AFB Smear and Culture
Also known as: TB culture and sensitivity; Mycobacterial smear and culture
Formal name: Acid-fast bacillus smear and culture and sensitivity
Why Get Tested?
To help detect and identify a mycobacterial infection; to diagnose tuberculosis (TB); to monitor the effectiveness of treatment
When to Get Tested?
When you have symptoms of a lung infection, such as a chronic cough, weight loss, fever, chills, and weakness, that may be due to TB or another mycobacterial infection; when your doctor suspects that you have an active TB 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; to monitor the effectiveness of TB treatment
For suspected cases of tuberculosis lung infections, 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.
Acid-fast bacilli (AFB) are a group of rod-shaped bacteria (bacilli). They get their name because they can be seen and counted under the microscope when smeared on a slide and treated with a special “acid-fast” staining procedure. There are a several types of bacteria that may be detected in this manner; however, the most common and medically important acid-fast bacilli (AFB) are members of the genus Mycobacterium.