HEPATITIS-C IN ASYMPTOMATIC BLOOD-DONORS

Among 248 asymptomatic blood donors positive for antibody to hepatitis C virus (anti-HCV) enrolled in a long-term prospective study, 86% had chronic HCV infection and 14% appeared to have recovered as assessed by serial determinations of serum alanine aminotransferase (ALT) level s and HCV RNA by polymerase chain reaction. Established parenteral ris k factors for HCV transmission were identified in 75% of donors. In ad dition, there was a strong independent association between HCV positiv ity and cocaine snorting, suggesting that shared snorting devices may be a covert route of parenteral transmission. Ear piercing in males wa s also significantly associated with transmission. There was no eviden ce for sexual spread, Although the majority of HCV carriers had both b iochemical and histological evidence of chronic viral hepatitis, the e xtent of liver injury was generally mild. Among a larger population of 280 HCV RNA-positive donors, 17% had repeatedly normal ALT levels, 45 % had levels that did not exceed twice, and only 22% had levels that e xceeded five times the upper limit of the normal range. Among 81 patie nts who underwent liver biopsy, only 13% had evidence of severe hepati tis (8%) or cirrhosis (5%), despite a duration of infection that gener ally exceeded 15 years. No severe histological lesions were observed i n blood donors with chronic HCV infection who had repeatedly normal AL T levels. In both donors and blood recipients, the frequency of severe morbidity or mortality related to HCV infection was less than 10% dur ing the first two decades of infection. Further longterm studies are r equired to see if the progression to severe outcomes continues to accr ue at this slow pace or whether it accelerates during subsequent decad es.