Pathogenesis (development of disease)
Hepatitis D virus (HDV, formerly also called delta virus or δ-agent) needs the envelope of hepatitis B virus to infect cells. Hepatitis D infection cannot occur without hepatitis B infection. Eight HDV genotypes can be distinguished.
Transmission is sexual, perinatal (during birth), or parenteral (via infusions/transfusions). The virus reaches the liver via the bloodstream and infects hepatocytes (liver cells). Severe tissue damage occurs due to the ensuing immune system response.
Etiology (causes)
Biographic causes
- Socioeconomic factors – low socioeconomic status.
- Geographic factors – high prevalence countries (Far East, tropical countries).
Behavioral causes
- Drug use (intravenous, i.e., through the vein).
- Sexual transmission
- Promiscuity (sexual contact with relatively frequently changing different partners or with parallel multiple partners).
- Prostitution
- Men who have sex with men (MSM).
- Sexual contacts in the vacation country
- Unprotected coitus
Medication
- Blood products
Other causes
- Vertical infection – pathogen transmission from a host (here: the mother) to its offspring (here: the child):
- Transmission of infection during birth from mother to child (perinatal).
- Iatrogenic transmission
