Incidence and risk factors of tuberculosis in patients with human immunodefciency virus infection

Korea is a low prevalence country for human immunodefciency virus (HIV) infection and has an intermediate tuberculosis (TB) burden. We previously reported that the incidence of TB in HIV-infected patients was 9.6 cases per 100 person-years (P-Y) between 1988 and 1997. The aims of the present study were to measure any change in incidence from the previous study, and to identify risk factors for TB in HIV-infected patients. We reviewed all medical records of HIV-infected patients who were followed-up in one tertiary hospital between 1998 and2010. Over the total observation period of 5858.33 P-Y, TB developedin 70 patients (1.19 cases per 100 P-Y; 95% confdence interval [CI], 0.91-1.47 cases per 100 P-Y). Based on Poisson regression, one risk factor associated with TB was an initial Received: 14 July 2012 CD4₊ cell count below 200 cells/μL (relative risk, 2.34; 95% CI, 1.47-3.73). Mean CD4₊ cell counts of pulmonary, extrapulmonary, and both pulmonary and extrapulmonary TB were 179.8 cells/μL, 138.3 cells/μL, and 114.2 cells/μL, respectively (P = 0.55). In Department of Internal Medicine, Seoul National conclusion, the incidence of TB in HIV-infectedpatients has decreased since the previous University study. An initial CD4₊ cell count below 200 cells/μL is an independent risk factor for development of TB in HIV-infected patients.