Under the National TB Elimination Programme (NTEP), the drug-susceptibility testing algorithm for a newly diagnosed TB patient in India mandates which initial investigation as the FIRST step?
- A Sputum smear microscopy (Ziehl-Neelsen staining)
- B Cartridge-Based Nucleic Acid Amplification Test (CB-NAAT/Xpert MTB/RIF) ✓
- C Line probe assay (LPA) for first-line drug resistance
- D Liquid culture with Mycobacterium Growth Indicator Tube (MGIT)
Correct answer: B. Cartridge-Based Nucleic Acid Amplification Test (CB-NAAT/Xpert MTB/RIF)
Explanation
Since 2019, NTEP mandates CB-NAAT (Xpert MTB/RIF) as the first-line diagnostic test for all presumptive TB patients, simultaneously detecting MTB and rifampicin resistance. Smear microscopy has been moved to a secondary role for follow-up monitoring. LPA is used as a reflex test for rifampicin-resistant or MDR suspects. Liquid culture is reserved for complex diagnostic scenarios and drug susceptibility testing of second-line drugs.
Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.