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Line 6:
Line 6: − + − + − * Gold standard Line 21:
Line 20: − *** Detects presence of toxigenic strains of C. diff+ − + − ** EIA / ELISA+ − *** Detects toxin in stool+ − *** Low sensitivity (0.73-0.87)+ − + − + − + − + − +
→DIAGNOSIS
=DIAGNOSIS=
=DIAGNOSIS=
* Laboratory testing cannot distinguish between asymptomatic colonization and active infection.
* Laboratory testing cannot always distinguish between asymptomatic colonization and active infection.
==Diagnostic criteria==
==Diagnostic criteria==
* Diarrhea
* Diarrhea
* Positive stool test for toxigenic C. diff or toxins or visualization of pseudomembranous colitis
* Positive stool test for toxigenic C. diff or toxins or visualization of pseudomembranous colitis
==Diagnostic approaches==
==Diagnostic approaches==
* Toxigenic Culture (TC) and/or Cell Cytotoxicity Assay (CCA)
* Gold Standard: Toxigenic Culture (TC) and/or Cell Cytotoxicity Assay (CCA)
** Anaerobic culture for 24-48 hrs followed by colony selection and culture with human cells to test for cell cytotoxicity which takes an additional 24-48 hours.
** Anaerobic culture for 24-48 hrs followed by colony selection and culture with human cells to test for cell cytotoxicity which takes an additional 24-48 hours.
** Time consuming and difficult, up to 5 days
** Time consuming and difficult, up to 5 days
** Detects a little as 3 picograms of toxin
** Detects a little as 3 picograms of toxin
* PCR / NAAT
* PCR / NAAT
** Detects tcdA/tcdB genes, mRNA for the toxins
** Detects tcdA/tcdB genes, mRNA for the toxins
** Detects presence of toxigenic strains of C. diff
* mRNA doesn't necessarily imply active infection
** mRNA doesn't necessarily imply active infection
* EIA / ELISA
** Detects toxin in stool
** Low sensitivity (0.73-0.87)
* Multistep algorithms, there are dozens
* Multistep algorithms, there are dozens
** EIA for GDH / Toxin A/B
** EIA for GDH / Toxin A/B
* Both positive = C. diff
*** Both positive = C. diff
* Both negative = NO C. diff
*** Both negative = NO C. diff
* Mixed results, use PCR for tcdB as tiebreaker
*** Mixed results, use PCR for tcdB as tiebreaker
** Toxin EIA 1 (Meridian), higher PPV, lower NPV
** Toxin EIA 1 (Meridian), higher PPV, lower NPV
** Toxin EIA 2 (TechLab), lower PPV, higher NPV
** Toxin EIA 2 (TechLab), lower PPV, higher NPV
* Highest NPV (99.8%) GDH EIA + NAAT
** Highest NPV (99.8%) GDH EIA + NAAT
* Highest PPV (93.5%) Toxin EIA 1 + NAAT
** Highest PPV (93.5%) Toxin EIA 1 + NAAT
=TREATMENT=
=TREATMENT=