Ascitic Fluid for (AFB Smear/ZN Stain)

Specimen Required

FLUID (All Body Fluid)

Fasting Required

Purpose of the Test

AFB smear or ZN stain is a laboratory test used to detect the presence of acid-fast bacilli (AFB) in ascitic fluid. The presence of AFB can indicate the presence of tuberculosis or other mycobacterial infections.

When this test is required

The AFB smear or ZN stain is requested when a patient has symptoms suggestive of tuberculosis or other mycobacterial infections, such as prolonged cough, fever, night sweats, weight loss, and fatigue. It is also requested when a patient has ascitic fluid accumulation, and the healthcare provider suspects an infection in the abdominal cavity.

What the Test Detects

AFB smear or ZN stain is a laboratory test used to detect the presence of acid-fast bacilli (AFB) in ascitic fluid. AFB are a type of bacteria that are difficult to stain with traditional laboratory techniques because they have a waxy outer coating.

Preparation for the Test

No special preparation is required for the AFB smear or ZN stain.

Sample Requirements

A sample of ascitic fluid is required for the AFB smear or ZN stain. The sample is usually collected through a procedure called paracentesis, in which a needle is inserted into the abdominal cavity to remove the fluid.

Additional Notes

The AFB smear or ZN stain is a rapid test that can provide preliminary results within a few hours. However, it has a relatively low sensitivity, meaning that false negative results can occur. Therefore, if the healthcare provider strongly suspects a mycobacterial infection, additional testing, such as culture and sensitivity testing, may be necessary even if the initial AFB smear or ZN stain is negative.

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