Genotypes of MDR-TB in Tanzania

Background: Multidrug-resistant tuberculosis (MDR-TB) continues to be a major public health threat, particularly in resource-limited areas. This study examines how bacterial mutations associated with drug resistance influence treatment outcomes in MDR-TB patients in Tanzania. Methods: The study enrolled 40 MDR-TB patients receiving TB diagnostic services at Kibong'oto and other health centres across the country. Patient data and outcomes were systematically captured through clinical assessments and health records. Drug susceptibility testing was conducted using the proportion method on Lowenstein-Jensen (LJ) medium. Whole genome sequencing (WGS) was performed to identify drug resistance-related mutations, while univariate and multivariate analyses were performed to establish, and the interplay between clinical information, resistance genotype, and patient outcomes. Results: The proportions of patients with the following outcome; completed treatment were 32.5% (13/40), cured (6/40)15%, failure (1/40) 2.5%, and defaulted (1/40)1.5% respectively, while 19 patients continued treatment . The highest rate of genotypic variants associated with drug resistance was recorded in rpoB (rifampicin) and katG (isoniazid) 100% followed by gyrA (moxifloxacin, levofloxacin) 62.5%, pncA (pyrazinamide) 35%, rpsL (streptomycin) 25%, rrs (streptomycin, amikacin, capreomycin, kanamycin) 22.5%, gid (streptomycin) 20%, mmpR5 (bedaquiline, clofazimine) 15%, gyrB 10% and inhA (isoniazid, ethionamide) 10%. Multivariable analysis revealed that drug resistance against ethambutol (embA variants, p=0.01) and individualized, tailored treatment (p=0.05) significantly impacted treatment outcomes. Conclusion: These findings emphasize the need for increased molecular surveillance for early detection of drug-resistant tuberculosis patients. The clinical significance of genotypic resistance markers, particularly in rpoB and katG, and risk factors such as age, embA mutations, and individualized treatment, underscore the need for enhanced therapeutic strategies and personalized treatment approaches to improve patient outcomes. While the approach may seem expensive, authorities should consider putting aside some funds along with the annual budget to support the approach which potentially has high impact in strategic disease control and management.