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

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

Trends in Clostridioides difficile infection rates in Canadian hospitals during the coronavirus disease 2019 (COVID-19) pandemic

The coronavirus disease 2019 (COVID-19) pandemic has placed significant burden on healthcare systems. We compared Clostridioides difficile infection (CDI) epidemiology before and during the pandemic across 71 hospitals participating in the Canadian Nosocomial Infection Surveillance Program. Using an interrupted time series analysis, we showed that CDI rates significantly increased during the COVID-19 pandemic.

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

BACKGROUND

Antimicrobial resistance threatens the ability to successfully prevent and treat infections. While hospital benchmarks regarding antimicrobial use (AMU) have been well documented among adult populations, there is less information from among paediatric inpatients. This study presents benchmark rates of antimicrobial use (AMU) for paediatric inpatients in nine Canadian acute-care hospitals.

METHODS

Acute-care hospitals participating in the Canadian Nosocomial Infection Surveillance Program submitted annual AMU data from paediatric inpatients from 2017 and 2018. All systemic antimicrobials were included. Data were available for neonatal intensive care units (NICUs), pediatric ICUs (PICUs), and non-ICU wards. Data were analyzed using days of therapy (DOT) per 1000 patient days (DOT/1000pd).

RESULTS

Nine hospitals provided paediatric AMU data. Data from seven NICU and PICU wards were included. Overall AMU was 481 (95% CI 409-554) DOT/1000pd. There was high variability in AMU between hospitals. AMU was higher on PICU wards (784 DOT/1000pd) than on non-ICU (494 DOT/1000pd) or NICU wards (333 DOT/1000pd). On non-ICU wards, the antimicrobials with the highest use were cefazolin (66 DOT/1000pd), ceftriaxone (59 DOT/1000pd) and piperacillin-tazobactam (48 DOT/1000pd). On PICU wards, the antimicrobials with the highest use were ceftriaxone (115 DOT/1000pd), piperacillin-tazobactam (115 DOT/1000pd), and cefazolin (111 DOT/1000pd). On NICU wards, the antimicrobials with the highest use were ampicillin (102 DOT/1000pd), gentamicin/tobramycin (78 DOT/1000pd), and cefotaxime (38 DOT/1000pd).

CONCLUSIONS

This study represents the largest collection of antimicrobial use data among hospitalized paediatric inpatients in Canada to date. In 2017/2018, overall AMU was 481 DOT/1000pd. National surveillance of AMU among paediatric inpatients is necessary for establishing benchmarks and informing antimicrobial stewardship efforts.

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

Importance

Trends in COVID-19 severe outcomes have significant implications for the health care system and are key to informing public health measures. However, data summarizing trends in severe outcomes among patients hospitalized with COVID-19 in Canada are not well described.

Objective

To describe trends in severe outcomes among patients hospitalized with COVID-19 during the first 2 years of the COVID-19 pandemic.

Design, Setting, and Participants

Active prospective surveillance in this cohort study was conducted from March 15, 2020, to May 28, 2022, at a sentinel network of 155 acute care hospitals across Canada. Participants included adult (aged ≥18 years) and pediatric (aged 0-17 years) patients hospitalized with laboratory-confirmed COVID-19 at a Canadian Nosocomial Infection Surveillance Program (CNISP)-participating hospital.

Exposures

COVID-19 waves, COVID-19 vaccination status, and age group.

Main Outcomes and Measures

The CNISP collected weekly aggregate data on the following severe outcomes: hospitalization, admission to an intensive care unit (ICU), receipt of mechanical ventilation, receipt of extracorporeal membrane oxygenation, and all-cause in-hospital death.

Results

Among 1 513 065 admissions, the proportion of adult (n = 51 679) and pediatric (n = 4035) patients hospitalized with laboratory-confirmed COVID-19 was highest in waves 5 and 6 of the pandemic compared with waves 1 to 4 (77.3 vs 24.7 per 1000 patient admissions). Despite this, the proportion of patients with positive test results for COVID-19 who were admitted to an ICU, received mechanical ventilation, received extracorporeal membrane oxygenation, and died were each significantly lower in waves 5 and 6 when compared with waves 1 through 4. Admission to the ICU and in-hospital all-cause death rates were significantly higher among those who were unvaccinated against COVID-19 when compared with those who were fully vaccinated (incidence rate ratio, 4.3 and 3.9, respectively) or fully vaccinated with an additional dose (incidence rate ratio, 12.2 and 15.1, respectively).

Conclusions and Relevance

The findings of this cohort study of patients hospitalized with laboratory-confirmed COVID-19 suggest that COVID-19 vaccination is important to reduce the burden on the Canadian health care system as well as severe outcomes associated with COVID-19.

High-dose cephalexin for cellulitis: a pilot randomized controlled trial

BACKGROUND

Up to 3% of all Emergency Department (ED) visits are due to skin and soft tissue infections such as non-purulent cellulitis. The current treatment failure rate is approximately 20%. Evidence is lacking regarding the optimal outpatient management of cellulitis.

OBJECTIVES

To evaluate the feasibility of a randomized trial comparing high-dose (1000 mg) to standard-dose (500 mg) cephalexin to treat ED patients with cellulitis.

METHODS

A parallel arm double-blind randomized controlled pilot trial conducted at two EDs in Canada. Eligible participants were adults (age ≥ 18 years) presenting to the ED with non-purulent cellulitis and determined by the treating emergency physician to be eligible for outpatient management with oral antibiotics. Participants were randomized to high-dose or standard-dose cephalexin four times daily for 7 days. The primary feasibility outcome was participant recruitment rate (target ≥ 35%). The preliminary primary effectiveness outcome was oral antibiotic treatment failure.

RESULTS

Of 134 eligible participants approached for trial participation, 69 (51.5%, 95% CI 43.1 to 59.8%) were recruited and randomized. After excluding three randomized participants due to an alternate diagnosis, 33 participants were included in each arm. Nineteen eligible cases (14.2%) were missed. Loss to follow-up was 6.1%. Treatment failure occurred in four patients (12.9%) in the standard-dose arm versus one patient (3.2%) in the high-dose arm. A greater proportion had minor adverse events in the high-dose arm. No patients had an unplanned hospitalization within 14 days.

CONCLUSION

This pilot randomized controlled trial comparing high-dose to standard-dose cephalexin for ED patients with cellulitis demonstrated a high participant recruitment rate and that a full-scale trial is feasible. High-dose cephalexin had fewer treatment failures but with a higher proportion of minor adverse effects. The findings of this pilot will be used to inform the design of a future large trial.

TRIAL REGISTRATION

This trial was registered at ClinicalTrials.gov (NCT04471246).

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

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

Polymicrobial Clostridioides difficile lung empyema

Clostridioides (Clostridium) difficile is a well-known cause of enteritis and antibiotic-associated diarrhea. Extraintestinal C. difficile infection is uncommon, with most extraintestinal infections involving the intra-abdominal cavity and anatomic structures adjacent to the colon. Empyema secondary to C. difficile is especially rare, with only a handful of cases reported in the medical literature. A standard antibiotic treatment regimen for C. difficile empyema does not currently exist, and data chronicling successful treatment is limited. We present the case of an 80-year-old woman with a polymicrobial C. difficile empyema who was successfully treated with multiple chest tube insertions and intravenous vancomycin.

