This Drug Susceptibility Test (DST) checks Mycobacterium tuberculosis (TB bacteria) isolated from a culture against the 4 standard first-line anti-TB medications (Isoniazid, Rifampicin, Pyrazinamide, and Ethambutol).

Why is This Test Ordered?

1. First-Line Treatment Planning: Helps doctors choose the correct standard antibiotic combination for newly diagnosed TB patients.
2. Detect Early Resistance: Identifies potential resistance to primary TB drugs before starting or continuing therapy.
3. Monitor Treatment Efficacy: Ensures the prescribed first-line medications effectively kill the specific strain of bacteria.

Preparation & Fasting

1. Fasting: Not required.
2. Instructions: Provide an early-morning deep-cough sputum sample (or follow specific medical advice for other sample types). Inform your doctor about any current TB medications.

Sample Collection

1. Type: Most commonly an early-morning sputum sample. Other body fluids or tissue biopsies may be collected depending on the infection site.

Turnaround Time

1. Because bacterial culture growth takes time, final sensitivity reports typically take 2 to 4 weeks.