Certification Board of Infection Control and Epidemiology (CBIC) Practice Exam 2025 – The All-in-One Guide for Exam Success

Suspecting a Clostridium difficile (C. diff) infection is primarily based on the clinical presentation of the patient. The occurrence of three or more unformed or watery stools within a 24-hour period is a hallmark sign of potential C. diff infection. This characteristic is consistent with the diarrhea typically associated with this pathogen, which is often the result of antibiotic use that disrupts the normal gut flora and allows for the overgrowth of C. difficile.

While fever and abdominal pain can be associated with various gastrointestinal illnesses, they are not specific indicators of a C. diff infection by themselves. Additionally, antibiotic use is a significant risk factor for C. diff, but merely being on antibiotics for more than a week does not necessarily confirm an infection without the accompanying symptom of diarrhea. Lastly, diarrhea occurring without any other symptoms does not provide enough context or evidence to suspect C. diff, as many other conditions can cause diarrhea that isn't specifically related to C. difficile. Thus, the clinical definition involving the frequency of stools is essential for making a proper suspicion of a C. diff infection.