Measuring waning protection from seasonal influenza vaccination during nine influenza seasons, Ontario, Canada, 2010/11 to 2018/19.

BackgroundWaning immunity from seasonal influenza vaccination can cause suboptimal protection during peak influenza activity. However, vaccine effectiveness studies assessing waning immunity using vaccinated and unvaccinated individuals are subject to biases.AimWe examined the association between time since vaccination and laboratory-confirmed influenza to assess the change in influenza vaccine protection over time.MethodsUsing linked laboratory and health administrative databases in Ontario, Canada, we identified community-dwelling individuals aged ≥ 6 months who received an influenza vaccine before being tested for influenza by RT-PCR during the 2010/11 to 2018/19 influenza seasons. We estimated the adjusted odds ratio (aOR) for laboratory-confirmed influenza by time since vaccination (categorised into intervals) and for every 28 days.ResultsThere were 53,065 individuals who were vaccinated before testing for influenza, with 10,264 (19%) influenza-positive cases. The odds of influenza increased from 1.05 (95% CI: 0.91-1.22) at 42-69 days after vaccination and peaked at 1.27 (95% CI: 1.04-1.55) at 126-153 days when compared with the reference interval (14-41 days). This corresponded to 1.09-times increased odds of influenza every 28 days (aOR = 1.09; 95% CI: 1.04-1.15). Individuals aged 18-64 years showed the greatest decline in protection against influenza A(H1N1) (aORper 28 days = 1.26; 95% CI: 0.97-1.64), whereas for individuals aged ≥ 65 years, it was against influenza A(H3N2) (aORper 28 days = 1.20; 95% CI: 1.08-1.33). We did not observe evidence of waning vaccine protection for individuals aged < 18 years.ConclusionsInfluenza vaccine protection wanes during an influenza season. Understanding the optimal timing of vaccination could ensure robust protection during seasonal influenza activity.

Predictors of later COVID-19 test seeking.

Background: Delays in COVID-19 testing may increase the risk of secondary household and community transmission. Little is known about what patient characteristics and symptom profiles are associated with delays in test seeking. Methods: We conducted a retrospective cohort study of all symptomatic patients diagnosed with COVID-19 and assessed in a COVID Expansion to Outpatients (COVIDEO) virtual care program between March 2020 and June 2021. The primary outcome was later test seeking more than 3 days from symptom onset. Multivariable logistic regression was used to examine predictors of later testing including patient characteristics and symptoms (30 individual symptoms or 7 symptom clusters). Results: Of 5,363 COVIDEO patients, 4,607 were eligible and 2,155/4,607 (46.8%) underwent later testing. Older age was associated with increased odds of late testing (adjusted odds ratio [aOR] 1.007/year; 95% CI 1.00 to 1.01), as was history of recent travel (aOR 1.4; 95% CI 1.01 to 1.95). Health care workers had lower odds of late testing (aOR 0.50; 95% CI 0.39 to 0.62). Late testing was associated with symptoms in the cardiorespiratory (aOR 1.2; 95% CI 1.05, 1.36), gastrointestinal (aOR = 1.2; 95% CI 1.04, 1.4), neurological (aOR 1.1; 95% CI 1.003, 1.3) and psychiatric (aOR 1.3; 95% CI 1.1, 1.5) symptom clusters. Among individual symptoms, dyspnea, anosmia, dysgeusia, sputum, and anorexia were associated with late testing; pharyngitis, myalgia, and headache were associated with early testing. Conclusion: Certain patient characteristics and symptoms are associated with later testing, and warrant further efforts to encourage earlier testing to minimize transmission.

Historique: Les retards à effectuer les tests de dépistage de la COVID-19 peuvent accroître le risque de transmission secondaire dans la famille et la communauté. On ne sait pas vraiment quels sont les caractéristiques des patients et leurs profils de symptômes associés aux retards à se faire dépister. Méthodologie: Les chercheurs ont réalisé une étude de cohorte auprès de tous les patients symptomatiques ayant obtenu un diagnostic de COVID-19 évalués dans le cadre du programme de soins virtuels COVID Expansion to Outpatients (COVIDEO, ou expansion de la COVID aux patients ambulatoires) entre mars 2020 et juin 2021. Le résultat primaire était une demande de dépistage plus de trois jours après l'apparition des symptômes. Les chercheurs ont utilisé la régression logistique multivariable pour examiner les prédicteurs d'un dépistage tardif, y compris les caractéristiques et les symptômes des patients (30 symptômes individuels ou sept grappes de symptômes). Résultats: Des 5 363 patients ayant participé au programme COVIDEO, 4 607 étaient admissibles et 2 155 de ces 4 607 (46,8 %) se sont soumis à un dépistage tardif. Une plus grande probabilité de dépistage tardif était liée à un âge avancé (rapport de cotes corrigé [RCc] 1,007/année, IC à 95 %, 1,00 à 1,01), de même qu'à un voyage récent (RCc = 1,4, IC à 95 %, 1,01 à 1,95). Les travailleurs de la santé étaient moins susceptibles de se faire dépister tardivement (RCc = 0,50, IC à 95 %, 0,39 à 0,62). Le dépistage tardif était associé à des symptômes de la grappe cardiorespiratoire (RCc = 1,2, IC à 95 %, [1,05, 1,36]), gastrointestinale (RCc = 1,2, IC à 95 %, [1,04, 1,4]), neurologique (RCc = 1,1, IC à 95 %, [1,003, 1,3]) et psychiatrique (RCc = 1,3, IC à 95 %, [1,1, 1,5]). Parmi les symptômes individuels, la dyspnée, l'anosmie, la dysgueusie, les expectorations et l'anorexie étaient associées à un dépistage tardif, et la pharyngite, les myalgies et les céphalées, à un dépistage précoce. Conclusion: Certaines caractéristiques des patients et certains symptômes étaient associés à un dépistage tardif, ce qui justifie des efforts supplémentaires pour favoriser un dépistage plus rapide afin de limiter la transmission. Summary: This study of more than 4,000 patients with COVID-19 identified predictors of later test seeking, including older age, recent travel, non-health care worker occupation, cardiorespiratory, gastrointestinal, neurologic and psychiatric symptom clusters, and dyspnea, anosmia, dysgeusia, sputum, and anorexia.

