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

Derivation and internal validation of the multivariate toxigenic C. difficile diarrhea model and risk score for emergency room and hospitalized patients with diarrhea

Background

Many factors have been associated with the risk of toxigenic C. difficile diarrhea (TCdD). This study derived and internally validated a multivariate model for estimating the risk of TCdD in patients with diarrhea using readily available clinical factors.

Methods

A random sample of 3,050 symptomatic emergency department or hospitalized patients undergoing testing for toxigenic C. difficile at a single teaching hospital between 2014 and 2018 was created. Unformed stool samples positive for both glutamate dehydrogenase antigen by enzyme immunoassay and tcdB gene by polymerase chain reaction were classified as TCdD positive. The TCdD Model was created using logistic regression and was modified to the TCdD Risk Score to facilitate its use.

Results

8.1% of patients were TCdD positive. TCdD risk increased with abdominal pain (adjusted odds ratio 1.3; 95% CI, 1.0-1.8), previous C. difficile diarrhea (2.5, 1.1-6.1), and prior antibiotic exposure, especially when sampled in the emergency department (4.2, 2.5-7.0) versus the hospital (1.7, 1.3-2.3). TCdD risk also increased when testing occurred earlier during the hospitalization encounter, when age and white cell count increased concurrently, and with decreased eosinophil count. In internal validation, the TCdD Model had moderate discrimination (optimism-corrected C-statistic 0.65, 0.62-0.68) and good calibration (optimism-corrected Integrated Calibration Index [ICI] 0.017, 0.001-0.022). Performance decreased slightly for the TCdD Risk Score (C-statistic 0.63, 0.62-0.63; ICI 0.038, 0.004-0.038).

Conclusions

TCdD risk can be predicted using readily available clinical risk factors with modest accuracy.

Effectiveness of Bio-K+ for the prevention of Clostridioides difficile infection: Stepped-wedge cluster-randomized controlled trial

OBJECTIVE

To evaluate the impact of administering probiotics to prevent Clostridioides difficile infection (CDI) among patients receiving therapeutic antibiotics.

DESIGN

Stepped-wedge cluster-randomized trial between September 1, 2016, and August 31, 2019.

SETTING

This study was conducted in 4 acute-care hospitals across an integrated health region.

PATIENTS

Hospitalized patients, aged ≥55 years.

METHODS

Patients were given 2 probiotic capsules daily (Bio-K+, Laval, Quebec, Canada), containing 50 billion colony-forming units of Lactobacillus acidophilus CL1285, L. casei LBC80R, and L. rhamnosus CLR2. We measured hospital-acquired CDI (HA-CDI) and the number of positive C. difficile tests per 10,000 patient days as well as adherence to administration of Bio-K+ within 48 and 72 hours of antibiotic administration. Mixed-effects generalized linear models, adjusted for influenza admissions and facility characteristics, were used to evaluate the impact of the intervention on outcomes.

RESULTS

Overall adherence of Bio-K+ administration ranged from 76.9% to 84.6% when stratified by facility and periods. Rates of adherence to administration within 48 and 72 hours of antibiotic treatment were 60.2% -71.4% and 66.7%-75.8%, respectively. In the adjusted analysis, there was no change in HA-CDI (incidence rate ratio [IRR], 0.92; 95% confidence interval [CI], 0.68-1.23) or C. difficile positivity rate (IRR, 1.05; 95% CI, 0.89-1.24). Discharged patients may not have received a complete course of Bio-K+. Our hospitals had a low baseline incidence of HA-CDI. Patients who did not receive Bio-K+ may have differential risks of acquiring CDI, introducing selection bias.

CONCLUSIONS

Hospitals considering probiotics as a primary prevention strategy should consider the baseline incidence of HA-CDI in their population and timing of probiotics relative to the start of antimicrobial administration.

Bacterial microbiome changes after fecal transplantation for recurrent Clostridioides difficile infection in the Brazilian center

Clostridioides difficile infection (CDI) poses a significant global health threat owing to its substantial morbidity and associated healthcare costs. A key challenge in controlling CDI is the risk of multiple recurrences, which can affect up to 30% of patients. In such instances, fecal microbiota transplantation (FMT) is increasingly recognized as the optimal treatment. However, few related studies have been conducted in developing countries, and the microbiota composition of Brazilian patients and its dynamic modification post-FMT remain largely unexplored. This study aimed to evaluate the changes in the bacterial gut microbiome in Brazilian patients with recurrent CDI post-FMT. Ten patients underwent FMT, and the primary and overall CDI resolution rates were 80% and 90% after the first and second FMT, respectively. FMT was associated with an early increase in Shannon's diversity, evident as soon as 1 week post-FMT and persisting for at least 25 days post-treatment. Post-treatment, the abundance of Firmicutes increased and that of Proteobacteria decreased. Specifically, the abundance of the genera Ruminococcus, Faecalibacterium, Lachnospira, and Roseburia of the Firmicutes phylum was significantly higher 1 week post-transplantation, with Ruminococcus and Faecalibacterium remaining enriched 25 days post-transplantation. This study is the first of its kind in Brazil to evaluate the microbiota of a donor and patients undergoing FMT. Our findings suggest that FMT can induce remarkable changes in the gut microbiota, characterized by an early and sustained increase in diversity lasting at least 25 days. FMT also promotes enrichment of genera such as Ruminococcus spp., Faecalibacterium spp., and Roseburia spp., essential for therapeutic success.

Multimodal vaccination targeting the receptor binding domains of Clostridioides difficile toxins A and B with an attenuated Salmonella Typhimurium vector (YS1646) protects mice from lethal challenge

Developing a vaccine against Clostridioides difficile is a key strategy to protect the elderly. Two candidate vaccines using a traditional approach of intramuscular (IM) delivery of recombinant antigens targeting C. difficile toxins A (TcdA) and B (TcdB) failed to meet their primary endpoints in large phase 3 trials. To elicit a mucosal response against C. difficile, we repurposed an attenuated strain of Salmonella Typhimurium (YS1646) to deliver the receptor binding domains (rbd) of TcdA and TcdB to the gut-associated lymphoid tissues, to elicit a mucosal response against C. difficile. In this study, YS1646 candidates with either rbdA or rbdB expression cassettes integrated into the bacterial chromosome at the attTn7 site were generated and used in a short-course multimodal vaccination strategy that combined oral delivery of the YS1646 candidate(s) on days 0, 2, and 4 and IM delivery of recombinant antigen(s) on day 0. Five weeks after vaccination, mice had high serum IgG titers and increased intestinal antigen-specific IgA titers. Multimodal vaccination increased the IgG avidity compared to the IM-only control. In the mesenteric lymph nodes, we observed increased IL-5 secretion and increased IgA+ plasma cells. Oral vaccination skewed the IgG response toward IgG2c dominance (vs IgG1 dominance in the IM-only group). Both oral alone and multimodal vaccination against TcdA protected mice from lethal C. difficile challenge (100% survival vs 30% in controls). Given the established safety profile of YS1646, we hope to move this vaccine candidate forward into a phase I clinical trial.IMPORTANCEClostridioides difficile remains a major public health threat, and new approaches are needed to develop an effective vaccine. To date, the industry has focused on intramuscular vaccination targeting the C. difficile toxins. Multiple disappointing results in phase III trials have largely confirmed that this may not be the best strategy. As C. difficile is a pathogen that remains in the intestine, we believe that targeting mucosal immune responses in the gut will be a more successful strategy. We have repurposed a highly attenuated Salmonella Typhimurium (YS1646), originally pursued as a cancer therapeutic, as a vaccine vector. Using a multimodal vaccination strategy (both recombinant protein delivered intramuscularly and YS1646 expressing antigen delivered orally), we elicited both systemic and local immune responses. Oral vaccination alone completely protected mice from lethal challenge. Given the established safety profile of YS1646, we hope to move these vaccine candidates forward into a phase I clinical trial.

