Epidemiology of HDV infection in Japan.

Anti-HD antibody was not detected in 342 patients with acute type B hepatitis including 8 patients with fulminant hepatitis. Anti-HD antibody was detected in 10 out of 1668 HBV carriers. The overall prevalence was 0.59 percent. Two (0.34%) out of 586 ASC, 3 (0.43%) out of 690 patients with CH and 5 (1.47%) out of 338 patients with LC were positive for anti-HD antibody. No anti-HD antibody was detected in sera of 54 patients with HCC. The prevalence of anti-HD antibody was relatively high in patients with LC, however, HDV infection was relatively rare in Japan and it does not always play a major role in progression of liver disease. The prevalence of HDV infection in HBV carriers has not changed in Japan during the last ten years (1.3% vs. 1.49%).