Relationship between the prevalence of hemoglobin S and the ethnic background of blood donors in Paraná state Relação entre prevalência da hemoglobina S e origem étnica de doadores de sangue no estado do Paraná
aBStRaCt Introduction: Hemoglobin S (HbS) is one of the most common inherited hematological disorders in humans. In Brazil, the sickle-cell disease (SCD) has significant epidemiological importance due to its prevalence and the morbidity-mortality and, therefore, it has been identified as a matter of public health. Objective: To determine the prevalence of HbS among Asian Brazilian, Afro Brazilian, and Euro Brazilian individuals of a blood bank in Curitiba. Material and method: The study was conducted from January 2008 to December 2009, and included 83,213 donors seen at the Instituto Paranaense de Hemoterapia e Hematologia. Results and discussion: The prevalence of HbS in the studied population was 0.9%, among them, 0% Asian Brazilians, 2.7% Afro Brazilians, and 0.7% Euro Brazilians. There was a positive association, statistically significant for the sickle cell trait in Afro-descendants, with odds ratio (OR) 4.01; confidence interval (CI) 3.42-4.72; and 95% confidence. Conclusion: This study showed higher rates of sickle cell trait in Afro Brazilians, which corroborates data published in other Brazilian regions and states