781. C.difficile PCR+/ Toxin EIA- treat or not treat? A clinician survey

Background

C.difficile Toxin Polymerase Chain Reaction (C.diff PCR) and C.difficile Toxin Enzyme Immunoassays (toxin EIA) are commonly used tests to diagnose Clostridoides difficile infection (CDI). C.diff PCR cannot differentiate between colonization and infection, leading to a higher false-positive diagnosis of CDI. Toxin EIA has low sensitivity leading to a missed diagnosis of CDI. In patients with C.diff PCR positive(+) and Toxin EIA negative(-), clinical judgment is often needed regarding the decision to treat or not to treat. C.diff cytotoxic assay (CCA), is a more sensitive method to detect the toxin but is time-consuming and not readily available.

Methods

Between 6/2019 and 12/2019, 83 patients who were admitted to the hospital, met our inclusion criteria (C.diff PCR+/EIA-). Clinicians who cared for these patients were contacted and surveyed with a predesigned questionnaire evaluating the rationale of treatment. Also, a simultaneous medical records review was done to ensure consistency. Along with this C.diff PCR+/EIA- stool samples were sent to ARUP laboratories for CCA. The CCA results were not available for clinicians and did not impact clinical care. Average cost for a CCA assay was $29

Results

Demographics of the clinicians were variable (Table 1). Several parameters were considered when making decisions regarding treatment and GI/ID were frequently involved (figure 1). Among the 83 patients, 41(49%) were CCA (+) and 42(51%) were CCA (-). 48 of 83 (58%) patients received treatment for CDI. 25 of 48 (52%) patients who were treated were CCA positive while 23 of 48 (48%) patients were CCA negative. Among the untreated patients, 16/35 (46%) were CCA+ while 19/35(54%) were CCA-. There was no statistically significant correlation between clinical judgment and CCA assay results (p: 0.56 on the Chi test).

Demographics of the clinicians

Conclusion

Clinicians regardless of their background and training face challenges with the treatment of C.diff PCR+/EIA- patients. Patient outcomes based on the incorporation of CCA assay into an algorithm for C.diff PCR+/EIA- patients, need to be evaluated. But it has a potential role in stopping unnecessary CDI treatment as well as avoidance of missed treatment opportunities while possibly also being cost-effective.

Disclosures

Ank E. Nijhawan, MD, MPH, Gilead (Grant/Research Support, Scientific Research Study Investigator, Research Grant or Support)