Global treatment outcomes of extensively drug-resistant tuberculosis in adults: A systematic review and meta-analysis

INTRODUCTION

Historically, extensively drug-resistant tuberculosis has been notoriously difficult to treat with devasting outcomes. As we are coming to the end of an era where the 2006 extensively drug-resistant tuberculosis definitions and old treatment regimens are being replaced, we aimed to estimate the proportion of extensively drug-resistant tuberculosis patients globally who achieved successful treatment outcomes.

METHODS

We conducted a systematic review of PubMed/MEDLINE, Scopus, Web of Science, and Embase from January 1, 2005, through April 3, 2023. Included studies reported WHO treatment outcomes, or adaptions hereof, for pre-extensively and/or extensively drug-resistant tuberculosis patients according to the 2006 WHO definition. Eligible studies included cohorts of at least 10 adults (aged>18 years) that were not pregnant. Using a random-effects model, we calculated pooled proportions of treatment outcomes and performed sensitivity and subgroup analyses. PROSPERO registration number: CRD42022340961.

RESULTS

Among 5056 studies reviewed, we identified 94 studies from 26 countries, involving 10,223 extensively drug-resistant tuberculosis patients. The pooled proportion of successful treatment outcomes was 44.2% (95%CI: 38.3-50.3). Sensitivity analyses consistently produced similar estimates. A slight improvement in treatment outcomes was observed after 2013. Furthermore, 25 studies reported outcomes for 3564 individuals with pre-extensively drug-resistant tuberculosis, of which 63.3% achieved successful treatment (95%CI: 43.1-72.5).

CONCLUSION

Globally, the success rate of extensively drug-resistant tuberculosis treatment is 44.2%, far below the WHO's target rate of 75%. These results may serve as a reference for future studies assessing extensively drug-resistant tuberculosis treatment outcomes under the 2021 definition treated with better treatment regimens available. Comprehensive surveillance data of extensively drug-resistant tuberculosis outcomes from the whole world are desirable to monitor treatment progress.

Efficacy and tolerability of concomitant use of bedaquiline and delamanid for multidrug- and extensively drug-resistant tuberculosis: a systematic review and meta-analysis

The introduction of two novel drugs, bedaquiline and delamanid, has given hope for better and shorter treatments of drug-resistant tuberculosis. A systematic review was conducted to evaluate the efficacy and safety of concomitant bedaquiline and delamanid administration. Pooled estimates of WHO-defined favorable treatment outcome and significant QTc-interval prolongation (QTc ≥500 ms or ≥60 ms increase from baseline) were calculated using a random effects model. Thirteen studies including a total of 1031 individuals with multidrug-resistant/rifampicin-resistant tuberculosis who received bedaquiline and delamanid were included. The pooled estimate of favorable treatment outcome was 73.1% (95%CI: 64.3-81.8). Sputum culture conversion at six months ranged from 61-95%. Overall, the pooled proportion of QTc-prolongation was 7.8% (95%CI: 4.1-11.6) and few cardiac events were reported (0.8%, n = 6/798). Rates of sputum culture conversion and favorable treatment outcome were high in patients treated concomitantly with bedaquiline and delamanid, and the treatment seemed tolerable with low rates of clinically significant cardiac toxicity.