High-risk medication use for Clostridium difficile infection among hospitalized patients with cancer

Frequency of Clostridioides difficile Infection Among Hospitalized Patients in Kerman City, Iran

Background: Clostridioides difficile is one of the major causes of nosocomial infections, being responsible for 15 to 25% of antibiotic-associated diarrhea. It is important to determine the epidemiology and prevalence of this bacterium at hospitals and healthcare centers. Objectives: This study aims to investigate the prevalence of C. difficile infection (CDI) by identifying toxigenic isolates of C. difficile in different wards of the hospital. Methods: A total of 417 diarrheal stool samples were taken from hospitalized patients in different wards of three educational hospitals in Kerman City, Iran from 2018 to 2020. The samples were cultured on cycloserine-cefoxitin fructose agar and C. difficile suspected colonies were isolated. Identification of the cdd-3 gene for definitive diagnosis of C. difficile and identification of toxin genes in the positive isolates was performed using the PCR method. Results: A total of 68 isolates (16.3%) of C. difficile were isolated from the specimens. Besides, 8.6% (36/417) and 7.6% (32/417) of the isolates were toxigenic and nontoxigenic, respectively; thus, the prevalence of CDI was 8.6%. Most of the toxigenic isolates had the A+B+CDT- toxin phenotype. The highest prevalence of CDI was observed in males, ICU ward, and age group of 41 - 60. Conclusions: A total of 8.6% of hospitalized patients with diarrhea were infected with C. difficile. The prevalence of CDI in Kerman City is lower than that in Europe, East Asia, and other parts of Iran, but it is almost the same as that in the Middle East.

Molecular Epidemiology and Genetic Relatedness of Clostridioides difficile Isolates in Pediatric Oncology and Transplant Patients Using Whole Genome Sequencing

BACKGROUND

The incidence of Clostridioides difficile infection (CDI) has been rising among hospitalized children, with poor understanding of genomic variability of C. difficile isolates in this population.

METHODS

This was a retrospective cohort study of CDI in inpatient and outpatient pediatric oncology and cell transplant patients (POTPs) in 2016 and 2017. CDI cases were identified by positive C. difficile toxin polymerase chain reaction tests. Retrieved residual stool specimens were cultured anaerobically and toxin-producing C. difficile isolates underwent whole genome sequencing (WGS) followed by core genome multilocus sequence typing. Plausible time and location epidemiologic links among the closely related strains were evaluated to identify potential transmission events.

RESULTS

Among 226 CDI episodes in 157 patients, 202 stool samples were cultured and had positive cytotoxicity tests. Sequencing identified 33 different strain types in 162 (80%) isolates. Thirty-nine (28%) patients had multiple episodes of CDI, and 31 clusters of related isolates were identified, 15 (47%) of which involved exclusively multiple specimens from the same patient. For the 16 clusters involving multiple patients, epidemiologic investigation revealed only 2 (12.5%) clusters with potential transmission events.

CONCLUSIONS

WGS identified a highly diverse group of C. difficile isolates among POTPs with CDI. Although WGS identified clusters of closely related isolates in multiple patients, epidemiologic investigation of shared inpatient exposures identified potential transmission in only 2 clusters. Clostridioides difficile transmission was uncommon in this population. More than 70% of new CDI reinfections in POTPs are actually recurrences caused by a previous CDI strain.

Using a Systems Engineering Framework to Evaluate Proton Pump Inhibitor Prescribing in Critically Ill Patients

Proton pump inhibitors (PPIs) are a risk factor for hospital-acquired Clostridium difficile infection (CDI). Much PPI use is inappropriate, and interventions to reduce PPI use, such as for stress ulcer prophylaxis in all critically ill patients, are essential to reduce CDI rates. This mixed-methods study in a combined medical-surgical intensive care unit at a tertiary academic medical center used a human factors engineering approach to understand barriers and facilitators to optimizing PPI prescribing in these patients. We performed chart review of patients for whom PPIs were prescribed to evaluate prescribing practices. Semistructured provider interviews were conducted to determine barriers and facilitators to reducing unnecessary PPI use. Emergent themes from provider interviews were classified according to the Systems Engineering Initiative for Patient Safety model. In our intensive care unit, 25% of PPI days were not clinically indicated. Barriers to optimizing PPI prescribing included inadequate provider education, lack of institutional guidelines for stress ulcer prophylaxis, and strong institutional culture favoring PPI use. Potential facilitators included increased pharmacy oversight, provider education, and embedded decision support in the electronic medical record. Interventions addressing barriers noted by front line providers are needed to reduce unnecessary PPI use, and future studies should assess the impact of such interventions on CDI rates.