Objective: Reports have suggested that human T-cell lymphotropic virus type 1 (HTLV-1) may influence immunological response and therefore the clinical course of tuberculosis (TB) in co-infected individuals. We wished to determine the prevalence of HTLV-1 infection among hospitalized patients in Salvador, Brazil, a region endemic for both HTLV-1 infection and latent TB infection.
Design: A cross-sectional study was conducted at a pulmonary disease hospital between 1 September 2006 and 31 August 2007. Study participants were interviewed and tested for HTLV-1 infection and current or past episode of TB.
Results: Of 607 participants recruited into the study, 360 (59.3%) had a current or past history of TB and 50 (8.2%) had HTLV-1 infection; 39 (6.4%) had both. After controlling for confounding variables, we found that the odds of patients with a positive HTLV-1 test having TB were 2.6 times the odds in those who tested negative for HTLV-1 infection (95%CI 1.2-5.4).
Conclusion: In a region endemic for both TB and HTLV-1 infection, HTLV-1 infection increases the risk of Mycobacterium tuberculosis infection. Such a risk may influence TB transmission and the epidemiology of the disease in this community.