The impact of an outpatient parenteral antibiotic therapy (OPAT) clinic for adults with cellulitis: an interrupted time series study

Emergency department (ED) patients with cellulitis requiring intravenous antibiotics may be eligible for outpatient parenteral antibiotic therapy (OPAT). The primary objective was to determine whether implementation of an OPAT clinic results in decreased hospitalizations and return ED visits for patients receiving OPAT. We conducted an interrupted time series study involving adults with cellulitis presenting to two EDs and treated with intravenous antibiotics. The intervention was the OPAT clinic, which involved follow up at 48-96 h with an infectious disease physician to determine the need for ongoing intravenous antibiotics (implemented January 1, 2014). The primary outcomes were hospital admission and return ED visits within 14 days. Secondary outcomes were treatment failure (admission after initiating OPAT) and adverse peripheral line or antibiotic events. We used an interrupted time series design with segmented regression analysis over one-year pre-intervention and one-year post-intervention. 1666 patients were included. At the end of the study period, there was a non-significant 12% absolute increase in hospital admissions (95% CI - 1.6 to 25.5%; p = 0.084) relative to what would have been expected in the absence of the intervention, but a significant 40.7% absolute reduction in return ED visits (95% CI 25.6-55.9%; p < 0.001). Treatment failure rates were < 2% and adverse events were < 6% in both groups. Implementation of an OPAT clinic significantly reduced return ED visits for cellulitis, but did not reduce hospital admission rates. An ED-to-OPAT clinic model is safe, and has a low rate of treatment failures.

A behavioural approach to specifying interventions: what insights can be gained for the reporting and implementation of interventions to reduce antibiotic use in hospitals?

Background

Reducing unnecessary antibiotic exposure is a key strategy in reducing the development and selection of antibiotic-resistant bacteria. Hospital antimicrobial stewardship (AMS) interventions are inherently complex, often requiring multiple healthcare professionals to change multiple behaviours at multiple timepoints along the care pathway. Inaction can arise when roles and responsibilities are unclear. A behavioural perspective can offer insights to maximize the chances of successful implementation.

Objectives

To apply a behavioural framework [the Target Action Context Timing Actors (TACTA) framework] to existing evidence about hospital AMS interventions to specify which key behavioural aspects of interventions are detailed.

Methods

Randomized controlled trials (RCTs) and interrupted time series (ITS) studies with a focus on reducing unnecessary exposure to antibiotics were identified from the most recent Cochrane review of interventions to improve hospital AMS. The TACTA framework was applied to published intervention reports to assess the extent to which key details were reported about what behaviour should be performed, who is responsible for doing it and when, where, how often and with whom it should be performed.

Results

The included studies (n = 45; 31 RCTs and 14 ITS studies with 49 outcome measures) reported what should be done, where and to whom. However, key details were missing about who should act (45%) and when (22%). Specification of who should act was missing in 79% of 15 interventions to reduce duration of treatment in continuing-care wards.

Conclusions

The lack of precise specification within AMS interventions limits the generalizability and reproducibility of evidence, hampering efforts to implement AMS interventions in practice.

Barriers and Facilitators to Implementation of Antibiotic Stewardship Programmes in Hospitals in Developed Countries: Insights From Transnational Studies

Objectives: To identify perceived influences on implementation of antibiotic stewardship programmes (ASPs) in hospitals, across healthcare systems, and to exemplify the use of a behavioral framework to conceptualize those influences. Methods: EMBASE and MEDLINE databases were searched from 01/2001 to 07/2017 and reference lists were screened for transnational studies that reported barriers and/or facilitators to implementing actual or hypothetical ASPs or ASP-supporting strategies. Extracted data were synthesized using content analysis with the Theoretical Domains Framework as an organizing framework. Commonly reported influences were quantified. Results: From 3,196 abstracts 75 full-text articles were screened for inclusion. Eight studies met the eligibility criteria. The number of countries involved in each study ranged from 2 to 36. These studies included a total of 1849 participants. North America, Europe and Australasia had the strongest representation. Participants were members of special interest groups, designated hospital representatives or clinical experts. Ten of the 14 theoretical domains in the framework were present in the results reported in the included studies. The most commonly reported (≥4 out of 8 studies) influences on ASP implementation were coded in the domain "environmental context and resources" (e.g., problems with data and information systems; lack of key personnel; inadequate financial resources) and "goals" (other higher priorities). Conclusions: Despite an extensive transnational research effort, there is evidence from international studies of substantial barriers to implementing ASPs in hospitals, even in developed countries. Large-scale efforts to implement hospital antibiotic stewardship in those countries will need to overcome issues around inadequacy of information systems, unavailability of key personnel and funding, and the competition from other priority initiatives. We have enhanced the evidence base to inform guidance by taking a behavioral approach to identify influences on ASP uptake. Systematic review registration: PROSPERO registration number CRD42017076425.

Trends in health care-associated infections in acute care hospitals in Canada: an analysis of repeated point-prevalence surveys

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.

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

BACKGROUND

The clinical and molecular epidemiology of health care-associated Clostridium difficile infection in nonepidemic settings across Canada has evolved since the first report of the virulent North American pulsed-field gel electrophoresis type 1 (NAP1) strain more than 15 years ago. The objective of this national, multicentre study was to describe the evolving epidemiology and molecular characteristics of health care-associated C. difficile infection in Canada during a post-NAP1-epidemic period, particularly patient outcomes associated with the NAP1 strain.

METHODS

Adult inpatients with C. difficile infection were prospectively identified, using a standard definition, between 2009 and 2015 through the Canadian Nosocomial Infection Surveillance Program (CNISP), a network of 64 acute care hospitals. Patient demographic characteristics, severity of infection and outcomes were reviewed. Molecular testing was performed on isolates, and strain types were analyzed against outcomes and epidemiologic trends.

RESULTS

Over a 7-year period, 20 623 adult patients admitted to hospital with health care-associated C. difficile infection were reported to CNISP, and microbiological data were available for 2690 patients. From 2009 to 2015, the national rate of health care-associated C. difficile infection decreased from 5.9 to 4.3 per 10 000 patient-days. NAP1 remained the dominant strain type, but infection with this strain has significantly decreased over time, followed by an increasing trend of infection with NAP4 and NAP11 strains. The NAP1 strain was significantly associated with a higher rate of death attributable to C. difficile infection compared with non-NAP1 strains (odds ratio 1.91, 95% confidence interval [CI] 1.29-2.82). Isolates were universally susceptible to metronidazole; one was nonsusceptible to vancomycin. The proportion of NAP1 strains within individual centres predicted their rates of health care-associated C. difficile infection; for every 10% increase in the proportion of NAP1 strains, the rate of health care-associated C. difficile infection increased by 3.3% (95% CI 1.7%-4.9%).

INTERPRETATION

Rates of health care-associated C. difficile infection have decreased across Canada. In nonepidemic settings, NAP4 has emerged as a common strain type, but NAP1, although decreasing, continues to be the predominant circulating strain and remains significantly associated with higher attributable mortality.

