Clostridium difficile Toxin PCR
| Order Code: | CDAB |
| Order Form: | Microbiology/Molecular Pathology Infectious Disease Requisition |
Specimen:
Stool
Collection Medium:
| Sterile container |
Rejection Criteria:
Formed stool; specimen submitted within 10 days of positive result;
more than 1 specimen/week.
Testing
Schedule:
24 hrs/day, 7 days a week, including holidays.
Turn Around
Time:
2 hours (upon receipt in laboratory)
Comments:
This test targets toxin B gene sequences. Most pathogenic C. difficile
strains produce toxin A and B, but some produce only toxin B. The
number of C. difficile toxin PCR test requests for a patient will
be limited to one per week. The higher sensitivity of PCR in comparison
to cell cytotoxicity and immunoassay methods supports this policy [Ann
Intern Med 2009; 151:176].
It is generally recommended that C. difficile PCR be performed only for patients with > 3 liquid stools within a 24 hour period. Since C. difficile colonization rather than infection may exist, only unformed stool specimens from patients with signs and symptoms of C. difficile infection should be tested. The significance of Clostridium difficile toxin detection in infants (<1 year old) is uncertain because of the high rate of asymptomatic C. difficile carriage in this age group.
Once a patient is diagnosed with C. difficile infection, therapeutic response should be based on clinical signs and symptoms; a "test of cure" should not be done since patients may remain colonized with toxin-producing strains following recovery.
It is generally recommended that C. difficile PCR be performed only for patients with > 3 liquid stools within a 24 hour period. Since C. difficile colonization rather than infection may exist, only unformed stool specimens from patients with signs and symptoms of C. difficile infection should be tested. The significance of Clostridium difficile toxin detection in infants (<1 year old) is uncertain because of the high rate of asymptomatic C. difficile carriage in this age group.
Once a patient is diagnosed with C. difficile infection, therapeutic response should be based on clinical signs and symptoms; a "test of cure" should not be done since patients may remain colonized with toxin-producing strains following recovery.
Methodology:
Polymerase Chain Reaction
Sample
Processing:
Label transport tube with two patient identifiers, date and time of collection.
Specimen should be collected and packaged as close to shipping time as possible.
Submit in leakproof container.
If transport is delayed, store specimen at 2-8°C (stable for up to 5 days). Alternatively, specimens can be kept at room temperature (20-30°C) for up to 24 hours.
Specimen should be collected and packaged as close to shipping time as possible.
Submit in leakproof container.
If transport is delayed, store specimen at 2-8°C (stable for up to 5 days). Alternatively, specimens can be kept at room temperature (20-30°C) for up to 24 hours.
Transport
Instructions:
Use refrigerated coolant packs.
Place requisition into outside pocket of bag.
Place specimen into zip-lock type bag, seal bag.
Place requisition into outside pocket of bag.
Place specimen into zip-lock type bag, seal bag.
CPT Code:
87493