Which of the following is a risk factor for Clostridium difficile infection?

• A. Antibiotic use
• B. Long-term hospitalization, nursing home stays, and antibiotic use
• C. Regular exercise
• D. Vaccination

Answer: (B)

Risk for Clostridioides difficile infection rises when antibiotics disrupt the normal gut microbiome and a patient is exposed to healthcare environments where C. difficile spores are common. Antibiotics reduce colonization resistance, allowing C. difficile to overgrow and produce toxins that cause illness. Being in long-term hospitalization or nursing home care increases contact with contaminated environments and other infected individuals, raising exposure to spores. Together, these factors create the strongest risk profile, which is why the statement that includes both antibiotic use and healthcare facility exposure is the best choice. Regular exercise or vaccination do not increase the risk.