[Confidentiality, genetic counseling, and public health: a case study on sickle cell trait].

Sickle cell anemia is the most prevalent genetic disease in Brazil. Screening for sickle cell trait in blood donation centers has been recommended by the Brazilian government since 1976. This screening mechanism is one of most common forms of genetic screening for sickle cell disease in the country. This article is based on an ethnographic survey of individuals undergoing genetic counseling in a large blood donation center. The article contends that confidentiality should be a prerequisite for the broad dissemination of genetic information in public health. The ethical principle of confidentiality needs to be seen as a human right and public health issue.