Clostridioides difficile infection

C. difficile disease is a disease of a disrupted microbiome, not simple exposure

Clostridioides difficile spores are common in the environment and are carried asymptomatically by some healthy people. Normally a diverse colonic microbiota provides colonisation resistance, outcompeting the organism for nutrients and space. Broad-spectrum antibiotics (especially cephalosporins, co-amoxiclav, clindamycin and fluoroquinolones) wipe out this competing flora, allowing spores to germinate and the organism to proliferate unopposed. This is why the single biggest risk factor is recent antibiotic use, and why antibiotic stewardship is itself a preventive treatment.