Infection with hepatitis delta virus in patients with fulminant hepatitis B and chronic HBsAg carriers in Bulgaria.

To evaluate the prevalence and clinical significance of delta infection in a Bulgarian population, 105 HBsAG positive patients with chronic liver diseases, and 42 patients who had died of fulminant hepatitis B were studied. Delta antigen was detected by direct immunofluorescence in the liver of 9 patients with chronic HBV infection (8.6%), and in 3 patients with fulminant hepatitis (7.14%). All chronic HBsAg carriers with delta superinfection had chronic active hepatitis or active liver cirrhosis. They were predominantly anti-HBe (+) in the serum. The mean age and the mean values of serum transaminase did not differ in delta antigen positive and negative patients with chronic liver diseases. A history of parenteral manipulations directly before the hepatitis was present in patients with delta antigen positive fulminant hepatitis. These results indicate a relatively low incidence of delta infection in our population, but it is invariably associated with severe liver disease.