Hepatitis D: Epidemiology
Last reviewed: 23.04.2024
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The main source of the causative agent of HDV infection is persons with chronic forms of HBV infection infected with HDV.
The mechanism of transmission of HDV infection is very similar to the transmission of HBV infection. Transmission of the delta virus is carried out parenterally, mainly with blood. The risk of contracting a delta infection is especially great for regular recipients of donated blood or its drugs (that is, patients with hemophilia); for people who undergo frequent parenteral interventions, as well as for drug addicts who inject drugs intravenously; for people who have contact with blood. Infection often occurs in the surgical departments, the centers of hemodialysis.
Transplacental transmission of HDV from a pregnant fetus is possible, mainly in HBe-positive mothers infected with HDV. The perinatal route of transmission is also quite rare, but the development of co-HBV-HDV infection in neonates is possible.
The distribution of HDV infection in families, especially among children, is revealed in most cases in the absence of registered parenteral interventions, which implies the presence of a natural way of transmission of delta infection. The high incidence of HDV infection among people who have a promiscuous sex life (especially among male homosexuals) suggests that sexual transmission is possible.
Patients with acute or chronic forms of viral hepatitis B, especially carriers of HBs-antigen, are susceptible to delta-infection. Postponed HDV infection leaves persistent immunity.
HDV replication requires the structural components of HBV (HBsAg), so delta infection is never self-sustained and develops only against the background of HBV infection. About 5% of carriers of HBs-antigen in the world (approximately 18 million people) are infected with HDV.