Increased Incidence and Risk of Septicemia and Urinary Tract Infection After Clostridioides difficile Infection

Background

Although increased occurrence of septicemia in persons with Clostridioides difficile infection (CDI) has been reported, incidence rates and risk of septicemia and urinary tract infection (UTI) after CDI are unclear.

Methods

The first episode of CDI was identified using 2011-2017 MarketScan and CMS Medicare data and CDI cases categorized by standard surveillance definitions. Uninfected persons were frequency matched 4:1 to cases by the CDI case surveillance definition. Multivariable Cox proportional hazards models were used to identify risk factors for septicemia and UTI within 90 days of CDI onset, accounting for the competing risk of death in the Medicare population.

Results

The incidence of septicemia was highest after hospital-onset CDI in the Medicare, younger commercial, and younger Medicaid populations (25.5%, 15.7%, and 19.5%, respectively) and lowest in those with community-associated CDI (3.8%, 4.3%, and 8.3%, respectively). In contrast, the incidence of UTI was highest in those with other healthcare facility onset CDI in all 3 populations (32.1%, 24.2%, and 18.1%, respectively). Hospital-onset CDI was associated with highest risk of septicemia compared with uninfected controls in all 3 populations. In the younger populations, risk of septicemia was more uniform across the CDI surveillance definitions. The risk of UTI was significantly higher in all CDI surveillance categories compared to uninfected controls, and among CDI cases it was lowest in those with community-associated CDI.

Conclusions

The incidence of septicemia is high after CDI, particularly after hospital-onset infection. Additional preventive measures are needed to reduce infectious complications of CDI.

Insights into the Evolving Epidemiology of Clostridioides difficile Infection and Treatment: A Global Perspective

Clostridioides difficile remains an important public health threat, globally. Since the emergence of the hypervirulent strain, ribotype 027, new strains have been reported to cause C. difficile infection (CDI) with poor health outcomes, including ribotypes 014/020, 017, 056, 106, and 078/126. These strains differ in their geographic distribution, genetic makeup, virulence factors, and antimicrobial susceptibility profiles, which can affect their ability to cause disease and respond to treatment. As such, understanding C. difficile epidemiology is increasingly important to allow for effective prevention measures. Despite the heightened epidemiological surveillance of C. difficile over the past two decades, it remains challenging to accurately estimate the burden and international epidemiological trends given the lack of concerted global effort for surveillance, especially in low- and middle-income countries. This review summarizes the changing epidemiology of C. difficile based on available data within the last decade, highlights the pertinent ribotypes from a global perspective, and discusses evolving treatments for CDI.

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

Background

Healthcare-associated infections (HAIs) and antimicrobial resistance (AMR) continue to contribute to excess morbidity and mortality among Canadians. This report describes epidemiologic and laboratory characteristics and trends of HAIs and AMR from 2017 to 2021 (Candida auris 2012-2021) using surveillance and laboratory data submitted by hospitals to the Canadian Nosocomial Infection Surveillance Program (CNISP) and by provincial laboratories to the National Microbiology Laboratory (NML).

Methods

Data collected from 88 Canadian sentinel acute care hospitals between January 1, 2017, and December 31, 2021, for Clostridioides difficile infections (CDI), carbapenemase-producing Enterobacterales (CPE), methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infections (BSIs) and vancomycin-resistant Enterococcus (VRE) BSIs. Candida auris (C. auris) surveillance was initiated in 2019 by CNISP and in 2012 by the NML. Case counts, rates, outcomes, molecular characterization and antimicrobial resistance profiles are presented.

Results

From 2017 to 2021, increased rates per 10,000 patient days were observed for MRSA BSIs (35%; 0.84-1.13), VRE BSIs (43%; 0.23-0.33) and CPE infections (166%, 0.03-0.08). CDI rates decreased 11% (5.68-5.05). Thirty-one C. auris isolates were identified in Canada from 2012 to 2021, with the majority from Western Canada (68%).

Conclusion

From 2017 to 2021, the incidence of MRSA and VRE BSIs, and CPE infections increased in Canadian acute care hospitals participating in a national sentinel network (CNISP) while CDI decreased. Few C. auris isolates were identified from 2012 to 2021. Reporting standardized surveillance data and the consistent application of infection prevention and control practises in acute care hospitals are critical to help decrease the burden of HAIs and AMR in Canada.

Costs Attributable to Clostridioides difficile Infection Based on the Setting of Onset

BACKGROUND

Although hospital-onset Clostridioides difficile infection (CDI) is associated with significant healthcare costs, the economic burden of CDI with onset in other facilities or the community has not been well studied.

METHODS

Incident CDI cases were identified using 2011-2017 Medicare fee-for-service data. Controls were randomly selected in a 4:1 ratio matching to the CDI case surveillance definition. Inverse probability of exposure weights were used to balance on measured confounders. One-, 3-, and 5-year cumulative costs attributable to CDI were computed using a 3-part estimator (parametric survival model and pair of 2-part models predicting costs separately in intervals where death did and did not occur).

RESULTS

A total of 60 492 CDI cases were frequency-matched to 241 968 controls. One-, 3-, and 5-year adjusted attributable costs were highest for hospital-onset CDI at $14 257, $18 953, and $21 792, respectively, compared with hospitalized controls and lowest for community-associated CDI compared with community controls at $1013, $3161, and $6454, respectively. Adjusted 1-, 3-, and 5-year costs attributable to community-onset healthcare facility-associated CDI were $8222, $13 066, and $16 329 and for other healthcare facility-onset CDI were $5345, $6764, and $7125, respectively.

CONCLUSIONS

Economic costs attributable to CDI in elderly persons were highest for hospital-onset and community-onset healthcare facility-associated CDI. Although lower, attributable costs due to CDI were significantly higher in cases with CDI onset in the community or other healthcare facility than for comparable persons without CDI. Additional strategies to prevent CDI in the elderly are needed to reduce morbidity and healthcare expenditures.

