Seroprevalence of anti-hepatitis C virus antibodies among blood donors, Brazil

Abstract

OBJECTIVE: To determine the seroprevalence of anti-hepatitis C virus antibodies (anti-HCV) in blood donors, and to describe the correlation between screening serological test results and confirmatory test. METHODS: Epidemiological and laboratorial records of 10,090 blood donors of the blood unit in the city of Apucarana, Brazil, from January 1997 to December 1999 were assessed. Anti-HCV serum antibodies were detected using enzyme-linked immunosorbent assay (ELISA). Serum reactive samples were tested using RIBA (recombinant immunoblot assay). Statistical analysis was performed using Chi-square test, Fischer's test and Kappa index of agreement. RESULTS: The results showed that of all the donors, 2,461 (24.4%) were females, 7,629 (75.6%) were males, with ages ranging from 18 to 65 years old. Of 10,090 serum samples tested using ELISA, 88 were reactive to anti-HCV, a seroprevalence of 0.9% that showed no association with either age groups (p=0.197) or sex (p=0.323). When the samples were tested using RIBA, 11 (12.5%) were positive, 14 (15.9%) were indeterminate, and 38 (43.2%) were negative. Statistical analysis revealed a high correlation (kappa index 0.939) between ELISA and RIBA test results. Poorly reactive samples in ELISA showed a high correlation with negative results in RIBA, and samples highly reactive in ELISA showed a high correlation with positive results in RIBA. CONCLUSIONS: The results stress the need of confirmatory tests for all anti-HCV reactive samples in screening tests. HVC infection confirmation is paramount for clinical, laboratorial, and histological evaluation of blood donors.