[Prevalence of and risk factors for hepatitis C in blood donors].

Objective: Determine hepatitis C prevalence and risk factors in blood donors from the Blood Bank at the Centro Médico Nacional 20 de Noviembre ISSSTE, in Mexico City.

Methods: A total of 41,957 blood donors were included in the study was done from January 1996 to August 2000. To study risk factors, a case-control study cases were defined as blood donors with repeatedly positive anti-hepatitis C virus (HCV) ELISA test. Controls were defined as blood donors with negative anti-HCV ELISA test. All cases were interviewed a second time on HCV infection-associated risk factors. Odd ratio (OR) and confidence interval 95% (CI 95%) were calculated for each risk factoring in a univariate analysis. Multivariate analysis was performed subsequents to determine the independent contribution or each risk factor.

Results: HCV crude total prevalence was 0.84%. Risk factors were found in 36.16% anti-HCV-positive blood donors. During the second interview, 30% of sero-positive blood donors recalled one or more risk factors they previously denied. The most important risk factors, found were as follows sexual relations with prostitutes (OR 7.48, CI 95% 1.43-38.92) transfusion (OR 6, CI 95% 2.62-13.72); nasal cocaine use (OR 8.89, CI 95%, 1.01-86.89); dental surgery (OR 8.89, CI 95% 1.01-86.89) and contact with hepatitis-infected subject (OR 3.01, CI 95% 1.17-7.70). Other risk factors did not show a significant association.

Discussion: In this study, we found a crude total prevalence of 0.84%, very close to the prevalence reported in Mexican population by the National Center for Blood Transfusion.