Incidence of healthcare-associated Clostridioides difficile infection in a quaternary referral university hospital in Brazil

Clostridioides difficile infection (CDI) is an important cause of diarrhea in hospitals worldwide. The incidence of CDI in Latin America has not yet been standardized. To fill this gap, the present study performed a daily active surveillance, for three months, between April to July of 2021, at a quaternary referral university hospital in Brazil. The incidence density was 9.2 cases per 10,000 patient-days. Cases were associated mostly with ribotypes 014 and 106 (44% and 22%, respectively). Ribotype 027 was not identified. The findings strongly reinforce the need for broad epidemiological studies on the incidence of CDI in Brazilian hospitals to increase the understanding, prevention, and treatment of this infection.

Molecular Epidemiology, Clinical Course, and Implementation of Specific Hygiene Measures in Hospitalised Patients with Clostridioides difficile Infection in Brandenburg, Germany

(1) Background: Clostridioides difficile infections (CDI) have increased worldwide, and the disease is one of the most common healthcare-associated infections (HAI). This study aimed to evaluate the molecular epidemiology of C. difficile, the clinical outcome, and the time of initiation of specific hygiene measures in patients with CDI in a large tertiary-care hospital in Brandenburg. (2) Methods: Faecal samples and data from hospitalised patients diagnosed with CDI were analysed from October 2016 to October 2017. The pathogens were isolated, identified as toxigenic C. difficile, and subsequently subtyped using PCR ribotyping and whole genome sequencing (WGS). Data regarding specific hygiene measures for handling CDI patients were collected. (3) Results: 92.1% of cases could be classified as healthcare-associated (HA)-CDI. The recurrence rate within 30 and 90 days after CDI diagnosis was 15.7% and 18.6%, and the mortality rate was 21.4% and 41.4%, respectively. The most frequent ribotypes (RT) were RT027 (31.3%), RT014 (18.2%), and RT005 (14.1%). Analysis of WGS data using cgMLST showed that all RT027 isolates were closely related; they were assigned to two subclusters. Single-room isolation or barrier measures were implemented in 95.7% patients. (4) Conclusions: These data show that RT027 is regionally predominant, thus highlighting the importance of specific hygiene measures to prevent and control CDI and the need to improve molecular surveillance of C. difficile at the local and national level.

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

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

Epidemiology of Clostridium (Clostridioides) difficile Infection in Southeast Asia

This review describes the current understanding of Clostridium (Clostridioides) difficile infection (CDI) in southeast Asia regarding the prevalence of CDI, C. difficile detection methods, antimicrobial susceptibility profiles, and the potential significance of a One Health approach to prevention and control. Our initial focus had been the Indochina region, however, due to limited studies/surveillance of CDI in Indochina, other studies in southeast Asian countries and neighboring Chinese provinces are presented here for comparison. Clostridium (Clostridioides) difficile infection is one of the most common causes of hospital-acquired gastroenteritis worldwide. Since its discovery as a cause of pseudomembranous colitis in 1978, C. difficile-related disease has been more prevalent in high-income rather than low-income countries. This may be because of a lack of knowledge and awareness about the significance of C. difficile and CDI, resulting in underreporting of true rates. Moreover, the abuse of antimicrobials and paucity of education regarding appropriate usage remain important driving factors in the evolution of CDI worldwide. The combination of underreporting of true CDI rates, along with continued misuse of antimicrobial agents, poses an alarming threat for regions like Indochina. C. difficile ribotype (RT) 027 has caused outbreaks in North America and European countries, however, C. difficile RT 017 commonly occurs in Asia. Toxin A-negative/toxin B-positive (A-B+) strains of RT 017 have circulated widely and caused outbreaks throughout the world and, in southeast Asia, this strain is endemic.

Clostridioides difficile Toxin B PCR Cycle Threshold as a Predictor of Toxin Testing in Stool Specimens from Hospitalized Adults

Rapid, accurate detection of Clostridioides difficile toxin may potentially be predicted by toxin B PCR cycle threshold (tcdB Ct). We investigated the validity of this approach in an inpatient adult population. Patients who tested positive by C. difficile PCR (Cepheid GeneXpert) from December 2016 to October 2020 (n = 368) at a tertiary medical center were included. All stool samples were further tested by rapid glutamate dehydrogenase (GDH)/toxin B EIA and cell cytotoxin neutralization assay (CCNA). Receiver operating characteristic curves were analyzed. The area under the curve for tcdB Ct predicting toxin result by EIA was 0.795 (95% confidence interval (CI) 0.747−0.843) and by CCNA was 0.771 (95% CI 0.720−0.822). The Youden Ct cutoff for CCNA was ≤27.8 cycles (sensitivity 65.0%, specificity 77.2%). For specimens with Ct ≤ 25.0 cycles (n = 115), CCNA toxin was positive in >90%. The negative predictive value of tcdB Ct for CCNA was no greater than 80% regardless of cutoff chosen. In summary, very low Ct values (≤25.0) could have limited value as a rapid indicator of positive toxin status by CCNA in our patient population. A broad distribution of Ct values for toxin-negative and toxin-positive specimens precluded more robust prediction. Additional data are needed before broader application of Ct values from qualitatively designed assays to clinical laboratory reporting.

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.

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.

Safety and immunogenicity of different Clostridioides (Clostridium) difficile vaccine formulations in two early phase randomized studies of healthy adults aged 50-85 years

BACKGROUND

Two phase 1/phase 2 studies assessed 2 formulations of investigational bivalent Clostridioides (Clostridium) difficile vaccine (QS-21 adjuvanted toxoid and toxoid-alone) in healthy adults 50-85 years of age.

METHODS

The QS-21 adjuvanted toxoid vaccine study randomized subjects 3:1 to 100 μg QS-21-containing C difficile vaccine or placebo administered in a shortened-month (Months 0, 1, 3) or day (Days 1, 8, 30) regimen. The toxoid-alone vaccine study randomized subjects 3:3:1 to receive 100 or 200 μg unadjuvanted C difficile vaccine formulation or placebo in Stages 1 and 2 (sentinel cohorts of different age groups), and 3:1 to receive the selected dose of unadjuvanted C difficile vaccine formulation or placebo in Stage 3 (Days 1, 8, 30). Safety was the primary outcome for both studies. Immunogenicity was determined by measuring serum toxin A- and B-specific neutralizing antibodies.

RESULTS

In the day regimen, 10 reports across both studies of grade 3 injection site redness postdose 2 triggered predefined stopping rules. Local reactions in both studies were more common among vaccine versus placebo recipients. Injection site pain predominated and was generally mild in severity. Systemic events were infrequent and generally mild-to-moderate in severity. Adverse events were reported by 50.0%-75.0% and 16.7%-50.0% of subjects in the QS-21 and toxoid-alone studies, respectively. Immune responses peaked around Day 37 (shortened-month regimen) or between Day 15 and Month 2 (day regimen) and remained above baseline throughout follow-up.

