AFB Susc. Isoniazid

What is the AFB Susceptibility – Isoniazid test?

This test determines whether Mycobacterium tuberculosis or other acid-fast bacilli (AFB) are susceptible or resistant to the antibiotic isoniazid.


Why is this test done?

To guide effective treatment by confirming whether the infecting organism is sensitive to isoniazid, a first-line anti-TB drug.


How is the test performed?

AFB isolated from a culture is exposed to isoniazid, and growth patterns are analyzed to determine resistance.


What do the results mean?

Resistance indicates that isoniazid may be ineffective, requiring alternative medications. Susceptibility suggests the drug should work.


Are there any precautions or preparations required?

No patient preparation is needed. Sample collection must be sterile.