Epidemiological information obtained from anti-hepatitis C virus screening in blood donors and candidates for autologous transfusion from 1992 to 1996 in the Alpes-Maritimes region

To determine the evolution of the frequency of anti-hepatitis C virus antibodies from 1992 to 1996 in blood donors and in candidates for autologous transfusion in the Alpes-Maritimes region and to assess risk factors. Anti-hepatitis C virus antibodies were assessed by second generation ELISA in 1992 and in the first quarter of 1993, and then by third generation ELISA; in all cases, anti-hepatitis C virus antibodies were confirmed by RIBA test. Since 1992 (when the second generation ELISA test became available), the prevalence of anti-hepatitis C virus antibodies in blood donors in the Alpes-Maritimes region (0.54% in 1992 to 0.20% in 1996) has decreased. Positive ELISA anti-hepatitis C virus was confirmed by RIBA in 53 to 68% of anti-hepatitis C virus blood donations. The percentage of anti-hepatitis C virus donors with ALT above the upper limit (donation exclusion threshold) was between 28 and 56%.The most frequent age interval for new anti-hepatitis C virus positive donors was between 30 and 40 years. Since 1992, a third of the anti-hepatitis C virus blood donors agreed to participate in a medical history questionnaire. One or several risk factors were found in almost all donors. The most frequent source of infection was nosocomial (50%). During the 5 years of the study, the number of candidates for autologous transfusion increased: 717 in 1992 to 1 528 in 1996. The prevalence of anti-hepatitis C virus in this older population (mean age: 64 years) decreased progressively (2.9% in 1992 to 1.1% in 1996, P