Sign in →

Test Code LAB257 Clostridium difficile Infection Testing Cascade

Important Note

To be accepted for C.difficile testing, patient samples must:

Overdiagnosing C.difficile infections (colonization vs. pathogen) can lead to unnecessary antibiotic usage and futher complications for the patient. 

 

Useful For

Detection of toxigenic Clostridium difficile associated with Clostridium difficile infection

Profile Information

Test Code Test Name Methodology

Always

Performed

Available

Separately
LAB731 Lactoferrin for Fecal Leukocytes Immunochromatographic Yes Yes
N/A C. diff antigen, A/B toxin EIA No No
N/A C. diff Toxin B Gene/027/NAP1/B1 PCR No No

Testing Algorithm:

Non-diarrheal samples will be rejected for testing.

If the stool sample is diarrheal (6 or 7 on Bristol stool chart), a fecal lactoferrin test will be performed.

 

If the fecal lactoferrin test is negative, low probability of C.diff infection will be reported.  No further testing will be performed.

If the fecal lactoferrin test is positive, C.diff PCR will be performed.

 

If the C.diff PCR is negative, low probability of C.diff infection will be reported.  No further testing will be performed.

If the C.diff PCR is positive, the C.diff antigen, A/B toxin EIA will be performed.

 

If the C.diff antigen, A/B toxin EIA test is negative, low probability of C.diff infection will be reported.

If the C.diff antigen, A/B toxin EIA test is positive,  high probability of C.diff  infection will be reported.

If the C.diff antigen, A/B toxin EIA test is inconclusive (GDH positive, toxin negative), intermediate probability of C.diff infection will be reported.

Performing Laboratory

Bozeman Health Laboratory Services

Specimen Requirements

Specimen Type: Fresh stool

Container/Tube: CLEAN VIAL (White top vial with no added preservatives)

Acceptable: Sterile container

Specimen Volume: 5 mL

Specimen Minimum Volume: 1 mL

Collection Instructions:

  1. Collect liquid or loose stool.
  2. Transfer stool to container.
  3. Label container with patient’s name (first and last), date and actual time of collection.
  4. Return specimen to laboratory ASAP 

 

Specimen Rejection:

1. Stool not typing a 6 or 7 on the Bristol Stool Chart 

2. Stool contaminated with urine or water

3. Stool in preservative/fixative

4. Stool collected in diapers

5. Frozen stool

Specimen Transport Temperature

Refrigerated

Specimen Stability

Specimen Type Temperature Time
Stool Refrigerated 72 hours

Reference Values

Fecal Lactoferrin:  Negative

C. diff EIA: Negative

C. diff PCR:  Not detected

 

Resulting Algorithm:

Fecal lactoferrin negative: low probability of C.difficile infection

Fecal lactoferrin positive, C.diff PCR negative: low probability of C.difficile infection

Fecal lactoferrin positive, C.diff PCR positive, C.diff EIA positve: high probability of C.difficile infection

Fecal lactoferrin positive, C.diff PCR positive, C.diff EIA negative: low probability of C.difficile infection

Fecal lactoferrin positive, C.diff PCR positive, C.diff EIA inconclusive, : intermediate probability of C.difficile infection

Additional Information

  • Overdiagnosing C.difficile infections (colonization vs. pathogen) can lead to unnecessary antibiotic usage and futher complications for the patient. 

  • Specimen optimal when obtained during acute phase of infection (5-7 days).
  • Patient should avoid recent antibiotics or x-ray contrast material, antidiarrheal medications, antacids, bismuth, or oil instillation.

Day(s) Test Set Up

Batch tested Monday through Sunday

Test Classification and CPT Coding

83630-Lactoferrin, fecal; qualitative

87324-C.diff antigen & A/B toxin EIA

87493-C.diff, toxin gene, amplified probe technique