Table 1.

Proposed risk factors for recurrent Clostridium difficile infection (CDI)

Host risk factors	• Age ≥65 years
	• Low C. difficile-specific antitoxin antibody levels
	• Host genetics
	• Compromised immune system
	• Chronic renal failure
	• Prior CDI episode
Severity of CDI episode	• Severe primary CDI
Exposures	• Previous fluoroquinolone use
	• Ongoing antibiotic use
	• Proton pump inhibitors/antacids
Pathogen-specific factors	• C. difficile strain type (ribotype 027, 078, or 244)

Note: Data collated from References 2, 46, 47, 48, and 49.