CONCLUSIONS

Both formulations demonstrated robust immunogenicity. Both studies stopped early due to grade 3 injection site redness postdose 2 of the day regimen; neither formulation progressed to later stage development. Instead, an aluminum hydroxide-containing formulation of the vaccine candidate administered at 0, 1, and 6 months, which was safe and immunogenic in phase 1 and 2 studies, advanced to phase 3 studies.

Increased Community-Associated Clostridioides difficile Infections in Quebec, Canada, 2008-20151

The annual incidence rate of community-associated Clostridioides difficile infections in Quebec, Canada, has increased by 33.3%, from 0.51 (2008) to 0.68 (2015) cases/100,000 population, while incidence of healthcare-associated cases remained relatively stable. Possible causes include increased disease severity, increased antimicrobial drug use, emergence of virulent strains, and heightened physician awareness.

Mortality review as a tool to assess the contribution of healthcare-associated infections to death: results of a multicentre validity and reproducibility study, 11 European Union countries, 2017 to 2018

IntroductionThe contribution of healthcare-associated infections (HAI) to mortality can be estimated using statistical methods, but mortality review (MR) is better suited for routine use in clinical settings. The European Centre for Disease Prevention and Control recently introduced MR into its HAI surveillance.AimWe evaluate validity and reproducibility of three MR measures.MethodsThe on-site investigator, usually an infection prevention and control doctor, and the clinician in charge of the patient independently reviewed records of deceased patients with bloodstream infection (BSI), pneumonia, Clostridioides difficile infection (CDI) or surgical site infection (SSI), and assessed the contribution to death using 3CAT: definitely/possibly/no contribution to death; WHOCAT: sole cause/part of causal sequence but not sufficient on its own/contributory cause but unrelated to condition causing death/no contribution, based on the World Health Organization's death certificate; QUANT: Likert scale: 0 (no contribution) to 10 (definitely cause of death). Inter-rater reliability was assessed with weighted kappa (wk) and intra-cluster correlation coefficient (ICC). Reviewers rated the fit of the measures.ResultsFrom 2017 to 2018, 24 hospitals (11 countries) recorded 291 cases: 87 BSI, 113 pneumonia , 71 CDI and 20 SSI. The inter-rater reliability was: 3CAT wk 0.68 (95% confidence interval (CI): 0.61-0.75); WHOCAT wk 0.65 (95% CI: 0.58-0.73); QUANT ICC 0.76 (95% CI: 0.71-0.81). Inter-rater reliability ranged from 0.72 for pneumonia to 0.52 for CDI. All three measures fitted 'reasonably' or 'well' in > 88%.ConclusionFeasibility, validity and reproducibility of these MR measures was acceptable for use in HAI surveillance.

Epidemiology of community-acquired and recurrent Clostridioides difficile infection

Clostridioides difficile infection is a leading cause of healthcare-associated infections with significant morbidity and mortality. For the past decade, the bulk of infection prevention and epidemiologic surveillance efforts have been directed toward mitigating hospital-acquired C. difficile. However, the incidence of community-associated infection is on the rise. Patients with community-associated C. difficile tend to be younger and have lower mortality rate. Rates of recurrent C. difficile infection overall have decreased in the United States, but future research and public health endeavors are needed to standardize and improve disease detection, stratify risk factors in large-scale population studies, and to identify regional and local variations in strain types, reservoirs and transmission routes to help characterize and combat the changing epidemiology of C. difficile.

Burden of Clostridioides difficile infection (CDI) - a systematic review of the epidemiology of primary and recurrent CDI

BACKGROUND

Clostridioides difficile is a Gram-positive anaerobic bacterium, which causes Clostridioides difficile infection (CDI). It has been recognised as a leading cause of healthcare-associated infections and a considerable threat to public health globally. This systematic literature review (SLR) summarises the current evidence on the epidemiology and clinical burden of CDI.

METHODS

A SLR was conducted to identify CDI and recurrent CDI (rCDI) epidemiology studies, to evaluate patient and disease characteristics, incidence rates, epidemiological findings and risk factors. Embase, MEDLINE and the Cochrane Library databases were searched for English articles from 2009 to 2019. Included territories were the United Kingdom, France, Germany, Italy, Spain, Poland, US, Canada, Australia, Japan and China.

RESULTS

Of 11,243 studies identified, 165 fulfilled the selection criteria. An additional 20 studies were identified through targeted review of grey literature. The most widely reported findings were incidence and risk factors for CDI and rCDI. Among key studies reporting both healthcare-associated (HA-CDI) and community-associated CDI (CA-CDI) incidence rates for each country of interest, incidence rates per 10,000 patient days in the US were 8.00 and 2.00 for HA-CDI and CA-CDI, respectively. The highest incidence in Europe was reported in Poland (HA-CDI: 6.18 per 10,000 patient days, CA-CDI: 1.4 per 10,000 patient days), the lowest from the UK, at 1.99 per 10,000 patient days and 0.56 per 10,000 patient days for HA-CDI and CA-CDI, respectively. No clear trend for incidence over time emerged, with most countries reporting stable rates but some either a decrease or increase. Rates of recurrent CDI varied based on geographical setting. The rate of recurrence was lower in community-associated disease compared to healthcare-associated disease. Independent CDI risk factors identified common to both initial CDI and recurrent CDI included increasing age, antibiotic use, recent hospitalisation, and proton pump inhibitor (PPI) use. In addition, leukocyte count, length of hospital stays, and Charlson comorbidity index score featured as statistically significant risk factors for recurrent CDI, but these are not reported among the most common statistically significant risk factors for initial CDI.

CONCLUSIONS

Despite considerable heterogeneity, evidence suggests substantial incidence of recurrent and primary CDI, even after considerable efforts in the last decade.

Clostridioides difficile infections in Alberta: The validity of administrative data using ICD-10 diagnostic codes for CDI surveillance versus clinical infection surveillance

BACKGROUND

Clostridioides difficile infection (CDI) is one of the most common health care-associated infections. This study assessed the validity of the Discharge Abstract Database (DAD) compared to a traditional clinical surveillance method for identifying CDI.

METHODS

Retrospective analysis of all DAD records with International Statistical Classification of Diseases and Related Health Problems 10th Revision (ie, ICD-10) diagnostic code A04.7 (enterocolitis due to CDI) between April 2015 and March 2019 were compared to a clinical dataset of positive inpatient CDI for all acute care facilities in Alberta, Canada. Sensitivity and positive predictive values were calculated using R version 3.6.0.