Duration of Antibiotic Therapy in Sepsis Secondary to Urinary Stones: A Retrospective Observational Study

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Evaluation of an emergency department to outpatient parenteral antibiotic therapy program for cellulitis

OBJECTIVE

Emergency department (ED) patients with non-purulent skin and soft tissue infections (SSTIs) requiring intravenous antibiotics may be managed via outpatient parenteral antibiotic therapy (OPAT). Prospective studies describing the performance of an ED-to-OPAT clinic program are lacking. The primary objective was to determine the OPAT treatment failure rate for ED patients with non-purulent SSTIs.

METHODS

We conducted a prospective observational cohort study of adults with non-purulent SSTIs managed via an ED-to-OPAT clinic program. OPAT treatment failure was defined as hospitalization after a minimum of 48 h of OPAT for: worsening infection; intravenous line complications; or adverse antibiotic effects. Secondary outcomes were to describe OPAT clinic processes, patient satisfaction, and physician rationale for selecting intravenous antibiotics.

RESULTS

We enrolled a consecutive sample of 153 patients [mean age 60.5 years, 82 male (53.6%)]; 137 patients (89.5%) attended their clinic appointment. OPAT treatment failure was 4.4%. None of the adverse intravenous line (10.9%) and adverse antibiotic (8.0%) events required hospitalization. Patients reported high satisfaction with timeliness of referral (median score 9 out of 10) and overall care received (median score of 10). The top five reasons given by physicians for selecting intravenous therapy were: clinical impression (52.9%); failed oral therapy (41.8%); diabetes (17.6%); severe pain (7.8%); and peripheral vascular disease (7.8%).

CONCLUSIONS

This prospective study demonstrates that an ED-to-OPAT clinic program for non-purulent SSTIs is safe, has a low rate of treatment failures and results in high patient satisfaction. The rationale for selecting intravenous antibiotics showed significant variability among ED physicians.

Hospital-acquired Clostridium difficile infection: an institutional costing analysis

BACKGROUND

Healthcare-acquired Clostridium difficile infection (HA-CDI) is a common infection and a financial burden on the healthcare system.

AIM

To estimate the hospital-based financial costs of HA-CDI by comparing time-fixed statistical models that attribute cost to the entire hospital stay to time-varying statistical models that adjust for the time between admission, diagnosis of HA-CDI, and discharge and that only attribute HA-CDI costs post diagnosis.

METHODS

A retrospective cohort study was conducted (April 2008 to March 2011) using clinical and administrative costing data of inpatients (≥15 years) who were admitted to The Ottawa Hospital with stays >72 h. Two time-fixed analyses, ordinary least square regression and generalized linear regression, were contrasted with two time-dependent approaches using Kaplan-Meier survival curve.

FINDINGS

A total of 49,888 admissions were included and 366 (0.73%) patients developed HA-CDI. Estimated total costs (Canadian dollars) from time-fixed models were as high as $74,928 per patient compared to $28,089 using a time-varying model, and these were 1.47-fold higher compared to a patient without HA-CDI (incremental cost $8,997 per patient). The overall annual institutional cost at The Ottawa Hospital associated with HA-CDI was as high as $10.07 million using time-fixed models and $1.62 million using time-varying models.

CONCLUSION

When calculating costs associated with HA-CDI, accounting for the time between admission, diagnosis, and discharge can substantially reduce the estimated institutional costs associated with HA-CDI.

Predictors of Oral Antibiotic Treatment Failure for Nonpurulent Skin and Soft Tissue Infections in the Emergency Department

BACKGROUND

Current guideline recommendations for optimal management of nonpurulent skin and soft tissue infections (SSTIs) are based on expert consensus. There is a lack of evidence to guide emergency physicians regarding selection of patients for oral versus intravenous antibiotic therapy. The primary objective was to identify predictors associated with oral antibiotic treatment failure.

METHODS

We performed a health records review of adults (age ≥ 18 years) with nonpurulent SSTIs treated at two tertiary care emergency departments (EDs). Oral antibiotic treatment failure was defined as any of the following after a minimum of 48 hours of oral therapy due to worsening infection: 1) hospitalization, 2) change in class of oral antibiotic, or 3) switch to intravenous therapy. Multivariable logistic regression was used to identify predictors independently associated with oral antibiotic treatment failure.

RESULTS

We identified 500 patients (mean ± SD age = 64 ± 19 years, 279 male [55.8%], and 126 [25.2%] with diabetes). Of 288 patients who had received a minimum of 48 hours of oral antibiotics, there were 85 oral antibiotic treatment failures (29.5%). Tachypnea at triage (odds ratio [OR] = 6.31, 95% confidence interval [CI] = 1.80 to 22.08), chronic ulcers (OR = 4.90, 95% CI = 1.68-14.27), history of methicillin-resistant Staphylococcus aureus (MRSA) colonization or infection (OR = 4.83, 95% CI = 1.51 to 15.44), and cellulitis in the past 12 months (OR = 2.23, 95% CI = 1.01 to 4.96) were independently associated with oral antibiotic treatment failure CONCLUSION: This is the first study to evaluate predictors of oral antibiotic treatment failure for nonpurulent SSTIs treated in the ED. Tachypnea at triage, chronic ulcers, history of MRSA colonization or infection, and cellulitis within the past year were independently associated with oral antibiotic treatment failure. Emergency physicians should consider these risk factors when deciding on oral versus intravenous antimicrobial therapy for outpatient management of nonpurulent SSTIs.

Patient- and hospital-level predictors of vancomycin-resistant Enterococcus (VRE) bacteremia in Ontario, Canada

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.

Prioritizing research areas for antibiotic stewardship programmes in hospitals: a behavioural perspective consensus paper

SCOPE

Antibiotic stewardship programmes (ASPs) are necessary in hospitals to improve the judicious use of antibiotics. While ASPs require complex change of key behaviours on individual, team organization and policy levels, evidence from the behavioural sciences is underutilized in antibiotic stewardship studies across the world, including high-income countries (HICs). A consensus procedure was performed to propose research priority areas for optimizing effective implementation of ASPs in hospital settings using a behavioural perspective.

METHODS

A workgroup for behavioural approaches to ASPs was convened in response to the fourth call for leading expert network proposals by the Joint Programming Initiative on Antimicrobial Resistance (JPIAMR). Eighteen clinical and academic specialists in antibiotic stewardship, implementation science and behaviour change from four HICs with publicly funded healthcare systems (e.g. Canada, Germany, Norway and the UK) met face-to-face to agree on broad research priority areas using a structured consensus method. Question addressed and recommendations: The consensus process assessing the ten identified research priority areas resulted in recommendations that need urgent scientific interest and funding to optimize effective implementation of ASPs for hospital inpatients in HICs with publicly funded healthcare systems. We suggest and detail behavioural science evidence-guided research efforts in the following areas: (a) comprehensively identifying barriers and facilitators to implementing ASPs and clinical recommendations intended to optimize antibiotic prescribing; (b) identifying actors ('who') and actions ('what needs to be done') of ASPs and clinical teams; (c) synthesizing available evidence to support future research and planning for ASPs; (d) specifying the activities in current ASPs with the purpose of defining a control group for comparison with new initiatives; (e) defining a balanced set of outcomes and measures to evaluate the effects of interventions focused on reducing unnecessary exposure to antibiotics; (f) conducting robust evaluations of ASPs with built-in process evaluations and fidelity assessments; (g) defining and designing ASPs; (h) establishing the evidence base for impact of ASPs on resistance; (i) investigating the role and impact of government and policy contexts on ASPs; and (j) understanding what matters to patients in ASPs in hospitals.

