For a short and sweet review on the hepatitis viruses see Robert Purcell's "Hepatitis viruses: Changing patterns of human disease." In Proc. Natl. Acad. Sci. 1994. 91:2401-2406. In it HCV is described as showing a sero-prevalence of .3% in adult blood donors and approximately 1% in developed countries. Greater than 50% of the acute HCV cases progress to chronic infection.