Clostridioides (Clostridium) difficile infection burden in Japan: A multicenter prospective study

Area of Science:

• Infectious Diseases
• Epidemiology
• Microbiology

Background:

• Clostridioides difficile infection (CDI) is a major cause of healthcare-associated diarrhea globally.
• Previous retrospective studies suggested lower CDI incidence in Japan compared to Western countries.
• The discrepancy may be due to differences in diagnostic testing frequency or true epidemiological variations.

Purpose of the Study:

• To prospectively determine the incidence of CDI in Japanese medical facilities.
• To investigate potential underdiagnosis of CDI in Japan.
• To characterize prevalent C. difficile strains and their antimicrobial resistance patterns.

Main Methods:

• Prospective cohort study conducted across 12 medical facilities in Japan (May 2014-May 2015).
• Enrolled patients with at least three diarrheal episodes (Bristol stool grade 6-7) in 24 hours.
• CDI diagnosis confirmed by toxin enzyme immunoassay, NAAT for toxin B gene, or toxigenic culture.
• C. difficile isolates underwent PCR-ribotyping (RT), slpA-sequence typing (slpA-ST), and antimicrobial susceptibility testing.

Main Results:

• Overall CDI incidence was 7.4 per 10,000 patient-days (PD), significantly higher than previously reported.
• Incidence was highest in intensive care unit (ICU) wards (22.2 CDI/10,000 PD).
• A strong correlation (R²=0.91) was observed between testing frequency and CDI incidence.
• RT018/018″ was the dominant strain (29%), followed by types 014 (23%), 002 (12%), and 369 (11%).
• All RT018/018″ isolates exhibited resistance to moxifloxacin, gatifloxacin, clindamycin, and erythromycin.

Conclusions:

• This study identified a substantially higher CDI incidence in Japanese hospitals than previously recognized.
• The findings suggest that numerous CDI cases are likely overlooked due to inadequate diagnostic testing in Japan.
• Increased diagnostic efforts are crucial for accurate CDI epidemiology and patient management in Japan.