ABSTRACT
Exploration of factors associated with re-infection of Mycobacterium tuberculosis can be helpful in prevention of disease and reduce the burden of tuberculosis on health care system. This study was designed to identify factors associated with re-infection of tuberculosis in patients with sputum smears positive pulmonary tuberculosis in five bordering provinces of Iran. In this cross sectional study that performed of 2010-2012, different and clinical, socio economic factors were evaluated to identify influencing factors on re-infection. Data were gathered from questionnaires and survey of medical records. Data were analyzed by statistical methods in 300 studied patients with average age 51.9 +/- 24.2 years. 7.2% of patients were diagnosed with reinfection. 64% of patients were in low-income classes, [10.6%] of patients had concomitant renal diseases, 10.2% had diabetes, and 9.8% of patients had liver dysfunction. In multiple analysis, migration from rural to urban areas [P=0.31] and weight loss [P=0.42] were significantly associated with increased risk re-infection. Compared to global reports recurrence rate in our cohort was in a moderate degree. Future studies should be done to identify the influential environmental and socioeconomic factors that affect the M tuberculosis in re-infection