Due to its distribution and clinical course, chronic viral hepatitis C has become one of the most common infectious diseases in the world. At present the number of the infected in the world is about 170 million, but in Europe it exceeds 9 million. The incidence of chronic viral hepatitis C in Latvia is relatively high. The antibody prevalence is 2.4%, HCV-RNA prevalence is 1.7%, it means that in Latvia there might be almost 40 000 chronic hepatitis C patients. This study gives an opportunity to calculate positive treatment result possibility for every chronic viral hepatitis C patient.