[Clostridioides difficile toxin B gen amplification cycle threshold as a predictor of severity]

Area of Science:

• Infectious Diseases
• Clinical Microbiology
• Diagnostic Accuracy

Background:

• Clostridioides difficile infection (CDI) is a leading cause of hospital-acquired diarrhea, often linked to antibiotic use.
• CDI can range from mild diarrhea to severe conditions like pseudomembranous colitis or toxic megacolon.
• The threshold cycle (Ct) value from RT-PCR assays is being explored as a rapid predictor of CDI outcomes.

Purpose of the Study:

• To assess the utility of the RT-PCR Ct value as a predictor of poor outcomes in patients with CDI.
• To determine if Ct values correlate with the clinical severity of C. difficile disease.

Main Methods:

• A retrospective study was conducted from January 2015 to December 2018.
• Included patients with and without clinical severity criteria for CDI, based on SHEA/IDSA guidelines.
• Analyzed 202 CDI episodes, comparing Ct values between severity groups.

Main Results:

• 77.7% of CDI episodes presented with clinical severity criteria.
• Risk factors for severe CDI (S-CDI) included ulcerative colitis, fever, leukocytosis, neutrophilia, and elevated creatininemia.
• No significant difference in Ct values was observed between patients with and without severe CDI (Ct=26.1 vs. Ct=27.4, p=0.326).

Conclusions:

• The Ct value of RT-PCR assays cannot be systematically implemented as a reliable predictor of CDI severity.
• The study did not find sufficient evidence to standardize Ct values for predicting severe C. difficile infection.