• chronic hepatitis type B;
  • hepatitis D virus;
  • superinfection

A 6–96-month prospective follow-up study on the natural course of chronic type B hepatitis after contracting acute hepatitis delta virus (HDV) superinfection was conducted in 30 patients with clear-cut onset of acute HDV superinfection (HDV group). Thirty patients with acute exacerbation without evidence of HDV infection, and well matched in terms of age, sex and hepatitis B e antigen/antibody status, served as the control group. The clinical and biochemical presentations tended to be more severe in the HDV group. More patients in the HDV group had persistent abnormal liver biochemical tests (69% vs 47%) and progressed to chronic active hepatitis (46% vs 20%) or cirrhosis (9.4%/year vs 5.2%/year), but the differences were not significant statistically. The results suggest that HDV superinfection induces slow progression of liver disease. However, in the early stage, the impact of HDV superinfection is not particularly different from that of the acute exacerbation unrelated to HDV in patients with chronic type B hepatitis.