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Older adults are at high risk of influenza-related complications or hospitalization. The purpose of this systematic review is to assess the relative cost-effectiveness of all influenza vaccine options for older adults.This systematic review identified economic evaluation studies assessing the cost-effectiveness of influenza vaccines in adults ≥65 years of age from 5 literature databases. Two reviewers independently selected, extracted, and appraised relevant studies using the JBI Critical Appraisal Checklist for Economic Evaluations and Heyland's generalizability checklist. Costs were converted to 2019 Canadian dollars and adjusted for inflation and purchasing power parity.A total of 27 studies were included. There were 18 comparisons of quadrivalent inactivated vaccine (QIV) versus trivalent inactivated vaccine (TIV): 5 showed QIV dominated TIV (ie, lower costs and higher health benefit), and 13 showed the results depended on willingness to pay (WTP). There were 9 comparisons of high-dose TIV (TIV-HD) versus TIV: 5 showed TIV-HD dominated TIV, and 4 showed the results depended on WTP. There were 8 comparisons of adjuvanted TIV (TIV-ADJ) versus TIV: 4 showed TIV-ADJ dominated TIV, and 4 showed the results depended on WTP. There were few pairwise comparisons among QIV, TIV-HD, and TIV-ADJ.The evidence suggests QIV, TIV-HD, and TIV-ADJ are cost-effective against TIV for a WTP threshold of $50 000 per quality-adjusted life-year. Future studies should include new and existing vaccine options for broad age ranges and use more robust methodologies-such as real-world evaluations or modeling studies accounting for methodological, structural, and parameter uncertainty.

Background: Reliable reports on hand hygiene performance throughout the COVID-19 pandemic are lacking as most hospitals continue to rely on direct observation to measure this quality indicator. Using group electronic hand hygiene monitoring, we sought to assess the impact of COVID-19 on adherence to hand hygiene. Methods: Across 12 Ontario hospitals (5 university and 7 community teaching hospitals), a group electronic hand hygiene monitoring system was installed before the pandemic to provide continuous measurement of hand hygiene adherence across 978 ward and 367 critical care beds. We performed an interrupted time-series study of institutional hand hygiene adherence in association with a COVID-19 inpatient census and the Ontario daily count of COVID-19 cases during a baseline period (Nov. 1, 2019, to Feb. 29, 2020), the pre-peak period of the first wave of the pandemic (Mar. 1 to Apr. 24, 2020), and the post-peak period of the first wave (Apr. 25 to July 5, 2020). We used a Poisson regression model to assess the association between the hospital COVID-19 census and institutional hand hygiene adherence while adjusting for the correlation within inpatient units. Results: At baseline, the rate of hand hygiene adherence was 46.0% (6 325 401 of 13 750 968 opportunities) and this improved beginning in March 2020 to a daily peak of 79.3% (66 640 of 84 026 opportunities) on Mar. 30, 2020. Each patient admitted with COVID-19 was associated with improved hand hygiene adherence (incidence rate ratio [IRR] 1.0621, 95% confidence interval [CI] 1.0619–1.0623). Increasing Ontario daily case count was similarly associated with improved hand hygiene (IRR 1.0026, 95% CI 1.0021–1.0032). After peak COVID-19 community and inpatient numbers, hand hygiene adherence declined and returned to baseline. Interpretation: The first wave of the COVID-19 pandemic was associated with significant improvement in hand hygiene adherence, measured using a group electronic monitoring system. Future research should seek to determine whether strategies that focus on health care worker perception of personal risk can achieve sustainable improvements in hand hygiene performance.

ObjectivesThe COVID-19 pandemic has stimulated growing research on treatment options. We aim to provide an overview of the characteristics of studies evaluating COVID-19 treatment.DesignRapid scoping reviewData sourcesMedline, Embase and biorxiv/medrxiv from inception to 15 May 2021.SettingHospital and community care.ParticipantsCOVID-19 patients of all ages.InterventionsCOVID-19 treatment.ResultsThe literature search identified 616 relevant primary studies of which 188 were randomised controlled trials and 299 relevant evidence syntheses. The studies and evidence syntheses were conducted in 51 and 39 countries, respectively.Most studies enrolled patients admitted to acute care hospitals (84%), included on average 169 participants, with an average age of 60 years, study duration of 28 days, number of effect outcomes of four and number of harm outcomes of one. The most common primary outcome was death (32%).The included studies evaluated 214 treatment options. The most common treatments were tocilizumab (11%), hydroxychloroquine (9%) and convalescent plasma (7%). The most common therapeutic categories were non-steroidal immunosuppressants (18%), steroids (15%) and antivirals (14%). The most common therapeutic categories involving multiple drugs were antimalarials/antibiotics (16%), steroids/non-steroidal immunosuppressants (9%) and antimalarials/antivirals/antivirals (7%). The most common treatments evaluated in systematic reviews were hydroxychloroquine (11%), remdesivir (8%), tocilizumab (7%) and steroids (7%).The evaluated treatment was in favour 50% and 36% of the evaluations, according to the conclusion of the authors of primary studies and evidence syntheses, respectively.ConclusionsThis rapid scoping review characterised a growing body of comparative-effectiveness primary studies and evidence syntheses. The results suggest future studies should focus on children, elderly ≥65 years of age, patients with mild symptoms, outpatient treatment, multimechanism therapies, harms and active comparators. The results also suggest that future living evidence synthesis and network meta-analysis would provide additional information for decision-makers on managing COVID-19.

Background: Outbreaks cause significant morbidity and mortality in healthcare settings. Current testing methods can identify specific viral respiratory pathogens, yet the approach to outbreak management remains general. Objectives: Our aim was to examine pathogen-specific trends in respiratory outbreaks, including how attack rates, case fatality rates and outbreak duration differ by pathogen between hospitals and long-term care (LTC) and retirement homes (RH) in Ontario. Methods: Confirmed respiratory outbreaks in Ontario hospitals and LTC/RH reported between September 1, 2007, and August 31, 2017, were extracted from the integrated Public Health Information System (iPHIS). Median attack rates and outbreak duration and overall case fatality rates of pathogen-specific outbreaks were compared in both settings. Results: Over the 10-year surveillance period, 9,870 confirmed respiratory outbreaks were reported in Ontario hospitals and LTC/RH. Influenza was responsible for most outbreaks (32% in LTC/RH, 51% in hospitals), but these outbreaks were shorter and had lower attack rates than most non-influenza outbreaks in either setting. Human metapneumovirus, while uncommon (

