Blood Culture, Acid-Fast Bacillus (AFB)
Also known as: MC BAFB
Use
The Blood Culture, Acid-Fast Bacillus (AFB) test is used to identify acid-fast bacteria, particularly in blood or bone marrow specimens, to detect infections caused by Mycobacterium species, such as Mycobacterium tuberculosis. This test is essential for diagnosing tuberculosis and other related infections in patients, providing critical information to guide treatment decisions, particularly in immunocompromised individuals or those with persistent infections.
Special Instructions
For PZA susceptibility testing of M. tuberculosis complex isolates, clinicians should contact local public health laboratories or the CDC. ARUP performs susceptibility testing for the first-line drugs rifampin, isoniazid, and ethambutol. Aseptic drawing of specimens is required.
Limitations
The test refers specifically to detection of Mycobacterium species and may not identify non-acid-fast bacteria. Susceptibility testing is only performed on positive cultures at an additional charge, meaning only certain drugs' resistances will be tested specifically. Negative results are not conclusive within a shorter timeframe; cultures are typically kept for up to 43 days before a negative result is confirmed, which might delay diagnosis and treatment.
New York Approved
Methodology
Culture-based
Biomarkers
LOINC Codes
- 533-0
Result Turnaround Time
1-43 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
1-5 mL
Minimum Volume
Not provided
Container
Bactec(R) Myco/F Lytic bottle
Collection Instructions
Aseptic draw.
Patient Preparation
Aseptic draw.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 72 hours |
| Refrigerated | 72 hours |
| Frozen | Unacceptable |