Global Alert and Response (GAR)

Hepatitis D

Incidence / Epidemiology

- Incidence/ Epidemiology
- Trends
- Immune prophylaxis
- Vaccines

Seroprevalence studies of anti-HD in HBsAg-positive patients has shown a worldwide but not uniform distribution.21

Epidemics of HDV infections have been described in the Amazon Basin, the Mediterranean Basin and Central Africa.

Two epidemiologic patterns of hepatitis D infections exist: in Mediterranean countries infection is endemic among HBV carriers, and the virus is transmitted by close personal contact. In Western Europe and North America, HDV is confined to persons exposed to blood or blood products, like e.g. intravenous drug addicts sharing unsterilized injection needles.

Worldwide, more than 10 million people are infected with HDV.10, 11

New foci of high HDV prevalence continue to be identified as in the case of the island of Okinawa in Japan, of areas of China, Northern India and Albania.10

There is a decreasing prevalence of both acute and chronic hepatitis D in the Mediterranean area and in many other parts of the world, which has been attributed to a decline in the prevalence of chronic HBsAg carriers in the general population.10

Immune prophylaxis
Immune prophylaxis against HDV is achieved by vaccination against HBV because HDV uses the envelope proteins of HBV. This mode of prevention is possible only for coinfections in HBV susceptible individuals.10, 21

Immunoglobulin (Ig), hepatitis B (HB) specific Ig and HB vaccine do not protect HBV carriers from infection with HDV.

No vaccines exist against HDV; however, vaccination against HBV of patients who are not chronic HBV carriers, provides protection against HDV infection.