Integration of hospital with congregate care homes in response to the COVID-19 pandemic.

Background: The coronavirus disease 2019 (COVID-19) pandemic has highlighted the need to improve the safety of the environments where we care for older adults in Canada. After providing assistance during the first wave, many Ontario hospitals formally partnered with local congregate care homes in a "hub and spoke" model during second pandemic wave onward. The objective of this article is to describe the implementation and longitudinal outcomes of residents in one hub and spoke model composed of a hospital partnered with 18 congregate care homes including four long-term care and 14 retirement or other congregate care homes. Intervention: Homes were provided continuous seven-day per week access to hospital support, including infection prevention and control (IPAC), testing, vaccine delivery and clinical support as needed. Any COVID-19 exposure or transmission triggered a same-day meeting to implement initial control measures. A minimum of weekly on-site visits occurred for long-term care homes and biweekly for other congregate care homes, with up to daily on-site presence during outbreaks. Outcomes: Case detection among residents increased following implementation in context of increased testing, then decreased post-immunization until the Omicron wave when it peaked. After adjusting for the correlation within homes, COVID-related mortality decreased following implementation (OR=0.51, 95% CI, 0.30-0.88; p=0.01). In secondary analysis, homes without pre-existing IPAC programs had higher baseline COVID-related mortality rate (OR=19.19, 95% CI, 4.66-79.02; p<0.001) and saw a larger overall decrease during implementation (3.76% to 0.37%-0.98%) as compared to homes with pre-existing IPAC programs (0.21% to 0.57%-0.90%). Conclusion: The outcomes for older adults residing in congregate care homes improved steadily throughout the COVID-19 pandemic. While this finding is multifactorial, integration with a local hospital partner supported key interventions known to protect residents.

Evaluating the impact of a virtual outpatient care programme in preventing hospitalizations, emergency department visits and mortality for patients with COVID-19: a matched cohort study.

OBJECTIVES: To evaluate the impact of virtual care in preventing unnecessary healthcare visits for patients with SARS-CoV-2. METHODS: We conducted a retrospective matched cohort study, evaluating the COVID-19 Expansion to Outpatients (COVIDEO) programme involving virtual assessments for all positive patients in the Sunnybrook assessment centre from January 2020 to June 2021, followed by risk-stratified routine follow-up, couriering of oxygen saturation devices, and 24 hour/day direct-to-physician pager for urgent questions. We linked COVIDEO data to province-wide datasets, matching each eligible COVIDEO patient to ≤10 other Ontario SARS-CoV-2 patients on age, sex, neighbourhood, and date. The primary outcome was emergency department (ED) visit, hospitalization or death within 30 days. Multivariable regression accounted for comorbidities, vaccination, and pre-pandemic healthcare utilization. RESULTS: Among 6508 eligible COVIDEO patients, 4763 (73.1%) were matched to ≥1 non-COVIDEO patient. COVIDEO care was protective against the primary composite outcome (adjusted odds ratio [aOR] 0.91, 95% CI, 0.82-1.02), with a reduction in ED visits (7.8% vs. 9.6%; aOR 0.79, 95% CI, 0.70-0.89), but increase in hospitalizations (3.8% vs. 2.7%, aOR 1.37, 95% CI, 1.14-1.63) reflecting more direct-to-ward admissions (1.3% vs. 0.2%, p < 0.0001). Results were similar when matched comparators were limited to patients who had not received virtual care elsewhere with a decrease in ED visits (7.8 vs. 8.6%, aOR 0.86, 95% CI, 0.75-0.99) and an increase in hospitalizations (3.7 vs. 2.4%, aOR 1.45, 95% CI, 1.17-1.80). DISCUSSION: An intensive remote care programme can prevent unnecessary ED visits and facilitate direct-to-ward hospitalizations and thereby mitigate the impact of COVID-19 on the healthcare system.