RESULTS

The DAD had a sensitivity of 85.0% (95% confidence interval: 84.1%-85.8%) and a positive predictive value of 80.0% (95% confidence interval: 79.2%-80.0%). The CDI rate per 1,000 admissions over the study period was 28% higher in the DAD compared to Infection Prevention and Control surveillance.

DISCUSSION

The DAD does not distinguish symptomatic cases from asymptomatic cases and so indicators to identify symptomatic disease would need to be applied, potentially through a linkage to antibiotic treatment orders available in patient management systems.

CONCLUSIONS

The DAD is moderately sensitive for identifying symptomatic CDI cases in Alberta, Canada and caution should be applied when interpreting rates based on administrative data.

Time trends and predictors of laboratory-confirmed recurrent and severe Clostridioides difficile infections in Manitoba: a population-based study

BACKGROUND

Many previous studies of Clostridioides difficile infection (CDI) epidemiology have used hospital discharge data codes, which can have limited accuracy. We used a data set of laboratory-confirmed cases of CDI in the province of Manitoba, Canada, to describe the epidemiology of CDI over a decade.

METHODS

We conducted a population-based historical cohort study using Manitoba Health's population-wide laboratory-based CDI data set linked to administrative health databases. All individuals living in Manitoba and experiencing a CDI episode between 2005 and 2015 were included (n = 8471) and followed up from CDI diagnosis. We assessed time trends of CDI, incidence and predictors of recurrence and severe outcomes, and health care encounters after CDI diagnosis. CDI episodes were stratified by community versus hospital site of acquiring CDI.

RESULTS

Between 2005 and 2009, overall CDI diagnoses decreased by an average of 12.6% per year (95% confidence interval [CI] -4.4 to -20.0), with no statistically significant change from 2010 to 2015. In stratified analysis, incident and recurrent CDI had a similar decrease in the initial study time period and then stabilized. The proportion of community-associated CDI cases increased by an average of 4.8% per year (95% CI 2.8 to 6.8) during the study period. CDI acquired in a health care facility had a higher recurrence rate and more severe outcomes. Recurrence of CDI increased the likelihood of admission to hospital.

INTERPRETATION

Between 2005 and 2015, the rates of overall laboratory-confirmed CDI, incident CDI, recurrent CDI and severe outcomes following CDI initially decreased before stabilizing, and an increasing proportion of CDI cases were community-associated. There is an increasing need to test for CDI among outpatients with diarrhea and to increase efforts to prevent recurrent CDI.

Cost-effectiveness analysis of a fecal microbiota transplant center for treating recurrent C.difficile infection

OBJECTIVE

We assessed the cost-effectiveness of establishing a fecal microbial transplant (FMT) unit in Canada for the treatment of recurrent CDI.

DESIGN

We performed a cost-effectiveness analysis to determine the number of patients with recurrent CDI needed to treat (NNT) annually to make establishing a FMT unit cost-effective. We compared treating patients for their second recurrence of CDI with FMT in a jurisdiction with a FMT unit, compared to being treated with antibiotics; then sent to a medical center with FMT available for the third recurrence. We used a willingness to pay threshold of $50,000 per quality-adjusted-life-year gained.

RESULTS

The minimum annual NNT was 15 for FMT via colonoscopy, 17 for FMT via capsule, and 44 for FMT via enema compared with vancomycin, and 16, 18, and 47 compared with fidaxomicin, respectively. A medical center's minimum catchment area when establishing a FMT unit would have to be 56,849 if using FMT via colonoscopy, or 64,429 if using capsules.

CONCLUSION

We report the minimum number of patients requiring treatment annually with FMT to achieve cost-effectiveness, when including start-up and ongoing costs. FMT is cost-effective in Canada in populations with a sufficient number of eligible patients, ranging from 15 to 47 depending on the FMT modality used. This is crucial for medical jurisdictions making decisions about establishing a FMT unit for the treatment of recurrent CDI. The cost-effectiveness can be generalized in other countries.

Clostridioides difficile toxin testing and positivity in Manitoba, Canada

We assessed Clostridioides difficile toxin testing and positivity for all patients in Manitoba hospitals during June 2016-November 2018. The testing rate was 30 per 10,000 patient bed days (95% confidence interval [CI], 30-31) and the incidence rate was 3.5 per 10,000 patient bed days (95% CI, 3.3-3.7). The context of testing is essential to the interpretation of data among jurisdictions.

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 susceptibility of Clostridioides difficile isolated from diarrhoeal stool specimens of Canadian patients: summary of results from the Canadian Clostridioides difficile (CAN-DIFF) surveillance study from 2013 to 2017

Objectives

To summarize data generated by the Canadian Clostridioides difficile (CAN-DIFF) surveillance study from 2013 to 2017.

Methods

Isolates of C. difficile (n = 2158) were cultured from toxin-positive diarrhoeal stool specimens submitted by eight hospital laboratories to a coordinating laboratory. Antimicrobial susceptibility testing was performed according to the CLSI agar dilution method (M11, 2018). Isolate ribotypes were determined using an international, standardized, high-resolution capillary gel-based electrophoresis protocol.

Results

Of the 2158 isolates of C. difficile, 2133 (98.8%) had vancomycin MICs ≤2 mg/L [i.e. were vancomycin susceptible (EUCAST breakpoint tables, v 9.0, 2019) or WT (CLSI M100, 29th edition, 2019)]. Fidaxomicin MICs were lower than those of all other agents tested (MIC90, 0.5 mg/L); however, one isolate with a fidaxomicin MIC of &gt;8 mg/L was identified. Metronidazole MICs ranged from 0.12 to 4 mg/L; all isolates were metronidazole susceptible by the CLSI breakpoint (≤8 mg/L) compared with 96.8% susceptible by the EUCAST breakpoint (≤2 mg/L). In total, 182 different ribotypes were identified from 2013 to 2017. The most common ribotypes identified were 027 (19.3% of isolates) and 106 (8.2%). Ribotype 027 isolates were frequently moxifloxacin resistant (87.3% of isolates) and MDR (48.6%), associated with vancomycin (10/25, 40.0%) and metronidazole (58/69, 84.1%) resistance and from patients aged ≥80 years. The prevalence of ribotype 027 decreased significantly (P &lt; 0.0001) from 2013 (27.5%) to 2017 (9.0%) and was replaced by increases in ribotype 106 (P = 0.0003) and multiple less common ribotypes.

Conclusions

Periodic surveillance is required to monitor clinical isolates of C. difficile for changes to in vitro susceptibility testing profiles and ribotype evolution.

Trends in U.S. Burden of Clostridioides difficile Infection and Outcomes

BACKGROUND

Efforts to prevent Clostridioides difficile infection continue to expand across the health care spectrum in the United States. Whether these efforts are reducing the national burden of C. difficile infection is unclear.

