Acid-Fast Bacilli(AFB) Smear And Culture

Acid-fast Bacilli (AFB) smear and culture are two different tests, performed together at MSPHL, Tuberculosis (TB) Unit. The term AFB smear is used to refer the microscopic examination of fluorochrome stain of the specimen. AFB culture is a shot of a specimen onto métier Becton-Dickinson Mycobacteria Growth Indicator Tube (B-D MGIT broth) and Lowenstein-Jensen (L-J) slant, incubation of 37oC for up to six weeks and the growth detection or no growth during this period. 

AFB is used to diagnose active tuberculosis infection (M. tuberculosis) and the infection which are non-tuberculosis myco-bacteria. The AFB culture is also used to diagnose some other type of infection related to the culture. The infections include: leprosy (a rare diseases affecting nerves, eyes and skin, easily treatable). The test is also be used to track the effectiveness of the treatment and can help in determining the presence or no presence of infections. 

SPECIMEN COLLECTION BY THE BEST DIAGNOSTIC CENTRE IN AMRITSAR

(1) Septum:

• Early morning deep cough for continuous days is the best option for initial diagnosis of tuberculosis. 
• If expectorations are collected in the same day for 24-hour period, the minimum gap between the specimens of around 8 hours is required. 
• The specimen should be at least of 2mL.
• Ship specimens each day should be collected for a rapid diagnosis (do not spot until the 3 day specimens are collected)
• Refrigerate until you submit the specimen. 

(2) Bronchial Washing:

• At least 2mL volume is acceptable.
• Refrigerate 

(3) Pleural Fluid

POSSIBLE RESULTS AS PER BEST DIAGNOSTIC CENTRE IN AMRITSAR

AFB Smear – 

• 1+ (Rare)
• 2+ (Few)
• 3+ (Moderate)
• 4+ (Many)

AFB Not Found

Smear not performed

AFB Culture

–Identification of Mycobacteria species

–No growth of Myco-bacteria after 6 weeks 

–Unsatisfactory 

Best Diagnostic Centre in Amritsar recommends the specimen to be collected as first thing in the morning. This test is helpful in getting the root cause of health issues and underlying infections.