Infective endocarditis of a native aortic valve due to Pseudomonas aeruginosa complicated by progressive multi-drug resistance.

BACKGROUND: Treatment of infective endocarditis secondary to Pseudomonas aeruginosa can be challenging because of this organism's ability to acquire antimicrobial resistance over time. METHODS: We describe a patient with native aortic valve infective endocarditis due to P. aeruginosa who developed progressive multi-drug resistance while on therapy. The resistance mechanisms were characterized using whole-genome sequencing. RESULTS: We identified two mutations in subsequent isolates (dacB and OprD) that conferred resistance to anti-pseudomonal penicillins, cephalosporins, and carbapenems. The patient was treated with combination high-dose continuous infusion meropenem and ciprofloxacin therapy, in addition to bioprosthetic aortic valve replacement and repair of ventricular septal wall defect. Antibiotics were continued for 6 weeks post-cardiac surgery and the patient remains infection free 18 months post-completion of antibiotic therapy. CONCLUSION: Clinicians should be aware of the ability of P. aeruginosa to acquire resistance mechanisms in response to selective antibiotic pressures in high-inoculum infections such as infective endocarditis. The mutations identified in this case report correlated well with the evolving antimicrobial resistance profile observed.

HISTORIQUE: Il peut être difficile de traiter une endocardite infectieuse causée par un Pseudomonas aeruginosa en raison de la capacité de cet organisme à acquérir une résistance aux antimicrobiens. MÉTHODOLOGIE: Les chercheurs décrivent un patient atteint d'une endocardite infectieuse de la valve aortique d'origine, attribuable à un P. aeruginosa, qui a acquis une multirésistance progressive pendant son traitement. Le mécanisme de résistance était caractérisé par le séquençage du génome entier. RÉSULTATS: Les auteurs ont dépisté deux mutations dans les isolats subséquents (dacB et OprD ), responsables d'une résistance aux pénicillines, aux céphalosporines et aux carbapénèmes antipseudomonaux. Le patient a reçu une polythérapie de perfusion continue de méropénem à forte dose et de ciprofloxacine, en plus du remplacement d'une valve aortique bioprothétique et de la réparation d'une communication interventriculaire. L'antibiothérapie s'est poursuivie six semaines après l'opération, et le patient n'avait pas d'infection 18 mois après la fin de l'antibiothérapie. CONCLUSION: Les cliniciens devraient savoir que le P. aeruginosa peut acquérir des mécanismes de résistance en réponse aux pressions antibiotiques sélectives en cas d'infections comportant un titre élevé d'inoculum comme une endocardite infectieuse. Les mutations constatées dans le présent rapport de cas étaient bien corrélées avec l'évolution du profil de résistance antimicrobienne observé.

Prevalence and predictors of persistent post-COVID-19 symptoms.

BACKGROUND: The pandemic has affected hundreds of millions of people; early reports suggesting high rates of prolonged symptoms may be prone to selection bias. METHODS: In a program caring for all SARS-CoV-2 positive inpatients and outpatients between March to October 2020, and offering universal 90-day follow-up, we compared those who died prior to 90 days, not responding to follow-up, declining, or accepting follow-up. Among those seen or declining follow-up, we determined the prevalence and predictors of persistent symptoms. RESULTS: Among 993 patients, 21 (2.1%) died prior to 90 days, 506 (50.9%) did not respond, 260 (26.1%) declined follow-up because they were well, and 206 (20.7%) were fully assessed. Of 466 who responded to follow-up inquiry, 133 (28.5%) reported ≥1 persistent symptom, including constitutional (15.5%), psychiatric (14.2%), rheumatologic (13.1%), neurologic (13.1%), cardiorespiratory (12.0%), and gastrointestinal (1.7%). Predictors differed for each symptom type. Any persistent symptom was more common in older patients (adjusted odds ratio [aOR] 1.11, 95% CI 1.04 to 1.18/5 years), those diagnosed in hospital (aOR 2.03, 95% CI 1.24 to 3.33) and those with initial constitutional and rheumatologic symptoms. Patients not responding to follow-up were younger and healthier at baseline. CONCLUSION: Persistent symptoms are common and diverse 3 months post-COVID-19 but are likely over-estimated by most reports.