METHODS

The Emerging Infections Program identified cases of C. difficile infection (stool specimens positive for C. difficile in a person ≥1 year of age with no positive test in the previous 8 weeks) in 10 U.S. sites. We used case and census sampling weights to estimate the national burden of C. difficile infection, first recurrences, hospitalizations, and in-hospital deaths from 2011 through 2017. Health care-associated infections were defined as those with onset in a health care facility or associated with recent admission to a health care facility; all others were classified as community-associated infections. For trend analyses, we used weighted random-intercept models with negative binomial distribution and logistic-regression models to adjust for the higher sensitivity of nucleic acid amplification tests (NAATs) as compared with other test types.

RESULTS

The number of cases of C. difficile infection in the 10 U.S. sites was 15,461 in 2011 (10,177 health care-associated and 5284 community-associated cases) and 15,512 in 2017 (7973 health care-associated and 7539 community-associated cases). The estimated national burden of C. difficile infection was 476,400 cases (95% confidence interval [CI], 419,900 to 532,900) in 2011 and 462,100 cases (95% CI, 428,600 to 495,600) in 2017. With accounting for NAAT use, the adjusted estimate of the total burden of C. difficile infection decreased by 24% (95% CI, 6 to 36) from 2011 through 2017; the adjusted estimate of the national burden of health care-associated C. difficile infection decreased by 36% (95% CI, 24 to 54), whereas the adjusted estimate of the national burden of community-associated C. difficile infection was unchanged. The adjusted estimate of the burden of hospitalizations for C. difficile infection decreased by 24% (95% CI, 0 to 48), whereas the adjusted estimates of the burden of first recurrences and in-hospital deaths did not change significantly.

CONCLUSIONS

The estimated national burden of C. difficile infection and associated hospitalizations decreased from 2011 through 2017, owing to a decline in health care-associated infections. (Funded by the Centers for Disease Control and Prevention.).

Clostridioides difficile ribotype 106: A systematic review of the antimicrobial susceptibility, genetics, and clinical outcomes of this common worldwide strain

Clostridioides difficile typing is invaluable for the investigation of both institution-specific outbreaks as well as national surveillance. While the epidemic ribotype 027 (RT027) has received a significant amount of resources and attention, ribotype 106 (RT106) has become more prevalent throughout the past decade. The purpose of this systematic review was to comprehensively summarize the genetic determinants, antimicrobial susceptibility, epidemiology, and clinical outcomes of infection caused by RT106. A total of 68 articles published between 1999 and 2019 were identified as relevant to this review. Although initially identified in the United Kingdom in 1999, RT106 is now found worldwide and became the most prevalent strain in the United States in 2016. Current data indicate that RT106 harbors the tcdA and tcdB genes, lacks binary toxin genes, and does not contain any deletions in the tcdC gene, which differentiates it from other epidemic strains, including ribotypes 027 and 078. Interestingly, RT106 produces more spores than other strains, including RT027. Overall, RT106 is highly resistant to erythromycin, clindamycin, fluoroquinolones, and third-generation cephalosporins. However, the MIC90 in most studies are one to two fold dilutions below the epidemiologic cut-off values of metronidazole and vancomycin, suggesting both are acceptable treatment options from an in vitro perspective. The few clinical outcomes studies available concluded that RT106 causes less severe disease than RT027, but patients were significantly more likely to experience multiple CDI relapses when infected with a RT106 strain. Specific areas warranting future study include potential survival advantages provided by genetic elements as well as a more robust investigation of clinical outcomes associated with RT106.

Investigating the relationship between vancomycin-resistant Enterococcus control practices and the incidence of health care-associated Clostridioides difficile infections in Ontario

We evaluated the impact of discontinuing vancomycin-resistant Enterococcus (VRE) screening and use of contact precautions on the incidence of health care-associated Clostridioides difficile infection (HA-CDI) in acute teaching hospitals in Ontario, Canada. Among hospitals that stopped VRE screening and contact precaution measures, there was a significant change in HA-CDI rates after the discontinuation of practices (incidence rate ratios, 1.11; 95% confidence interval, 1.01-1.22). No change in rate was observed among hospitals that continued VRE control practices. Screening and use of contact precautions for VRE may provide hospitals additional advantages for broadened HA-CDI control and prevention.

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.

PCR ribotypes of Clostridioides difficile across Texas from 2011 to 2018 including emergence of ribotype 255

Clostridioides difficile infection (CDI) is the most prevalent healthcare-associated infection in the United States and carries a significant healthcare system burden. As part of an ongoing, active surveillance system of C. difficile throughout Texas, the objective of this study was to assess changes in C. difficile ribotypes of clinical isolates obtained from hospitalized patients in Texas over the past seven years. Fifty hospitals located in Texas, USA sent C. difficile positive stool specimens to a centralized laboratory for PCR ribotyping and toxin characterization between 2011 and 2018. Data collected included specimen collection date, patient age, and sex. Strain genotypes were compiled, and changes in ribotype distribution over time were assessed. Overall, 7796 samples were ribotyped from predominately female patients (58.4%) aged 62 ± 19 years. Samples were obtained from all geographic regions of Texas including Houston/Southwest region (n = 5129; 85%), Dallas/North Texas (n = 579, 9.6%), Central Texas (n = 164; 2.7%), and South Texas (n = 162; 2.6%). The 10 most common ribotypes comprised 73% of all isolates tested during the study period. The most common ribotypes were 027 (17.5%), followed by 014-020 (16.1%), 106 (11.6%), and 002 (9.1%). The prevalence of ribotypes 027, 001, and 078-126 declined significantly over time, while ribotypes 106 and 054 increased in prevalence (P < 0.001). Furthermore, the emergence of a novel ribotype 255 strain was observed. Differences in ribotype distribution were also noted based on age and geographic distribution (P < 0.001, each). This seven-year study demonstrated changing molecular epidemiology of C. difficile in Texas, including the emergence of a novel ribotype 255.

Incidence and economic burden of Clostridioides difficile infection in Ontario: a retrospective population-based study

BACKGROUND

Understanding the impact of prevention programs on Clostridioides difficile infection rates is important, and decisions on future program changes, including how to use vaccines currently in development, requires a detailed understanding of the epidemiologic features of C. difficile infection. We analyzed Ontario health administrative data to determine incidence rates and medical costs of C. difficile infection, based on whether acquisition and onset occurred in acute care hospitals (ACHs), long-term care facilities or the community.

METHODS

We performed a retrospective analysis using individual-level data from Ontario health databases from Apr. 1, 2005, to Mar. 31, 2015, identifying rates of C. difficile infection requiring hospital admission per 100 000 person-years in adults aged 18 years or more for categories of acquisition and onset. We estimated health care system costs of infection 180 and 365 days after admission by matching patients with C. difficile infection with control patients with similar characteristics.

