Mycobacterium avium complex (MAC) PCR
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| WSLH Department: | CDD - Communicable Disease Division |
| WSLH Test Code: | MM00260 |
| Day(s) Performed: | Monday - Friday |
| Turn-around Time: | 1-3 days |
| Recommended Uses: | CDC recommends that TB 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). M. avium complex PCR can be used to release a patient from respiratory isolation in the case of an AFB smear positive, TB PCR negative result. |
| Pre-approval: | No |
| Contraindications: | Specimens from patients who have been undergoing antimicrobial therapy for MAC for more than 7 days (in the past 12 months) are not appropriate for this assay. Testing is not recommended for patients for whom suspicion of TB or M. avium complex infection is low. |
| Additional Tests Performed: |
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| Preparation for Collection: | 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). 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. MAC PCR must be performed within 7 days of specimen collection. |
| Collection Instructions: | Special Instructions for Sputum: Collect three specimens, each collected in 8-24 hour intervals with at least one being an early morning specimen (CDC MMWR 2005: 54, RR-17). Optimally 5mL of sputum, minimum 3mL. Sputum specimens collected less than 8 hours apart will be pooled into a single smear and culture. Special Instructions for Gastric Lavage: Collect fasting specimen soon after patient awakens in order to obtain sputum swallowed during sleep; place in neutralizing buffer immediately. |
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| Requisition Form: |
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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 which is required to have a minimum of two identifiers. |
| Rejection Criteria: | Specimens from patients who have received anti-mycobacterial drug treatment for more than 7 days in the past 12 months should not be submitted for this assay. Specimens from patients with known TB or NTM infections should not be submitted for this assay unless it has been >12 months since their last positive AFB smear or culture. AFB smear-negative specimens are not acceptable. This test is only performed on primary specimen material; positive cultures are not acceptable for this testing. Concentrated sediment volume of less than 0.2 mL is not acceptable for this testing. |
| Specimen Handling: | Store specimens at 2-8°C. Ship with frozen cold pack. Use pressure-resistant bags as inner packaging. |
| Packaging Requirements: | |
| Courier Information: | Not eligible for fee exempt courier |
| Specimen Receiving Hours: | Monday-Friday 6:00 AM - 4:30 PM, Saturday 6:30 AM - 12:30 PM |
| Results Include: | Negative for M. avium complex DNA, M. avium complex DNA detected, Equivocal |
| Limitations: | This real-time PCR assay detects the presence of M. avium complex DNA in clinical specimens. It detects a target in the 16S-23S internal transcribed spacer, which is specific for members of M. avium complex (M. avium, M. avium subsp. avium, M. avium subsp. paratuberculosis, M. intracellulare, M. chimaera, M. arosiense, M. colombiense, M. marseillense, M. bouchedurhonense, and M. timonense). MAC PCR is only performed on AFB smear-positive specimens due to limitations in sensitivity of the test. Low-grade smear-positive specimens may be below the limit of detection of this assay. A negative result does not rule out infection with M. avium complex. MAC PCR must always be performed in conjunction with Mycobacteria (AFB) Smear and Culture (Test Code MM00250). |
| Additional Tests Recommended: | For AFB smear-positive, MAC PCR-negative results, consider testing a second smear-positive specimen to confirm the PCR result. No more than two specimens should be tested. |
| Additional Comments: |
| Methodology: | This real-time PCR assay detects the presence of M. avium complex DNA in clinical specimens. It detects a target in the 16S-23S internal transcribed spacer, which is specific for members of M. avium complex (M. avium, M. avium subsp. avium, M. avium subsp. paratuberculosis, M. intracellulare, M. chimaera, M. arosiense, M. colombiense, M. marseillense, M. bouchedurhonense, and M. timonense). |
| Includes: | Nucleic acid amplification test (NAAT) for direct detection of M. avium complex DNA in human respiratory and non-respiratory specimens |
| Regulatory Compliance: |
| CPT Code: | 87561 |
| Price: | $175.00 |
| Fee Exempt Eligible: | Yes, with DHS pre-approval |
| Billing and Revenue Office: | 1-800-862-1065 arbill@slh.wisc.edu |