Question

A 35-year-old homeless man presented with a 1-month history of fever, cough, and weight loss. Both sputum smears turned out to be negative, but the chest x-ray ordered was suggestive of tuberculosis. According to the recent NTEP guidelines, which is the next best line of management?

• A. Repeat sputum smears
• B. Ask for CBNAAT
• C. Ask for line probe assay
• D. Wait until TB culture results to start ATT

Answer 1

The Correct Option is B

In the case of a 35-year-old homeless man presenting with symptoms such as fever, cough, and weight loss, combined with a suggestive chest x-ray for tuberculosis (TB), but negative sputum smears, it is crucial to follow the guidelines set by the National TB Elimination Program (NTEP) for the next steps in diagnosis and management. The NTEP guidelines recommend employing molecular diagnostic techniques like Cartridge Based Nucleic Acid Amplification Test (CBNAAT) to confirm the diagnosis of tuberculosis when sputum smears are negative but there is a high suspicion of TB.
Here are the reasons for choosing CBNAAT:

• High Sensitivity and Specificity: CBNAAT has a higher sensitivity and specificity compared to sputum microscopy, especially for detecting Mycobacterium tuberculosis in smear-negative cases.
• Rapid Results: CBNAAT provides quick outcomes, often within a few hours, which accelerates the initiation of appropriate treatment.
• Detection of Drug Resistance: It not only helps in confirming the presence of TB but can also detect rifampicin resistance, which is crucial for tailoring TB treatment regimens.

Considering these points, asking for CBNAAT is the optimal choice for further investigation in this clinical scenario.