Hepatitis C: what progress?

The new serologic assay for hepatitis C has made it possible to identify patients infected with this agent and to better characterize their clinical illness and its sequelae. As the clinical entity has become better recognized, our understanding of the infectious process has also progressed. Hepatitis C is a chloroform-sensitive RNA virus, only 30-60 nm in diameter, containing a lipid coat. Both erythrocytes and plasma can transmit infection. The viral genome consists of single-stranded linear RNA of approximately 10 kilobases. The first serologic assay developed was a radioimmunoassay, followed shortly by an enzyme-linked immunoassay. Secondary tests for specificity now exist. Blood donor populations may have a significant frequency of false positives on the antibody test, making it important that positive results be confirmed with a secondary assay. The antibody is only detected 2 months after infection, by means of currently available assays, and may not appear in many patients until 3 to 6 months after infection. Hepatitis C infection is commonly chronic. This may lead to an asymptomatic chronic carrier state without demonstrable liver disease, or to chronic progressive or non-progressive hepatitis.