HISTORIQUE: La pandémie touche des centaines de millions de gens. Les rapports précoces laissant croire à des symptômes prolongés pourraient être assujettis à un biais de sélection. MÉTHODOLOGIE: Dans un programme de soins auprès de tous les patients ambulatoires et hospitalisés ayant reçu un résultat positif au SRAS-CoV-2 entre mars et octobre 2020, assorti d'un suivi universel de 90 jours, les chercheurs ont comparé les personnes qui ont succombé avant 90 jours, n'ont pas répondu au suivi ou ont décliné ou accepté le suivi. Chez celles qui ont été vues ou ont décliné le suivi, ils ont déterminé la prévalence et les prédicteurs de symptômes persistants. RÉSULTATS: Chez les 993 patients, 21 (2,1 %) sont décédés avant les 90 jours, 506 (50,9 %) n'ont pas répondu, 260 (26,1 %) ont décliné le suivi parce qu'ils se sentaient bien et 206 (20,7 %) se sont soumis à une évaluation complète. Des 466 qui ont répondu à l'offre de suivi, 133 (28,5 %) ont signalé ressentir au moins un symptôme persistant, y compris d'ordre constitutionnel (15,5 %), psychiatrique (14,2 %), rhumatologique (13,1 %), neurologique (13,1 %), cardiorespiratoire (12,0 %) et gastro-intestinal (1,7 %). Les prédicteurs différaient en fonction de chaque type de symptômes. Les symptômes persistants étaient courants chez les personnes âgées (rapport de cotes corrigé [RCc] 1,11, IC à 95 %, 1,04 à 1,18/cinq ans), les personnes diagnostiquées à l'hôpital (RCc 2,03, IC à 95 %, 1,24 à 3,33) et celles dont les manifestations initiales comportaient des symptômes constitutionnels et rhumatologiques. Les patients qui ne répondaient pas au suivi étaient plus jeunes et en meilleure santé au départ. CONCLUSION: Les symptômes persistants sont courants et diversifiés trois mois après la COVID-19, mais sont probablement surestimés dans la plupart des rapports.

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

OBJECTIVES: 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. METHODS: 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%. RESULTS: 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). CONCLUSIONS: 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.

Diagnostic accuracy of subjective dyspnoea in detecting hypoxaemia among outpatients with COVID-19: a retrospective cohort study.

OBJECTIVES: The majority of patients with mild-to-moderate COVID-19 can be managed using virtual care. Dyspnoea is challenging to assess remotely, and the accuracy of subjective dyspnoea measures in capturing hypoxaemia have not been formally evaluated for COVID-19. We explored the accuracy of subjective dyspnoea in diagnosing hypoxaemia in COVID-19 patients. METHODS: This is a retrospective cohort study of consecutive outpatients with COVID-19 who met criteria for home oxygen saturation monitoring at a university-affiliated acute care hospital in Toronto, Canada from 3 April 2020 to 13 September 2020. Dyspnoea measures were treated as diagnostic tests, and we determined their sensitivity (SN), specificity (SP), negative/positive predictive value (NPV/PPV) and positive/negative likelihood ratios (+LR/-LR) for detecting hypoxaemia. In the primary analysis, hypoxaemia was defined by oxygen saturation <95%; the diagnostic accuracy of subjective dyspnoea was also assessed across a range of oxygen saturation cutoffs from 92% to 97%. RESULTS: During the study period, 89/501 (17.8%) of patients met criteria for home oxygen saturation monitoring, and of these 17/89 (19.1%) were diagnosed with hypoxaemia. The presence/absence of dyspnoea had limited accuracy for diagnosing hypoxaemia, with SN 47% (95% CI 24% to 72%), SP 80% (95% CI 68% to 88%), NPV 86% (95% CI 75% to 93%), PPV 36% (95% CI 18% to 59%), +LR 2.4 (95% CI 1.2 to 4.7) and -LR 0.7 (95% CI 0.4 to 1.1). The SN of dyspnoea was 50% (95% CI 19% to 81%) when a cut-off of <92% was used to define hypoxaemia. A modified Medical Research Council dyspnoea score >1 (SP 98%, 95% CI 88% to 100%), Roth maximal count <12 (SP 100%, 95% CI 75% to 100%) and Roth counting time <8 s (SP 93%, 95% CI 66% to 100%) had high SP that could be used to rule in hypoxaemia, but displayed low SN (≤50%). CONCLUSIONS: Subjective dyspnoea measures have inadequate accuracy for ruling out hypoxaemia in high-risk patients with COVID-19. Safe home management of patients with COVID-19 should incorporate home oxygenation saturation monitoring.

Household Transmission of Carbapenemase-producing Enterobacterales in 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.

Association between initial symptoms and subsequent hospitalization in outpatients with COVID-19: A cohort study.

Background: Most individuals with coronavirus disease 2019 (COVID-19) experience mild symptoms and are managed in the outpatient setting. The aim of this study was to determine whether self-reported symptoms at the time of diagnosis can identify patients at risk of clinical deterioration. Methods: This was a retrospective cohort study of 671 outpatients with laboratory-confirmed COVID-19 diagnosed in Toronto between March 1 and October 16, 2020. We examined the association between patients' baseline characteristics and self-reported symptoms at the time of diagnosis and the risk of subsequent hospitalization. Results: Of 671 participants, 26 (3.9%) required hospitalization. Individuals aged 65 years or older were more likely to require hospitalization (odds ratio [OR] 5.29, 95% CI 2.19 to 12.77), whereas those without medical comorbidities were unlikely to be hospitalized (OR 0.02, 95% CI 0.00 to 0.17). After adjusting for age and presence of comorbidities, sputum production (adjusted OR [aOR] 5.01, 95% CI 1.97 to 12.75), arthralgias (aOR 4.82, 95% CI 1.85 to 12.53), diarrhea (aOR 4.56, 95% CI 1.82 to 11.42), fever (aOR 3.64, 95% CI 1.50 to 8.82), chills (aOR 3.62, 95% CI 1.54 to 8.50), and fatigue (aOR 2.59, 95% CI 1.04 to 6.47) were associated with subsequent hospitalization. Conclusions: Early assessment of symptoms among outpatients with COVID-19 can help identify individuals at risk of clinical deterioration. Additional studies are needed to determine whether more intense follow-up and early intervention among high-risk individuals can alter the clinical trajectory of and outcomes among outpatients with COVID-19.

