🦠 What is the Test?
The AFB (Acid-Fast Bacilli) Sensitivity Test for Isoniazid determines whether Mycobacterium tuberculosis (TB bacteria) is susceptible or resistant to isoniazid (INH), a critical first-line antibiotic used in TB treatment.
📊 Normal Ranges:
Susceptible (S) → TB bacteria respond to isoniazid (effective treatment).
Resistant (R) → TB bacteria do not respond to isoniazid (alternative treatment needed).
Intermediate (I) → Partial response; dose adjustment or an alternative drug may be necessary.
(Results may vary based on laboratory testing methods.)
🎯 Purpose of the Test:
✅ Determines if isoniazid can be used to treat TB
✅ Helps detect isoniazid-resistant tuberculosis, which may indicate multi-drug resistant TB (MDR-TB)
✅ Prevents ineffective antibiotic use and further resistance
✅ Assists in customizing TB treatment plans
🩺 When is it Recommended?
🔹 Patients newly diagnosed with tuberculosis
🔹 Individuals not responding to standard TB treatment
🔹 Patients at risk for drug-resistant TB (previous TB treatment, exposure to MDR-TB cases)
🔹 To ensure effective TB therapy and prevent resistance spread
📝 How is the Test Done?
A sputum, tissue, or body fluid sample is collected.
The bacteria are cultured in a lab and tested against isoniazid.
Results may take a few days to weeks, depending on the method used.
⚠️ What Do Abnormal Results Mean?
📉 Susceptible (S) → Isoniazid can be used as part of TB treatment.
📈 Resistant (R) → Alternative first-line or second-line antibiotics should be considered.
🔍 Infographic Design Idea:
Blue, red, and white medical-themed colors
Illustration of TB bacteria with an antibiotic resistance test diagram
Simple table for result interpretation (S, R, I)