Drug resistance pattern, prevalence and risk factors for resistance to second line anti-tuberculosis drugs in Balochistan, Pakistan

Background. Pakistan is high burden drug resistant tuberculosis (DR-TB) country. For devising a treatment regimen and optimizing empirical drug therapy, the local epidemiology and drug resistance patterns are needed to be considered. Objectives. To evaluate the drug resistance pattern, prevalence and risk factors for resistance to second line anti-tuberculosis drugs (SLD) among DR-TB patients in Balochistan, Pakistan. Design and setting. This cross-sectional study was carried out at the Fatimah Jinnah Chest and General Hospital in Quetta's programmatic management unit of the DR-TB (PMDT). Methods. This study included all DR-TB patients, regardless of their age, TB location, or medication resistance pattern. The sociodemographic, microbiological, and clinical data of the patients were gathered using a standard data collecting form. SPSS 20 was used to analyze the data. A statistically significant p-value was defined as less than 0.05. Results. A total of 354 patients were included in the final analysis. Among them majority were females (61.7%), belonged to the age group 19-30 years (36.7%), were previously treated for TB (95.8%) at public sector hospital (42.7%) and did not suffer from any other comorbidity(88.7%). The study participants were resistant to a median of three anti-TB drugs (range 1-8). The most common type of DR-TB was multi DR-TB (77.1%), followed by mono DR-TB (18.1%), extensive DR-TB(3.1%) and poly-DR (1.7%). A total of 147 (41.5%) patients were resistant to any second line anti-TB drug (SLD). Among SLD, the resistance was high for fluoroquinolones (38.4%), followed by ethionamide (4.8%) and injectable SLD(4.2%). Upon multivariate binary logistic regression analysis previous treatment of cat-II regimen had statistical significant association with resistance to any SLD (OR=5.273, 95%CI=1.098-25.316). Conclusion. It is concerning to see such a high level of SLD resistance, especially to fluoroquinolones. More stringent regulations are advised to regulate the non-prescription sale and indiscriminate use of fluoroquinolones, as well as testing for drug resistance in cat-I failures instead of placing patients on cat-II therapy.