Historique: La plupart des personnes atteintes de la maladie à coronavirus 2019 (COVID-19) éprouvent des symptômes légers et sont prises en charge en milieu ambulatoire. La présente étude visait à déterminer si les symptômes autodéclarés au moment du diagnostic permettent de dépister les patients à risque de détérioration clinique. Méthodologie: Les chercheurs ont réalisé la présente étude de cohorte rétrospective auprès de 671 patients ambulatoires atteints d'une COVID-19 diagnostiquée à Toronto et confirmée en laboratoire entre le 1er mars et le 16 octobre 2020. Ils ont examiné l'association entre les caractéristiques de référence et les symptômes autodéclarés des patients au moment du diagnostic, d'une part, et le risque d'hospitalisation, d'admission en soins intensifs ou de décès par la suite, d'autre part. Résultats: Des 671 participants, 26 (3,9 %) ont dû être hospitalisés, sept (1,0 %) ont été admis en soins intensifs et trois (0,4 %) sont décédés dans les 30 jours suivant le diagnostic. Les personnes de 65 ans ou plus étaient plus susceptibles de devoir être hospitalisées (RC 5,29, IC à 95 % 2,19 à 12,77) et celles qui n'avaient pas d'autres problèmes de santé l'étaient moins (RC 0,02, IC à 95 % 0,00 à 0,17). Après redressement pour tenir compte de l'âge et de la présence d'autres problèmes de santé, la production de mucus (RC ajusté [RCa] 5,01, IC à 95 % 2,11 à 13,66), les arthralgies (RCa 4,82, IC à 95 % 1,85 à 12,53), la diarrhée (RCa 4,56, IC à 95 % 1,82 à 11,42), la fièvre (RCa 3,64, IC à 95 % 1,50 à 8,82), les frissons (RCa 3,62, IC à 95 % 1,54 à 8,50) et la fatigue (RCa 2,59, IC à 95 % 1,04 à 6,47) étaient associés à des hospitalisations. Conclusions: L'évaluation précoce des symptômes des patients ambulatoires atteints de la COVID-19 peut contribuer à dépister les personnes vulnérables à une détérioration clinique. Lorsque ce facteur s'ajoute à l'âge et à l'histoire de problèmes de santé, la symptomatologie fournit plus d'information pronostique aux cliniciens qui prennent en charge les patients atteints de COVID-19 en milieu ambulatoire. D'autres études s'imposent pour déterminer si un suivi plus intense et une intervention précoce auprès des personnes très vulnérables peuvent modifier la trajectoire clinique et le pronostic des patients ambulatoires atteints de la COVID-19.

Dissemination of Verona Integron-encoded Metallo-ß-lactamase among clinical and environmental Enterobacteriaceae isolates in Ontario, Canada.

Surveillance data from Southern Ontario show that a majority of Verona Integron-encoded Metallo-ß-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.

Emergence of pstS-Null Vancomycin-Resistant Enterococcus faecium Clone ST1478, Canada, 2013-2018.

Rates of vancomycin-resistant enterococci bloodstream infections have remained relatively low in Canada. We recently observed an increase of 113% in these infections rates, which coincided with emergence of Enterococcus faecium pstS-null sequence type 1478. The proportion of this sequence type increased from 2.7% to 38.7% for all tested isolates from 2013-2018.

Genomic Epidemiology of Invasive Methicillin-Resistant Staphylococcus aureus Infections Among Hospitalized Individuals in Ontario, Canada.

BACKGROUND: Prevention and control of methicillin-resistant Staphylococcus aureus (MRSA) infections remain challenging. In-depth surveillance integrating patient and isolate data can provide evidence to better inform infection control and public health practice. METHODS: We analyzed MRSA cases diagnosed in 2010 (n = 212) and 2016 (n = 214) by hospitals in Ontario, Canada. Case-level clinical and demographic data were integrated with isolate characteristics, including antimicrobial resistance (AMR), classic genotyping, and whole-genome sequencing results. RESULTS: Community-associated MRSA (epidemiologically defined) increased significantly from 23.6% in 2010 to 43.0% in 2016 (P < .001). The MRSA population structure changed over time, with a 1.5× increase in clonal complex (CC)8 strains and a concomitant decrease in CC5. The clonal shift was reflected in AMR patterns, with a decrease in erythromycin (86.7% to 78.4%, P = .036) and clindamycin resistance (84.3% to 47.9%, P < .001) and a >2-fold increase in fusidic acid resistance (9.0% to 22.5%, P < .001). Isolates within both CC5 and CC8 were relatively genetically diverse. We identified 6 small genomic clusters-3 potentially related to transmission in healthcare settings. CONCLUSIONS: Community-associated MRSA is increasing among hospitalized individuals in Ontario. Clonal shifting from CC5 to CC8 has impacted AMR. We identified a relatively high genetic diversity and limited genomic clustering within these dominant CCs.