CONCLUSIONS

Assessment, revisions and updates of our priority-setting exercise should be considered at intervals of 2 years. To propose research priority areas in low- and middle-income countries, the methodology reported here could be applied.

Risk Factors for Methicillin-Resistant Staphylococcus aureus (MRSA) Colonization Among Patients Admitted to Obstetrical Units: A Nested Case-Control Study

OBJECTIVE

Methicillin-resistant Staphylococcus aureus (MRSA) among obstetrical patients can increase birth complications for both mothers and infants, but little is known about the risk factors for MRSA in this population. The objective of this study was to determine the prevalence of MRSA among obstetrical patients and identify risk factors associated with MRSA colonization.

METHODS

This nested case-control study used obstetrical patients with MRSA colonization identified through a universal screening program at The Ottawa Hospital (February 2008-January 2010). Cases and three matched controls were compared using chi-square tests for categorical variables, median and interquartile range (IQR), and Wilcoxon rank-sum tests for continuous variables. Conditional logistic regression using ORs and 95% CIs was used to identify risk factors. Standard microbiologic techniques and pulsed-field gel electrophoresis of the MRSA isolates from case patients were performed.

RESULTS

Out of 11 478 obstetrical patients, 39 (0.34%) were MRSA colonized; 117 patients were selected as matched controls. The median age was 30 (IQR 27.5-35.00) and median length of stay was 2.55 days (IQR 1.95-3.24). Only MRSA cases had a previous MRSA infection (4 vs. 0). MRSA cases had significantly higher parity (median 3; IQR 2-5) compared with controls (median 2; IQR 1-3) (OR 1.52; 95% CI 1.22-1.90) CONCLUSION: This study identified a low prevalence of MRSA among obstetrical patients. Risk factors associated with MRSA colonization were previous MRSA infection and multiparity. Obstetrical patients who previously tested positive for MRSA should be placed on contact precautions at the time of hospital admission because this is a risk factor for future colonization.

Cost Analysis of Universal Screening vs. Risk Factor-Based Screening for Methicillin-Resistant Staphylococcus aureus (MRSA)

Background

The literature remains conflicted regarding the most effective way to screen for MRSA. This study was designed to assess costs associated with universal versus risk factor-based screening for the reduction of nosocomial MRSA transmission.

Methods

The study was conducted at The Ottawa Hospital, a large multi-centre tertiary care facility with approximately 47,000 admissions annually. From January 2006-December 2007, patients underwent risk factor-based screening for MRSA on admission. From January 2008 to August 2009 universal MRSA screening was implemented. A comparison of costs incurred during risk factor-based screening and universal screening was conducted. The model incorporated probabilities relating to the likelihood of being tested and the results of polymerase chain reaction (PCR) testing with associated effects in terms of MRSA bacteremia and true positive and negative test results. Inputted costs included laboratory testing, contact precautions and infection control, private room costs, housekeeping, and length of hospital stay. Deterministic sensitivity analyses were conducted.

Results

The risk factor-based MRSA screening program screened approximately 30% of admitted patients and cost the hospital over $780 000 annually. The universal screening program screened approximately 83% of admitted patients and cost over $1.94 million dollars, representing an excess cost of $1.16 million per year. The estimated additional cost per patient screened was $17.76.

Conclusion

This analysis demonstrated that a universal MRSA screening program was costly from a hospital perspective and was previously known to not be clinically effective at reducing MRSA transmission. These results may be useful to inform future model-based economic analyses of MRSA interventions.

Assessing the magnitude and trends in hospital acquired infections in Canadian hospitals through sequential point prevalence surveys

Background

Healthcare acquired infections (HAI) are an important public health problem in developed countries, but comprehensive data on trends over time are lacking. Prevalence surveys have been used as a surrogate for incidence studies and can be readily repeated.

Methods

The Canadian Nosocomial Infection Surveillance Program conducted prevalence surveys in 2002 and 2009 in a large network of major Canadian acute care hospitals. NHSN definitions of HAI were used. Use of isolation precautions on the survey day was documented.

Results

In 2009, 9,953 acute care inpatients were surveyed; 1,234 infections (124/1000) were found, compared to 111/1000 in 2002, (p < 0.0001). There was increased prevalence of urinary tract infection (UTI) and Clostridium difficile, offset by decreases in pneumonia and bloodstream infection. Use of isolation precautions increased from 77 to 148 per 1000 patients (p < 0.0001), attributable to increased use of contact precautions in patients infected or colonized with antimicrobial resistant organisms.

Conclusion

Between 2002 and 2009 HAI prevalence increased by 11.7 % in a network of major Canadian hospitals due to increases in Clostridium difficile and urinary tract infection. The use of isolation precautions increased by 92.2 % attributable to increased contact isolation. National prevalence surveys are useful tools to assess evolving trends in HAI.

Identifying changes in the role of the infection preventionist through the 2014 practice analysis study conducted by the Certification Board of Infection Control and Epidemiology, Inc

The Certification Board of Infection Control and Epidemiology, Inc (CBIC) is a voluntary autonomous multidisciplinary board that provides direction and administers the certification process for professionals who are responsible for the infection prevention and control program in a health care facility. The CBIC performs a practice analysis approximately every 4-5 years. The practice analysis is an integral part of the certification examination development process and serves as the backbone of the test content outline. In 2013, the CBIC determined that a practice analysis was required and contracted with Prometric to facilitate the process. The practice analysis was carried out in 2014 by a diverse group of subject matter experts from the United States and Canada. The practice analysis results showed a significant change in the number of tasks and associated knowledge required for the competent practice of infection prevention. As authorized by the CBIC, the test committee is currently reclassifying the bank of examination questions as required and is writing and reviewing questions based on the updated test specifications and content outline. The new content outline will be reflected in examinations that are taken beginning in July 2015. This iterative process of assessing and updating the certification examination ensures not only a valid competency tool but a true reflection of current practices.

Prevalence of antimicrobial use in a network of Canadian hospitals in 2002 and 2009

BACKGROUND

Increasing antimicrobial resistance has been identified as an important global health threat. Antimicrobial use is a major driver of resistance, especially in the hospital sector. Understanding the extent and type of antimicrobial use in Canadian hospitals will aid in developing national antimicrobial stewardship priorities.

METHODS

In 2002 and 2009, as part of one-day prevalence surveys to quantify hospital-acquired infections in Canadian Nosocomial Infection Surveillance Program hospitals, data were collected on the use of systemic antimicrobial agents in all patients in participating hospitals. Specific agents in use (other than antiviral and antiparasitic agents) on the survey day and patient demographic information were collected.

RESULTS

In 2002, 2460 of 6747 patients (36.5%) in 28 hospitals were receiving antimicrobial therapy. In 2009, 3989 of 9953 (40.1%) patients in 44 hospitals were receiving antimicrobial therapy (P<0.001). Significantly increased use was observed in central Canada (37.4% to 40.8%) and western Canada (36.9% to 41.1%) but not in eastern Canada (32.9% to 34.1%). In 2009, antimicrobial use was most common on solid organ transplant units (71.0% of patients), intensive care units (68.3%) and hematology/oncology units (65.9%). Compared with 2002, there was a significant decrease in use of first-and second-generation cephalosporins, and significant increases in use of carbapenems, antifungal agents and vancomycin in 2009. Piperacillin-tazobactam, as a proportion of all penicillins, increased from 20% in 2002 to 42.8% in 2009 (P<0.001). There was a significant increase in simultaneous use of >1 agent, from 12.0% of patients in 2002 to 37.7% in 2009.