Contexte : Les éclosions provoquent une morbidité et une mortalité importantes dans les établissements de soins de santé. Les méthodes de dépistage actuelles permettent de cerner des agents pathogènes respiratoires viraux spécifiques, mais l’approche de la gestion des éclosions reste générale. Objectifs : Notre objectif était d’examiner les tendances spécifiques aux agents pathogènes dans les éclosions respiratoires, y compris la façon dont le taux d’attaque, le taux de létalité et la durée de l’éclosion diffèrent par agent pathogène entre les hôpitaux, et les établissements de soins de longue durée et les maisons de retraite en Ontario. Méthodes : Les éclosions d’infections respiratoires confirmées dans les hôpitaux et les établissements de soins de longue durée ou les maisons de retraite de l’Ontario signalées entre le 1er septembre 2007 et le 31 août 2017 ont été extraites du Système intégré d’information sur la santé publique (SIISP). Les taux d’attaque médians, la durée des éclosions et les taux généraux de létalité des éclosions spécifiques à un pathogène ont été comparés dans les deux types d’établissements. Résultats : Au cours de la période de surveillance de 10 ans, 9 870 éclosions respiratoires confirmées ont été signalées dans les hôpitaux et les établissements de soins de longue durée ou les maisons de retraite de l’Ontario. La grippe était à l’origine de la plupart des éclosions (32 % dans les établissements de soins de longue durée et les maisons de retraite, 51 % dans les hôpitaux), mais ces éclosions étaient plus courtes et présentaient des taux d’attaque inférieurs à ceux de la plupart des éclosions non grippales dans les deux types d’établissements. Le métapneumovirus humain, bien que peu fréquent (moins de 4 % des éclosions), présentait des taux de létalité élevés dans les deux types d’établissements. Conclusion : Les taux d’attaque et les taux de létalité variaient selon l’agent pathogène, tout comme la durée de l’éclosion. L’élaboration de conseils propres à la gestion des éclosions, qui tiennent compte de l’agent pathogène et de l’établissement de soins de santé, pourrait être utile pour limiter la charge des éclosions respiratoires.

BackgroundPost-exposure prophylaxis (PEP) is a well-established strategy for the prevention of infectious diseases, in which recently exposed people take a short course of medication to prevent infection. The primary objective of the COVID-19 Ring-based Prevention Trial with lopinavir/ritonavir (CORIPREV-LR) is to evaluate the efficacy of a 14-day course of oral lopinavir/ritonavir as PEP against COVID-19 among individuals with a high-risk exposure to a confirmed case.MethodsThis is an open-label, multicenter, 1:1 cluster-randomized trial of LPV/r 800/200 mg twice daily for 14 days (intervention arm) versus no intervention (control arm), using an adaptive approach to sample size calculation. Participants will be individuals aged > 6 months with a high-risk exposure to a confirmed COVID-19 case within the past 7 days. A combination of remote and in-person study visits at days 1, 7, 14, 35, and 90 includes comprehensive epidemiological, clinical, microbiologic, and serologic sampling. The primary outcome is microbiologically confirmed COVID-19 infection within 14 days after exposure, defined as a positive respiratory tract specimen for SARS-CoV-2 by polymerase chain reaction. Secondary outcomes include safety, symptomatic COVID-19, seropositivity, hospitalization, respiratory failure requiring ventilator support, mortality, psychological impact, and health-related quality of life. Additional analyses will examine the impact of LPV/r on these outcomes in the subset of participants who test positive for SARS-CoV-2 at baseline. To detect a relative risk reduction of 40% with 80% power atα = 0.05, assuming the secondary attack rate in ring members (p0) = 15%, 5 contacts per case and intra-class correlation coefficient (ICC) = 0.05, we require 110 clusters per arm, or 220 clusters overall and approximately 1220 enrollees after accounting for 10% loss-to-follow-up. We will modify the sample size target after 60 clusters, based on preliminary estimates ofp0, ICC, and cluster size and consider switching to an alternative drug after interim analyses and as new data emerges. The primary analysis will be a generalized linear mixed model with logit link to estimate the effect of LPV/r on the probability of infection. Participants who test positive at baseline will be excluded from the primary analysis but will be maintained for additional analyses to examine the impact of LPV/r on early treatment.DiscussionHarnessing safe, existing drugs such as LPV/r as PEP could provide an important tool for control of the COVID-19 pandemic. Novel aspects of our design include the ring-based prevention approach, and the incorporation of remote strategies for conducting study visits and biospecimen collection.Trial registrationThis trial was registered atwww.ClinicalTrials.gov(NCT04321174) on March 25, 2020.

Background Hand hygiene (HH) is an important patient safety measure linked to the prevention of health care-associated infection, yet how outbreaks affect HH performance has not been formally evaluated. Methods A controlled, interrupted time series was performed across 5 acute-care academic hospitals using group electronic monitoring. This system captures 100% of all hand sanitizer and soap dispenser activations via a wireless signal to a wireless hub; the number of activations is divided by a previously validated estimate of the number of daily HH opportunities per patient bed, multiplied by the hourly census of patients on the unit. Daily HH adherence 60 days prior and 90 days following outbreaks on inpatient units was compared to control units not in outbreaks over the same period, using a Poisson regression model adjusting for correlations within hospitals and units. Predictors of HH improvement were assessed in this multivariate model. Results In the 60 days prior to outbreaks, units destined for outbreaks had significantly lower HH adherence compared to control units (incidence rate ratio [IRR], 0.91; 95% confidence interval [CI], .90–.93; P Conclusions Hospital outbreaks tend to occur in units with lower HH adherence and are associated with rapid improvements in HH performance. Group electronic monitoring of HH could be used to develop novel, prospective feedback interventions designed to avert hospital outbreaks.

Background The objective of this review was to examine the current guidelines for infection prevention and control (IPAC) of coronavirus disease-19 (COVID-19) or other coronaviruses in adults 60 years or older living in long-term care facilities (LTCF). Methods EMBASE, MEDLINE, Cochrane library, pre-print servers, clinical trial registries, and relevant grey literature sources were searched until July 31, 2020, using database searching and an automated method called Continuous Active Learning® (CAL®). All search results were processed using CAL® to identify the most likely relevant citations that were then screened by a single human reviewer. Full-text screening, data abstraction, and quality appraisal were completed by a single reviewer and verified by a second. Results Nine clinical practice guidelines (CPGs) were included. The most common recommendation in the CPGs was establishing surveillance and monitoring systems followed by mandating the use of PPE; physically distancing or cohorting residents; environmental cleaning and disinfection; promoting hand and respiratory hygiene among residents, staff, and visitors; and providing sick leave compensation for staff. Conclusions Current evidence suggests robust surveillance and monitoring along with support for IPAC initiatives are key to preventing the spread of COVID-19 in LTCF. However, there are significant gaps in the current recommendations especially with regard to the movement of staff between LTCF and their role as possible transmission vectors. Systematic review registration PROSPERO CRD42020181993

BACKGROUND: In pandemics, local hospitals need to anticipate a surge in health care needs. We examined the modelled surge because of the coronavirus disease 2019 (COVID-19) pandemic that was used to inform the early hospital-level response against cases as they transpired. METHODS: To estimate hospital-level surge in March and April 2020, we simulated a range of scenarios of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spread in the Greater Toronto Area (GTA), Canada, using the best available data at the time. We applied outputs to hospital-specific data to estimate surge over 6 weeks at 2 hospitals (St. Michael’s Hospital and St. Joseph’s Health Centre). We examined multiple scenarios, wherein the default (R(0) = 2.4) resembled the early trajectory (to Mar. 25, 2020), and compared the default model projections with observed COVID-19 admissions in each hospital from Mar. 25 to May 6, 2020. RESULTS: For the hospitals to remain below non-ICU bed capacity, the default pessimistic scenario required a reduction in non-COVID-19 inpatient care by 38% and 28%, respectively, with St. Michael’s Hospital requiring 40 new ICU beds and St. Joseph’s Health Centre reducing its ICU beds for non-COVID-19 care by 6%. The absolute difference between default-projected and observed census of inpatients with COVID-19 at each hospital was less than 20 from Mar. 25 to Apr. 11; projected and observed cases diverged widely thereafter. Uncertainty in local epidemiological features was more influential than uncertainty in clinical severity. INTERPRETATION: Scenario-based analyses were reliable in estimating short-term cases, but would require frequent re-analyses. Distribution of the city’s surge was expected to vary across hospitals, and community-level strategies were key to mitigating each hospital’s surge.

