Around 170 million throughout the world people have been infected with hepatitis C. The lowest prevalences are found in Western Europe and North America (1%), and it is thought to be very low in the Netherlands (<0.5%). Prevalences in high-risk groups such as (ex-) drug addicts and haemophilia patients may be up to 25-60%.
The disease usually has a mild course and most of the afflicted persons are not even aware of it. About 20% of them show liver cirrhosis 10-20 years after the infection, after which the risk of development of hepatocellular carcinoma has strongly increased. The rate of progression is highly dependent on individual patient characteristics such as age at the time of infection, alcohol use, obesity, and the presence of other infections such as HBV en HIV. Since the discovery of the hepatitis C virus in 1989, therapy potentials have strongly improved. Present-day treatment consists of weekly subcutaneous injections pegylated interferon (peginterferon-alpha) and daily ribavirin tablets. Dependent on the genotype, treatment will last 24 weeks (genotype 2 or 3) or 48 weeks (genotype 1 or 4). Reaction of the hepatitis C virus is monitored during treatment: the treatment period may be shortened in case of a favourable response, whereas delayed response may necessitate longer treatment. The primary endpoint of treatment is achieving a sustained virological response (SVR). This is the situation in which the virus is no longer found in blood 24 weeks after discontinuation of treatment. The risk of virus recurrence is almost nil by then, so SVR can be taken to indicate cure. For patients with genotype 2 or 3 the chance of achieving SVR is about 80%; for those with genotype 1 or 4 patients it is considerably lower, i.e. some 50%. This treatment has a major disadvantage, however, in terms of the many adverse side effects; notably flu-like symptoms, emotional distress and abnormal blood counts.
The clinical scientific research in our department has a focus on improving the current peginterferon-ribavirin therapy. Furthermore, efforts are directed at assessing novel antiviral drugs that perhaps may raise the proportion of successful treatments in the next years. At present there is not yet a vaccine against hepatitis C.