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AFB Testing

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Also known as: AFB Smear and Culture; TB Culture and Sensitivity; Mycobacteria Smear; Mycobacteria Culture; TB NAAT
Formal name: Acid-Fast Bacillus Smear and Culture and Sensitivity; Mycobacteria tuberculosis Nucleic Acid Amplification Test

At a Glance

Why Get Tested?

To help detect and identify infections caused by Mycobacterium tuberculosis, the cause of tuberculosis (TB), and other Mycobacterium species, which are known as acid-fast bacilli (AFB); to monitor the effectiveness of treatment

When to Get Tested?

When you have signs and symptoms of a lung infection, such as a chronic cough, weight loss, fever, chills, and weakness, that may be due to TB or a nontuberculous mycobacterial (NTM) infection; when you have a positive TB screening test and you are in a high-risk group for progressing to active disease; when you have a skin or other body site infection that may be due to mycobacteria; when you are undergoing treatment for TB

Sample Required?

For suspected cases of tuberculosis lung infections, usually three sputum samples are collected early in the morning on different days. If the affected person is unable to produce sputum, a bronchoscope may be used to collect fluid during a procedure called a bronchoscopy. In children, gastric washings/aspirates may be collected. Depending on symptoms, urine, an aspirate from the site of suspected infection, cerebrospinal fluid (CSF), other body fluids, or biopsied tissue samples may be submitted for AFB smear and culture.

Test Preparation Needed?