Background The current approach to measuring hand hygiene (HH) relies on human auditors who capture Methods A stepped-wedge cluster randomized quality improvement study was performed on 26 inpatient medical and surgical units across 5 acute care hospitals in Ontario, Canada. The intervention involved daily HH reporting as measured by group electronic monitoring to guide unit-led improvement strategies. The primary outcome was monthly HH adherence (percentage) between baseline and intervention. Secondary outcomes included transmission of antibiotic-resistant organisms such as methicillin-resistant Staphylococcus aureus (MRSA) and other healthcare-associated infections. Results After adjusting for the correlation within inpatient units and hospitals, there was a significant overall improvement in HH adherence associated with the intervention (incidence rate ratio [IRR], 1.73 [95% confidence interval {CI}, 1.47–1.99]; P Conclusions The introduction of a system for group electronic monitoring led to rapid, significant improvements in HH performance within a 2-year period. This method offers significant advantages over direct observation for measurement and improvement of HH.

IntroductionCOVID-19 vaccines require enhanced safety monitoring after emergency approval. The Canadian National Vaccine Safety Network monitors the safety of COVID-19 vaccines and provides enhanced monitoring for healthy, auto-immune, immunocompromised, pregnant and breastfeeding populations and allows for the detection of safety signals.Methods and analysisOnline participant reporting of health events in vaccinated and unvaccinated individuals 12 years of age and older is captured in three surveys: 1 week after dose 1, 1 week after dose 2 and 7 months after dose 1. Medically attended events are followed up by telephone. The number, percentage, rate per 10 000 and incident rate ratios with 95% CIs are calculated by health event, vaccine type, sex and in 10-year age groups.Ethics and disseminationEach study site has Research Ethics Board approvals for the project (UBC Children’s & Women’s, CIUSSS de l'Estrie—CHUS, Health PEI, Conjoint Health Research Ethics Board, University of Calgary and Alberta Health Services, IWK Health, Unity Health Toronto and CHU de Québec-Université Laval Research Ethics Boards). Individuals are invited to participate in this active surveillance and electronic consent is given before proceeding to each survey. Weekly reports are shared with public health and posted on the study website. At least one peer-reviewed manuscript is produced.

The IR Biotyper and matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) using ClinProTools software (MALDI-TOF MS–ClinProTools) are two novel typing methods that rely on the analysis of carbohydrate and peptide residues in intact bacterial cells. These two methods have shown promising results in the rapid and accurate typing of bacteria. In this study, we evaluated these novel typing methods in comparison with genotypic typing for cluster analysis of Burkholderia cenocepacia epidemic strain ET12, isolated from adult cystic fibrosis patients. Sixty-six isolates of B. cenocepacia were used in this study, 35 of which were identified as the ET12 strain and 31 as non-ET12 strains by repetitive-element PCR (rep-PCR). Twelve isolates were used for the creation of typing models using IR Biotyper and MALDI-TOF MS–ClinProTools, and 54 isolates were used for external validation of the typing models. The IR Biotyper linear discriminant analysis (LDA) model had a diagnostic sensitivity of 84.6% for typing the epidemic strain, ET12. At a cutoff of 70%, MALDI-TOF MS–ClinProTools had 87.5% diagnostic sensitivity in detecting the ET12 strain (P = 1.00). Both methods had a diagnostic specificity of ≥80% for detecting the ET12 strain. In conclusion, IR Biotyper and MALDI-TOF MS–ClinProTools offer rapid typing using proteomics and analysis of small cellular molecules with a low running cost. Our pilot study showed suboptimal accuracy of both methods for typing outbreak strains of B. cenocepacia. Extending the spectral region analyzed by the IR Biotyper can improve the accuracy and has the potential of improving the generalizability of this technique for typing other organisms. IMPORTANCE Respiratory infections due to Burkholderia cenocepacia, particularly the ET12 epidemic strain, are considered sentinel events for persons with cystic fibrosis, as they are often associated with person-to-person transmission and accelerated decline in lung function and early mortality. Current typing methods are generally only available at reference centers, with long turn-around-times, which can affect the identification of outbreaks and critical patient triage. This pilot study aims to add to the growing literature illustrating the potential utility of Fourier transform infrared spectroscopy (FTIR), a novel rapid method, for the successful typing of clinically significant bacteria. In this study, we evaluated its utility to discriminate between the ET12 clone and non-ET12 isolates of B. cenocepacia and compared it to proteomics cluster analysis using MALDI-TOF MS and ClinProTools software. Both methods had encouraging but suboptimal accuracy (≥85% sensitivity and ≥83% specificity), which will likely be improved by extending the spectral region analyzed by the IR Biotyper with updated software.

Background:Healthcare workers (HCWs) are at risk of acquiring and transmitting respiratory viruses while working in healthcare settings.Objectives:To investigate the incidence of and factors associated with HCWs working during an acute respiratory illness (ARI).Methods:HCWs from 9 Canadian hospitals were prospectively enrolled in active surveillance for ARI during the 2010–2011 to 2013–2014 influenza seasons. Daily illness diaries during ARI episodes collected information on symptoms and work attendance.Results:At least 1 ARI episode was reported by 50.4% of participants each study season. Overall, 94.6% of ill individuals reported working at least 1 day while symptomatic, resulting in an estimated 1.9 days of working while symptomatic and 0.5 days of absence during an ARI per participant season. In multivariable analysis, the adjusted relative risk of working while symptomatic was higher for physicians and lower for nurses relative to other HCWs. Participants were more likely to work if symptoms were less severe and on the illness onset date compared to subsequent days. The most cited reason for working while symptomatic was that symptoms were mild and the HCW felt well enough to work (67%). Participants were more likely to state that they could not afford to stay home if they did not have paid sick leave and were younger.Conclusions:HCWs worked during most episodes of ARI, most often because their symptoms were mild. Further data are needed to understand how best to balance the costs and risks of absenteeism versus those associated with working while ill.

