What diagnostic test is used for C. difficile infection?

What diagnostic test is used for C. difficile infection?

• A. Abdominal ultrasound
• B. Stool culture
• C. C. diff toxin PCR
• D. Gram stain of stool

Answer: (C)

Detecting the toxigenic C. difficile in stool is how CDI is diagnosed. The toxin PCR test looks for the genes that encode the C. difficile toxins (such as tcdA/tcdB). Because it directly identifies a toxigenic strain, it has high sensitivity and specificity and gives a rapid result, making it the best choice among the options. Imaging with ultrasound, and basic stool Gram stain don’t diagnose CDI. Stool culture can grow the organism but takes too long and can’t distinguish infection from harmless colonization on its own. A molecular test that detects the toxin genes provides the most reliable confirmation of C. difficile infection when the clinical picture fits.

Detecting the toxigenic C. difficile in stool is how CDI is diagnosed. The toxin PCR test looks for the genes that encode the C. difficile toxins (such as tcdA/tcdB). Because it directly identifies a toxigenic strain, it has high sensitivity and specificity and gives a rapid result, making it the best choice among the options. Imaging with ultrasound, and basic stool Gram stain don’t diagnose CDI. Stool culture can grow the organism but takes too long and can’t distinguish infection from harmless colonization on its own. A molecular test that detects the toxin genes provides the most reliable confirmation of C. difficile infection when the clinical picture fits.