Clostridioides difficile infection (CDI) epidemiology and patient characteristics in Switzerland

Core genome multilocus sequence typing of Clostridioides difficile to investigate transmission in the hospital setting

PURPOSE

Traditional epidemiological investigations of healthcare-associated Clostridioides difficile infection (HA-CDI) are often insufficient. This study aimed to evaluate a procedure that includes secondary isolation and genomic typing of single toxigenic colonies using core genome multilocus sequence typing (cgMLST) for the investigation of C. difficile transmission.

METHODS

We analyzed retrospectively all toxigenic C. difficile-positive stool samples stored at the Lausanne University Hospital over 6 consecutive months. All isolates were initially typed and classified using a modified double-locus sequence typing (DLST) method. Genome comparison of isolates with the same DLST and clustering were subsequently performed using cgMLST. The electronic administrative records of patients with CDI were investigated for spatiotemporal epidemiological links supporting hospital transmission. A comparative descriptive analysis between genomic and epidemiological data was then performed.

RESULTS

From January to June 2021, 86 C. difficile isolates were recovered from thawed samples of 71 patients. Thirteen different DLST types were shared by > 1 patient, and 13 were observed in single patients. A genomic cluster was defined as a set of isolates from different patients with ≤ 3 locus differences, determined by cgMLST. Seven genomic clusters were identified, among which plausible epidemiological links were identified in only 4/7 clusters.

CONCLUSION

Among clusters determined by cgMLST analysis, roughly 40% included unexplained HA-CDI acquisitions, which may be explained by unidentified epidemiological links, asymptomatic colonization, and/or shared common community reservoirs. The use of DLST, followed by whole genome sequencing analysis, is a promising and cost-effective stepwise approach for the investigation of CDI transmission in the hospital setting.

Frailty level at discharge predicts mortality in older patients with Clostridioides difficile more accurately than age or disease severity

PURPOSE

Clostridioides difficile infection (CDI) has a high mortality among older patients. Identification of older patients with CDI in increased mortality risk is important to target treatment and thereby reduce mortality. The aim of this study was to investigate mortality rates and compare frailty levels at discharge, measured by the record-based Multidimensional Prognostic Index (MPI), with age and severity of CDI as mortality predictors in patients with CDI diagnosed during hospitalisation.

METHODS

This was a population-based cohort study from Central Denmark Region, Denmark, including all patients  ≥ 60 years with a positive CD toxin test without prior infection and diagnosed from 1 January to 31 December 2018. Frailty level, estimated from the electronic medical record, was defined as low, moderate, or severe frailty. CDI severity was graded according to international guidelines. Primary outcome was 90-day mortality.

RESULTS

We included 457 patients with median age 77 years (interquartile range 69-84) and females (49%). Overall, 90-day mortality was 28%, and this was associated with age (hazard ratio (HR): 2.71 (95% confidence interval 1.64-4.47)), CDI severity (HR 4.58 (3.04-6.88)) and frailty (HR 10.15 (4.06-25.36)). Frailty was a better predictor of 90-day mortality than both age (p < 0.001) and CDI severity (p = 0.04) with a receiver operating characteristic curve area of 77%.

CONCLUSION

The 90-day mortality among older patients with CDI in a Danish region is 28%. Frailty measured by record-based MPI at discharge outperforms age and disease severity markers in predicting mortality in older patients with CDI.

Treatment and Outcomes of Clostridioides difficile Infection in Switzerland: A Two-Center Retrospective Cohort Study

Objectives: Clostridioides difficile infection (CDI) is the leading cause of healthcare-associated diarrhea, often complicated by severe infection and recurrence with increased morbidity and mortality. Data from large cohorts in Switzerland are scarce. We aimed to describe diagnostic assays, treatment, outcomes, and risk factors for CDI in a large cohort of patients in Switzerland. Methods: We conducted a retrospective cohort study of CDI episodes diagnosed in patients from two tertiary care hospitals in Switzerland. During a 3-month follow-up, we used a composite outcome combining clinical cure at day 10, recurrence at week 8, or death, to evaluate a patient’s response. Unfavorable outcomes consisted in the occurrence of any of these events. Results: From January 2014 to December 2018, we included 826 hospitalized patients with documented CDI. Overall, 299 patients (36.2%) had a severe infection. Metronidazole was used in 566 patients (83.7%), compared to 82 patients (12.1%) treated with vancomycin and 28 patients (4.1%) treated with fidaxomicin. Overall mortality at week 8 was at 15.3% (112/733). Eighty-six patients (12.7%) presented with clinical failure at day 10, and 78 (14.9%) presented with recurrence within 8 weeks; 269 (39.8%) met the composite outcome of death, clinical failure, or recurrence. The Charlson Comorbidity Index score (p < 0.001), leukocytes > 15 G/L (p = 0.008), and the use of metronidazole (p = 0.012) or vancomycin (p = 0.049) were factors associated with the composite outcome. Conclusions: Our study provides valuable insights on CDI treatment and outcomes in Switzerland, highlights the heterogeneity in practices among centers, and underlines the need for the active monitoring of clinical practices and their impact on clinical outcomes through large multicentric cohorts.