Abstract Objective: To determine if hospital characteristics were associated with rates of healthcare-associated (HA) viral respiratory infections (VRIs) in a large Canadian acute care hospital network. Design: Survey of hospital characteristics and prospective surveillance of HA-VRI. Setting: The Canadian Nosocomial Infection Surveillance Program is a sentinel surveillance system with 89 hospitals participating in adult and pediatric VRI surveillance. Patients Patients with laboratory confirmed infection from SARS-CoV-2, Influenza A/B or RSV associated with their hospitalization from participating hospitals between January 1-December 31, 2024. Methods: A 15-item survey was distributed to hospitals to collect information on hospital infrastructure, infection prevention and control practices, and occupational health measures for healthcare workers. HA-VRI rates/10,000 patient-days were analyzed alongside survey responses using univariable and multivariable negative binomial regression models in R to determine associations. Hospitals without case data were excluded. Results: Of 89 hospitals, 93% (n = 83) responded to the survey, with 79 included in the analysis. The national HA-VRI rate was 8.15/10,000 patient-days. Pediatric hospitals had a 56% lower HA-VRI rate than adult/mixed hospitals ( P < .001) that increased with the exclusion of SARS-CoV-2. Each 10% increase in the percentage of single-bed rooms corresponded to a 12% reduction in infection rate ( P < .001). Teaching vs. Non-teaching hospitals were associated with a 32% lower HA-VRI rate. Universal masking was not associated with a statistically significant reduction in HA-VRI rates (RR 0.82, 95% CI: 0.56–1.19). Conclusions: In a large surveillance network, lower HA-VRI rates were seen in pediatric hospitals, teaching hospitals, and in hospitals with higher proportions of single-bed rooms.

Long-term care facilities (LTCFs) were disproportionately impacted during the COVID-19 pandemic. Site-specific wastewater-based surveillance (WBS) offers a non-invasive alternative to traditional mass testing by capturing collective viral loads in wastewater. This study assessed the effectiveness of WBS in detecting new COVID-19 cases in nine Edmonton LTCFs from January 2021 to May 2023. We used constrained distributed lag models to identify critical windows when wastewater viral loads were significantly associated with new cases. Using this critical window, we evaluated the predictive accuracy of wastewater samples for mass testing outcomes. Fisher’s exact test and Mann-Whitney U test compared WBS accuracy for predicting resident vs. staff cases and examined whether factors like sample type, quantity, outbreak duration, or collection timing influenced accuracy. Among 2,515 wastewater samples, 909 were positive, alongside 825 COVID-19 cases identified from 18,226 clinical specimens. Before the clinical testing scale-down in 2022, eight of nine facilities had critical windows within three days. Wastewater collected three days in advance predicted 85% of negative and 60% of positive mass testing outcomes. WBS more accurately predicted resident cases than staff cases (74% vs. 33%, p=0.02). Other factors did not significantly affect prediction accuracy. Findings support using site-specific WBS to enable timely outbreak responses and better testing allocation among vulnerable populations.

Viruses are common causes of acute gastroenteritis worldwide. They are detected in large quantities in raw sewage making them amenable to wastewater-based surveillance (WBS). To monitor the prevalence of gastroenteritis viruses in wastewater and assess their correlation with clinical cases, wastewater samples collected between July 2020 and June 2024 from 12 wastewater treatment plants across Alberta, Canada were analyzed for norovirus (NoV) GI & GII, rotavirus (RoV), adenovirus (AdV), sapovirus (SaV) and astrovirus (AsV). Among the 5726 wastewater samples tested, AdV (80.5%) had the highest detection rate followed by NoV GII (75.6%), SaV (63.2%), NoV GI (59.4%), RoV (42.2%) and AsV (20.2%). Winter and spring seasonality was found for NoV and RoV in both wastewater and clinical disease. Public health interventions especially in the 1st year of the COVID-19 pandemic had a significant impact on their burden with marked reduction in wastewater detected viruses and clinical cases. NoV showed a strong correlation between its level in wastewater and the number of clinical cases, while moderate correlation was observed for the other four viruses. Cross-correlation analysis showed that changes of viral RNA concentration in wastewater lagged behind reported gastroenteritis cases by approximately 6 days to 3 weeks. To our knowledge, this is the longest multi-region WBS study monitoring multiple gastroenteritis viruses spanning both COVID-19 pandemic and post-pandemic periods. The data obtained from this study supported WBS as a complementary tool to track population-based circulation of gastroenteritis viruses, providing actionable public health data.