Background: People receiving in-center hemodialysis face a high risk for contracting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and experience poor outcomes. During the first wave of the coronavirus disease 2019 (COVID-19) pandemic in Ontario (between March and June 2020), it was unclear whether asymptomatic or presymptomatic cases were common and whether widespread testing of all dialysis patients and staff would identify cases earlier and prevent transmission. Ontario has a population of about 14.5 million. Approximately 8900 people receive dialysis across 102 in-center dialysis units. Objective: The objective of this study was to determine participation rates for patients and staff in point prevalence testing in dialysis units across the province and to determine the prevalence of asymptomatic or presymptomatic infection. Design: Cross-sectional study design. Setting: In-center hemodialysis units at 27 renal programs across Ontario. Participants: Patients and staff in in-center dialysis units in Ontario. Measurements: Participation rates, demographic data, SARS-CoV-2 positivity rates, and COVID-19-related symptom data. Methods: From June 8 to 30, 2020, all in-center dialysis patients and staff in the Province of Ontario were requested to undergo a symptom screening assessment and nasopharyngeal swab. Testing was done using polymerase chain reaction to detect SARS-CoV-2. A standardized questionnaire of atypical and typical COVID-19-related symptoms was administered to patients, to assess for new or worsening COVID-19-related symptoms. Results: Patient participation was 83% (7155 of 8612) of which 15 tests were positive: less than 5 (Limitations: As point prevalence testing was voluntary, not all patients and staff participated. Lower participation rate may be due to decreasing new cases in Ontario, and testing or pandemic fatigue, among other factors. This study did not use serology to identify prior infections because it was not widely available in Ontario. With respect to the standardized symptom questionnaire, it was only available in English and French and could not be tested due to the urgency of the initiative. Conclusions: Participation among patients in point prevalence testing was good, but participation among staff was relatively low. Asymptomatic positivity in the dialysis patient and staff population was rare during the first wave of the COVID-19 pandemic in Ontario.

Surveillance data from Southern Ontario show that a majority of Verona Integron-encoded Metallo-β-lactamase (VIM)-producing Enterobacteriaceae are locally acquired. To better understand the local epidemiology, we analysed clinical and environmental blaVIM-positive Enterobacteriaceae from the area. Clinical samples were collected within the Toronto Invasive Bacterial Diseases Network (2010–2016); environmental water samples were collected in 2015. We gathered patient information on place of residence and hospital admissions prior to the diagnosis. Patients with and without plausible source of acquisition were compared regarding risk exposures. Microbiological isolates underwent whole-genome sequencing (WGS); blaVIM carrying plasmids were characterized. We identified 15 patients, thereof 11 with blaVIM-1-positive Enterobacter hormaechei within two genetic clusters based on WGS. Whereas no obvious epidemiologic link was identified among cluster I patients, those in cluster II were connected to a hospital outbreak. Except for patients with probable acquisition abroad, we did not identify any further risk exposures. Two blaVIM-1-positive E. hormaechei from environmental waters matched with the clinical clusters; plasmid sequencing suggested a common ancestor plasmid for the two clusters. These data show that both clonal spread and horizontal gene transfer are drivers of the dissemination of blaVIM-1-carrying Enterobacter hormaechei in hospitals and the aquatic environment in Southern Ontario, Canada.

Background Data on household transmission of carbapenemase-producing Enterobacterales (CPE) remain limited. We studied risk of CPE household co-colonization and transmission in Ontario, Canada. Methods We enrolled CPE index cases (identified via population-based surveillance from January 2015 to October 2018) and their household contacts. At months 0, 3, 6, 9, and 12, participants provided rectal and groin swabs. Swabs were cultured for CPE until September 2017, when direct polymerase chain reaction (PCR; with culture of specimens if a carbapenemase gene was detected) replaced culture. CPE risk factor data were collected by interview and combined with isolate whole-genome sequencing to determine likelihood of household transmission. Risk factors for household contact colonization were explored using a multivariable logistic regression model with generalized estimating equations. Results Ninety-five households with 177 household contacts participated. Sixteen (9%) household contacts in 16 (17%) households were CPE-colonized. Household transmission was confirmed in 3/177 (2%) cases, probable in 2/177 (1%), possible in 9/177 (5%), and unlikely in 2/177 (1%). Household contacts were more likely to be colonized if they were the index case’s spouse (odds ratio [OR], 6.17; 95% confidence interval [CI], 1.05–36.35), if their index case remained CPE-colonized at household enrollment (OR, 7.00; 95% CI, 1.92–25.49), or if they had at least 1 set of specimens processed after direct PCR was introduced (OR, 6.46; 95% CI, 1.52–27.40). Conclusions Nine percent of household contacts were CPE-colonized; 3% were a result of household transmission. Hospitals may consider admission screening for patients known to have CPE-colonized household contacts.

BackgroundA hospital-level pandemic response involves anticipating local surge in healthcare needs.MethodsWe developed a mechanistic transmission model to simulate a range of scenarios of COVID-19 spread in the Greater Toronto Area. We estimated healthcare needs against 2019 daily admissions using healthcare administrative data, and applied outputs to hospital-specific data on catchment, capacity, and baseline non-COVID admissions to estimate potential surge by day 90 at two hospitals (St. Michael’s Hospital [SMH] and St. Joseph’s Health Centre [SJHC]). We examined fast/large, default, and slow/small epidemics, wherein the default scenario (R0 2.4) resembled the early trajectory in the GTA.ResultsWithout further interventions, even a slow/small epidemic exceeded the city’s daily ICU capacity for patients without COVID-19. In a pessimistic default scenario, for SMH and SJHC to remain below their non-ICU bed capacity, they would need to reduce non-COVID inpatient care by 70% and 58% respectively. SMH would need to create 86 new ICU beds, while SJHC would need to reduce its ICU beds for non-COVID care by 72%. Uncertainty in local epidemiological features was more influential than uncertainty in clinical severity. If physical distancing reduces contacts by 20%, maximizing the diagnostic capacity or syndromic diagnoses at the community-level could avoid a surge at each hospital.InterpretationAs distribution of the city’s surge varies across hospitals over time, efforts are needed to plan and redistribute ICU care to where demand is expected. Hospital-level surge is based on community-level transmission, with community-level strategies key to mitigating each hospital’s surge.

We analyzed population-based surveillance data from the Toronto Invasive Bacterial Diseases Network to describe carbapenemase-producing Enterobacteriaceae (CPE) infections during 2007-2015 in south-central Ontario, Canada. We reviewed patients' medical records and travel histories, analyzed microbiologic and clinical characteristics of CPE infections, and calculated incidence. Among 291 cases identified, New Delhi metallo-β-lactamase was the predominant carbapenemase (51%). The proportion of CPE-positive patients with prior admission to a hospital in Canada who had not received healthcare abroad or traveled to high-risk areas was 13% for patients with oxacillinase-48, 24% for patients with New Delhi metallo-β-lactamase, 55% for patients with Klebsiella pneumoniae carbapenemase, and 67% for patients with Verona integron-encoded metallo-β-lactamase. Incidence of CPE infection increased, reaching 0.33 cases/100,000 population in 2015. For a substantial proportion of patients, no healthcare abroad or high-risk travel could be established, suggesting CPE acquisition in Canada. Policy and practice changes are needed to mitigate nosocomial CPE transmission in hospitals in Canada.

