New actors come into play against hepatitis delta.

Currently chronic hepatitis delta (CHD) represents the most severe form of chronic viral hepatitis. The risk of developing cirrhosis, hepatocellular carcinoma (HCC) and decompensated liver disease is 2-3 times greater in hepatitis delta virus (HDV) infection than in hepatitis B virus (HBV). For instance, in a study carried out in Italy including 299 CHD patients followed for 28 years, 82 (27%) developed cirrhosis, and among these, 46 (56%) developed HCC. The real number of subjects infected by HDV worldwide remains unknown due to the lack of information in many areas, though it has been suggested that the rate of HBsAg carriers co-infected by HDV may be situated between 4.5 and 18%.