from 2012 to 2021. Reporting standardized surveillance data and the consistent application of infection prevention and control practises in acute care hospitals are critical to help decrease the burden of HAIs and AMR in Canada.

Device and surgical procedure-related infections in Canadian acute care hospitals, 2017-2021.

Healthcare-associated infections (HAIs) are a significant healthcare burden in Canada. National surveillance of HAIs at sentinel acute care hospitals is conducted by the Canadian Nosocomial Infection Surveillance Program. This article describes device and surgical procedure-related HAI epidemiology in Canada from 2017 to 2021. Data were collected from over 60 Canadian sentinel acute care hospitals between January 1, 2017, and December 31, 2021, for central line-associated bloodstream infections (CLABSIs), hip and knee surgical site infections (SSIs), cerebrospinal fluid shunt SSIs and paediatric cardiac SSIs. Case counts, rates, patient and hospital characteristics, pathogen distributions and antimicrobial resistance data are presented. Between 2017 and 2021, 2,898 device and surgical procedure-related infections were reported, with CLABSIs in intensive care units representing 69% (n=2,002) of all reported infections under surveillance. Significant rate increases were observed in adult mixed intensive care unit CLABSIs (1.08-2.11 infections per 1,000 line days, p=0.014) while decreases were observed in SSIs following knee arthroplasty (0.34-0.27 infections per 100 surgeries, p=0.05). No changes in trends were observed in the other reported HAIs. Of the 3,089 pathogens identified, the majority were gram-positive (66%), followed by gram negative (23%) and fungi (11%). Coagulase-negative staphylococci (22%) and Staphylococcus aureus (17%) were the most frequently isolated pathogens. Epidemiological and microbiological trends among select device and surgical procedure-related HAIs are essential for benchmarking infection rates nationally and internationally, identifying any changes in infection rates or antimicrobial resistance patterns and helping inform hospital infection prevention and control and antimicrobial stewardship policies and programs.

Trends in Severe Outcomes Among Adult and Pediatric Patients Hospitalized With COVID-19 in the Canadian Nosocomial Infection Surveillance Program, March 2020 to May 2022

Trends in COVID-19 severe outcomes have significant implications for the health care system and are key to informing public health measures. However, data summarizing trends in severe outcomes among patients hospitalized with COVID-19 in Canada are not well described. To describe trends in severe outcomes among patients hospitalized with COVID-19 during the first 2 years of the COVID-19 pandemic. Active prospective surveillance in this cohort study was conducted from March 15, 2020, to May 28, 2022, at a sentinel network of 155 acute care hospitals across Canada. Participants included adult (aged ≥18 years) and pediatric (aged 0-17 years) patients hospitalized with laboratory-confirmed COVID-19 at a Canadian Nosocomial Infection Surveillance Program (CNISP)-participating hospital. COVID-19 waves, COVID-19 vaccination status, and age group. The CNISP collected weekly aggregate data on the following severe outcomes: hospitalization, admission to an intensive care unit (ICU), receipt of mechanical ventilation, receipt of extracorporeal membrane oxygenation, and all-cause in-hospital death. Among 1 513 065 admissions, the proportion of adult (n = 51 679) and pediatric (n = 4035) patients hospitalized with laboratory-confirmed COVID-19 was highest in waves 5 and 6 of the pandemic compared with waves 1 to 4 (77.3 vs 24.7 per 1000 patient admissions). Despite this, the proportion of patients with positive test results for COVID-19 who were admitted to an ICU, received mechanical ventilation, received extracorporeal membrane oxygenation, and died were each significantly lower in waves 5 and 6 when compared with waves 1 through 4. Admission to the ICU and in-hospital all-cause death rates were significantly higher among those who were unvaccinated against COVID-19 when compared with those who were fully vaccinated (incidence rate ratio, 4.3 and 3.9, respectively) or fully vaccinated with an additional dose (incidence rate ratio, 12.2 and 15.1, respectively). The findings of this cohort study of patients hospitalized with laboratory-confirmed COVID-19 suggest that COVID-19 vaccination is important to reduce the burden on the Canadian health care system as well as severe outcomes associated with COVID-19.

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

BackgroundAntimicrobial 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.MethodsAcute-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).ResultsNine 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).ConclusionsThis 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.

