New definitions of extensively drug resistant tuberculosis: update from the World Health Organization

The objectives of a WHO convened online expert consultation meeting held in October 2020 were to determine how recent changes in treatment regimens and diagnostics for drug-resistant TB might affect the definition of XDR-TB and discuss options for changing it.Methods: The latest WHO policy recommendations on treatment regimens and diagnostics for drug resistant TB were presented as well as independent research.Results: The WHO has proposed a definition of pre-XDR-TB as well as a revised definition of XDR-TB, which apply from January 2021 (Table 1) (WHO, 2021). Table 1:The new definition of pre-XDR-TB and the revised definition of XDR-TB, effective from January 2021Pre-XDR-TB: TB caused by Mycobacterium tuberculosis (M. tuberculosis) strains that fulfil the definition of MDR/RR-TB and that are also resistant to any fluoroquinoloneaXDR-TB: TB caused by Mycobacterium tuberculosis (M. tuberculosis) strains that fulfil the definition of MDR/RR-TB and that are also resistant to any fluoroquinolonea and at least one additional Group A drugba The fluoroquinolones include levofloxacin and moxifloxacin, which are the fluoroquinolones currently recommended by WHO for inclusion in shorter and longer regimens.b The Group A drugs are currently levofloxacin or moxifloxacin, bedaquiline and linezolid.
Source: European Respiratory Journal - Category: Respiratory Medicine Authors: Tags: Tuberculosis and non-tuberculous mycobacterial diseases Source Type: research