Acid fast bacilli stain; AFB stain; Tuberculosis smear; TB smear
Sputum stain for mycobacteria is a test to check for a type of bacteria that cause tuberculosis and other infections.
This test requires a sample of sputum.
The test sample is examined under a microscope. Another test, called a culture, is done to confirm the results. A culture test takes a few days to get results. This sputum test can give your doctor a quick answer.
It can help to drink a lot of fluids the night before the test. It makes the test more accurate if it is done first thing in the morning.
There is no discomfort, unless a bronchoscopy needs to be performed.
The test is performed when the doctor suspects tuberculosis or other Mycobacterium infection.
Results are normal when no mycobacterial organisms are found.
Abnormal results show that the stain is positive for:
There are no risks, unless bronchoscopy is performed.
To increase the accuracy of this test, it is sometimes done three times, often three days in a row.
More sophisticated tests are sometimes used to stain sputum for mycobacteria. Check with your health care provider to see if these are available in the laboratory.
Murray PR. The clinician and the microbiology laboratory. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglass, and Bennett's Principles and Practice of Infectious Diseases. 6th ed. Philadelphia, PA: Elsevier Saunders; 2014:chap 16.
Septimus EJ. Pleural effusion and empyema. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglass, and Bennett's Principles and Practice of Infectious Diseases. 6th ed. Philadelphia, PA: Elsevier Saunders; 2014:chap 70.BACK TO TOP
Review Date: 11/24/2014
Reviewed By: Daniel Levy, MD, PhD, Infectious Diseases, Lutherville Personal Physicians, Lutherville, MD. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.
The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- 2016 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.