Revista de Saúde Pública
On-line version ISSN 1518-8787
MARTELLI, Celina Maria Turchi et al. Methological issues in the interpretation of serologic screening for hepatitis B virus among blood donor's. Rev. Saúde Pública [online]. 1991, vol.25, n.1, pp. 11-16. ISSN 1518-8787. http://dx.doi.org/10.1590/S0034-89101991000100003.
Between October 1988 and February 1989, 1,033 voluntary first-time blood donors were screened for hepatitis B infection in five blood banks in Goiânia, Central Brazil. The survey was part of a major study designed to estimate seroprevalence of HBsAg and anti-HBs and to discuss methodological issues related to prevalence estimation based on data from blood banks. Donors were interviewed and blood samples were collected and tested for HBsAg and anti-HBs by ELISA tests. Prevalences of 1.9% and 10.9% were obtained for HBsAg and anti-HBs, respectively, and no statistical difference was found between the sexes. Prevalence of anti-HBs increased with age (X² for trend = 7.9 p = 0.004). The positive predictive value and sensitivity of history of jaundice or hepatitis reported in the interview in detecting seropositives were 13.6% and 2.2%, respectively. The methodological issues, including internal and external validity of HBV prevalence estimated among blood donors are discussed. The potential usefulness of blood banks as a source of morbidity information for surveillance for Hepatitis B virus infection is stressed.
Keywords : Hepatitis B, diagnosis; Serodiagnosis; Prevalence studies; Blood donors.