We analyzed population-based surveillance data from the Toronto Invasive Bacterial Diseases Network to describe carbapenemase-producing Enterobacteriaceae (CPE) infections during 2007–2015 in south-central Ontario, Canada. We reviewed patients’ medical records and travel histories, analyzed microbiologic and clinical characteristics of CPE infections, and calculated incidence. Among 291 cases identified, New Delhi metallo-β-lactamase was the predominant carbapenemase (51%). The proportion of CPE-positive patients with prior admission to a hospital in Canada who had not received healthcare abroad or traveled to high-risk areas was 13% for patients with oxacillinase-48, 24% for patients with New Delhi metallo-β-lactamase, 55% for patients with Klebsiella pneumoniae carbapenemase, and 67% for patients with Verona integron-encoded metallo-β-lactamase. Incidence of CPE infection increased, reaching 0.33 cases/100,000 population in 2015. For a substantial proportion of patients, no healthcare abroad or high-risk travel could be established, suggesting CPE acquisition in Canada. Policy and practice changes are needed to mitigate nosocomial CPE transmission in hospitals in Canada.

Background Antimicrobial stewardship programs (ASPs) using audit and feedback in the intensive care unit (ICU) setting can reduce harms related to inappropriate antibiotic use. However, inappropriate discontinuation or narrowing of antibiotic treatment could increase infection-related mortality in this population. Individual ASP studies are underpowered to detect differences in mortality. Methods We conducted a systematic review and meta-analysis of audit and feedback in the ICU setting, using mortality as our outcome. Results Of 2447 citations, 11 studies met our inclusion criteria. Although a variety of study designs were used to assess reductions in antibiotic use, mortality was analyzed using an uncontrolled before-after study design in all studies. Five studies directed audit and feedback to all or most ICU patients receiving antibiotics and measured overall ICU mortality. In the meta-analysis of these studies, the pooled relative risk of ICU mortality was 1.03 (95% confidence interval, .93-1.14). A second meta-analysis of 3 smaller studies that evaluated mortality only in patients directly assessed by the ASP found a pooled relative risk of ICU mortality of 1.06 (95% confidence interval, .80 to 1.4). Three studies were not appropriate for meta-analysis, but their results were consistent with our overall findings. Conclusions Our systematic review did not identify a change in mortality associated with antimicrobial stewardship using audit and feedback in the ICU setting. These results increase our confidence that audit and feedback can be safely implemented in this setting. Future studies should report standardized estimates of mortality and use more robust study designs to assess mortality, when feasible.

Background Influenza vaccine coverage rates among healthcare workers (HCWs) in acute care facilities in Canada remain below national targets. Objective To determine factors associated with influenza vaccine uptake among HCWs. Methods This secondary analysis of a prospective cohort study included HCWs aged 18-69 years, working ≥20 h/wk in a Canadian acute care hospital. Questionnaires were administered to participants in the fall of the season of participation (2011/12-2013/14) which captured demographic/household characteristics, medical histories, occupational, behavioural and risk factors for influenza. Generalized estimating equation logistic regression was used to determine factors associated with vaccine uptake in the season of participation. Results The adjusted odds ratio for influenza vaccination in the current season was highest for those vaccinated in 3 of 3 previous seasons (OR 156; 95% CI 98, 248) followed by those vaccinated in 2 of 3 and 1 of 3 previous seasons when compared with those not vaccinated. Compared with nurses, physicians (OR 4.2; 95% CI 1.4, 13.2) and support services staff (OR 1.8; 95% CI 1.3, 2.4) had higher odds ratios for vaccine uptake. Conversely, HCWs identifying as Black had lower odds of uptake compared with those with European ancestry (OR 0.44, 95% CI 0.26-0.75) when adjusted for other factors in the model. Conclusion Healthcare workers differ in their annual uptake of influenza vaccine based on their past vaccination history, occupation and ethnicity. These findings indicate a need to determine whether there are other vaccine-hesitant groups within healthcare settings and learn which approaches are successful in increasing their uptake of influenza vaccines.

Objectives To determine whether a smartphone app, containing local bacterial resistance patterns (antibiogram) and treatment guidelines, improved knowledge of prescribing antimicrobials among medical trainees. Methods We conducted a prospective, controlled, pre-post study of medical trainees with access to a smartphone app (app group) containing our hospital's antibiogram and treatment guidelines compared to those without access (control group). Participants completed a survey which included a knowledge assessment test (score range, 0 [lowest possible score] to 12 [highest possible score]) at the start of the study and four weeks later. The primary outcome was change in mean knowledge assessment test scores between week 0 and week 4. Change in knowledge assessment test scores in the app group were compared to the difference in scores in the control group using multivariable linear regression. Results Sixty-two residents and senior medical students participated in the study. In a multivariable analysis controlling for sex and prior knowledge, app use was associated with a 1.1 point (95% CI: 0.10, 2.1) [β = 1.08, t(1) = 2.08, p = 0.04] higher change in knowledge score compared to the change in knowledge scores in the control group. Among those in the app group, 88% found it easy to navigate, 85% found it useful, and about one- quarter used it daily. Conclusions An antibiogram and treatment algorithm app increased knowledge of prescribing antimicrobials in the context of local antibiotic resistance patterns. These findings reinforce the notion that smartphone apps can be a useful and innovative means of delivering medical education.

Background The hospital water environment is a CPE reservoir, and transmission of CPE from drains to patients is a risk. Methods We cultured sink and shower drains in patient rooms and communal shower rooms that were exposed to inpatients with CPE colonization/infection from October 2007 to December 2017 at 10 hospitals. We compared patient room drain CPE to prior room occupant CPE using Illumina and MinION whole-genome sequencing. Results Three-hundred and ten inpatients exposed 1,209 drains, of which 53 (4%) yielded 62 CPE isolates at 7 (70%) hospitals. Compared to room occupant CPE isolates, drain CPE isolates were more likely Enterobacter spp. (6, 10% vs. 25, 51%, p< 0.0001) or KPC-producers (9, 15% vs. 23, 47%, p=0.0002). Of the 49 CPE isolates in patient room drains, 4 (8%) were linked to a prior room occupant (Table), 24 (49%) had the same carbapenemase as a prior room occupant but isolates/carbapenemase gene-containing plasmids that were unrelated, and 21 (43%) did not share a carbapenemase with a prior room occupant. The 4 drains linked to prior room occupants were likely contaminated by these room occupants, who were CPE-colonized prior to drain exposure. Despite few links between drain and room occupant CPE, there were 10 isolates harbouring related blaNDM-1-containing IncHI2A/HI2-type plasmids in 8 rooms on two units at one hospital. Nine of these were Enterobacter hormaechei ST66 isolates that were 0 to 6 SNVs apart and one was a Klebsiella oxytoca STnovel isolate. Table. Four patient room drain CPE isolates (D1b, D4, D5, D12) and isolates from prior room occupants that they were related to by whole-genome sequencing. Conclusion It was uncommon for drain CPE to be linked to prior patient exposure. This suggests contamination of most drains by undetected colonized patients and a need for more aggressive patient screening in our hospitals. This may also suggest retrograde (drain-to-drain) transmission, especially considering the 10 isolate drain cluster at one hospital. Reasons for the preponderance of Enterobacter spp. in drains requires further study. Disclosures Allison McGeer, MD, FRCPC, GlaxoSmithKline (Advisor or Review Panel member, Research Grant or Support)Merck (Advisor or Review Panel member, Research Grant or Support)Pfizer (Research Grant or Support)

