Prevalence of hepatitis B virus, delta agent and human immunodeficiency virus infections in drug addicts.

Infections with the hepatitis B (HBV) and delta (HDV) viruses and with the human immunodeficiency virus (HIV) are very common among intravenous drug addicts. The serum of 80 percent of drug addicts contains one of the HBV markers, and 15 percent of them carry an anti-D antibody. Infections with the hepatitis A and non A-non B viruses are also very common among drug abusers. Some of them may harbour several of these pathogens. This can explain the frequency of liver disease (biological anomalies and histological lesions) observed in drug addicts, as does alcohol consumption associated with drug abuse. Fifty to 60 per cent of intravenous drug addicts are seropositive for HIV. This prevalence varies across studies and countries. The high prevalence of infection by HIV in drug addicts may be explained by the use of a shared syringe. This prevalence exposes drug addicts to an increase in AIDS cases in the near future. The high prevalence of infections by HBV, HDV and HIV in drug addicts represents a risk factor for the spread of HBV, HDV and HIV infections among the general population. Preventing the rapid spread of these viruses among drug addicts is of utmost importance for the future.