The importance ot hepatitis C virus (HCV) infection as a cause ot chro
nic liver disease has become clear with the introduction of serologic
detection methods. On the basis of epidemiologic evidence the parenter
al way of infection has been considered to be the most important one.
However, the epidemiologic data regarding the significant route of inf
ection are still limited. To study the ways of HCV-infection and their
possible influence on the course of the disease, 73 patients with chr
onic hepatitis C infection were examined. Setting was the out-patient
department of Gastroenterology of our University Hospital. Patients hi
story, completed by a questionnaire, laboratory findings and liver his
tology were analysed. The study indicated that in 50% of the patients
transmission had occurred through parenteral infection, the other 50%
had been infected through the non-parenteral (sporadic) way. The study
revealed further that the way of infection has an influence on the pr
ogression of liver disease with the patients infected sporadically sho
wing histologically more serious hepatic changes. In 50 patients HCV-i
nfection was the only cause of their chronic liver disease, in 23 pati
ents additional pathogenic factors were detected. These 23 patients sh
owed a rapid progress of the disease. Therefore, HCV-infection cannot
be considered any longer as a disease that is primarily transmitted pa
renterally. Due to the large number of sporadic infections, HCV-infect
ion will continue to be of great epidemiologic importance even after t
he effective elimination of contaminated blood products.