The incidence of acute hepatitis C infection dropped more than 10-fold between 1982 and 2006, according to a recent report in the Archives of Internal Medicine (Williams IT et al. 2011;171:242-248).

This is not a new finding, noted Albert D. Min, MD, professor of clinical medicine and director of hepatology, Division of Digestive Diseases, Beth Israel Medical Center, New York City, who was not involved in the study. But despite the hopeful outlook regarding rates of hepatitis C virus (HCV) infection, the rate of cirrhosis may continue to rise.
“Since the risk of developing cirrhosis after an acute HCV infection ranges from 5% to 25% over 25 to 30 years, the study reinforces that gastroenterologists and hepatologists will continue to see an increasing number of patients with HCV-related, long-term sequelae such as cirrhosis and hepatocellular carcinoma,” said Dr. Min. “We will need to be prepared to meet the increasing burden of managing them for the rest of this decade.”
Using data from Sentinel Counties Surveillance for Acute HCV at the Centers for Disease Control and Prevention (CDC), investigators analyzed trends in incidence and transmission of HCV infection. They determined that the incidence of HCV infection averaged 7.4 cases per 100,000 people from 1982 to 1989. From 1994 to 2006, the incidence had dropped to approximately 0.7 per 100,000 people.
Furthermore, people aged 20 to 29 years had the highest incidence of HCV from 1982 to 1989, at 17.2 cases per 100,000 people, but this declined to 0.9 cases per 100,000 between 1994 and 2006. In the latter period, the highest incidence of HCV infection occurred among 30- to 39-year-olds, at 1.6 cases per 100,000 people. Hispanics had a higher incidence during all periods than white non-Hispanics or black non-Hispanics. The incidence rates from 1994 to 2006 in these three groups were 1.2, 0.7 and 0.5 cases per 100,000 people, respectively.
The researchers interviewed 1,748 people with HCV infection and found that the most common risk factor for infection was injection drug use (IDU). Although the absolute number of IDU-related cases dropped in parallel with the decline in HCV infection, the proportion of IDU-related cases rose, increasing from 31.8% in 1982-1989 to 45.6% in 1994-2006.