BRIEF REPORT: EPIDEMIOLOGY AND SOCIAL SCIENCE Increased Risk of Tuberculosis With Human T-Lymphotropic Virus-1 Infection A Case-Control Study

The human T-lymphotropic virus type 1 (HTLV-1) was the first human retrovirus identified. It has been clearly implicated in the pathogenesis of adult T-cell leukemia/lymphoma and myelopathy/tropical spastic paraparesis. Other infectious, inflammatory, or immune-related diseases (uveitis, infective dermatitis, polymyositis, arthropathy, Sjögren syndrome, interstitial lymphocytic pneumonia) are suspected to be associated with infection with HTLV-1. A higher prevalence of HTLV-1 infections has been described in patients with tuberculosis, as well as an increased mortality rate in HTLV-1and tuberculosis-coinfected patients. However, studies addressing this question have been small and failed to provide conclusive evidence of an association. The case-control study reported here investigated whether infection with HTLV1 is associated with increased risk of tuberculosis. The study was conducted in Salvador, a city known to have a relatively high prevalence of HTLV-1 infection (1.76% in the overall population) and a yearly incidence of tuberculosis varying around 120 cases per 100,000 inhabitants.