Incidence of and risk factors for active tuberculosis in human immunodeficiency virus-infected patients in South Korea

BACKGROUND: In South Korea, a high-income country with an intermediate tuberculosis (TB) burden and low human immunodeficiency virus (HIV) prevalence, studies on incidence and risk factors of TB in HIV-infected persons have rarely been reported. OBJECTIVE: To investigate the incidence of and risk factors for active TB in HIV-infected persons in South Korea. METHODS: A retrospective analysis was conducted of 1265 HIV-1 infected patients who visited four hospitals in South Korea between 1985 and 2012. We analysed the incidence of TB during the follow-up period. To investigate risk factors associated with active TB, we conducted a 1:2 matched case-control study of HIV-infected patients with newly active TB and controls without active TB who had similar CD4⁺ T-cell counts and dates of first visit. RESULTS: Over a total of 4457 person-years (py), 185 (14.6%) subjects were diagnosed with active TB; the incidence was 4.2 cases/100 py. In multivariate analysis, low body mass index (P = 0.033) and current smoking (P = 0.003) were independent risk factors for TB in HIV-infected patients. CONCLUSION: Further strategies on prevention and treatment of active TB among HIV-infected patients should be implemented in South Korea. Encouraging smoking cessation and supporting good nutrition may be ways to reduce the incidence of active TB in HIV-infected patients.