CONCLUSION

From 2002 to 2009, the prevalence of antimicrobial agent use in Canadian Nosocomial Infection Surveillance Program hospitals significantly increased; additionally, increased use of broad-spectrum agents and a marked increase in simultaneous use of multiple agents were observed.

Laboratory-Confirmed Pandemic H1N1 Influenza in Hospitalized Adults: Findings from the Canadian Nosocomial Infections Surveillance Program, 2009-2010

Surveillance for pandemic H1N1 influenza was conducted between June 1, 2009, and May 31, 2010, among adults at 40 participating hospitals in the Canadian Nosocomial Infection Surveillance Program. The first wave was characterized by a higher proportion of Aboriginals and pregnant women as well as severe outcomes, compared to the second wave.

Infect Control Hosp Epidemiol 2012;33(10):1043-1046

Understanding practice: factors that influence physician hand hygiene compliance

OBJECTIVE

To identify the behavioral determinants--both barriers and enablers--that may impact physician hand hygiene compliance.

DESIGN

A qualitative study involving semistructured key informant interviews with staff physicians and residents.

SETTING

An urban, 1,100-bed multisite tertiary care Canadian hospital.

PARTICIPANTS

A total of 42 staff physicians and residents in internal medicine and surgery.

METHODS

Semistructured interviews were conducted using an interview guide that was based on the theoretical domains framework (TDF), a behavior change framework comprised of 14 theoretical domains that explain health-related behavior change. Interview transcripts were analyzed using thematic content analysis involving a systematic 3-step approach: coding, generation of specific beliefs, and identification of relevant TDF domains.

RESULTS

Similar determinants were reported by staff physicians and residents and between medicine and surgery. A total of 53 specific beliefs from 9 theoretical domains were identified as relevant to physician hand hygiene compliance. The 9 relevant domains were knowledge; skills; beliefs about capabilities; beliefs about consequences; goals; memory, attention, and decision processes; environmental context and resources; social professional role and identity; and social influences.

CONCLUSIONS

We identified several key determinants that physicians believe influence whether and when they practice hand hygiene at work. These beliefs identify potential individual, team, and organization targets for behavior change interventions to improve physician hand hygiene compliance.

The feasibility of e-learning as a quality improvement tool

RATIONAL, AIMS AND OBJECTIVES

Many quality problems exist in health care. We aim to investigate the feasibility and acceptability of using e-learning (defined as computer-based learning modules) to address gaps in quality of care.

METHODS

We performed a qualitative evaluation of participants in a pilot e-learning program. Physician members of six medical teaching units (MTUs) at a multi-site tertiary care teaching hospital were asked to complete two e-learning modules addressing hand hygiene practices and management of community-acquired pneumonia (CAP). An e-learning design team created online modules that were made available to members of the six MTUs for 4 weeks using a password secured website. Use of the modules was voluntary. Participants' perceptions of module content, mode of delivery, and suggestions for improvement were determined through focus groups. We then performed content analysis on the transcripts. We used system data to define patterns of module access.

RESULTS

Out of 55 eligible users, 30 (55%) logged onto the system at least once. Residents (14/30, 47%) were less likely to use the system than medical students (9/14, 64%) and attending staff (7/11, 64%). Learners at all levels thought the modules were easy to use. Participants liked the knowledge-based material in the CAP module because it directly applied to their work. There were less favourable opinions of the hand hygiene module

CONCLUSIONS

Generating e-learning modules targeted at gaps in quality of care is feasible and acceptable to learners. Future studies should assess whether these approaches lead to desired changes in behavior.

Evaluating and operationalizing an environmental auditing program: a pilot study

BACKGROUND

Environmental auditing is an important tool to ensure consistent and effective cleaning. Our pilot study compared an alcohol-based fluorescent marking product and an adenosine-5'-triphosphate bioluminescence product for use in an environmental auditing program to determine which product was more practical and acceptable to users.

METHODS

Both products were tested on 15 preselected high touch objects in randomly selected patient rooms, following regular daily cleaning. A room was considered a "pass" if ≥80% of surfaces were adequately cleaned as defined by manufacturers' guidelines. A qualitative survey assessed user preference and operational considerations.

RESULTS

Using fluorescent marking, 9 of 37 patient rooms evaluated (24%) were considered a "pass" after daily cleaning. Using adenosine-5'-triphosphate bioluminescence, 21 of 37 patient rooms passed (57%). There was great variability in results between different high touch objects. Eighty percent of users preferred the alcohol-based fluorescent marking product because it provided an effective visual aid to coach staff on proper cleaning techniques and allowed simple and consistent application.

CONCLUSIONS

Environmental auditing using translucent, alcohol-based fluorescent marking best met the requirements of our organization. Our results reinforce the importance of involving a multidisciplinary team in evaluating and operationalizing an environmental auditing program.

Trends in antiviral therapy of adults hospitalized with influenza in Canada since the end of the 2009 pandemic

Background

Multiple observational studies have associated antiviral treatment of patients hospitalized with influenza with improved outcome, including reduced mortality. During the 2009–2010 H1N1 pandemic increased use of antiviral treatment of hospital patients was reported. We have carried out prospective surveillance for influenza in patients in a large network of Canadian hospitals since 2006. We wished to assess trends in antiviral use in the two seasons (2010–2011 and 2011–2012) since the end of the pandemic.

Findings

Adults (>16 years) testing positive for influenza at the time of or during admission to participating Canadian hospitals were prospectively reviewed. In 2009–2010 there were 1132 confirmed cases, 1107 in 2010–2011 and 631 in 2011–2012. Information on antiviral therapy was available in >95% in each year. Rising to 89.6% in 2009, the proportion of adult patients treated with antiviral therapy fell to 79.9% and 65.7% in the two subsequent seasons (p < 0.001). Oseltamivir was the antiviral agent used in >98% of cases in each year. The median time from onset of symptoms to initiation of antiviral therapy was three days. The treatment proportion fell across all age groups, co-morbid conditions and disease severity.

Conclusion

Despite evidence for benefit of antiviral therapy, and clinical practice guidelines recommending treatment of this population, antiviral therapy of Canadian adults hospitalized with influenza has progressively fallen in the two seasons since the end of the 2009–2010 influenza pandemic.

Healthcare-associated influenza in Canadian hospitals from 2006 to 2012

OBJECTIVE

To determine trends, patient characteristics, and outcome of patients with healthcare-associated influenza in Canadian hospitals.

DESIGN

Prospective surveillance of laboratory-confirmed influenza among hospitalized adults was conducted from 2006 to 2012. Adults with positive test results at or after admission to the hospital were assessed. Influenza was considered to be healthcare associated if symptom onset was equal to or more than 96 hours after admission to a facility or if a patient was readmitted less than 96 hours after discharge or admitted less than 96 hours after transfer from another facility. Baseline characteristics of influenza patients were collected. Patients were reassessed at 30 days to determine the outcome.

SETTING

Acute care hospitals participating in the Canadian Nosocomial Infection Surveillance Program.