Background Wastewater-based surveillance can be an important part of pandemic management, especially when testing capacity of individuals is limited. Statistical modeling can be used to examine the relationship between wastewater pathogen levels and clinical cases. The objective of this study was to examine the utility of distributed lag nonlinear modeling to derive the relationship between wastewater SARS-CoV-2 RNA levels and COVID-19 clinical cases across communities in Alberta, Canada when clinical testing was comprehensive.Methods This retrospective cohort study used data from 24-hour composite wastewater collected and tested two to three times per week from 11 wastewater treatment plants (WWTPs) in Alberta, Canada during May 10, 2020, to March 15, 2022. The number of daily new cases of COVID-19 downloaded from Alberta Health's centralized dataset of clinical surveillance of COVID-19 were mapped to each sewershed. Distributed lag nonlinear models were fit to describe the exposure-response relationship between the 7-day rolling average of SARS-CoV-2 RNA and daily new cases for each WWTP separately.Results The 11 WWTPs served a population of 3,422,062 (77% of Alberta's population) and 386,528 cases were documented during the study period. From 2021 onward, peaks in both wastewater viral RNA levels and cases tracked reasonably well. For almost all WWTPs, the best fitting model was a Poisson additive model with a P-spline for time. Models for the larger communities had better fits than smaller communities as represented by adjusted pseudo-R2 ranging from 80.7% to 94.4%. Models followed the same general trends as the actual COVID-19 cases over time.Conclusions With relationships between wastewater viral RNA levels for SARS-CoV-2 and COVID-19 cases expected to vary over time and to be non-linear, distributed lag nonlinear models are promising. While the form of the models was similar across WWTPs, the resulting estimates were different among sites suggesting site-specific analyses are essential.

This study explores antimicrobial use (AMU) in a voluntary sample of Canadian adult hematology/oncology wards between 2018 and 2023. Although use of third- and fourth-generation cephalosporins significantly increased, overall AMU decreased by 25%. As trends change over time, ongoing surveillance is needed to guide AMU optimization in this high-risk setting.

OBJECTIVE:Vancomycin-resistant Enterococcus (VRE) is an important cause of healthcare-associated infections. We adapted wastewater-based surveillance as a tool to longitudinally monitor VRE in hospitals through the detection of vancomycin resistance genes vanA and vanB. METHODS:Wastewater from four tertiary-care hospitals (three adult and one pediatric, totaling >2300 inpatient beds) and all three municipal wastewater treatment plants (WWTP) in Calgary, Canada (∼1.8 million) was sampled weekly (March to September 2022) and every other week (September 2022 to March 2023). Wastewater pellets were collected, DNA extracted, and vanA and vanB quantified by qPCR. vanA and vanB gene copies were assessed as raw (copies/mL) and normalized with three different fecal biomarkers - total bacterial 16S-rRNA, Bacteroides HF183 16S-rRNA, and human 18S-rRNA. Raw and normalized vanA and vanB abundance from each site was compared with clinically identified infections, vancomycin prescribing and hemodialysis services. RESULTS:The abundance of vanA was up to 1085-fold higher (p < 0.0001, Mann-Whitney) and vanB up to 32-fold higher (p < 0.01, Mann-Whitney) in adult hospitals compared to an aggregate municipal signal and exhibited significantly greater variation. Strong correlations between each method of fecal normalization and raw-measured vanA and vanB were observed, and no normalization method proved superior (Spearman's r = 0.50-0.96, p < 0.0001). vanA abundance was strongly correlated with hemodialysis provision (Spearman's r = 0.8357, p < 0.0001) but not vancomycin prescribing. CONCLUSIONS:Wastewater-based surveillance is a comprehensive tool capable of longitudinal real-time hospital surveillance for VRE with the potential to transform the ability of infection control and antimicrobial stewardship programs to dynamically track, understand, and mitigate nosocomial antimicrobial-resistant pathogens.

