Risk factors associated with pulmonary tuberculosis relapses in Cali, Colombia

INTRODUCTION: Relapses in tuberculosis occur due to endogenous reactivations or exogenous reinfections and represent up to 27% of tuberculosis cases. Its importance lies in the risk of the appearance of multidrug-resistant Mycobacterium tuberculosis strains. According to the reports published in 2011 by the Colombian Instituto Nacional de Salud, there were 572 relapse cases reported in the country, i.e., a rate of 4.9%. Data of the tuberculosis control program from the Secretaría de Salud Municipal in Cali reported a relapse rate of 6%, higher than the national one, during 2013 and 2014. OBJECTIVE: To determine the risk factors associated with relapse in patients with pulmonary tuberculosis in Cali. MATERIALS AND METHODS: We conducted an observational, analytical, and case-control study (1:1), which comprised 81 cases of pulmonary tuberculosis relapses detected in 2013 and 2014. Additionally, we collected data on socio-demographic and clinical variables, as well as lifestyle and health services, to identify the potential risk factors associated with tuberculosis relapses. We used logistic regression to identify the risk factors. RESULTS: After adjustments for some variables, our multivariate logistic regression analysis showed that the body mass index (BMI) (OR=0.90, 95%CI: 0.81-0.99) and population density (OR=0.99, 95%CI: 0.98-1.00) were inversely associated with tuberculosis relapses. Alcohol consumption increased the likelihood of tuberculosis relapse (OR=5.56, 95%CI: 1.18-26.26). CONCLUSIONS: Body mass index and population density were inversely associated with pulmonary tuberculosis relapses in Cali. On the contrary, alcohol consumption increased the likelihood of tuberculosis relapses.