Background: The current approach to measuring hand hygiene (HH) relies on human auditors who capture Methods: A stepped-wedge cluster randomized quality improvement study was undertaken across 5 acute-care hospitals in Ontario, Canada. Overall, 746 inpatient beds were electronically monitored across 26 inpatient medical and surgical units. Daily HH performance as measured by group electronic monitoring was reported to inpatient units who discussed results to guide unit-led improvement strategies. The primary outcome was monthly HH adherence (%) between baseline and intervention. Secondary outcomes included transmission of antibiotic resistant organisms such as methicillin resistant Staphylococcus aureus (MRSA) and other healthcare-associated infections. Results: After adjusting for the correlation within inpatient units, there was a significant overall improvement in HH adherence associated with the intervention (IRR, 1.73; 95% CI, 1.47–1.99; P < .0001). Monthly HH adherence relative to the intervention increased from 29% (1,395,450 of 4,544,144) to 37% (598,035 of 1,536,643) within 1 month, followed by consecutive incremental increases up to 53% (804,108 of 1,515,537) by 10 months (P < .0001). We identified a trend toward reduced healthcare-associated transmission of MRSA (0.74; 95% CI, 0.53–1.04; P = .08). Conclusions: The introduction of a system for group electronic monitoring led to rapid, significant, and sustained improvements in HH performance within a 2-year period.Funding: NoneDisclosures: None

Background Prosthetic hip and knee joint infections (PJIs) are challenging to eradicate despite prosthesis removal and antibiotic therapy. There is a need to understand risk factors for PJI treatment failure in the setting of prosthesis removal. Methods A retrospective cohort of individuals who underwent prosthesis removal for a PJI at 5 hospitals in Toronto, Canada, from 2010 to 2014 was created. Treatment failure was defined as recurrent PJI, amputation, death, or chronic antibiotic suppression. Potential risk factors for treatment failure were abstracted by chart review and assessed using a Cox proportional hazards model. Results A total of 533 individuals with prosthesis removal were followed for a median (interquartile range) of 814 (235–1530) days. A 1-stage exchange was performed in 19% (103/533), whereas a 2-stage procedure was completed in 88% (377/430). Treatment failure occurred in 24.8% (132/533) at 2 years; 53% (56/105) of recurrent PJIs were caused by a different bacterial species. At 4 years, treatment failure occurred in 36% of 1-stage and 32% of 2-stage procedures (P = .06). Characteristics associated with treatment failure included liver disease (adjusted hazard ratio [aHR], 3.12; 95% confidence interval [CI], 2.09–4.66), the presence of a sinus tract (aHR, 1.53; 95% CI, 1.12–2.10), preceding debridement with prosthesis retention (aHR, 1.68; 95% CI, 1.13–2.51), a 1-stage procedure (aHR, 1.72; 95% CI, 1.28–2.32), and infection due to Gram-negative bacilli (aHR, 1.35; 95% CI, 1.04–1.76). Conclusions Failure of PJI therapy is common, and risk factors are not easily modified. Improvements in treatment paradigms are needed, along with efforts to reduce orthopedic surgical site infections., Prosthetic joint infections are challenging to eradicate and in this retrospective cohort the characteristics associated with treatment failure included liver disease, presence of a sinus tract, prior debridement with prosthesis retention, a one-stage procedure, and infection with a Gram-negative bacilli.

Background Timely strain typing of group A Streptococci (GAS) is necessary to guide outbreak recognition and investigation. We evaluated the use of (matrix-assisted laser desorption ionization time-of-flight mass spectrometry) combined with cluster analysis software to rapidly distinguish between related and unrelated GAS isolates in real-time. Methods We developed and validated a typing model using 177 GAS isolates with known emm types. The typing model was created using 43 isolates, which included 8 different emm types, and then validated using 134 GAS isolates of known emm types that were not included in model generation. Results Twelve spectra were generated from each isolate during validation. The overall accuracy of the model was 74% at a cutoff value of 80%. The model performed well with emm types 4, 59, and 74 but showed poor accuracy for emm types 1, 3, 12, 28, and 101. To evaluate the ability of this tool to perform typing in an outbreak situation, we evaluated a virtual outbreak model using a “virtual outbreak strain; emm74” compared with a non-outbreak group or an “outgroup “ of other emm types. External validation of this model showed an accuracy of 91.4%. Conclusions This approach has the potential to provide meaningful information that can be used in real time to identify and manage GAS outbreaks. Choosing isolates characterized by whole genome sequencing rather than emm typing for model generation should improve the accuracy of this approach in rapidly identifying related and unrelated GAS strains.

Rationale & Objective Hemodialysis patients are at increased risk for COVID-19 transmission due, in part, to difficulty maintaining physical distancing. Our hemodialysis unit experienced a COVID-19 outbreak despite following symptom-based screening guidelines. We describe the course of the COVID-19 outbreak and the infection control measures taken for mitigation. Study Design Retrospective cohort study Setting & Participants 237 maintenance hemodialysis patients and 93 hemodialysis staff at a single hemodialysis centre in Toronto, Canada. Exposure Universal screening of patients and staff with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Outcomes The primary outcome was detection of SARS-CoV-2 in nasopharyngeal samples from patients and staff using reverse transcriptase-polymerase chain reaction (RT-PCR) . Analytical Approach Descriptive statistics were used for clinical characteristics and the primary outcome. Results Eleven (4.6%) of 237 hemodialysis patients and 11 of 93 (12%) staff members had a positive RT-PCR test for SARS-CoV-2. Among individuals testing positive, 12 of 22 (55%) were asymptomatic at time of testing, and 7 of 22 (32%) were asymptomatic for the duration of follow-up. One patient was hospitalized at the time of SARS-CoV-2 infection and four additional patients with positive tests were subsequently hospitalized. Two patients (18%) required admission to the intensive care unit. After 30 days follow-up no patients had died or required mechanical ventilation. No hemodialysis staff required hospitalization. Universal droplet and contact precautions were implemented during the outbreak. Hemodialysis staff with SARS-CoV-2 infection were placed on home quarantine regardless of symptom status. Patients with SARS-CoV-2 infection including asymptomatic individuals were treated with droplet and contact precautions until confirmation of negative SARS-CoV-2 RT-PCR testing. Analysis of the outbreak identified two index cases with subsequent nosocomial transmission within the dialysis unit and in shared shuttle buses to the hemodialysis unit. Limitations Single centre study. Conclusions Universal SARS-CoV-2 testing and universal droplet and contact precautions in the setting of an outbreak appeared to be effective in preventing further transmission., Graphical abstract, Plain Language Summary: The COVID-19 pandemic has presented unique challenges to patients on hemodialysis. Despite having risk factors for severe infection, dialysis patients must visit healthcare facilities thrice weekly, where physical distancing is challenging. Despite protocols in place to identify and isolate symptomatic individuals, we report a COVID-19 outbreak in a hemodialysis unit in Toronto, Ontario, which prompted the screening of all hemodialysis patients and most staff for SARS-CoV-2 infection detected in nasopharyngeal swabs specimens, regardless of symptoms. Eleven of 237 (4.6%) hemodialysis patients and 11 of 93 (12%) of staff tested positive for COVID-19. Notably 55% of those testing positive were asymptomatic at the time of testing. This study demonstrates the importance of universal testing in stopping the spread of COVID-19 during an outbreak.