Understanding factors associated with antimicrobial resistance (AMR) distribution across populations is a necessary step in planning mitigation measures. While associations between AMR and socioeconomic-status (SES), including employment and education have been increasingly recognized in low- and middle-income settings, connections are less clear in high-income countries where SES remains an important influence on other health outcomes. We explored the relationship between SES and AMR in Calgary, Canada using spatially-resolved wastewater-based surveillance of resistomes detected by metagenomics across eight socio-economically diverse urban neighborhoods. Resistomes were established by shotgun-sequencing of wastewater pellets, and qPCR of targeted-AMR genes. SES status was established using 2021 Canadian census data. Conducting this comparison during the height of COVID-related international travel restrictions (Dec. 2020–Oct. 2021) allowed the hypotheses linking SES and AMR to be assessed with limited confounding. These were compared with sewage metagenomes from 244 cities around the world, linked with Human Development Index (HDI). Wastewater metagenomes from Calgary’s socioeconomically diverse neighborhoods exhibit highly similar resistomes, with no quantitative differences (p > 0.05), low Bray-Curtis dissimilarity, and no significant correlations with SES. By comparison, dissimilarity is observed between globally-sourced resistomes (p < 0.05), underscoring the homogeneity of resistomes in Calgary’s sub-populations. The analysis of globally-sourced resistomes alongside Calgary’s resistome further reveals lower AMR burden in Calgary relative to other cities around the world. This is particularly pronounced for the most clinically-relevant AMR genes (e.g., beta-lactamases, macrolide-lincosamide-streptogramin). This work showcases the effectiveness of inclusive and comprehensive wastewater-based surveillance for exploring the interplay between SES and AMR. Antimicrobial resistance (AMR) occurs when antimicrobial treatments fail to work and microbes continue to grow. This is a result of microbes acquiring AMR genes. Antimicrobial resistance (AMR) is an increasing public health threat. Some studies have suggested an association between AMR and socioeconomic factors. The amount of AMR can be monitored by investigating the presence of specific genes indicative of AMR in wastewater. To explore this within a high-income country with publicly funded health care, we collected wastewater from eight socioeconomically diverse neighborhoods across a large Canadian city. Conducted over eleven months during COVID-19-related travel restrictions, we did not observe an association between socioeconomic status of residents and the amount or types of AMR genes in wastewater. We also compared AMR genes from wastewater from cities across the globe, where we observed the presence of AMR genes significantly differed along established socio-economic parameters. Overall, our findings revealed the relationship between AMR genes and socioeconomic factors is dynamic, and context dependent. Lee et al. investigate whether the wastewater resistome of a large Canadian city associates with socioeconomic status (SES) of resident populations using a granular, neighborhood-based approach. No correlation is seen, in contrast with data from other cities around the world, where AMR genes disproportionately concentrate in cities with lower SES.

