[Delta virus superinfection in a patient with chronic viral hepatitis B].

Hepatitis-Delta virus is a defective RNA virus enclosing the Delta antigen and genome within a coat of hepatitis B surface antigen (HBsAg). Prevalence of Delta virus is limited to individuals with hepatitis B infection. Two modes of infection have been identified: coinfection with hepatitis virus B of healthy individuals and superinfection of HBsAg carriers. In a prospective study of 485 liver biopsies from HBsAg seropositive patients, 320 non-replicative HBsAg carriers (without evidence of core antigen) were discovered. In only one of these cases could a Delta virus superinfection be confirmed by immunohistology. It caused a shift from a preexisting chronic persistent to a chronic active hepatitis. This is the first case of chronic Delta virus infection confirmed by immunhistology in the G.D.R.