The epidemiology of Clostridioides difficile infection (CDI) has drastically changed since the emergence of the epidemic strain BI/NAP1/027, also known as ribotype 027 (R027). However, the relationship between the infecting C. difficile strain and clinical outcomes is still debated. We hypothesized that certain subpopulations of R027 isolates could be associated with unfavorable outcomes. We applied high-resolution multilocus variable-number tandem-repeat analysis (MLVA) to characterize C. difficile R027 isolates collected from confirmed CDI patients recruited across 10 Canadian hospitals from 2005 to 2008. PCR ribotyping was performed first to select R027 isolates that were then analyzed by MLVA (n = 450). Complicated CDI (cCDI) was defined by the occurrence of any of admission to an intensive care unit, colonic perforation, toxic megacolon, colectomy, and if CDI was the cause or contributed to death within 30 days after enrollment. Three major MLVA clusters were identified, MC-1, MC-3, and MC-10. MC-1 and MC-3 were exclusive to Quebec centers, while MC-10 was found only in Ontario. Fewer cases infected with MC-1 developed cCDI (4%) than those infected with MC-3 and MC-10 (15% and 16%, respectively), but a statistically significant difference was not reached. Our data did not identify a clear association between subpopulations of R027 and different clinical outcomes; however, the data confirmed the utility of MLVA’s higher discrimination potential to better characterize CDI populations in an epidemiological analysis. For a patient with CDI, the progression toward an unfavorable outcome is a complex process that probably includes several interrelated strain and host characteristics.

To compare immunogenicity, reactogenicity and acceptability of high- and standard-dose trivalent inactivated influenza vaccine (HDTIV, SDTIV) in 18- to 64-year-olds.We randomized 18- to 64-year-olds to HDTIV or SDTIV in two consecutive years. We collected serum on days 0 and 21, measured haemagglutination inhibition geometric mean titres (GMT) and compared seroconversion, day 21 titres, seroprotection, reactogenicity and acceptability.Immunogenicity was evaluable in 42 of 47 2014 participants, all 33 both-year participants and 87 of 90 2015-only participants. First-dose HDTIV recipients experienced seroconversion more frequently than SDTIV recipients to A(H3N2) in 2014 (13/21, 62% vs. 4/21, 19%, p 0.01) and to all vaccine strains in 2015: (A(H1N1): 24/42, 57% vs. 15/59, 25%; A(H3N2): 42/42, 100% vs. 47/59, 80%; B: 25/42, 60% vs. 13/59, 22%; all p0.01). Day 21 haemagglutination inhibition GMT were higher in first and two sequential-year HDTIV vs. SDTIV recipients: A(H1N1): GMT 749 and 768 vs. 384 (p0.0001, p 0.002); A(H3N2): 1238 and 956 vs. 633 (p 0.0003, p 0.1); and B: 1113 and 1086 vs. 556 (p 0.0005, p 0.02). HDTIV was more reactogenic (local pain score 3 vs. 1 of 10 on day 0/1, p 0.0003), but recipients were equally willing to be revaccinated (HDTIV: 76/83 (92%); SDTIV: 76/80 (95%), p 0.54). The ratios of day 21 GMT in SDTIV recipients vaccinated in 0 to 4 prior years to those in SDTIV and HDTIV recipients vaccinated in 15 or more prior years were A(H1N1): 3.73 and 1.38; A(H3N2) 3.07 and 1.16; and B: 2.01 and 1.21.HDTIV is more immunogenic and reactogenic and as acceptable as SDTIV in 18- to 64-year-olds.

Background Data are limited on risk factors for vancomycin-resistant Enterococcus (VRE) bacteremia. Methods All patients with a confirmed VRE bacteremia in Ontario, Canada, between January 2009 and December 2013 were linked to provincial healthcare administrative data sources and frequency matched to 3 controls based on age, sex, and aggregated diagnosis group. Associations between predictors and VRE bacteremia were estimated by generalized estimating equations and summarized using odds ratios (ORs) and corresponding 95% confidence intervals (CIs). Results In total, 217 cases and 651 controls were examined. In adjusted analyses, patient-level predictors included bone marrow transplant (OR 106.99 [95% CI 12.19–939.26]); solid organ transplant (OR 17.17 [95% CI 4.95–59.54]); any cancer (OR 8.64 [95% CI 3.88–19.21]); intensive care unit (ICU) admission (OR 6.81 [95% CI 3.53–13.13]); heart disease (OR 5.27 [95% CI 2.00–13.90]); and longer length of stay (OR 1.07 per day [95% CI 1.06–1.09]). Hospital-level predictors included hospital size (per increase in 100 beds (OR 1.26 [95% CI 1.07–1.48]) and teaching hospitals (OR 3.87 [95% CI 1.85–8.08]). Conclusions Patients with a bone marrow transplant, solid organ transplant, cancer, or who are admitted to the ICU are at highest risk of VRE bacteremia, particularly at large hospitals and teaching hospitals.