A standardized infection prevention bundle for reduction of CSF shunt infections in adult ventriculoperitoneal shunt surgery performed without antibiotic-impregnated catheters.

Ventriculoperitoneal (VP) shunt insertion and revision surgeries are some of the most common procedures that are performed by neurosurgeons. Shunt infections within the adult population are associated with significant morbidity and mortality and rates remain high. The objective of the current study was to use quality improvement (QI) methodology to create a standardized infection prevention bundle aimed at reducing the rate of shunt infections. A prospective, single-center, single-surgeon QI study was undertaken. Patients were included if they were 18 years of age or older and were undergoing a VP shunt insertion or revision. The primary outcome of the study was the development of a shunt-related surgical site infection, within 1 year of surgery, as defined according to the Canadian Nosocomial Infection Surveillance Program guidelines. There was no standardized protocol prior to July 2013. A bundle coined as the Calgary Adult Shunt Infection Prevention Protocol (CASIPP) was implemented on July 1, 2013, and updated on July 1, 2015, when 2% chlorhexidine gluconate in 70% isopropyl alcohol replaced povidone-iodine for preoperative skin antisepsis. Protocol compliance was regularly monitored using a standardized process. No antibiotic-impregnated catheters were used. A total of 621 consecutive VP shunt insertions and revisions were included in the study. The rate of shunt infection was 5.8% during the period in which there was no standardized shunt protocol. After the implementation of the CASIPP the infection rate decreased to 4.0%, and after introduction of the chlorhexidine/alcohol skin antisepsis, the infection rate was 0% in 379 consecutive procedures (p < 0.0001). Multivariable logistic regression analysis demonstrated that the use of chlorhexidine/alcohol with CASIPP was associated with a significant reduction in the odds of developing a shunt infection (OR 0.032, 95% CI 0-0.19, p = 0.0005). The implementation of a standardized shunt infection prevention bundle within the adult population, without the use of antibiotic-impregnated catheters, significantly reduced the rate of shunt infections which was sustained over many years. The use of 2% chlorhexidine gluconate in 70% isopropyl alcohol for preoperative antisepsis may have played a significant role. Multicenter studies should be completed to verify the effectiveness of the authors' protocol.

The Canadian Nosocomial Infection Surveillance Program: Keeping an eye on antimicrobial resistance in Canadian hospitals since 1995.

Surveillance is essential to inform evidence-based policy and control measures that combat antimicrobial resistance (AMR). The Canadian Nosocomial Infection Surveillance Program (CNISP) collaborates with 88 sentinel hospitals across Canada to conduct prospective surveillance of infections and antimicrobial resistant organisms important to hospital infection prevention and control. This article aims to increase awareness of CNISP hospital-based surveillance activities. Since its inception in 1995, the scope of CNISP has expanded to include community-associated infections, outpatient Clostridioides difficile infections, viral respiratory infections such as coronavirus disease 2019, and emerging pathogens such as Candida auris. This change in scope, along with expansion to include rural, northern and community hospitals, has improved the generalizability of CNISP surveillance data. To generate actionable surveillance data, CNISP integrates demographic and clinical data abstracted from patient charts with molecular and microbiological data abstracted from laboratory testing. These data serve as a benchmark for participating hospitals and stakeholders to assess the burden of AMR in hospital and intervene as needed. Further, CNISP surveillance data are now available on a public-facing data blog that provides interactive visualizations and data syntheses sooner than peer-reviewed publications. Future directions of CNISP include the Simplified Dataset, which will capture aggregate AMR data from hospitals outside of the CNISP network, surveillance in long-term care facilities and a fourth point prevalence survey. Given its strengths and future directions, CNISP is well positioned to serve as the reference point for hospital-based AMR data in Canada.

Overview of Canada's Antimicrobial Resistance Network (AMRNet): A data-driven One Health approach to antimicrobial resistance surveillance.

