Spectrum: Local Antimicrobial Stewardship, for Island Health

Test Interpretation

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Therapy Guidance

OUTPATIENTS

Outpatients stool samples are tested with a multi-pathogen Nucleic Acid Amplification Test (NAAT) panel that includes

C. difficile TOXIN GENE. If this is positive an EIA test for FREE TOXIN is subsequently performed.

Possible results

NAAT toxin gene NEGATIVE - This rules out C. difficile colonization or disease.

NAAT toxin gene POSITIVE / EIA free toxin POSITIVE - This strongly suggests active C. difficile disease and therapy should be initiated. Click for Therapy.

NAAT toxin gene POSITIVE / EIA free toxin NEGATIVE - This suggests colonization with C. difficile only. However, if the clinical suspicion of CDI remains high, therapy should be initiated and testing repeated once. Click for Therapy.

INPATIENTS

Inpatient samples are tested for C. difficile using a test for ANTIGEN (GDH) and a test for FREE TOXIN simultaneously.

Possible Results

ANTIGEN negative / FREE TOXIN negative - This rules out C. difficile colonization or disease.

**ANTIGEN positive /

FREE TOXIN positive** - This strongly suggests active C. difficile disease and therapy should be initiated. Click for Therapy.

ANTIGEN Positive / FREE TOXIN negative - This suggests colonization with C. difficile only. However, if the clinical suspicion of CDI remains high, therapy should be initiated and testing repeated once. Click for Therapy.