The Contribution of the Xpert^&#174 MTB/RIF Assay to the Surveillance of Drug-Resistant Tuberculosis in the Central African Republic

Introduction: The Central African Republic is one of the 30 high Tuberculosis burden countries in the world, with an incidence of 540 cases per 100,000 population and a mortality of 91 deaths per 100,000 population. Since 2020, following WHO recommendations, the National Reference Laboratory for Tuberculosis has been using the Xpert® MTB/RIF assay as a first-line diagnostic test for the early detection of Drug Resistance Tuberculosis. The goal of this study was to evaluate the contribution of the Xpert® MTB/RIF assay to the surveillance of rifampicin resistance in new and previously treated tuberculosis cases. Materials and Methods: The data relative to the Xpert® MTB/RIF assay carried out on various categories of tuberculosis patients registered at the National Reference Laboratory for Tuberculosis in 2020 were analyzed retrospectively. The categories of tuberculosis patients were new cases, failed treatment cases, relapse cases, lost-to-follow-up cases and multidrug-resistant tuberculosis contact cases. Results: A total of 1404 tuberculosis patients were registered at the NRL-TB in 2020;the mean age was 39.2 years (2 - 90 years) and the male-to-female sex ratio was 1.16:1. Overall, 32.7% (454/1404) proved infected with tuberculosis, of which 22.5% (102/454) cases showed resistance to rifampicin. The primary resistance rate was 9.1% (27/298) and the secondary resistance rate was 46.6% (75/161). Treatment failures and relapsed cases were significantly associated with rifampicin resistance (p 0.005). Conclusion: Large-scale use of Xpert® MTB/RIF, especially in the provinces of the Central African Republic, will help the Ministry of Health to better control Drug Resistance Tuberculosis in the country.