Prevalence of drug resistance-conferring mutations associated with isoniazid- and rifampicin-resistant mycobacterium tuberculosis in Ethiopia : a systematic review and meta-analysis

Abstract

OBJECTIVES : Globally, the incidence and mortality of tuberculosis (TB) are declining; however, low detection of drug-resistant disease threatens to reverse current progress toward global TB control. Multiple rapid molecular diagnostic tests have recently been developed to detect genetic mutations in Mycobacterium tuberculosis (Mtb) known to confer drug resistance. However, their utility depends on the frequency and distribution of resistance-associated mutations in the pathogen population. This review aimed to assess the prevalence of gene mutations associated with rifampicin (RIF)- and isoniazid (INH)-resistant Mtb in Ethiopia. METHODS : We searched the literature in PubMed/MEDLINE, Web of Science, Scopus and Cochrane Library. Data analysis was conducted in Stata 11. RESULTS : Totally, 909 (95.8%) of 949 INH-resistant Mtb isolates had detectable gene mutations: 95.8% in katG 315 and 5.9% in the inhA promoter region. Meta-analysis resulted in an estimated pooled prevalence of katG MUT1(S315T1) of 89.2% (95% CI 81.94–96.43%) and a pooled prevalence of inhA MUT1(C15T) of 77.5% (95% CI 57.84–97.13%). Moreover, 769 (90.8%) of 847 RIF-resistant strains had detectable rpoB gene mutations. Meta-analysis resulted in a pooled prevalence of rpoB MUT3(S531L) of 74.2% (95% CI 66.39–82.00%). CONCLUSION : RIF-resistant Mtb were widespread, particularly those harbouring rpoB (S531L) mutation. Sim- ilarly, INH-resistant Mtb with katG (S315T1) and inhA (C15T) mutations were common. Tracking S531L, S315T1 and C15T mutations among RIF- and INH-resistant isolates, respectively, would be diagnostically and epidemiologically valuable. Rapid diagnosis of RIF- and INH-resistant Mtb would expedite modifica- tion of TB treatment regimens, and proper timely infection control interventions could reduce the risk of development and transmission of multidrug-resistant TB.