Drug Resistance Pattern of Mycobacterium tuberculosis in Eastern Amhara Regional State, Ethiopia

Background: Tuberculosis (TB) is a major public health problem in Amhara region, Ethiopia where the TB case detection rate is low (22%). This situation has been worsened by the emergence and spread of drug resistance strains which have been threatening efforts of TB control. Objectives: The aim of this study was to assess the magnitude of drug resistance patterns of M. tuberculosis in Eastern Amhara region, Ethiopia. Methods: A facility based cross sectional study was conducted among 230 (165 new and 65 retreated) smear positive TB patients (age ≥18 years old) from September 2010 to June 2011. Socio-demographic data of the study participants and possible factors for development of drug resistance were collected using pre-tested structured questionnaire. Smear positive sputum samples were processed and decontaminated by the modified Petrof method. Primary isolation and drug susceptibility testing (DST) were carried out on egg based Lowenstein -Jensen media (LJ). Data were entered and analyzed using SPSS version 16 software. Multivariate analysis using the logistic regression model was computed. P-values less than 0.05 were considered as statistically significant. Results: The overall prevalence of drug resistance to at least a single drug was 77/230(33.5%). The prevalence of MDR-TB in all, new and re-treated patients was 15/230(6.5%), 3/165(1.8%) and 12/65 (18.5%), respectively. In the multivariate analysis previous exposure to anti-TB drugs and 1+ bacterial load were significantly associated with anti TB drug resistance (P<0.05). Conclusion: A high rate of drug resistance for main anti-tuberculosis drugs was observed on new and previously treated cases. Previous exposure to anti-TB drugs and bacterial load were important determinants of development of drug resistance. So, patient's adherence to anti-TB drugs (especially re-treated cases) and scaling up of DST service at district hospital level will help to reduce the development of drug resistance in the study area. © 2014 Esmael A, et al.