The association of hepatitis delta virus and hepatitis B virus in parenteral drug abusers. 1971 to 1972 and 1986 to 1987.

From 1971 to 1972 (N = 105) and 1986 to 1987 (N = 160), parenteral drug abusers seropositive for hepatitis B virus (HBV) markers were screened for antibodies to the hepatitis delta virus (anti-HD). In both time frames anti-HD was independently associated with the hepatitis B surface antigen. It was observed that 31% of those positive for hepatitis B surface antigen from the early sample and 20% of those from the latter sample had detectable anti-HD, as opposed to 10% and 7%, respectively, of those negative for hepatitis B surface antigen. Anti-HD seropositivity was unrelated to gender and ethnicity, and in the 1971 and 1972 nationwide sample, its presence was unrelated to geographic location. The probability of manifesting anti-HD increased with the more HBV markers detected, particularly the number of different HBV antibody markers. We conclude that anti-HD was wide-spread in parenteral drug abusers at least as early as 1971, and that its expression was associated with hepatitis B surface antigen and the intensity of the immune response to HBV as evidenced by the number of different circulating HBV antibodies.