RESULTS

A total of 570 (17.3%) of 3,299 influenza cases were healthcare associated; 345 (60.5%) were acquired in a long-term care facility (LTCF), and 225 (39.5%) were acquired in an acute care facility (ACF). There was year-to-year variability in the rate and proportion of cases that were healthcare associated and variability in the proportion that were acquired in a LTCF versus an ACF. Patients with LTCF-associated cases were older, had a higher proportion of chronic heart disease, and were less likely to be immunocompromised compared with patients with ACF-associated cases; there was no significant difference in 30-day all-cause and influenza-specific mortality.

CONCLUSIONS

Healthcare-associated influenza is a major component of the burden of disease from influenza in hospitals, but the proportion of cases that are healthcare associated varies markedly from year to year, as does the proportion of healthcare-associated infections that are acquired in an ACF versus an LTCF.

Understanding the burden of influenza infection among adults in Canadian hospitals: a comparison of the 2009-2010 pandemic season with the prepandemic and postpandemic seasons

BACKGROUND

The degree to which the 2009-2010 influenza pandemic season differed from previous and subsequent influenza seasons in Canadian hospitals has not yet been assessed.

METHODS

Surveillance for laboratory-confirmed influenza among adults in 51 Canadian Nosocomial Infection Surveillance Program hospitals was conducted between November 1, 2006, and May 31, 2011. Inpatient characteristics, treatment, and outcomes of influenza cases in the pandemic season (2009-2010) were compared with those in the prepandemic (2006-2007 to 2008-2009) and postpandemic (2010-2011) seasons.

RESULTS

The incidence of influenza infection was lower in the postpandemic season (1.59/1,000 admissions) compared with the prepandemic seasons (2.00/1,000 admissions; P < .001) and the pandemic season (1.80/1,000 admissions; P < .001). The proportion of cases classified as health care-associated was much smaller during the pandemic season (6.6%) than in either the prepandemic season (23.2%; P < .001) or the postpandemic season (23.6%; P < .001). Inpatients in the pandemic season were significantly younger compared with those in the prepandemic and postpandemic seasons (P < .001). Inpatients in the pandemic season were less likely to have been vaccinated (P < .001), but more likely to be treated with antiviral agents (P < .001), than inpatients in both the prepandemic and postpandemic seasons. Intensive care unit admission was greater during the pandemic season, but there were no significant differences in 30-day mortality among the seasons.

CONCLUSIONS

Among adult inpatients, the pH1N1 pandemic season differed from seasonal influenza in terms of age, vaccination status, antiviral use, and intensive care unit admission, but not in terms of 30-day mortality.

Epidemiology and outcome of pneumonia caused by methicillin-resistant Staphylococcus aureus (MRSA) in Canadian hospitals

Background

MRSA remains a leading cause of hospital-acquired (HAP) and healthcare-associated pneumonia (HCAP). We describe the epidemiology and outcome of MRSA pneumonia in Canadian hospitals, and identify factors contributing to mortality.

Methods

Prospective surveillance for MRSA pneumonia in adults was done for one year (2011) in 11 Canadian hospitals. Standard criteria for MRSA HAP, HCAP, ventilator-associated pneumonia (VAP), and community-acquired pneumonia (CAP) were used to identify cases. MRSA isolates underwent antimicrobial susceptibility testing, and were characterized by pulsed-field gel electrophoresis (PFGE) and Panton-Valentine leukocidin (PVL) gene detection. The primary outcome was all-cause mortality at 30 days. A multivariable analysis was done to examine the association between various host and microbial factors and mortality.

Results

A total of 161 patients with MRSA pneumonia were identified: 90 (56%) with HAP, 26 (16%) HCAP, and 45 (28%) CAP; 23 (14%) patients had VAP. The mean (± SD) incidence of MRSA HAP was 0.32 (± 0.26) per 10,000 patient-days, and of MRSA VAP was 0.30 (± 0.5) per 1,000 ventilator-days. The 30-day all-cause mortality was 28.0%. In multivariable analysis, variables associated with mortality were the presence of multiorgan failure (OR 8.1; 95% CI 2.5-26.0), and infection with an isolate with reduced susceptibility to vancomycin (OR 2.5, 95% CI 1.0-6.3).

Conclusions

MRSA pneumonia is associated with significant mortality. Severity of disease at presentation, and infection caused by an isolate with elevated MIC to vancomcyin are associated with increased mortality. Additional studies are required to better understand the impact of host and microbial variables on outcome.

Predicting influenza vaccination uptake among health care workers: what are the key motivators?

BACKGROUND

Health care worker (HCW) vaccination was critical to protecting HCW during the H1N1 pandemic. However, vaccine uptake rates fell below recommended targets. This study examined motivators and barriers influencing HCW pH1N1 vaccination to identify modifiable factors that can improve influenza vaccine uptake.

METHODS

A cross-sectional survey was conducted at a large Canadian tertiary care hospital. HCW (N = 3,275) completed measures of demographics, vaccination history, influenza risk factors, and attitudes toward pH1N1 vaccination. Self-reported vaccination was verified with staff vaccination records. Of the total sample, 2,862 (87.4%) HCW received the pH1N1 vaccine. Multiple logistic regression analyses were used to predict HCW vaccination.

RESULTS

HCW attitudes toward vaccination significantly predicted vaccination, even after adjusting for demographics, vaccine history, and influenza risk factors. This model correctly predicted 95% (confidence interval [CI]: 0.93-0.96) of HCW vaccination. Key modifiable factors driving HCW vaccination include (1) desire to protect family members and patients, (2) belief that vaccination is important even if one is healthy, (3) confidence in vaccine safety, and (4) supervisor and physician encouragement.

CONCLUSION

This research identified fundamental reasons why HCW get vaccinated and provides direction for future influenza vaccination programs. To enhance vaccine uptake, it is important to target HCW attitudes in influenza vaccine campaigns and create a culture of vaccine promotion in the workplace, including strong messaging from supervisors and physicians.

Patient-level factors associated with methicillin-resistant Staphylococcus aureus carriage at hospital admission: a systematic review

BACKGROUND

Selective methicillin-resistant Staphylococcus aureus (MRSA) screening programs target high-risk populations. To characterize high-risk populations, we conducted this systematic review to identify patient-level factors associated with MRSA carriage at hospital admission.

METHODS

Studies were identified in the MEDLINE (1950-2011) and EMBASE (1980-2011) databases. English studies were included if they examined adult populations and used multivariable analyses to examine patient-level factors associated with MRSA carriage at hospital admission. From each study, we abstracted details of the population, the risk factors examined, and the association between the risk factors and MRSA carriage at hospital admission.

RESULTS

Our electronic search identified 972 citations, from which we selected 27 studies meeting our inclusion criteria. The patient populations varied across the studies. Ten studies included all patients admitted to hospital, and the others were limited to specific hospital areas. MRSA detection methods also varied across studies. Ten studies obtained specimens from the nares only, whereas other studies also swabbed wounds, catheter sites, and the perianal region. Methods of MRSA diagnoses included polymerase chain reaction tests, cultures in various agar mediums, and latex agglutination tests. Patient age, gender, previous admission to hospital, and previous antibiotic use were the risk factors most commonly examined. The risk factor definition and study methods varied among studies to an extent that precluded meta-analysis.

