Tattooing and transfusion-transmitted diseases in Brazil: A hospital-based cross-sectional matched study

Background: Presence of tattoos has been a criterion for temporary deferral of blood donors. Scientific evidence remains equivocal regarding the association between tattooing and transfusion-transmitted diseases (TTDs). Methods: A cross-sectional matched study was undertaken among adults attending a Brazilian hospital and blood bank. The exposure of interest was having at least one permanent tattoo, and the outcomes were the presence of serological markers for the following TTDs: hepatitis B virus (HBV), hepatitis C virus (HCV) and human immunodeficiency virus (HIV) infections, syphilis, and Chagas' disease. Exposed and unexposed subjects were matched on age, sex, and main clinical complaint. Associations were assessed by odds ratios (ORs), adjusted for confounders by unconditional logistic regression. Findings: The study recruited 345 subjects, 182 with tattoos. Having a tattoo was associated with HCV ( OR: 6.41; 95% confidence interval (CI) 1.29, 31.84), and with having at least one positive test for any TTD ( OR: 2.05, 95% CI: 1.11, 3.81). No statistically significant associations were found between tattooing and HBV or HIV infection, syphilis or Chagas' disease, but these results are inconclusive given the large CI obtained. Interpretation: Having a tattoo is not an important indicator for testing positive for a TTD, except for HCV infection. Taking into consideration the increasing prevalence of tattooing in the general population, the absolute need of a safe and sustainable blood supply and optimization of the cost-effectiveness of screening blood donors, further research on tattoos is urgently required.