A virtual care program for outpatients diagnosed with COVID-19: a feasibility study.

BACKGROUND: In patients who are discharged home to self-isolate while coronavirus disease 2019 (COVID-19) test results are pending, there is no formal method for physician assessments or counselling to occur if the result returns positive. Our aim was to develop and test the feasibility of a virtual care program for self-isolating outpatients diagnosed with COVID-19. METHODS: In preparation for this gap in health care, the COVID-19 Expansion to Outpatients (COVIDEO) program was developed at the Sunnybrook Health Sciences Centre, Toronto, Ontario, to provide ongoing care for outpatients diagnosed with COVID-19. As part of a feasibility study, we describe our experiences with the first 50 patients managed using this program from its inception (Mar. 1, 2020) until Mar. 27, 2020. RESULTS: All 50 people who tested positive for COVID-19 at the Sunnybrook Health Sciences Centre and were discharged home to self-isolation during the study period were assessed through the COVIDEO program. Thirty-two patients (64%) were assessed via the Ontario Telemedicine Network virtual care platform, and the remainder by telephone. The median time from viral swab collection to first COVIDEO program assessment was 2 (interquartile range [IQR] 1-2) days. Among the 26 patients for whom further follow-up care through the COVIDEO program was discontinued by the end of March 2020, the median duration of virtual care was 12.5 (IQR 8.75-16) days. During the study period, 6 patients required transfer to hospital for assessment, of whom 4 required admission. INTERPRETATION: We have shown that a virtual care program can be used in the management of outpatients diagnosed with COVID-19. Further studies evaluating its sustainability and impact on health outcomes are underway.

Antimicrobial use among adult inpatients at hospital sites within the Canadian Nosocomial Infection Surveillance Program: 2009 to 2016.

BACKGROUND: Antimicrobial resistance is a growing threat to the world's ability to prevent and treat infections. Links between quantitative antibiotic use and the emergence of bacterial resistance are well documented. This study presents benchmark antimicrobial use (AMU) rates for inpatient adult populations in acute-care hospitals across Canada. METHODS: In this retrospective surveillance study, acute-care adult hospitals participating in the Canadian Nosocomial Infection Surveillance Program (CNISP) submitted annual AMU data on all systemic antimicrobials from 2009 to 2016. Information specific to intensive care units (ICUs) and non-ICU wards were available for 2014-2016. Data were analyzed using defined daily doses (DDD) per 1000 patient days (DDD/1000pd). RESULTS: Between 2009 and 2016, 16-18 CNISP adult hospitals participated each year and provided their AMU data (22 hospitals participated in ≥1 year of surveillance; 11 in all years). From 2009 to 2016, there was a significant reduction in use (12%) (from 654 to 573 DDD/1000pd, p = 0.03). Fluoroquinolones accounted for the majority of this decrease (47% reduction in combined oral and intravenous use, from 129 to 68 DDD/1000pd, p < 0.002). The top five antimicrobials used in 2016 were cefazolin (78 DDD/1000pd), piperacillin-tazobactam (53 DDD/1000pd), ceftriaxone (49 DDD/1000pd), vancomycin (combined oral and intravenous use was 44 DDD/1000pd; 7% of vancomycin use was oral), and ciprofloxacin (combined oral and intravenous use: 42 DDD/1000pd). Among the top 10 antimicrobials used in 2016, ciprofloxacin and metronidazole use decreased significantly between 2009 and 2016 by 46% (p = 0.002) and 26% (p = 0.002) respectively. Ceftriaxone (85% increase, p = 0.0008) and oral amoxicillin-clavulanate (140% increase, p < 0.0001) use increased significantly but contributed only a small component (8.6 and 5.0%, respectively) of overall use. CONCLUSIONS: This study represents the largest collection of dispensed antimicrobial use data among inpatients in Canada to date. Between 2009 and 2016, there was a significant 12% decrease in AMU, driven primarily by a 47% decrease in fluoroquinolone use. Modest absolute increases in parenteral ceftriaxone and oral amoxicillin-clavulanate use were noted but contributed a small amount of total AMU. Ongoing national surveillance is crucial for establishing benchmarks and antimicrobial stewardship guidelines.

The impact of repeated vaccination using 10-year vaccination history on protection against influenza in older adults: a test-negative design study across the 2010/11 to 2015/16 influenza seasons in Ontario, Canada.