The Antimicrobial Resistance Network (AMRNet) is a laboratory-based antimicrobial resistance (AMR) surveillance system under development at the Public Health Agency of Canada's (PHAC's) National Microbiology Laboratory. The AMRNet surveillance system captures information on antimicrobial susceptibility testing from clinical and veterinary laboratories including both public and private facilities. In the future, the AMRNet system will also capture relevant data from existing PHAC surveillance systems for AMR including the Canadian Integrated Program for Antimicrobial Resistance Surveillance, the Canadian Nosocomial Infection Surveillance Program and the Enhanced Surveillance of Antimicrobial-Resistant Gonorrhea program, and contribute to the Canadian Antimicrobial Resistance Surveillance System. AMRNet's integrated "One Health" approach will allow health professionals and researchers to take a multi-dimensional perspective of AMR in both human and animal health in Canada and will make Canada a leader in AMR surveillance. AMRNet is a collaboration between PHAC, provincial and territorial public health organizations as well as clinical and veterinary laboratories across the country. As part of a phased rollout, AMRNet is now collecting human clinical data from three provinces, from both inpatients and outpatients. Ultimately, AMRNet aims to capture all antimicrobial susceptibility testing results from all bacterial and fungal pathogens across Canada. This article describes the AMRNet surveillance system, including program objectives, system structure and the data collected. The integration of human and animal data in AMRNet will inform One Health responses to AMR issues. The capacity to collect and to disseminate data to stakeholders in real time is a critical step to addressing emerging AMR issues in Canada.

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.

Characterization of Extensively Drug-Resistant (XDR) Carbapenemase-Producing Enterobacterales (CPE) in Canada from 2019 to 2020.

ABSTRACTData regarding the epidemiology of extensively drug-resistant (XDR) carbapenemase-producing Enterobacterales (CPE) in Canada are scarce. Among CPE patients identified by the Canadian Nosocomial Infection Surveillance Program, the following were each significantly associated with XDR status: international travel history; CPE acquisition from a health care exposure abroad; presence of the New Delhi metallo-β-lactamase (NDM) carbapenemase gene; E. coli sequence type (ST) 167, ST405, and ST648; E. cloaceae ST177; C. freundii ST22; and resistance to all antimicrobials except colistin, tigecycline, and ceftazidime-avibactam.IMPORTANCE Extensively drug-resistant (XDR) carbapenemase-producing Enterobacterales (CPE) are a global public health concern. XDR CPE are among the most drug-resistant and difficult-to-treat bacteria, and infected patients are likely to experience adverse outcomes. Because XDR status further reduces effective therapeutic options, it is critical for clinicians to consider resistance and therapeutic options not only in the context of a patient with CPE but also in the context of potential XDR status. Our study reports on patient characteristics associated with the acquisition of an XDR CPE. Our study also reports on the species and carbapenemases associated with XDR status among Enterobacterales identified in Canada. Among a panel of 22 antibiotics, including novel combination drugs, we showed which retained the highest activity against XDR CPE, which may help guide the selection of antibiotic treatments.

Device and surgical procedure-related infections in Canadian acute care hospitals from 2011 to 2020.

Healthcare-associated infections (HAIs) continue to place a burden on patient health and safety as well as on the healthcare system. In Canada, national surveillance of HAIs at sentinel acute care hospitals is conducted by the Canadian Nosocomial Infection Surveillance Program. This article describes ten years of device and surgical procedure-related HAI epidemiology in Canada from 2011 to 2020. Data were collected from over 40 Canadian sentinel acute care hospitals between January 1, 2011, and December 31, 2020, for central line-associated bloodstream infections (CLABSIs), hip and knee surgical site infections (SSIs), cerebrospinal fluid shunt SSIs and paediatric cardiac SSIs. Case counts, rates, patient and hospital characteristics, pathogen distributions, and antimicrobial resistance are presented. Between 2011 and 2020, 4,751 device and surgical procedure-related infections were reported, with CLABSIs in intensive care units (ICUs) representing 67% (n=3,185) of all reported infections. Over the surveillance period, significant rate increases were observed in adult mixed ICU CLABSIs (0.8 to 1.6 per 1,000 line days, p=0.004) while decreases were observed in neonatal ICU CLABSIs (4.0 to 1.6 per 1,000 line days, p=0.002) and SSIs following knee arthroplasty (0.69 to 0.29 infections per 100 surgeries, p=0.002). No trends were observed in the other reported HAIs.Of the 5,071 pathogens identified, the majority were gram-positive (68%), followed by gram-negative (23%) and fungi (9%). Coagulase-negative staphylococci (27%) and Staphylococcus aureus (16%) were the most frequently isolated pathogens. This report describes epidemiological and microbiological trends among select device and surgical procedure-related HAIs, essential for benchmarking infection rates nationally and internationally, to identify any changes in infection rates or antimicrobial resistance patterns and to help inform hospital infection prevention and control and antimicrobial stewardship policies and programs.

