The prevalence of hepatitis delta virus (HDV) infection was studied in 25 adult patients with fulminant hepatitis who were admitted consecutively to our unit from February, 1986, to September, 1988. Enzyme and radioimmunoassays were used for the detection of serological markers of HAV, HBV, and HDV (HDAg, IgM anti‐HD, total [IgG] anti‐HD) infections. Two hundred twenty‐nine serum samples (three to 19 samples/patient) were tested for serological markers of HDV infection. Of the 25 patients, 17 (68%) were HBsAg‐positive, and the remaining eight (32%) were HBsAg‐negative on admission to the hospital. All patients were seropositive for IgM anti‐HBc. Serological markers of HDV infection were detected in 13 (52%) of the 25 patients. In particular, HDV infection was observed in nine (53%) of the 17 HBsAg‐positive and in four (50%) of the eight HBsAg‐negative patients with type B fulminant hepatitis. Survival was 16.7% for patients with hepatitis B and 57.8% for patients with B and D coinfection. Coinfections were responsible for fulminant hepatitis in 100% of drug addicts and 40% in patients who were not drug addicts. All patients with HBV/HDV coinfections became seropositive for IgM anti‐HD. The results show that HDV infection has a significant role (52%) in type B fulminant hepatitis in an area with a moderate prevalence of HBV infections, that it should be tested in cases with early clearance of HBsAg, and that it does not seem to be accompanied by a high fatality rate. Testing for IgM anti‐HD is mandatory for accurate evaluation of the incidence of HBV/HDV coinfections in patients with fulminant hepatitis. Copyright © 1990 Wiley‐Liss, Inc., A Wiley Company
