• Hepatitis delta;
  • HDV;
  • HDV epidemiology;
  • HDV infection


Hepatitis D virus (HDV) infection has considerably diminished in Europe since the 1970–1980s. The prevalence rates of chronic hepatitis D in HBsAg carriers in Italy have declined from 25% at the beginning of the 1980s to 8% in the 1990s. Similar declines in prevalence have been reported in Spain, Taiwan and Turkey. Better public health standards, HBV vaccination and the effect of measures to control the spread of human immunodeficiency virus have brought about a decline in the numbers of HBsAg carriers and therefore a decline in the HBV-dependent HDV. However, HDV has not declined further in Europe in the last decade, as the pool of fresh infections in migrants from HDV-endemic areas is counterbalancing the shrinking cohort of long-standing domestic infections acquired in the epidemic of the 1970–1980s. Hepatitis D remains an important health problem outside Europe, and new foci of infection continue to be identified in developing countries.