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HelpTest Code AFB Culture, Mycobacteria
Synonyms/Keywords
TB Culture, AFB Culture, Mycobacteria, Mycobacterial, Acid fast bacilli
Specimen Requirements
| Fasting Required | Specimen Type | Preferred Container/Tube | Acceptable Container/Tube | Specimen Volume | Specimen Minimum Volume (allows for 1 repeat) |
Pediatric Minimum Volume (no repeat) |
|---|---|---|---|---|---|---|
| No | Any (except blood and bone marrow) |
Sterile leakproof containers without preservatives (e.g. Sage container) |
5-10 mL |
1 mL fluids and secretions
0.5 g tissues |
Acceptable Specimen Types
Bone, Bronchial, Catheter Tip, Environmental, Feces, Fine Needle Aspirate, Fluid, Hardware, Milk, Respiratory Secretions, Synovial, Tissue, or Urine.
Collection/Processing Instructions
Specimens should be delivered to the microbiology laboratory as soon as possible. Culture of specimens older than 24 hours may lead to a reduction in recovery of microorganisms. Do not freeze specimens at -20oC, or in a frost-free freezer.
Specimens should be collected in sterile leakproof containers without preservatives. A sterile anticoagulant such as heparin or SPS may be used in collection tubes to prevent clots in body fluids.
For sputum, three samples are recommended (one early morning from deep cough or expectorated sputa induced by aerosolization) eight to twelve hours apart.
For urine, three specimens, one per day for three consecutive days are recommended.
For gastric lavage fluid, three early morning specimens collected on separate days are recommended. Volumes >15 mL will NOT be accepted.
For blood and bone marrow mycobacteria culture, see Test Code CTBBLSO (CULTURE, MYCOBACTERIA, BLOOD).
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| CSF | Room Temperature | N/A |
| All other specimen types | Room temperature | ≤ 1 hour |
| Refrigerated | > 1 hour |
Rejection Criteria
| Pooled sputum or urine |
|---|
| Dried swabs or tissues |
| Specimens submitted in formalin or other preservatives |
| Gastric lavage specimens >4 hours old or >15 mL in volume |
| Specimens older than 4 days |
| Leaking specimens |
| Specimens received on swabs |
Test Components
This test includes a smear exam.
Test Information
The mycobacterial load in a clinical specimen may be low. Specimens with less than the recommended volumes may therefore lead to a false negative result.
Prior antimycobacterial therapy or an inadequate volume of specimen may impact correlation of positive smears with positive cultures.
First time positive M. tuberculosis isolates are routinely submitted for susceptibility testing at an additional charge. All other isolates will receive susceptibility testing only upon provider's request.
Interpretations
If a positive smear is detected on any patient without a history of mycobacterial infection, the specimen will be submitted to the Wisconsin State Laboratory of Hygiene for TB-PCR testing. This testing is performed free of charge.
Reference Range Information
| Performing Location | Reference Range |
|---|---|
| All Performing Sites |
Concentrated/unconcentrated specimen negative for acid-fast bacilli
Culture negative for acid-fast bacilli |
| See Critical Value List for list of current critical values. | |
Marshfield Labs Performing Department
Marshfield Labs Microbiology
Performing Information
| Performing Location | Day(s) Test Performed | Analytical Time | Methodology/Instrumentation |
|---|---|---|---|
| Marshfield | Monday through Friday | 6 weeks |
Conventional culture, microscopic exam with mycobacteria-specific stain, standard susceptibility testing, manual or automated identification methods, and nucleic acid sequence analysis as needed |
CPT Codes
| CPT | Modifier (if needed) |
Quantity | Description | Comments |
|---|---|---|---|---|
| 87116 | Culture | |||
| 87206 | Smear | |||
| 87118 | Mycobacteria definitive identification, as needed | |||
| 87153 | Identification by nucleic acid sequencing method, as needed |
|
||
| 87015 | Specimen concentration, as needed |
Outreach CPT Codes
| CPT | Modifier (if needed) |
Quantity | Description | Comments |
|---|---|---|---|---|
| 87116 | Culture | |||
| 87206 | Smear | |||
| 87118 | Mycobacteria definitive identification, as needed | |||
| 87153 | Identification by nucleic acid sequencing method, as needed |
|
||
| 87015 | Specimen concentration, as needed |
Ordering Applications
| Ordering Application | Description |
|---|---|
| Cerner | Acid Fast Bacilli Culture w/stain |