From the Guidelines
Testing for cure is not recommended after treatment of Clostridioides difficile (C. diff) infection, as it has no clinical value and can lead to unnecessary additional antibiotic treatment. The 2017 update by the Infectious Diseases Society of America (IDSA) and Society for Healthcare Epidemiology of America (SHEA) suggests that repeat testing should not be performed in the absence of clear changes to the clinical presentation of suspected CDI 1. This is because the diagnostic yield of repeat testing within a 7-day period is approximately 2%, and highly sensitive testing strategies have a high negative predictive value for CDI.
Some key points to consider when managing C. diff infection include:
- The absence of diarrhea (defined as ≤3 loose stools per day) for at least 48 hours indicates treatment success
- If symptoms persist or recur within 8 weeks of treatment completion, then repeat testing is appropriate to confirm recurrent C. diff infection
- Empiric treatment without confirmatory testing of suspected recurrence is discouraged, as it may be unnecessary and possibly harmful to microbiome restoration 1
- Patients can have reduced health scores for months after CDI, and may experience altered bowel habits for prolonged periods, making clinical response a more reliable indicator of treatment success than test results.
Overall, clinical response should guide management, and testing after symptom resolution can lead to unnecessary additional antibiotic treatment, which may actually increase the risk of recurrence by further disrupting the gut microbiome 1.
From the Research
Test of Cure for C. diff
- The test of cure for Clostridioides difficile (C. diff) infection is not explicitly defined in the provided studies, but the resolution of symptoms and negative results from a polymerase chain reaction test for C. difficile toxin can be used as indicators of cure 2, 3.
- Fecal microbiota transplantation (FMT) has been shown to be effective in treating recurrent C. difficile infection, with a high rate of clinical resolution and negative test results for C. difficile toxin 2, 3, 4.
- The studies suggest that FMT can be used as a treatment option for patients with recurrent C. difficile infection who have failed traditional antibiotic therapy 2, 3, 5, 4.
- The route of administration for FMT can vary, including colonoscopy, nasoduodenal tube, or enema, and the choice of route may depend on the individual patient's needs and clinical determination 4.
Diagnostic Tests
- Polymerase chain reaction (PCR) test for C. difficile toxin can be used to diagnose C. difficile infection 2, 3.
- Enzyme immunoassay (EIA) testing for C. difficile toxins A/B can also be used for diagnosis 5.
- Stool tests, such as stool antigen tests or stool PCR, can be used to detect the presence of C. difficile in the stool 6.
Treatment Outcomes
- FMT has been shown to result in a high rate of clinical resolution and negative test results for C. difficile toxin, with a risk ratio of 1.92 compared to control groups 4.
- FMT may also result in a reduction in serious adverse events, although the evidence is moderate-certainty and the confidence intervals are wide 4.
- The number of events for all-cause mortality was small, and the confidence intervals were wide, making it difficult to draw conclusions about the effect of FMT on mortality 4.