Clinical heterogeneity of patients with stool samples testing PCR+/Tox- from a two-step Clostridium difficile diagnostic algorithm.

The clinical significance of indeterminate (PCR+/Tox-) results for patients tested with a two-step algorithm for Clostridium difficile infection (CDI) is uncertain. We aimed to evaluate the clinical presentation and 8-week outcomes of patients with indeterminate test results. Patients with stool samples testing positive by PCR and negative by toxin A/B immunoassay between February 1, 2017, and April 30, 2018, were assessed by antimicrobial stewardship program (ASP) clinicians and classified as colonized or infected. Retrospective chart review was performed to obtain outcomes occurring within 8 weeks of testing, including recurrent C. difficile diarrhea, subsequent treatment for CDI, follow-up C. difficile testing, all-cause mortality, and CDI-related complications. In total, 110 PCR+/Tox- patients were evaluated. ASP classified 54% of patients as infected and 46% as colonized. Patients assessed and classified as colonized did not have increased adverse outcomes by 8 weeks compared to those assessed as infected, despite not receiving treatment for CDI. We conclude that PCR+/Tox- patients are heterogeneous with respect to clinical presentation. Negative toxin A/B immunoassay in a two-step algorithm should not be interpreted in isolation to distinguish colonization from infection as many PCR+/Tox- results may be clinically significant for CDI.

Characterization of Prescribing Practices for Uncomplicated Streptococcal and Enterococcal Bacteremias: The NARRATE Study.

Background: Bloodstream infections (BSIs) rank among the top causes of death in North America. Despite the prevalence of these infections, there remain significant practice variations in the prescribing of antibiotics. Objective: To investigate current prescribing practices for management of uncomplicated streptococcal and enterococcal BSIs. Methods: A retrospective cohort study was conducted using charts for patients admitted to an acute care centre in British Columbia between November 16, 2019, and October 20, 2020. Adult patients (≥ 18 years of age) with a diagnosis of uncomplicated streptococcal or enterococcal BSI were included. Patients were excluded if they had polymicrobial bacteremia or deep-seated infection or had been admitted for no more than 48 hours. The primary outcomes were duration of antibiotic therapy (IV and oral) and time to appropriate oral therapy for treatment of BSI. The secondary outcomes were observed rates of re-initiation of antibiotics and readmission with recurrent BSI. Descriptive statistics were calculated and regression analysis was performed for the primary and secondary outcomes. Results: A total of 96 patients met the inclusion criteria. The median total duration of therapy for uncomplicated streptococcal and enterococcal BSI was about 2 weeks. Streptococcus pneumoniae BSIs were associated with a significantly shorter duration of IV therapy and were more likely to be associated with transition to oral antibiotics. No recurrent BSIs were observed in patients for whom therapy was transitioned to oral antibiotics. Conclusions: Further study is warranted to explore shorter duration of antibiotic therapy and transition to oral therapy as treatment approaches for uncomplicated streptococcal and enterococcal BSI. Other outcomes of interest for future research include determining the optimal time for transition to oral therapy.

Contexte: Les infections du sang (IS), ou bactériémies, se classent parmi les causes principales de décès en Amérique du Nord. Malgré leur prévalence, la pratique de la prescription d'antibiotiques continue de varier grandement. Objectif: Étudier les pratiques actuelles de la prescription pour la gestion des bactériémies à streptocoque et à entérocoque non compliquées. Méthodes: Une étude de cohorte rétrospective a été menée à l'aide de dossiers de patients admis à un centre de soins aigus en Colombie-Britannique entre le 16 novembre 2019 et le 20 octobre 2020. Des patients adultes (≥ 18 ans) ayant reçu un diagnostic de bactériémie a streptocoque ou à entérocoque non compliquée ont été inclus. Les patients étaient exclus s'ils présentaient une bactériémie polymicrobienne ou une infection profonde ou s'ils avaient été hospitalisés depuis moins de 48 heures. Les résultats principaux étaient la durée de l'antibiothérapie (IV et orale) et le temps écoulé avant la transition à une thérapie orale adaptée pour le traitement de l'IS. Les résultats secondaires étaient les taux observés de reprise des antibiotiques et de réadmission avec une IS récurrente. Des statistiques descriptives ont été calculées et une analyse de régression a été effectuée pour les résultats principaux et secondaires. Résultats: Au total, 96 patients répondaient aux critères d'inclusion. La durée totale médiane du traitement pour les bactériémies à streptocoque et à entérocoque non compliquées était d'environ 2 semaines. Les bactériémies à Streptococcus pneumoniae étaient associées à une durée significativement plus courte du traitement IV et étaient plus susceptibles d'être associées à la transition vers des antibiotiques oraux. Aucune IS récurrente n'a été observée chez les patients pour lesquels le traitement était passé à des antibiotiques oraux. Conclusions: Une étude plus approfondie est justifiée pour explorer une durée plus courte de l'antibiothérapie et la transition vers une thérapie orale en tant qu'approches de traitement pour les IS à streptocoque et à entérocoque non compliquées. D'autres résultats d'intérêt pour les recherches futures comprennent la détermination du moment optimal pour la transition vers la thérapie orale.

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.

Evaluation of the FilmArray Blood Culture Identification Panel compared to direct MALDI-TOF MS identification for rapid identification of pathogens.

To improve time to identification of pathogens and detection of resistance genes, we evaluated the BioFire FilmArray Blood Culture Identification Panel (BCID) as compared to: (1) direct MALDI-TOF MS (DM) and (2) standardized culture-based identification (ID) with antibiotic susceptibility testing (AST). BCID gave an accurate identification in 102/112 (91 %) of cases (102/103 for on-panel organisms). DM gave an accurate identification in 91/112 (81 %) of cases, with 13/91 (14 %) requiring repeat testing from the residual pellet. The mean time to an identification result was 2.4 and 2.9 h for BCID and DM, respectively. Standardized ID and AST results were available at a mean time of 26.5 and 33 h, respectively. There were 44 BCID/DM results that had an antimicrobial treatment change made based on rapid identification and resistant gene detection of pathogens. Both BCID and DM are accurate and rapid methods for the identification of new positive blood culture pathogens.