Prevalence and predictors of second-line drug resistance in rifampicin-resistant TB patients in Niger

Abstract

Introduction: Tuberculosis is a real public health problem mainly in the developing country, aggravated by the emergence of resistance to second-line anti-tuberculosis drugs. The objective of this study was to determine the prevalence of resistance to second-line anti-tuberculosis drugs and the associated predictive factors in Niger.

Methodology: This was a retrospective, descriptive, and analytical multicenter study conducted from January 1, 2018 to October 30, 2019. Patients detected with rifampicin-resistant tuberculosis on the Xpert MTB/RIF test were included. The GenoTypeMTBDRsl V2.0 line probe assay (LPA) was performed to detect different mutations associated with resistance to second-line anti-tuberculosis drugs. Results: A total of 112 rifampicin-resistant patients were included of which 83.07% were male. The mean age of the patients was 34.54 ± 11.58 years with extremes ranging from 17 to 70 years. Of the 112 rifampicin-resistant patients included, 93 (83.03%) had valid PCL results and were analyzed. Of these, 25 patients were resistant to at least one of the second-line anti-tuberculosis drugs, representing a prevalence of 27% (25/93). Detailed analysis of the 25 patients resistant to second-line drugs showed that 48% (12/25) were resistant only to fluoroquinolones, 32% (8/25) were resistant only to SLI and 20% (5/25) were resistant to fluoroquinolones and SLI. Patients with resistance to second-line drugs were predominantly male (84.00%), between 19 and 40 years old (80.00%), from the multidrug-resistant tuberculosis unit of Niamey (72.00%), and in treatment failure (36.00%). However, no factor was statistically associated with resistance to second-line anti-tuberculosis drugs in univariate and multivariate logistic analysis.

Conclusion: The prevalence of resistance to second-line anti-tuberculosis drugs is high in Niger, especially in MDR and treatment failure patients. It is more urgent to reinforce surveillance and to make systematic the search for resistance to second-line anti-tuberculosis drugs in patients in situation of therapeutic failure and relapse.