CONCLUSION

The existing literature cannot be used to identify risk factors for MRSA colonization at the time of hospitalization. Future studies should be aware of the differences in the existing literature and aim to develop standardized risk factor definitions.

Improving physician hand hygiene compliance using behavioural theories: a study protocol

BACKGROUND

Healthcare-associated infections affect 10% of patients in Canadian acute-care hospitals and are significant and preventable causes of morbidity and mortality among hospitalized patients. Hand hygiene is among the simplest and most effective preventive measures to reduce these infections. However, compliance with hand hygiene among healthcare workers, specifically among physicians, is consistently suboptimal. We aim to first identify the barriers and enablers to physician hand hygiene compliance, and then to develop and pilot a theory-based knowledge translation intervention to increase physicians' compliance with best hand hygiene practice.

DESIGN

The study consists of three phases. In Phase 1, we will identify barriers and enablers to hand hygiene compliance by physicians. This will include: key informant interviews with physicians and residents using a structured interview guide, informed by the Theoretical Domains Framework; nonparticipant observation of physician/resident hand hygiene audit sessions; and focus groups with hand hygiene experts. In Phase 2, we will conduct intervention mapping to develop a theory-based knowledge translation intervention to improve physician hand hygiene compliance. Finally, in Phase 3, we will pilot the knowledge translation intervention in four patient care units.

DISCUSSION

In this study, we will use a behavioural theory approach to obtain a better understanding of the barriers and enablers to physician hand hygiene compliance. This will provide a comprehensive framework on which to develop knowledge translation interventions that may be more successful in improving hand hygiene practice. Upon completion of this study, we will refine the piloted knowledge translation intervention so it can be tested in a multi-site cluster randomized controlled trial.

Skin and soft tissue infections caused by methicillin-resistant Staphylococcus aureus (MRSA): an affliction of the underclass

OBJECTIVE

The objective of this study was to determine whether skin and soft tissue infections (SSTIs) caused by methicillin-resistant Staphylococcus aureus (MRSA) in patients presenting to The Ottawa Hospital emergency departments (TOHEDs) differed from SSTIs caused by methicillin-susceptible Staphylococcus aureus (MSSA) with regard to risk factors, management, and outcomes.

METHODS

All patients seen at TOHEDs in 2006 and 2007 with SSTIs who yielded MRSA or MSSA in cultures from the site of infection were eligible for inclusion. We excluded patients with decubitus ulcers and infections related to diabetes or peripheral vascular disease. We used an unmatched case-control design. Cases were defined as patients with MRSA isolated from the infection site, and controls were defined as patients with MSSA isolated from the infection site. Data were collected retrospectively from health records and laboratory and hospital information systems.

RESULTS

A total of 153 patients were included in the study (81 cases and 72 controls). The mean age of cases was 37 years, compared to 47 years for the controls (p < 0.001). Cases were more likely to have transient residence (31% v. 3% [OR 15.6, 95% CI 3.9-61.8, p < 0.001]), present with abscesses (64% v. 15% [OR 9.9, 95% CI 4.3-23.7, p < .001]), have a documented history of hepatitis C infection (28% v. 3% [OR 13.9, 95% CI 3.9-55.0, p < 0.001]), and have a history of substance abuse (53% v. 10% [OR 10.5, 95% CI 4.4-25.1, p < 0.001]). Cases most commonly used crack cocaine and injection drugs.

CONCLUSION

SSTIs caused by MRSA at TOHEDs mainly occur in a population that is young and transient with comorbidities such as hepatitis C and substance abuse.

Factors associated with staff and physician influenza immunization at a children's hospital in Ontario, Canada

In 2005, employees and physicians of the Children’s Hospital of Eastern Ontario were surveyed about their experiences with and receipt of the 2003–2004 influenza vaccination. With a 29% response rate, 91% of respondents stated that they had received the 2003–2004 vaccine, and physicians were the most likely to have done so (97.2%). Using logistic regression, the only factor significantly predictive of whether an employee or physician received the vaccine was whether they had awareness of a previous formal influenza immunization campaign.

A decrease in the number of cases of necrotizing enterocolitis associated with the enhancement of infection prevention and control measures during a Staphylococcus aureus outbreak in a neonatal intensive care unit

OBJECTIVE

Most cases of necrotizing enterocolitis (NEC) are sporadic, but outbreaks in hospital settings suggest an infectious cause. Our neonatal intensive care unit (NICU) experienced an outbreak of methicillin-sensitive Staphylococcus aureus (MSSA). We aimed to assess whether the enhancement of infection prevention and control measures would be associated with a reduction in the number of cases of NEC.

DESIGN

Retrospective chart review.

SETTING

A 24-bed, university-affiliated, inborn level 3 NICU.

PARTICIPANTS

Infants of less than 30 weeks gestation or birth weight ≤ 1,500 g admitted to the NICU between January 2007 and December 2008 were considered at risk of NEC. All cases of NEC were reviewed.

INTERVENTIONS

Infection prevention and control measures, including hand hygiene education, were enhanced during the outbreak. Avoidance of overcapacity in the NICU was reinforced, environmental services (ES) measures were enhanced, and ES hours were increased.

RESULTS

Two hundred eighty-two at-risk infants were admitted during the study. Their gestational age and birth weight (mean ± SD) were 28.2 ± 2.7 weeks and 1,031 ± 290 g, respectively. The proportion of NEC was 18/110 (16.4%) before the outbreak, 1/54 (1.8%) during the outbreak, and 4/118 (3.4%) after the outbreak. After adjustment for gestational age, birth weight, gender, and singleton versus multiple births, the proportion was lower in the postoutbreak period than in the preoutbreak period (P < .002).

CONCLUSION

Although this observational study cannot establish a causal relationship, there was a significant decrease in the incidence of NEC following implementation of enhanced infection prevention and control measures to manage an MSSA outbreak.

Tropheryma whipplei aortic valve endocarditis without systemic Whipple's disease

Culture-negative endocarditis is most often the result of prior antimicrobial therapy. Tropheryma whipplei is the etiologic agent of Whipple's disease, which is typically characterized by diarrhea, weight loss, and intra-abdominal lymphadenopathy. We present the case of a 48-year-old male with Whipple's endocarditis of the aortic valve who did not develop signs of systemic Whipple's disease. Our patient was treated with a regimen that included ceftriaxone for 6 weeks prior to his cardiac surgery, yet valve pathology demonstrated abundant T. whipplei, suggesting that a prolonged antibiotic course is necessary for the treatment of Whipple's endocarditis.

Use of personal protective equipment in Canadian pediatric emergency departments

OBJECTIVE

Numerous barriers to maintaining infection control practices through the use of personal protective equipment (PPE) exist in the emergency department (ED). This study examined the knowledge, self-reported behaviours, and barriers to compliance with infection control practices and the use of PPE in Canadian pediatric EDs.

METHODS

A self-administered survey instrument consisting of 21 questions was developed and piloted for this study. The survey was mailed to all individuals listed in the Pediatric Emergency Research Canada database of physicians practicing pediatric emergency medicine in Canada.

