Global control of hepatitis C: where challenge meets opportunity

Abstract

We are entering an important new chapter in the story of hepatitis C virus (HCV) infection. There are clear challenges and opportunities. On the one hand, new HCV infections are still occurring, and an estimated 185 million people are or have previously been infected worldwide. Most HCV-infected persons are unaware of their status yet are at risk for life-threatening diseases such as cirrhosis and hepatocellular carcinoma (HCC), whose incidences are predicted to rise in the coming decade. On the other hand, new HCV infections can be prevented, and those that have already occurred can be detected and treated--viral eradication is even possible. How the story ends will largely be determined by the extent to which these rapidly advancing opportunities overcome the growing challenges and by the vigor of the public health response.

Figure 1. Outcomes associated with HCV infection

After acute infection, most persons develop viral persistence. Fatigue, joint pain, depression and a variety of skin manifestations can occur but are uncommonly diagnostic. In otherwise-healthy persons infected at young ages, after decades some develop cirrhosis, end state liver disease or hepatocellular cancer (HCC). There are wide ranges of the frequencies of these outcomes due to difference in host factors such as race, age, HIV infection, and for progression to end stage disease, alcohol use (see text).

Figure 2. Global prevalence of HCV antibodies

Based on meta-analysis of 232 studies published 1997–2007, point prevalences are calculated using regional population weights. GBD-Global Burden of Diseases

Figure 3. Importance of expanded testing and treatment to impact the global prevalence of HCV infection

Because the % cured is a function of the distribution of many variables such as genotype, age, and race, the y axis arbitrarily shows the efficacy of treatment, which is increasing but having little impact on the overall burden of disease represented by the total area of the figure. 130–170 million are estimated to have chronic HCV infection, while >185 million were estimated to have HCV antibodies in 2005.

Figure Box 1. Dynamic course of HCV infection in the US.

As the cohort born between 1945 and 1965 ages, a greater fraction will have HCV infection for sufficient time at old enough ages to develop liver failure and HCC.