Increased Risk of Tuberculosis With Human T-Lymphotropic Virus-1 Infection: A Case-Control Study

Abstract

Objectives: To investigate whether infection with human T-lymphotropic virus type 1 (HTLV-1) increases the risk of tuberculosis. Design: A case-control study. Setting: City of Salvador, Brazil. Participants: A total of 375 patients with tuberculosis (cases) and 378 individuals without tuberculosis (controls), matched by age and sex. Main Outcome Measure: Tuberculosis of lung or lymph node. Main Exposure: Human HTLV-1 infection. Results: The prevalence of HTLV-1 infection was 4.27% (16/375) in patients with tuberculosis and 1.32% (5/378) in controls, resulting in a crude odds ratio of 3.31 (95% CI, 1.20-9.13) and an adjusted odds ratio of 3.01 (95% CI, 1.06-8.58). Conclusion: HTLV-1 infection is associated with a first diagnosis of tuberculosis. This may have implications for tuberculosis control in places with high prevalence of HTLV-1.