drug resistance pattern and associated risk factors of tuberculosis patients in iran's central province

background: one of the fundamental issues of infectious disease treatment is drug resistance. the aim of the present study was to investigate the first-line anti-tuberculosis drug resistance rates and determine the risk factors related to multidrug resistant mycobacterium tuberculosis.methods: from march 2011 to september 2012, mycobacterial strains were collected from one hundred fifteen diagnosed smear positive patients in the central province of iran and tested for drug susceptible against ethambutol, rifampicin, isoniazid and streptomycin and the risk factors influencing the development of drug resistance were determined.results: the mean age of patients was 52.23±19.75 years. the rate of multi-drug resistant tuberculosis (mdr-tb) was 7.8%. our study revealed that there were significant associations between prior treatment, age < 45 years, positive smear result at the end of the second month and positive smear result at the end of the third month. however, there was no association found between gender, inhabitant, nationality, close contact with tb patient, hiv infection and size of mantoux test.conclusion: the results show that about 8% of tb cases in arak are mdr tb. the age under 45 years, previous tb treatment and positive smear at the end of the second and third months of treatment were the main factors in the development of mdr-tb.