RESULTS

Over the study period, 33 909 people in Ontario were admitted to hospital with C. difficile infection; 17 272 cases (50.9%) were associated with ACHs. The number of cases per 100 000 person-years ranged from 27.7 in 2009/10 to 37.0 in 2012/13. Annually, the highest incidence of infection was for ACH-associated/ACH-onset. Community-associated infection became more prevalent over time, rising from 19.4% of cases in 2005/06 to 29.2% in 2014/15. Infection costs were mostly due to hospital admission within 180 days after hospital discharge. Infection associated with ACHs had the highest total costs and the largest cost attributable to C. difficile infection (median $38 953 for infected patients v. $13 542 for control patients). Median costs attributable to C. difficile infection were $1051 for that associated with long-term care facilities, $13 249 for community-associated infection and $11 917 for ACH-associated/community-onset infection.

INTERPRETATION

Community-associated C. difficile infection had similar health care cost implications as hospital-associated infection. With rates of community-associated C. difficile infection on the rise, family physicians should be supported to prevent this infection in their patients.

Clostridium difficile intervention timelines for diagnosis, isolation, and treatment

BACKGROUND

Developing timelines of nosocomial Clostridium difficile infection (CDI) is critical to improving control and preventive measures. The objective of this study was to provide data-driven estimates of CDI timelines of diagnosis, isolation, and treatment in a hospital setting.

METHODS

We obtained data for all CDI inpatients with symptoms onset occurring between January 1, 2013, and December 30, 2017, from St Joseph's Healthcare in Hamilton, Canada. We analyzed full empirical distributions of timelines associated with the diagnosis, isolation, and treatment of CDI.

RESULTS

A total of 683 inpatients with CDI symptoms were recorded, of which 243 cases were identified as health care-associated infection (HAI). The mean time intervals between the onset of CDI symptoms after admission and the release of laboratory results were 1.2 days and 1.9 days for the HAI and community-associated infection (CAI) patient groups, respectively. The mean time intervals from symptoms onset to the start of isolation were 1.5 days and 2.6 days for the corresponding patient groups. The initiation of treatment within 2 days of symptoms onset reduced the duration of first isolation (P value < .0001); however, the type of initial antibiotic used for CDI treatment was not associated with the duration of isolation.

CONCLUSIONS

Estimated timelines did not differ (P values > .6) between HAI and CAI patient groups with symptoms onset after admission. These estimates are useful for evaluating the effectiveness of CDI interventions.

Time-Series Analysis of Health Care-Associated Infections in a New Hospital With All Private Rooms

IMPORTANCE

Health care-associated infections are often caused by multidrug-resistant organisms and substantially factor into hospital costs and avoidable iatrogenic harm. Although it is recommended that new facilities be built with single-room, low-acuity beds, this process is costly and evidence of reductions in health care-associated infections is weak.

OBJECTIVE

To examine whether single-patient rooms are associated with decreased rates of common multidrug-resistant organism transmissions and health care-associated infections.

DESIGN, SETTING, AND PARTICIPANTS

A time-series analysis comparing institution-level rates of new multidrug-resistant organism colonization and health care-associated infections before (January 1, 2013-March 31, 2015) and after (April 1, 2015-March 31, 2018) the move to the hospital with 100% single-patient rooms. In the largest hospital move in Canadian history, inpatients in an older, tertiary care, 417-bed hospital in Montréal, Canada, that consisted of mainly mixed 3- and 4-person ward-type rooms were moved to a new 350-bed facility with all private rooms.

EXPOSURES

A synchronized move of all patients on April 26, 2015, to a new hospital with 100% single-patient rooms equipped with individual toilets and showers and easy access to sinks for hand washing.

MAIN OUTCOMES AND MEASURES

Rates of nosocomial vancomycin-resistant Enterococcus (VRE) and methicillin-resistant Staphylococcus aureus (MRSA) colonization, VRE and MRSA infection, and Clostridioides difficile (formerly known as Clostridium difficile) infection (CDI) per 10 000 patient-days.

RESULTS

Compared with the 27 months before, during the 36 months after the hospital move, an immediate and sustained reduction in nosocomial VRE colonization (from 766 to 209 colonizations; incidence rate ratio [IRR], 0.25; 95% CI, 0.19-0.34) and MRSA colonization (from 129 to 112 colonizations; IRR, 0.57; 95% CI, 0.33-0.96) was noted, as well as VRE infection (from 55 to 14 infections; IRR, 0.30, 95% CI, 0.12-0.75). Rates of CDI (from 236 to 223 infections; IRR, 0.95; 95% CI, 0.51-1.76) and MRSA infection (from 27 to 37 infections; IRR, 0.89, 95% CI, 0.34-2.29) did not decrease.

CONCLUSION AND RELEVANCE

The move to a new hospital with exclusively single-patient rooms appeared to be associated with a sustained decrease in the rates of new MRSA and VRE colonization and VRE infection; however, the move was not associated with a reduction in CDI or MRSA infection. These findings may have important implications for the role of hospital construction in facilitating infection control.

Prospective Review of Clostridioides difficile Testing Indications to Inform Local Laboratory Stewardship Initiatives

We conducted a prospective chart review to determine the prevalence of and reasons for inappropriate Clostridioides difficile test-ordering at a tertiary care hospital. Inappropriate orders accounted for 54% of all tests. The two primary aetiologies of inappropriate test-ordering were an alternative reason for diarrhoea (34%) and an asymptomatic patient (20%). These results highlight the need to focus diagnostic stewardship of C. difficile testing on pre-analytical factors.

Attributable costs and length of stay of hospital-acquired Clostridioides difficile: A population-based matched cohort study in Alberta, Canada

OBJECTIVE

To determine the attributable cost and length of stay of hospital-acquired Clostridioides difficile infection (HA-CDI) from the healthcare payer perspective using linked clinical, administrative, and microcosting data.

DESIGN

A retrospective, population-based, propensity-score-matched cohort study.

SETTING

Acute-care facilities in Alberta, Canada.

PATIENTS

Admitted adult (≥18 years) patients with incident HA-CDI and without CDI between April 1, 2012, and March 31, 2016.

METHODS

Incident cases of HA-CDI were identified using a clinical surveillance definition. Cases were matched to noncases of CDI (those without a positive C. difficile test or without clinical CDI) on propensity score and exposure time. The outcomes were attributable costs and length of stay of the hospitalization where the CDI was identified. Costs were expressed in 2018 Canadian dollars.

RESULTS

Of the 2,916 HA-CDI cases at facilities with microcosting data available, 98.4% were matched to 13,024 noncases of CDI. The total adjusted cost among HA-CDI cases was 27% greater than noncases of CDI (ratio, 1.27; 95% confidence interval [CI], 1.21-1.33). The mean attributable cost was $18,386 (CAD 2018; USD $14,190; 95% CI, $14,312-$22,460; USD $11,046-$17,334). The adjusted length of stay among HA-CDI cases was 13% greater than for noncases of CDI (ratio, 1.13; 95% CI, 1.07-1.19), which corresponds to an extra 5.6 days (95% CI, 3.10-8.06) in length of hospital stay per HA-CDI case.

