Mycobacterium tuberculosis complex PCR
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| WSLH Department: | CDD - Communicable Disease Division |
| WSLH Test Code: | MM00256 |
| Day(s) Performed: | Monday - Friday |
| Turn-around Time: | 1-3 days |
| Recommended Uses: | CDC recommends that NAAT be performed on at least one respiratory specimen from each patient with signs and symptoms of pulmonary TB for whom diagnosis of TB is being considered but has not yet been established, and for whom the test would alter case management or TB control activities, such as contact investigations (MMWR. 2009; 58: 7-10). Patients must meet criteria established by the Wisconsin TB Control Program to qualify for fee-exempt testing. These criteria include that the patient be reported to the local or state public health department as a suspect TB case. If the patient does not reach this level of suspicion, fee-exempt NAAT is not provided, but fee-for-service NAAT may be performed at the request of the submitter. Fee-exempt testing for smear-negative pulmonary specimens must be pre-approved by the WI State TB Program. Contact the WI State TB Program at 608-261-6319. TB PCR should always be performed in conjunction with mycobacterial culture and smear. Patients must meet criteria established by the Wisconsin TB Control Program to qualify for fee-exempt testing. These criteria include that the patient be reported to the local or state public health department as a suspect TB case. If the patient does not reach this level of suspicion, fee-exempt NAAT is not provided, but fee-for-service NAAT may be performed at the request of the submitter. Contact the WI State TB Program at 608-261-6319. TB PCR should always be performed in conjunction with mycobacterial culture and smear. |
| Contraindications: | **Specimens from patients who have been undergoing antimicrobial therapy for TB for more than 7 days in the past 12 months are not appropriate for this assay. **Patients for whom suspicion of TB is low. **Not to be used for test of cure. **Not to be used for decisions to release patients from airborne isolation. |
| Additional Tests Performed: |
| Patient Preparations: | Collect specimens prior to anti-mycobacterial drug treatment or within 7 days of start of therapy. Sterile preparation of site if applicable. |
| Specimen Requirements: | ** Submit 3-10 mL of a primary respiratory specimen (sputum, tracheal aspirate, bronchial washings, BAL). For primary, non-respiratory specimens (body fluids, CSF, stool, urine, lung and other tissues), please use the "Mycobacteriology Culture and Smear" section of the WSLH Reference Manual for recommended specimen volumes. Specimens with visible blood will be accepted. If AFB smear has not been performed, WSLH will perform AFB smear and culture testing and the submitter will be billed. ** Submit 0.5mL of decontaminated and/or concentrated sediment. ** All specimens should be submitted in sterile, leak-proof containers. ** If a specimen from a non-sterile site has not been decontaminated, WSLH will perform decontamination and the submitter will be billed. ** TB PCR must be performed within 7 days of specimen collection. |
| Specimen Handling & Transport: | Store specimens at 2-8 degrees Celsius. Ship with cool pack. Use pressure-resistant bags as inner packaging. Call WSLH (800-262-1013) for information on free next-day courier service. |
| Collection Kit/Container: |
Mycobacteria (AFB,TB) Gastric Specimens
TB Sputum/Legionella |
| Collection Instructions: | See Mycobacteria (AFB) Smear and Culture (MM00250) for detailed specimen requirements, patient preparation and collection instructions. |
| Unacceptable Conditions: | Specimens from patients who have received TB drug treatment for more than 7 days in the past 12 months should not be submitted for this assay. Smear-negative extrapulmonary specimens are not tested. |
| Requisition Form: |
CDD Requisition Form A
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| Required Information: | Laboratory regulations require the following minimum information to be provided on the requisition form for a specimen to be accepted for testing: Patient name or unique identifier; date and time of collection, patient date of birth and sex, specimen type/site of collection, test request(s), clinician name and UPIN, and address for reporting results. Please be certain that name/identifier on the form matches that on the specimen label. |
| Results Include: | |
| Limitations: | **This real-time PCR assay detects the presence of M. tuberculosis complex DNA in clinical specimens. It detects a target within an insertion sequence (IS6110), which is specific for, but does not differentiate among, members of M. tuberculosis complex. This assay was developed and its performance characteristics determined by the Wisconsin State Laboratory of Hygiene. It has not been approved by the U.S. Food and Drug Administration. A negative result does not rule out infection with M. tuberculosis complex. **TB PCR should always be performed in conjunction with mycobacterial culture and smear. This test should only be performed on patients with signs and symptoms of TB for whom a diagnosis of TB is being considered but has not yet been established, and for whom the test result would alter case management activities such as contact investigations. **Not performed on smear-negative extrapulmonary specimens. |
| Additional Tests Recommended: | **For smear-positive, TB PCR-negative results, consider testing a second specimen to confirm the PCR result. **No more than two specimens should be tested. |
| Additional Comments: | **We recommend contacting the laboratory before submitting specimen to arrange for testing and transport: (800) 862-1013. **This test is not intended for screening asymptomatic contacts of TB patients. **GeneXpert MTB/RIF testing will automatically be performed on any TB-positive respiratory specimens. **Susceptibility testing is performed automatically on all initial M. tuberculosis complex isolates. **An initial M. tuberculosis complex isolate is also genotyped as part of the CDC universal genotyping program. |
| Methodology: | This real-time PCR assay detects the presence of M. tuberculosis complex DNA in clinical specimens. It detects a target within an insertion sequence (IS6110), which is specific for members of M. tuberculosis complex. |
| Includes: | Nucleic acid amplification (NAAT) test for direct detection of M. tuberculosis complex DNA in human respiratory and non-respiratory specimens. |
| CPT Code: | 87556 |
| Price: | $307.00 Price Effective 1/1/25 |