A patient is diagnosed with pre-XDR TB (extensively drug-resistant TB). According to the WHO 2022 revised definition, pre-XDR TB is defined as TB that is resistant to rifampicin AND:
- A Resistant to both fluoroquinolone and at least one of bedaquiline or linezolid
- B Resistant to fluoroquinolone, injectable aminoglycoside, AND isoniazid
- C Resistant to bedaquiline AND delamanid with or without other drugs
- D Resistant to any fluoroquinolone (levofloxacin or moxifloxacin) ✓
Explanation
The WHO revised definitions (2021/2022) for drug-resistant TB are: MDR-TB = resistant to rifampicin + isoniazid; RR-TB = resistant to rifampicin regardless of isoniazid susceptibility; pre-XDR-TB = MDR/RR-TB PLUS resistant to any fluoroquinolone (levofloxacin or moxifloxacin); XDR-TB = MDR/RR-TB PLUS fluoroquinolone resistance PLUS resistance to at least one of bedaquiline OR linezolid. The older definition (requiring resistance to injectable aminoglycosides) was retired. This updated classification reflects the shift to all-oral regimens (BPaL: bedaquiline-pretomanid-linezolid) and the central role of fluoroquinolones and novel agents.
Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.