The following is a summary of “Epidemiology of extensively drug-resistant tuberculosis among patients with multidrug-resistant tuberculosis: A systematic review and meta-analysis,” published in the July 2023 issue of the Infectious Disease by Diriba et al.

In patients with multidrug-resistant tuberculosis (MDR-TB), the objective is to estimate the proportion of extensively drug-resistant tuberculosis (XDR-TB) and pre-extensively drug-resistant tuberculosis (pre-XDR-TB). Researchers systematically searched MEDLINE (PubMed), ScienceDirect, and Google Scholar for relevant articles. The review’s primary outcome was either XDR-TB or pre-XDR-TB in patients with MDR-TB. 

They also combed through gray literature from various sources. They utilized the random-effects model due to the substantial heterogeneity between investigations. The heterogeneity was evaluated using subgroup analyses. Version 14 of STATA was used for analysis. About 64 investigations involving 12,711 MDR-TB patients from 22 countries were retrieved. The pooled proportion of pre-XDR-TB was 26% (95% CI: 22-31%), whereas the proportion of XDR-TB in MDR-TB cases was 9% (95% CI: 7-11%) in patients receiving MDR-TB treatment. Resistance to fluoroquinolones was 27% (95% CI: 22-33%), and resistance to second-line injectables was 11% (95% CI: 9-13%). 

Comparatively, the pooled proportions of resistance to bedaquiline, clofazimine, delamanid, and linezolid were 5% (95% CI: 1-8%), 4% (95% CI: 0-10%), 5% (95% CI; 2-8%), and 4% (95% CI: 2-10%), respectively. The prevalence of pre-XDR-TB and XDR-TB in MDR-TB was substantial. The prevalence of pre-XDR-TB and XDR-TB in MDR-TB patients suggests that TB programs and drug resistance surveillance must be strengthened.

Source: sciencedirect.com/science/article/pii/S1201971223005246