Abstract Background Hepatitis A virus (HAV) incident infection in Canada is rarely diagnosed (i.e. incidence of 3.6-10 cases/100,000 persons) (PMID: 18159360). Infections generally relate to imported contaminated food-products, or travelers returning from endemic countries. Due to its fecal-oral spread, possible underdiagnosis, and often-cryptic presentation, HAV is an ideal candidate for wastewater (WW)-based surveillance, a tool increasingly utilized to monitor infectious diseases globally.Figure 1.Longitudinal monitoring of HAV RNA wastewater abundance across eight Alberta municipalities over a 4-month period. Methods 24-hour composite WW was collected weekly from eight geographically disparate, and socioeconomically diverse municipal WW treatment plants in Alberta from August to December 2023. After short-term cold storage, WW was centrifuged, and RNA from the raw pellet was extracted using Qiagen’s RNeasy PowerFecal pro. HAV levels were quantified by RT-qPCR of the vp1 gene. 2021 Canadian census data was used to define population demographics for each participating site. Results HAV was detected in 18/117 (15.4%) WW samples and 5/8 (62.5%) municipalities over the 4-month period (Figure 1). RNA abundance in HAV positive WW samples was a median of 3.4 copies/mL (IQR 0.44 - 6.97). Larger population size (p=0.007), and greater density (p=0.001) were associated with increased likelihood of HAV WW detection, whereas social and economic demographics of populations within sewershed catchments did not associate with likelihood of HAV detection (Table 1). Conclusion HAV RNA is rarely detected in the wastewater of Alberta. Detection was more frequently observed in larger municipalities, which is consistent with non-endemic, imported disease. WW surveillance can potentially be adapted to monitor HAV in the context of outbreaks to reduce secondary transmission, and safeguard public health. Disclosures Mark Swain, MD MSc, Abbott: Advisor/Consultant|Advanz: Advisor/Consultant|Gilead, BMS, CymaBay, Intercept, Genfit, Pfizer, Novartis, Astra Zeneca, GSK, Celgene, Novo Nordisk, Axcella Health Inc., Merck, Galectin Therapeutics: Grant/Research Support|GSK: Advisor/Consultant|Ipsen: Advisor/Consultant|Novo Nordisk: Advisor/Consultant Carla Coffin, MD MSc, Altimmune: Grant/Research Support|Gilead: Grant/Research Support|GSK: Grant/Research Support|Janssen: Grant/Research Support Steven J. Drews, PhD FCCM D(ABMM), Abbott: Grant/Research Support|Danaher: Honoraria|Roche: Advisor/Consultant|Roche: Grant/Research Support

Abstract Background Shigatoxin-producing E. coli (STEC) are responsible for significant human morbidity, with the potential to cause severe food-borne illness and outbreaks. STEC incidence varies between communities and peaks in summer months (PMID 31652648). Leveraging a SARS-CoV-2 WBS program, we sought to explore genomic targets for STEC WBS.Figure 1.Prevalence of STEC differs across Alberta’s municipal sewer sheds Methods Composite-24h wastewater (WW) was collected from geographically disparate, and socioeconomically diverse Alberta communities (n=5) at the level of municipal WW treatment plants. From 04/2022-03/2024, monthly WW underwent pelleting and DNA extraction by Qiagen DNeasy PowerSoil Pro kit. WW extracts were assessed for four potential genomic STEC targets: Shiga Toxin 1 (stx1), Shiga Toxin 2 (stx2), Intimin (eae) and LPS O antigen gene specific for O157 (rfbEO157), by multiplex PCR. Each target was normalized by 16S rRNA-for total bacterial burden. WW STEC targets were assessed for correlation using Spearman’s and compared between communities and seasonality (July-Sept vs Jan-Mar) by Mann-Whitney U-test.Figure 2.STEC WBS demonstrates seasonal prevalence trends Results Of 111 WW samples assessed, 108 (97%) were positive for all targets, and individual targets were identified in 110 (99%) stx1; 110 (99%;) stx2; 111 (100%) eae, and 110 (99%) rfbEO157. Gene abundance for each STEC target exhibited strong correlations across sites (stx1 vs stx2, r=0.802, p< 0.0001; stx2 vs rfbEO157, r=0.634, p< 0.0001; eae vs rfbEO157, r =0.551, p< 0.0001; stx2 vs. eae r=0.542, p< 0.0001). WW measured STEC gene targets exhibited significant differences between municipalities (Figure 1) with strong seasonal trends (Figure 2). Conclusion WBS for STEC yielded patterns consistent with established patterns of disease (PMID 31652648). All four STEC genomic targets demonstrated significant correlation across sewersheds. STEC WBS may represent a novel tool to understand and monitor population-level activity and prevent disease. Disclosures All Authors: No reported disclosures