Background Though CPE in Canada are mainly acquired abroad, outbreaks/transmission in Canadian hospitals have been reported. We determined the incidence of HA CPE in southern Ontario, Canada, to inform prevention and control programs. Methods Toronto Invasive Bacterial Diseases Network (TIBDN) has performed population-based surveillance for CPE in the Toronto area/Peel region of southern Ontario, Canada, since CPE were first identified in October 2007. Clinical microbiology laboratories report all CPE isolates to TIBDN; annual lab audits are performed. Incidence calculations used first isolates as numerator; denominator (patient-days/fiscal year for Toronto/Peel hospitals) was from the Ontario Ministry of Health and Long-Term Care. Results The incidence of HA CPE has risen from 0 in 2007/2008 to 0.45 and 0.28 per 100,000 patient-days for all and clinical cases, respectively, in 2017/2018 (Figure, P < 0.0001). 190/790 (24%) incident cases of CPE colonization/infection in southern Ontario from October 2007 to December 2018 were likely HA (hospitalized in Ontario with no history of hospitalization abroad/high-risk travel). Eighty (25%) were female and the median age was 73 years (IQR 57–83 years). 157 (83%) had no prior travel abroad and 33 (17%) had prior low-risk travel. 122 (64%) had their CPE identified >72 hours post-admission (of which 83 also had ≥1 other prior Ontario hospitalization); 68 (36%) had their CPE identified at admission but had recent prior Ontario hospitalization. HA cases vs. foreign acquisitions were significantly more likely K. pneumoniae (48% vs. 38%, P = 0.02) and Enterobacter spp. (20% vs. 7%, P < 0.0001) and less likely E. coli (20% vs. 48%, P < 0.0001). Genes of HA vs. foreign acquisitions were significantly more likely blaKPC (34% vs. 12%, P < 0.0001) and blaVIM (12% vs. 2%, P < 0.0001) and less likely blaNDM±OXA (38% vs. 56%, P < 0.0001) and blaOXA (13% vs. 27%, P = 0.0001). 36 (19%) HA cases had a negative CPE screen before their first positive CPE test (10/36 (28%) were on admission). The median incidence of HA CPE per 100,000 patient-days at each hospital was 0.44 (IQR 0.15–0.68) (P < 0.0001). Conclusion A quarter of CPE cases in southern Ontario were HA and the incidence of HA cases is increasing. Most cases were admitted to >1 Ontario hospital. Strategies to control transmission are critical. Disclosures All authors: No reported disclosures.

Background In Ontario, Canada, PCV13 is covered for immunocompromised (IC) adults over 50y. PCV13 programs are thought not to be cost-effective in other adults because it is assumed that herd immunity from pediatric vaccination programs (PCV7 since 2005; PCV13 since 2010) will reduce PCV13 disease burden dramatically in adults. We analyzed data from the Toronto Invasive Bacterial Diseases Network (TIBDN) to ask whether PCV13-type invasive pneumococcal disease (IPD) in adults persists in our population. Methods TIBDN performs population-based surveillance for IPD in Toronto+Peel Region, Ontario (pop4.1M). All microbiology laboratories receiving specimens from residents report cases of IPD and submit isolates to a central study lab for serotyping; annual audits are conducted. Demographic, medical and vaccination information are obtained from patients, families and physicians. Population data are from Statistics Canada. Results Since 1995, 10,365 episodes of IPD have been identified; detailed medical information was available for 9,801 (95%) and serotyping for 9411 (91%). Among 8658 adult cases, 4,273 (49%) were in those aged 15–64 years, and 4,285 (51%) in those aged >645 years. The most common diagnoses were pneumonia (5,978/8,025, 74%) and bacteremia without focus (1,030, 13%); 470 (4.6%) cases had meningitis; the case fatality rate (CFR) was 21%. The incidence of disease due to STs in PCV13 in adults declined from 7.0/100,000/year 2001 to 2.9/100,000/year in 2015–2018 and was stable from 2015–2018 (Figure 1). The incidence was > 5/100,000/year in non-IC patients over 65 years, and younger patients with cancer and kidney disease (Figure 2). In IPD from 2015 to 2018, adult patients with PCV13 ST disease were younger (median age 64 years vs. 67 years, P = .03) than other patients; there was no significant difference in the proportion with at least one underlying chronic condition (253, 69% PCV13ST, vs. 541,74% other ST, P = 0.08), or in CFR (59, 16% PCV13 vs. 145, 20% other, P = 0.13). The ST distribution of cases due to PCV13 STs is shown in Figure 3. Conclusion A significant burden of IPD due to PCV13 serotypes persists in adults in our population despite 8 years of routine pediatric PCV13 vaccination. This burden needs to be considered in assessing the value and cost-effectiveness of PCV programs for adults. Disclosures All authors: No reported disclosures.

BACKGROUND: Health care–associated infections are a common cause of patient morbidity and mortality. We sought to describe the trends in these infections in acute care hospitals, using data from 3 national point-prevalence surveys. METHODS: The Canadian Nosocomial Infection Surveillance Program (CNISP) conducted descriptive point-prevalence surveys to assess the burden of health care–associated infections on a single day in February of 2002, 2009 and 2017. Surveyed infections included urinary tract infection, pneumonia, Clostridioides difficile infection, infection at surgical sites and bloodstream infections. We compared the prevalence of infection across the survey years and considered the contribution of antimicrobial-resistant organisms as a cause of these infections. RESULTS: We surveyed 28 of 33 (response rate 84.8%) CNISP hospitals (6747 patients) in 2002, 39 of 55 (response rate 71.0%) hospitals (8902 patients) in 2009 and 47 of 66 (response rate 71.2%) hospitals (9929 patients) in 2017. The prevalence of patients with at least 1 health care–associated infection increased from 9.9% in 2002 (95% confidence interval [CI] 8.4%–11.5%) to 11.3% in 2009 (95% CI 9.4%–13.5%), and then declined to 7.9% in 2017 (95% CI 6.8%–9.0%). In 2017, device-associated infections accounted for 35.6% of all health care–associated infections. Methicillin-resistant Staphylococcus aureus (MRSA) accounted for 3.9% of all organisms identified from 2002 to 2017; other antibiotic-resistant organisms were uncommon causes of infection for all survey years. INTERPRETATION: In CNISP hospitals, there was a decline in the prevalence of health care–associated infection in 2017 compared with previous surveys. However, strategies to prevent infections associated with medical devices should be developed. Apart from MRSA, few infections were caused by antibiotic-resistant organisms.

Background Estimating the risk of antibiotic resistance is important in selecting empiric antibiotics. We asked how the timing, number of courses, and duration of antibiotic therapy in the previous 3 months affected antibiotic resistance in isolates causing invasive pneumococcal disease (IPD). Methods We conducted prospective surveillance for IPD in Toronto, Canada, from 2002 to 2011. Antimicrobial susceptibility was measured by broth microdilution. Clinical information, including prior antibiotic use, was collected by chart review and interview with patients and prescribers. Results Clinical information and antimicrobial susceptibility were available for 4062 (90%) episodes; 1193 (29%) of episodes were associated with receipt of 1782 antibiotic courses in the prior 3 months. Selection for antibiotic resistance was class specific. Time elapsed since most recent antibiotic was inversely associated with resistance (cephalosporins: adjusted odds ratio [OR] per day, 0.98; 95% confidence interval [CI], .96-1.00; P = .02; macrolides: OR, 0.98; 95% CI, .96-.99; P = .005; penicillins: OR [log(days)], 0.62; 95% CI, .44-.89; P = .009; fluoroquinolones: profile penalized-likelihood OR [log(days)], 0.62; 95% CI, .39-1.04; P = .07). Risk of resistance after exposure declined most rapidly for fluoroquinolones and penicillins and reached baseline in 2-3 months. The decline in resistance was slowest for macrolides, and in particular for azithromycin. There was no significant association between duration of therapy and resistance for any antibiotic class. Too few patients received multiple courses of the same antibiotic class to assess the significance of repeat courses. Conclusions Time elapsed since last exposure to a class of antibiotics is the most important factor predicting antimicrobial resistance in pneumococci. The duration of effect is longer for macrolides than other classes.