RESULTS

A total of 186 physicians were surveyed, and 123 (66%) participated. Twenty-two percent of participants reported that they had never received PPE training and 32% had not been trained in the previous 2 years. Fifty-three percent reported being very or somewhat comfortable with their knowledge of transmission-based isolation practices. Participants were correct on a mean of 4.9 of 11 knowledge-based questions (SD 1.7). For scenarios assessing self-reported use of PPE, participants selected answers that reflected PPE use in accordance with national infection control standards in a mean of 1.0 of 6 scenarios (SD 1.0). Participants reported that they would be more likely to use PPE if patients were clearly identified prior to physician assessment, equipment was accessible, and PPE use was made a priority in their ED.

CONCLUSIONS

Knowledge and self-reported adherence to recommended infection control practices among Canadian pediatric emergency physicians is suboptimal. Early identification of patients requiring PPE, convenient access to PPE, and improved education regarding isolation and PPE practices may improve adherence.

Cardiac complications in patients with community-acquired pneumonia: a systematic review and meta-analysis of observational studies

BACKGROUND

Community-acquired pneumonia (CAP) is a leading cause of morbidity and mortality. CAP can trigger acute cardiac events. We sought to determine the incidence of major cardiac complications in CAP patients to characterize the magnitude of this problem.

METHODS AND FINDINGS

Two investigators searched MEDLINE, Scopus, and EMBASE for observational studies of immunocompetent adults with clinical and radiological evidence of CAP that reported any of the following: overall cardiac complications, incident heart failure, acute coronary syndromes (ACS), or incident cardiac arrhythmias occurring within 30 days of CAP diagnosis. At a minimum, studies had to establish enrolment procedures and inclusion and exclusion criteria, enroll their patients sequentially, and report the incidence of cardiac complications as a function of their entire cohorts. Studies with focus on nosocomial or health care-associated pneumonia were not included. Review of 2,176 citations yielded 25 articles that met eligibility and minimum quality criteria. Seventeen articles (68%) reported cohorts of CAP inpatients. In this group, the pooled incidence rates for overall cardiac complications (six cohorts, 2,119 patients), incident heart failure (eight cohorts, 4,215 patients), acute coronary syndromes (six cohorts, 2,657 patients), and incident cardiac arrhythmias (six cohorts, 2,596 patients), were 17.7% (confidence interval [CI] 13.9-22.2), 14.1% (9.3-20.6), 5.3% (3.2-8.6), and 4.7% (2.4-8.9), respectively. One article reported cardiac complications in CAP outpatients, four in low-risk (not severely ill) inpatients, and three in high-risk inpatients. The incidences for all outcomes except overall cardiac complications were lower in the two former groups and higher in the latter. One additional study reported on CAP outpatients and low-risk inpatients without discriminating between these groups. Twelve studies (48%) asserted the evaluation of cardiac complications in their methods but only six (24%) provided a definition for them. Only three studies, all examining ACS, carried out risk factor analysis for these events. No study analyzed the association between cardiac complications and other medical complications or their impact on other CAP outcomes.

CONCLUSIONS

Major cardiac complications occur in a substantial proportion of patients with CAP. Physicians and patients need to appreciate the significance of this association for timely recognition and management of these events. Strategies aimed at preventing pneumonia (i.e., influenza and pneumococcal vaccination) in high-risk populations need to be optimized. Further research is needed to understand the mechanisms underlying this association, measure the impact of cardiac complications on other CAP outcomes, identify those patients with CAP at high risk of developing cardiac complications, and design strategies to prevent their occurrence in this population.

Staphylococcus aureus bacteraemia of unknown primary source: where do we stand?

There is no generally held definition of Staphylococcus aureus bacteraemia (SAB) of unknown source. For this paper, we consider it to occur when one or more positive blood cultures obtained from a patient grows S. aureus and the origin of the bacteraemia is uncertain after history, physical examination, chest radiography and any further investigations provoked by clinical findings. The incidence of SAB appears to be rising, particularly community-acquired (CA), but also hospital- or healthcare-acquired (HA). Major drivers appear to be intravenous drug use and increasing use of indwelling intravascular devices. There is an increasing prevalence of meticillin-resistant S. aureus (MRSA), both CA and HA. There is increasing hospital acquisition of MRSA that is phenotypically like CA strains, and there is increasing community-based treatment of HA infection. Metastatic infection is a risk of SAB. Infective endocarditis (IE) is a longstanding dreaded concern of SAB. Transoesophageal echocardiography appears to be a superior modality of recognising IE in the context of SAB and can guide the duration of therapy. Prosthetic joints and heart valves are at particular risk of haematogenous seeding from SAB. Implications of the rise of CA-MRSA in terms of metastatic infection warrant further study.

USE OF AN ELECTRONIC DATA WAREHOUSE TO ENHANCE CARDIAC SURGICAL SITE SURVEILLANCE AT A LARGE CANADIAN CENTRE

Background/Purpose: Surgical site infection surveillance to determineincidence is a key infection control activity. Case detection is labour-intensive, therefore most infection control programs use manual or simple electronic mechanisms to “trigger” chart review. However, such “trigger” mechanisms are also labour-intensive, and often of poor specificity. Our objective is to develop a complex trigger mechanism using data from an electronic data warehouse, to improve specificity of surveillance of surgical site infection compared to current trigger mechanisms. Methods: We will derive an electronic trigger tool for cardiac surgical site infection surveillance using a nested case-control design, among a cohort of all patients undergoing coronary artery bypass grafting, cardiac valve repairor replacement, or heart transplant at the University of Ottawa Heart Institute, from July 1 2004 to June 30 2007. We will perform a systematic literature review to identify potential trigger factors to include in the model, then construct the trigger tool by backwards stepwise logistic regression. The best-fit model will be used to calculate the probability of surgical site infection. We will select the threshold probability to use in surveillance by visual inspection of receiver-operator-characteristic curves. The accuracy of this electronic trigger mechanism will be compared to pre-existing manual and simple electronic mechanisms using relative true positive ratios and relative false positive ratios. Results/Conclusions: We have selected 200 cases of surgical site infection and 541 controls from among 3744 procedures performed during the study period. As of the date ofthis abstract we are still undertaking the systematic review.

Transvaginal oocyte retrieval for in vitro fertilization complicated by ovarian abscess during pregnancy

OBJECTIVE

To describe an ovarian abscess presenting very late after oocyte retrieval for IVF with several unusual clinical features.

DESIGN

Case report.

SETTING

Academic medical center.

PATIENT(S)

A 35-year-old nulliparous woman underwent IVF with uncomplicated transvaginal oocyte retrieval (TVOR), resulting in a dizygotic twin pregnancy. At 13 weeks of pregnancy she presented with vaginal discharge, but was otherwise constitutionally well. At 30 weeks she developed a low-grade fever, and the diagnosis of ovarian abscess was made. She received broad-spectrum antibiotics, and the abscess was drained percutaneously after cesarean delivery of twins.

INTERVENTION(S)

Antimicrobial therapy; cesarean section; postpartum percutaneous drainage.

MAIN OUTCOME MEASURE(S)

Clinical and radiologic resolution of infection.

RESULT(S)

Complete resolution of the abscess; delivery of healthy twins.

CONCLUSION(S)

Infectious complications of TVOR and other surgical procedures usually occur within days of the intervention. Our case illustrates the possibility of infectious complications of TVOR presenting months after the procedure. Our patient did not become acutely ill due to the formation of a spontaneous vaginal fistula, which allowed the abscess to drain. The optimal management of this complication is unclear, but final resolution of any pelvic abscess generally requires drainage.