IntroductionAnnual influenza vaccination is recommended for older adults, but evidence regarding the impact of repeated vaccination has been inconclusive.AimWe investigated vaccine effectiveness (VE) against laboratory-confirmed influenza and the impact of repeated vaccination over 10 previous seasons on current season VE among older adults.MethodsWe conducted an observational test-negative study in community-dwelling adults aged > 65 years in Ontario, Canada for the 2010/11 to 2015/16 seasons by linking laboratory and health administrative data. We estimated VE using multivariable logistic regression. We assessed the impact of repeated vaccination by stratifying by previous vaccination history.ResultsWe included 58,304 testing episodes for respiratory viruses, with 11,496 (20%) testing positive for influenza and 31,004 (53%) vaccinated. Adjusted VE against laboratory-confirmed influenza for the six seasons combined was 21% (95% confidence interval (CI): 18 to 24%). Patients who were vaccinated in the current season, but had received no vaccinations in the previous 10 seasons, had higher current season VE (34%; 95%CI: 9 to 52%) than patients who had received 1-3 (26%; 95%CI: 13 to 37%), 4-6 (24%; 95%CI: 15 to 33%), 7-8 (13%; 95%CI: 2 to 22%), or 9-10 (7%; 95%CI: -4 to 16%) vaccinations (trend test p = 0.001). All estimates were higher after correcting for misclassification of current season vaccination status. For patients who were not vaccinated in the current season, residual protection rose significantly with increasing numbers of vaccinations received previously.ConclusionsAlthough VE appeared to decrease with increasing numbers of previous vaccinations, current season vaccination likely provides some protection against influenza regardless of the number of vaccinations received over the previous 10 influenza seasons.

Assessing the utilization and impact of a newly established outpatient parenteral antimicrobial therapy (OPAT) program.

Background: Outpatient parenteral antimicrobial therapy (OPAT) is a safe and effective alternative to hospitalization for many patients with infectious disease. The objective of this study was to describe the experience with a newly established formal OPAT program at a Canadian academic centre. Methods: We conducted a retrospective cohort study including all patients referred to the OPAT clinic between July 2016 and June 2017 and a contemporary cohort of patients who received home parenteral therapy without clinic referral. A quasi-experimental design was used to assess the impact of the clinic on patient outcomes compared with a pre-intervention cohort of patients from 2012 to 2013. Results: Between July 2016 and June 2017, 334 patients were referred to the OPAT clinic; 33% of the patients visited the emergency department (ED), and 21% required readmission within 60 days. Compared with the clinic patients, urinary tract infection diagnoses were more common among the 39 contemporary patients who were treated with home parenteral antibiotics without OPAT clinic referral (51% versus 4%, respectively; p < 0.001) and treatment durations were shorter (median 10 days versus 42 days; p < 0.001). Compared with a pre-intervention cohort, OPAT clinic implementation was associated with a trend toward decreased ED visits (33% versus 43%; p = 0.07). On multivariable analysis, this translated to an overall adjusted odds ratio of 0.64 (95% CI 0.40 to 1.04, p = 0.07) for readmission and ED visits. Conclusions: The OPAT clinic served a high volume of patients in its first year of operation and may be helpful in reducing unfavourable patient outcomes.

Historique: L'antibiothérapie parentérale ambulatoire (APA) remplace l'hospitalisation de manière sécuritaire et efficace pour bien des patients atteints d'une maladie infectieuse. La présente étude visait à décrire l'expérience d'un nouveau programme officiel d'APA dans un centre universitaire canadien. Méthodologie: Les auteurs ont procédé à une étude de cohorte rétrospective incluant tous les patients orientés vers une clinique d'APA entre juillet 2016 et juin 2017 et une cohorte de patients qui, pendant la même période, ont reçu un traitement parentéral à domicile sans être orientés en clinique. Ils ont utilisé une méthodologie quasi-expérimentale pour évaluer les répercussions du suivi en clinique sur les patients par rapport à une cohorte de patients avant l'intervention, entre 2012 et 2013. Résultats: Entre juillet 2016 et juin 2017, 334 patients ont été orientés vers la clinique d'APA; 33 % ont consulté à l'urgence et 21 % ont dû être réhospitalisés dans les 60 jours. Les diagnostics d'infection urinaire étaient plus courants chez les 39 patients recevant une antibiothérapie parentérale à domicile sans être dirigés vers une clinique d'APA que dans la cohorte suivie en clinique (51 % par rapport à 4 %, respectivement; p < 0,001) et la durée du traitement était plus courte (médiane de dix jours par rapport à 42 jours; p < 0,001). Par rapport à la cohorte observée avant l'intervention, le suivi en clinique d'APA était associé à une tendance vers une diminution des consultations à l'urgence (33 % par rapport à 43 %; p = 0,07). À l'analyse multivariable, ces résultats se traduisaient par un rapport de cotes rajusté global de 0,64 (IC à 95 %, 0,40 à 1,04, p = 0,07) pour la réhospitalisation et les consultations à l'urgence. Conclusions: La clinique d'APA a accueilli un fort volume de patients pendant sa première année de fonctionnement et peut contribuer à réduire les résultats cliniques défavorables chez les patients.

Influenza Vaccine Effectiveness in Preventing Hospitalizations in Older Patients With Chronic Obstructive Pulmonary Disease.

