Current studies indicate that most (80%) people infected with hepatitis C will develop a chronic state of infection. About 30% those with chronic infection will go on to develop cirrhosis of the liver. The disease appears to progress slowly, symptoms often do not appear for ten or twenty years.
The overall severity of chronic hepatitis C is controversial. There is no question that HCV can lead to cirrhosis and hepatocellur carcinoma (HCC) and that end-stage chronic hepatitis C is now the leading indication for liver transplantation. At question is how frequently and how soon these serious consequences occur. A controlled prospective study (Seeff) has shown that after 20 years of follow-up, patients with transfusion associated hepatitis C had no increase in overall mortality and only a slight increase in liver-related mortality compared to controls who did not develop hepatitis. Another prospective study (Koretz) has shown that the probability of developing clinical cirrhosis or liver related mortality was 20% and 5%, respectively after 16 years; comparable values were 24% and 3% in the NIH series. The paradox between the relatively benign mortality figures and the observed fatal outcomes resides in the indolent nature of progressive HCV infection. Progression is generally measured in decades and most subjects acquiring infection in mid-life or later will succumb to their underlying disease or old age before they develop end-stage chronic hepatitis C. By inference, it appears that the HCV mortality risk is approximately 4% in the first two decades and the risk will increase over time in those that do not succumb to other events. -
"Natural History and Clinical Aspects of HCV Infection." H.J. Alter. Department of Transfusion Medicine, National Institutes of Health, Bethesda, Maryland. Cancer Biotechnology Weekly, 01-29-1996, pp 20.
Despite the increased risk of cirrhosis and liver cancer, some question exists about HCV's overall contribution to premature mortality. In one study with almost 20 years of follow-up, patients with chronic, posttransfusion hepatitis C did not have significantly higher mortality when compared to an uninfected control group. - Hepatitis C & E: How Much of a Threat?
(Special Issue: Emerging Infectious Diseases). Brown, Edwin A. Patient Care. May 15 1994, v28, n9, p105(8)