We investigated epidemiologic and molecular characteristics of healthcare-associated (HA) and community-associated (CA) Clostridioides difficile infection (CDI) among adult and pediatric patients in Canadian Nosocomial Infection Surveillance Program hospitals during 2015-2022. Of 30,824 reported CDI cases, 94.9% (29,250/30,824) were among adult (73.2% HA; 26.8% CA) and 5.1% (1,574/30,824) pediatric (77.6% HA; 22.4% CA) patients. During the study period, adult HA CDI rates decreased by 19.9% and CA CDI rates remained stable; pediatric HA CDI rates decreased by 29.6% and CA CDI decreased by 58.3%. Ribotype (RT) 106 was most common among both groups and replaced RT027 as the predominant strain type. RT027 was most associated with adult patients, HA acquisition, severe CDI, and severe outcomes. Moxifloxacin resistance was higher in adult than pediatric cases; clindamycin and rifampin resistance rates were similar between groups. Continued national surveillance is integral to understanding the epidemiology of adult and pediatric CDI in Canada and informing prevention efforts.

Background Ebola virus disease (EVD) is associated with multisystem organ failure and high mortality. Severe hypoglycaemia is common, life-threatening, and correctable in critically ill patients, but glucose monitoring may be limited in EVD treatment units. Methods We conducted a retrospective review of patients admitted to EVD treatment units in Butembo and Katwa, Eastern DRC. Glucose measurements were done using a handheld glucometer at the bedside or using the Piccolo xpress Chemistry Analyzer on venous samples. Findings 384 patients (median age 30 years (interquartile range, IQR, 20-45), 57% female) and 6422 glucose measurements (median 11 per patient, IQR 4-22) were included in the analysis. Severe hypoglycaemia (<= 2.2 mmol/L) and hyperglycaemia (>10 mmol/L) were recorded at least once during the ETU admission in 97 (25%) and 225 (59%) patients, respectively. A total of 2004 infusions of glucose-containing intravenous solutions were administered to 302 patients (79%) with a median cumulative dose of 175g (IQR 100-411). The overall case fatality rate was 157/384 (41%) and was 2.2-fold higher (95% CI 1.3-3.8) in patients with severe hypoglycaemia than those without hypoglycaemia (p = 0.0042). In a multivariable Cox proportional hazards model, periods of severe hypoglycaemia (adjusted hazard ratio (aHR) 6.2, 95% CI 3.2-12, p < 0.0001) and moderate hypoglycaemia (aHR 3.0, 95% CI 1.9-4.8, p < 0.0001) were associated with elevated mortality. Interpretation Hypoglycaemia is common in EVD, requires repeated correction with intravenous dextrose solutions, and is associated with mortality.