BACKGROUND: Annual influenza immunization is recommended for people with chronic obstructive pulmonary disease (COPD) by all major COPD clinical practice guidelines. We sought to determine the seasonal influenza vaccine effectiveness (VE) against laboratory-confirmed influenza-associated hospitalizations among older adults with COPD. METHODS: We conducted a test-negative study of influenza VE in community-dwelling older adults with COPD in Ontario, Canada using health administrative data and respiratory specimens collected from patients tested for influenza during the 2010-11 to 2015-16 influenza seasons. Influenza vaccination was ascertained from physician and pharmacist billing claims. Multivariable logistic regression was used to estimate the adjusted odds ratio of influenza vaccination in people with, compared to those without, laboratory-confirmed influenza. RESULTS: Receipt of seasonal influenza vaccine was associated with an adjusted 22% (95% confidence interval [CI], 15%-27%) reduction in laboratory-confirmed influenza-associated hospitalization. Adjustment for potential misclassification of vaccination status increased this to 43% (95% CI, 35%-52%). Vaccine effectiveness was not found to vary by patient- or influenza-related variables. CONCLUSIONS: During the studied influenza seasons, influenza vaccination was at least modestly effective in reducing laboratory-confirmed influenza-associated hospitalizations in people with COPD. The imperfect effectiveness emphasizes the need for better influenza vaccines and other preventive strategies.

Impact of a Comprehensive Antimicrobial Stewardship Program on Institutional Burden of Antimicrobial Resistance: A 14-Year Controlled Interrupted Time-series Study.

BACKGROUND: Antimicrobial resistance (AMR) constitutes an international public health threat widely believed to result from excessive antimicrobial use (AMU). Numerous authorities have recommended antimicrobial stewardship programs (ASPs) to curb the selection of AMR, but there is a lack of data confirming this benefit. METHODS: A controlled interrupted time-series study spanning 14 years was performed to assess impact of a comprehensive hospital-based ASP that included pharmacist-led audit and feedback on institutional AMR. Patient-level microbiologic and AMU data were obtained from October 2002 to September 2016. Poisson regression models were used to identify changes in the incidence and trend of hospital-acquired (HA) antibiotic-resistant organisms (AROs) and multidrug-resistant organisms (MDROs). Changes in community-acquired (CA)-ARO, CA-MDRO, and inpatient AMU were assessed as controls and process outcomes. RESULTS: Statistically significant shifts in AMU, HA-ARO, and HA-MDRO trends coinciding with ASP implementation were observed, corresponding with a 9% reduction in HA-ARO burden (incidence rate ratio [IRR], 0.91 [95% confidence interval {CI}, .83-.99]; P = .03) and a 13% reduction in HA-MDRO burden (IRR, 0.87 [95% CI, .73-1.04]; P = .13) in the intervention period. In contrast, CA-ARO and CA-MDRO incidence continued to rise, with 40% (IRR, 1.40 [95% CI, 1.28-1.54]; P < .0001) and 68% (IRR, 1.68 [95% CI, 1.57-1.82]; P < .0001) increases in burden found, respectively. CONCLUSIONS: Implementation of a comprehensive ASP resulting in reduced AMU was associated with a significant reduction in institutional AMR, even though community AMR increased during the same period. These results confirm that ASPs play an important role in the fight against AMR.

External validation of clinical prediction rules for complications and mortality following Clostridioides difficile infection.

BACKGROUND: Several clinical prediction rules (CPRs) for complications and mortality of Clostridioides difficile infection (CDI) have been developed but only a few have gone through external validation, and none is widely recommended in clinical practice. METHODS: CPRs were identified through a systematic review. We included studies that predicted severe or complicated CDI (cCDI) and mortality, reported at least an internal validation step, and for which data were available with minimal modifications. Data from a multicenter prospective cohort of 1380 adults with confirmed CDI were used for external validation. In this cohort, cCDI occurred in 8% of the patients and 30-day all-cause mortality occurred in 12%. The performance of each tool was assessed using individual outcomes, with the same cut-offs and standard parameters. RESULTS: Seven CPRs were assessed. Three predictive scores for cCDI showed low sensitivity (25-61%) and positive predictive value (PPV; 9-31%), but moderate specificity (54-90%) and negative predictive value (NPV; 82-95%). One model [using age, white blood cell count (WBC), narcotic use, antacids use, and creatinine ratio > 1.5× the normal level as covariates] showed a probability of 25% of cCDI at the optimal cut-off point with 36% sensitivity and 84% specificity. Two scores for mortality had low sensitivity (4-55%) and PPV (25-31%), and moderate specificity (71-78%) and NPV (87-92%). One predictive model for 30-day all-cause mortality [Charlson comorbidity index, WBC, blood urea nitrogen (BUN), diagnosis in ICU, and delirium] showed an AUC-ROC of 0.74. All other CPRs showed lower AUC values (0.63-0.69). Errors in calibration ranged from 12%- 27%. CONCLUSIONS: Included CPRs showed moderate performance for clinical use in a large validation cohort with a majority of patients infected with ribotype 027 strains and a low rate of cCDI and mortality. These data show that better CPRs need to be developed and validated.