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HelpTest Code LABSAFB Acid-Fast Smear for Mycobacterium, Varies
Additional Codes
| Test Name in EPIC | EPIC Test Code | Mnemonic | Mayo Test ID |
|---|---|---|---|
| AFB SMEAR-MYCOBACTERIUM | LABSAFB | SAFB | SAFB |
Reporting Name
Acid Fast Smear For MycobacteriumUseful For
Detection of acid-fast bacilli in clinical samples
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
VariesOrdering Guidance
For the preferred test for rapid, direct detection of Mycobacterium tuberculosis from clinical specimens, order MTBRP / Mycobacterium tuberculosis Complex, Molecular Detection, PCR, Varies.
Necessary Information
Specimen source is required.
Specimen Required
Fresh tissue or body fluid are the preferred specimen types. Recovery of mycobacteria from swabs is generally very low yield.
Submit only 1 of the following specimens:
Preferred:
Specimen Type: Body fluid
Container/Tube: Sterile container
Specimen Volume: 1 mL
Collection Information: Saliva is not acceptable.
Additional Information: If a mycobacterial culture is also requested, collect 1.5 mL.
Specimen Type: Bone marrow
Container/Tube: Sterile container or green top (lithium heparin)
Specimen Volume: Entire collection
Collection Instructions:
1. Invert several times to mix bone marrow.
2. Send bone marrow specimen in original tube. Do not aliquot.
Specimen Type: Gastric washing
Container/Tube: Sterile container
Specimen Volume: 10 mL
Collection Instructions: Neutralize specimen within 4 hours of collection with 100 mg of sodium carbonate per 5 to 10 mL of gastric wash.
Specimen Type: Respiratory
Sources: Bronchoalveolar lavage fluid, bronchial washing, sputum
Container/Tube: Sterile container
Specimen Volume:Â mL
Collection Instructions: Collect 3 respiratory specimens for acid-fast smears and culture in patients with clinical and chest X-ray findings compatible with tuberculosis. These 3 specimens should be collected at 8- to 24-hour intervals (24 hours when possible) and should include at least 1 first-morning specimen.
Specimen Type: Feces
Supplies: Stool Collection Kit, Random (T635)
Container/Tube: Sterile container
Specimen Volume: 5 to10 g
Specimen Type: Tissue
Container/Tube: Sterile container
Specimen Volume: 5 to10 mm
Collection Instructions: Collect a fresh, unfixed tissue specimen. Fixed tissue is not acceptable.
Specimen Type: Urine
Container/Tube: Sterile container
Specimen Volume: 2 mL
Collection Instructions: Collect a random urine specimen.
Acceptable:
Specimen Type: Swab
Sources: Wound, tissue, or body fluid
Container/Tube:
Preferred: Flocked swab (eg, Eswab)
Acceptable: Culture transport swab, noncharcoal (eg, Culturette)
Specimen Volume: Swab
Collection Instructions:
1. Before collecting specimen, wipe away any excessive amount of secretion and discharge, if appropriate.
2. Obtain secretions or fluid from source with sterile swab.
3. If smear and culture are requested or both a bacterial culture and mycobacterial culture are requested, collect a second swab to maximize test sensitivity.
4. Swabs from the following sources are not acceptable: respiratory fluid (eg, sputum), nasal, sinus, ear, mouth, throat, or scalp.
Specimen Minimum Volume
See Specimen Required
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Varies | Refrigerated (preferred) | 7 days | |
| Ambient | 7 days |
Reference Values
Negative (reported as positive or negative)
Day(s) Performed
Monday through Sunday
Test Classification
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.CPT Code Information
87206
87176-Tissue processing (if appropriate)
87015-Mycobacteria culture, concentration (if appropriate)
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| SAFB | Acid Fast Smear For Mycobacterium | 676-7 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| SAFB | Acid Fast Smear For Mycobacterium | 676-7 |
Clinical Information
Mycobacterium tuberculosis is a leading infectious disease cause of death worldwide. The Centers for Disease Control and Prevention has reported a rise in the incidence of tuberculosis associated with AIDS, foreign-born cases, and increased transmission in high-risk populations. There has also been a rise in the number of M tuberculosis strains that exhibit resistance to one or more antituberculosis drugs. The public health implications of these facts are considerable. Because M tuberculosis is readily spread by airborne particles, rapid diagnosis and isolation of infected persons is important. Nontuberculous mycobacteria infections also cause significant morbidity and mortality in humans, particularly in immunocompromised persons. Detection of acid-fast bacilli in sputum and other specimens allows rapid identification of individuals who are likely to be infected with mycobacteria while definitive diagnosis and treatment are pursued.
Interpretation
Patients whose sputum samples are identified as acid-fast positive should be considered potentially infected with Mycobacterium tuberculosis, pending definitive diagnosis by molecular methods or mycobacterial culture.
Cautions
Artifacts may exhibit nonspecific fluorescence and be confused with organisms.
Method Description
Auramine-rhodamine fluorochrome stain prepared and read with fluorescent microscope.(Martin I, Pfyffer GE, Parrish N: Mycobacterium: General Characteristics, Laboratory Processing, Staining, Isolation and Detection Procedures. In: Carroll KC, Pfaller MA, Pritt BS, et al. Manual of Clinical Microbiology. 13th ed. ASM Press; 2023)
Report Available
1 daySpecimen Retention Time
3 to 7 daysReject Due To
| Specimen in viral transport medium (including but not limited to M4, M5, BD viral transport media, thioglycolate broth) Wood shaft, charcoal or gel swab Prepared slide, glass slide, microscope slide |
 Reject |
Reflex Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| TBT | Concentration, Mycobacteria | No, (Bill Only) | No |
| TISSR | Tissue Processing | No, (Bill Only) | No |
Testing Algorithm
When this test is ordered, the reflex tests may be performed at an additional charge.
For more information see Meningitis/Encephalitis Panel Algorithm
Method Name
Auramine-Rhodamine Stain
Forms
If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:
-Microbiology Test Request (T244)
-General Request (T239)