CONCLUSIONS

In this population-based, propensity score matched analysis using microcosting data, HA-CDI was associated with substantial attributable cost.

Epidemiology of Clostridioides difficile infection in Canada: A six-year review to support vaccine decision-making

BACKGROUND

Two vaccines against Clostridioides difficile infections (CDI) are currently in phase III trials. To enable decision-making on their use in public health programs, national disease epidemiology is necessary.

OBJECTIVES

To determine the epidemiology of hospital-acquired CDI (HA-CDI) and community-associated CDI (CA-CDI) in Canada using provincial surveillance data and document discrepancies in CDI-related definitions among provincial surveillance programs.

METHODS

Publicly-available CDI provincial surveillance data from 2011 to 2016 that distinguished between HA-CDI and CA-CDI were included and the most common surveillance definitions for each province were used. The HA-, CA-CDI incidence rates and CA-CDI proportions (%) were calculated for each province. Both HA- and CA-CDI incidence rates were examined for trends. Types of disparities were summarized and detailed discrepancies were documented.

RESULTS

Canadian data were analyzed from nine provinces. The HA-CDI rates ranged from 2.1/10,000 to 6.5/10,000 inpatient-days, with a decreasing trend over time. Available data on CA-CDI showed that both rates and proportions have been increasing over time. Discrepancies among provincial surveillance definitions were documented in CDI case classifications, surveillance populations and rate calculations.

CONCLUSION

In Canada overall, the rate of HA-CDI has been decreasing and the rate of CA-CDI has been increasing, although this calculation was impeded by discrepancies in CDI-related definitions among provincial surveillance programs. Nationally-adopted common definitions for CDI would enable better comparisons of CDI rates between provinces and a calculation of the pan-Canadian burden of illness to support vaccine decision-making.

Changes in molecular epidemiology and antimicrobial resistance profiles of Clostridioides (Clostridium) difficile strains in the United States between 2011 and 2017

PCR ribotyping and antimicrobial susceptibility testing were used to characterize 940 Clostridioides (Clostridium) difficile isolates collected from 26 U S. hospitals over three time periods from 2011 to 2017. The proportion of ribotype (RT) 027 isolated during the three surveys decreased significantly over time from 31% in 2011-2012, to 22% in 2013-2014, and to 14% in 2015-2017 (p < 0.001 and p = 0.010, respectively), while we observed an increase in prevalence of RT106, that rose from 7% in our first survey to 19% of isolates in our last survey (p < 0.001). In addition, both RT056 and RT002 rose from 3% to 10% (p < 0.001). The proportions of all other ribotypes remained steady over time, and RT014/020 was the third most common strain type in our convenience sample in the final survey. Overall, resistance to moxifloxacin, rifampin, and vancomycin decreased during our studies, mainly due to the decline in RT027 isolates. A decrease in moxifloxacin resistance and an increase in tetracycline resistance were found among RT027 strains isolated in the last survey. Although the proportion of RT027 isolates declined, multidrug resistance among this ribotype continues to be common.

Predictors of mortality and length of stay in patients with hospital-acquired Clostridioides difficile infection: a population-based study in Alberta, Canada

In a population-based, five-year retrospective cohort study of 5304 adult patients with hospital-acquired Clostridioides difficile infection across Alberta (N=101 hospitals), 30-day all-cause and attributable mortality were 12.2% and 4.5%, respectively. Patients >75 years of age had the highest odds of attributable mortality (odds ratio (OR) 9.34, 95% confidence interval (CI) 2.92-29.83) and largest difference in mean length of stay (11.7 days, 95% CI 8.2-15.2). A novel finding was that elevated white blood cell count at admission was associated with reduced attributable mortality (OR 0.67, 95% CI 0.50-0.90) which deserves further study. Advancing age was incrementally and significantly associated with all outcomes.

Thrombin generation is increased in patients with Clostridium difficile colitis - a pilot study

Background: There are only limited data in the literature on the thrombotic risk of patients with Clostridium difficile (CD) colitis, although this disease is widespread throughout the world. Objective: The aim of this study was to explore thrombin generation in these patients - the best way to evaluate their coagulation. Methods: A prospective observational study was conducted during 15 months on hospitalized patients with CD colitis. Thrombin generation was performed in platelet-poor plasma using a Ceveron^® alpha analyzer and was compared with a group of volunteer control subjects. Results: Thirty-three patients and 51 control subjects were enrolled in the study. Two biomarkers - mean velocity index and peak thrombin - were significantly higher in patient group, compared to the control subjects (p = 0.010, respectively, p = 0.0395). This pattern of thrombin generation suggests that patients with CD colitis without septic shock have a potential thrombotic risk. The mean velocity index significantly correlated with the estimated related risk of death according to the Charlson age-comorbidity index. Conclusions: The higher values of thrombin generation suggest that CD colitis increases the thromboembolic risk. The pattern of thrombin generation could identify patients with particularly higher thromboembolic risk. They are potential candidates for thromboprophylaxis strategies and monitorization.

Clostridium difficile-related hospitalizations and risk factors for in-hospital mortality in Spain between 2001 and 2015

AIMS

To examine trends in the incidence, characteristics and in-hospital outcomes of Clostridium difficile infection (CDI) hospitalizations from 2001 to 2015, to compare clinical variables among patients according to the diagnosis position (primary or secondary) of CDI, and to identify factors associated with in-hospital mortality (IHM).

METHODS

A retrospective study was performed using the Spanish National Hospital Discharge Database, 2001-2015. The study population included patients who had CDI as the primary or secondary diagnosis in their discharge report. Annual hospitalization rates were calculated and trends were assessed using Poisson regression models and Jointpoint analysis. Multi-variate logistic regression models were performed to identify variables associated with IHM.

FINDINGS

In total, 49,347 hospital discharges were identified (52.31% females, 33.69% with CDI as the primary diagnosis). The rate of hospitalization increased from 3.9 cases per 100,000 inhabitants in 2001-2003 to 12.97 cases per 100,000 inhabitants in 2013-2015. Severity of CDI and mean cost per patient increased from 6.36% and 3750.11€ to 11.19% and 4340.91€, respectively, while IHM decreased from 12.66% to 10.66%. Age, Charlson Comorbidity Index, severity, length of hospital stay and mean cost were significantly higher in patients with a primary diagnosis of CDI. Irrespective of the CDI diagnosis position, IHM was associated with male sex, older age, comorbidities, readmission and severity of CDI. Primary diagnosis of CDI was associated with lower IHM (odds ratio 0.60; 95% confidence interval 0.56-0.65).

CONCLUSION

CDI-related hospitalization rates are increasing, leading to a high cost burden, although IHM has decreased in recent years. Factors associated with IHM should be considered in strategies for the prevention and management of CDI.