Mycobacterium tuberculosis Nucleic Acid Amplification Testing (NAAT)
Brief Description
PCR testing is performed on new smear positive patients who have not had a positive NAAT or culture elsewhere and have been on treatment for less than 3 days. PCR testing may be performed on smear negative patients at the request of the submitter if TB disease is highly suspected.
Laboratory Unit
Mycobacteriology
Methodology
Cepheid GeneXpert- PCR
Specimen Collection
Sputum:
An early morning, deep cough in a sterile container.
Storage/Transport
Sputum (Sedimented and Raw) can be maintained at refrigerated temperature (2-8°C) during transit for no more than seven days after collection.
Acceptable Specimen Type(s)
- Sputum (Sedimented) – Minimum sample volume = 0.5 mL
- Sputum (Raw) – Minumum sample volume = 1.0 mL
Test Request
- GPHL Apollo Web Portal
-
Web
Portal Instructions
- For manual orders, download the
GPHL
Submission Form
Possible Results
- Mycobacterium tuberculosis Not Detected
- Mycobacterium tuberculosis Detected; Rifampin Resistance Not Detected
- Mycobacterium tuberculosis Not Detected; Rifampin Resistance Detected
- Unsatisfactory
Reference Range
- MTB not detected
- Rifampin Resistance not Detected
Unacceptable Conditions
- Missing testing requisition
- Missing minimum of 2 patient identifiers
- Improper labeling
- Improper storage/transport of specimen
- No specimen received (empty collection tube).
- Wrong specimen type
- Specimen broken, damaged, or leaking upon arrival.
Interfering Substances
N/A
Result Reported
1 business day
Fees
LOINC/Order Codes
17296-5 (Order code: 30800)