Background: The molecular and epidemiological landscape of C. difficile infection (CDI) has evolved markedly in the last decade; however, limited information is available contrasting differences between adult and pediatric populations. We describe a multicenter study evaluating healthcare-associated (HA) and community-associated (CA) adult and pediatric-CDI identified in the Canadian Nosocomial Infection Surveillance Program (CNISP) network from 2015 to 2022. Methods: Hospitalized patients with CDI were identified from up to 84 hospitals between 2015–2022 using standardized case definitions. Cases were confirmed by PCR, cultured, and further characterized using ribotyping and E-test. We used two-tailed tests for significance (p≤0.05). Results: Of 30,817 cases reported, 29,245 were adult cases [HA-CDI (73.2%), CA-CDI (26.8%)] and 1,572 were pediatric cases [HA-CDI (77.7%), CA-CDI (22.3%)]. From 2015 to 2022, HA-CDI rates decreased 19.7% (p=0.007) and 29.4% (p=0.004) in adult and pediatric populations, respectively (Figure 1). CA-CDI rates remained relatively stable in the adult population (p=0.797), while decreasing 60.7% in the pediatric population (p=0.013). Median ages of adult and pediatric patients were 70 (interquartile range (IQR), 58–80) and seven (IQR, 3–13) years, respectively. Thirty-day all-cause mortality was significantly higher among adult vs. Pediatric CDI patients (11.0% vs 1.4%, p < 0.0001). No significant differences in other severe outcomes were found. Ribotyping and susceptibility data were available for 4,620 samples: 3,558 adult (77.0%) and 1,062 pediatric (23.0%). The predominant adult and pediatric ribotypes (RT) were 106 (12.2/16.2%), 027 (11.4/3.2%), and 014 (8.8/8.2%). Overall, RT027 prevalence significantly decreased from 17.9% in 2015 to 3.2% in 2022 (p=0.003), while RT106 increased from 8.5% to 14.4%. Resistance rates among adult and pediatric isolates were similar for all antimicrobials tested except moxifloxacin (16.2% vs. 6.2%, p < 0.0001, respectively). Adult moxifloxacin resistance decreased from 30% to 6.3% from 2015 to 2022 (p=0.006). Adults with moxifloxacin-resistant CDI were older (median: 74 vs. 69 years, p < 0.001) and had higher thirty-day all-cause mortality (13% vs. 9.8%, p=0.041) and recurrence (10% vs. 5.7%, p < 0.001) compared to those with moxifloxacin non-resistant CDI, while these trends were not observed in pediatric patients. Among RT027 strains, moxifloxacin resistance decreased from 91.0% in 2015 to 7.1% in 2022. There was one metronidazole-resistant pediatric sample in 2018 and no resistance to vancomycin or tigecycline in either population. Conclusion: We have found differences in the epidemiological and molecular characteristics of adult and pediatric CDI, with higher thirty-day all-cause mortality among adults. Overall, RT106 has replaced RT027 as the predominant ribotype with a concomitant decrease in fluoroquinolone resistance.

Evidence-based insertion and maintenance bundles are effective in reducing the incidence of central line-associated bloodstream infections (CLABSI) in intensive care unit (ICU) settings. We studied the adoption and compliance of CLABSI prevention bundle programs and CLABSI rates in ICUs in a large network of acute care hospitals across Canada.

Wastewater-based surveillance (WBS) has undergone dramatic advancement in the context of the coronavirus disease 2019 (COVID-19) pandemic. The power and potential of this platform technology were rapidly realized when it became evident that not only did WBS-measured SARS-CoV-2 RNA correlate strongly with COVID-19 clinical disease within monitored populations but also, in fact, it functioned as a leading indicator. Teams from across the globe rapidly innovated novel approaches by which wastewater could be collected from diverse sewersheds ranging from wastewater treatment plants (enabling community-level surveillance) to more granular locations including individual neighborhoods and high-risk buildings such as long-term care facilities (LTCF). Efficient processes enabled SARS-CoV-2 RNA extraction and concentration from the highly dilute wastewater matrix. Molecular and genomic tools to identify, quantify, and characterize SARS-CoV-2 and its various variants were adapted from clinical programs and applied to these mixed environmental systems. Novel data-sharing tools allowed this information to be mobilized and made immediately available to public health and government decision-makers and even the public, enabling evidence-informed decision-making based on local disease dynamics. WBS has since been recognized as a tool of transformative potential, providing near-real-time cost-effective, objective, comprehensive, and inclusive data on the changing prevalence of measured analytes across space and time in populations. However, as a consequence of rapid innovation from hundreds of teams simultaneously, tremendous heterogeneity currently exists in the SARS-CoV-2 WBS literature. This manuscript provides a state-of-the-art review of WBS as established with SARS-CoV-2 and details the current work underway expanding its scope to other infectious disease targets.