Healthcare-associated infections and antimicrobial resistance in Canadian acute care hospitals, 2016–2020

Epidemiologic and laboratory characteristics of healthcare-associated infections and antimicrobial resistance from 2016 to 2020 using surveillance data provided by Canadian hospitals participating in the Canadian Nosocomial Infection Surveillance Program.

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.

Vancomycin-resistant Enterococcus sequence type 1478 spread across hospitals participating in the Canadian Nosocomial Infection Surveillance Program from 2013 to 2018.

To analyze the spread of a novel sequence type (ST1478) of vancomycin-resistant Enterococcus faecium across Canadian hospitals. Retrospective chart review of patients identified as having ST1478 VRE bloodstream infection. Canadian hospitals that participate in the Canadian Nosocomial Infection Surveillance Program (CNISP). From 2013 to 2018, VRE bloodstream isolates collected from participating CNISP hospitals were sent to the National Microbiology Laboratory (NML). ST1478 isolates were identified using multilocus sequence typing, and whole-genome sequencing was performed. Patient characteristics and location data were collected for patients with ST1478 bloodstream infection (BSI). The sequence and patient location information were used to generate clusters of infections and assess for intrahospital and interhospital spread. ST1478 VRE BSI occurred predominantly in a small number of hospitals in central and western Canada. Within these hospitals, infections were clustered on certain wards, and isolates often had <20 single-nucleotide variants (SNV) differences from one another, suggesting a large component of intrahospital spread. Furthermore, some patients with bloodstream infections were identified as moving from one hospital to another, potentially having led to interhospital spread. Genomic analysis of all isolates revealed close relatedness between isolates at multiple different hospitals (<20 SNV) not predicted from our epidemiologic data. Both intrahospital and regional interhospital spread have contributed to the emergence of VRE ST1478 infections across Canada. Whole-genome sequencing provides evidence of spread that might be missed with epidemiologic investigation alone.

Antimicrobial use in Canadian acute-care hospitals: Findings from three national point-prevalence surveys between 2002 and 2017.

The Canadian Nosocomial Infection Surveillance Program conducted point-prevalence surveys in acute-care hospitals in 2002, 2009, and 2017 to identify trends in antimicrobial use. Eligible inpatients were identified from a 24-hour period in February of each survey year. Patients were eligible (1) if they were admitted for ≥48 hours or (2) if they had been admitted to the hospital within a month. Chart reviews were conducted. We calculated the prevalence of antimicrobial use as follows: patients receiving ≥1 antimicrobial during survey period per number of patients surveyed × 100%. In each survey, 28-47 hospitals participated. In 2002, 2,460 (36.5%; 95% CI, 35.3%-37.6%) of 6,747 surveyed patients received ≥1 antimicrobial. In 2009, 3,566 (40.1%, 95% CI, 39.0%-41.1%) of 8,902 patients received ≥1 antimicrobial. In 2017, 3,936 (39.6%, 95% CI, 38.7%-40.6%) of 9,929 patients received ≥1 antimicrobial. Among patients who received ≥1 antimicrobial, penicillin use increased 36.8% between 2002 and 2017, and third-generation cephalosporin use increased from 13.9% to 18.1% (P < .0001). Between 2002 and 2017, fluoroquinolone use decreased from 25.7% to 16.3% (P < .0001) and clindamycin use decreased from 25.7% to 16.3% (P < .0001) among patients who received ≥1 antimicrobial. Aminoglycoside use decreased from 8.8% to 2.4% (P < .0001) and metronidazole use decreased from 18.1% to 9.4% (P < .0001). Carbapenem use increased from 3.9% in 2002 to 6.1% in 2009 (P < .0001) and increased by 4.8% between 2009 and 2017 (P = .60). The prevalence of antimicrobial use increased between 2002 and 2009 and then stabilized between 2009 and 2017. These data provide important information for antimicrobial stewardship programs.