Screening and diagnosis for DRTB

Drug-resistant TB (DR-TB) diagnosis is predominantly based on laboratory diagnosis. Presumptive-TB/ DR-TB is identified by the health facility doctor during passive screening or by health staff/ community volunteers during Active Case Finding (ACF). 

The vision of National TB Elimination Programme (NTEP) is to provide early diagnosis to all persons with any form of DR-TB through Universal Drug Susceptibility Testing (UDST).

All diagnosed TB patients are eligible for a NAAT test to know their Rifampicin sensitivity status. The integrated diagnostic algorithm for diagnosis of TB offers upfront Nucliec Acid Amplification Test (NAAT) for diagnosis of TB to vulnerable population. Among other eligible groups for NAAT are: non-responders to treatment and contact persons of DR-TB patients are also offered upfront NAAT.

Rapid identification of DR-TB is achieved by using a combination of NAAT (CBNAAT/ Truenat) followed by sequential testing by first- and second-line Line Probe Assay (LPA) and Liquid Culture (LC) and Drug Susceptibility Testing (DST) for specific drugs as described below:

• When Rifampicin resistance is not detected by NAAT, the patient is offered First-line (FL) LPA.FL-LPA provides information on Isoniazid resistance.
• For Rif resistance/Inh resistance cases, SL-LPA  is done and it provides information on resistance to Levofloxacin, Moxifloxacin and Amikacin.
• For all Rif resistance cases, LC and DST is done for Pyrazinamid, Moxifloxacin (if resistance detected by LPA), Linezolid, Clofazimine*, Bedaquiline* and Delamanid*.

(* when available)

Resources

• Guidelines for PMDT in India, 2021.

Assessment