CDI recurrence stratified by genotypes and rCDI risk categories: rs2516513 genotype (A) and HLA-DRB1*07:01 genotype (B). The high-risk subgroup included participants with one or more of the following factors: prior episode of CDI in the past 6 months, severe CDI at baseline (per Zar score [37]), age of ≥65 years, CDI due to a hypervirulent strain (027, 078, or 244 ribotypes), immunocompromised, or receiving concomitant systemic antibiotics. Participants at low risk of rCDI were those with none of the above risk factors. BEZ, bezlotoxumab; CDI, Clostridium difficile infection; CI, confidence interval; PBO, placebo; rCDI, recurrent Clostridium difficile infection.