How does fidaxomicin compare with vancomycin in preventing recurrence of C. difficile infection?

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This question is about how fidaxomicin affects recurrence of C. difficile infection compared with vancomycin. Fidaxomicin tends to produce lower recurrence rates than vancomycin, even when the initial cure rates are similar. The reason is its narrow activity and minimal disruption of the normal gut microbiota. By preserving the gut’s colonization resistance, fidaxomicin reduces the chance that C. difficile will rebound after treatment. This benefit is especially evident for non-NAP1 strains, where recurrence is significantly lower with fidaxomicin than with vancomycin. For the NAP1/027 strain, the reduction in recurrence exists but is less pronounced. Vancomycin, while effective for the initial infection, tends to disturb gut flora more broadly, which can lead to higher relapse rates. The other options contradict the clinical evidence showing fidaxomicin’s advantage in reducing recurrence, particularly for non-NAP1 strains.