> Hepatitis D is a disease caused by a small circular RNA virus (Hepatitis delta virus or    hepatitis D virus, HDV).
> Hepatitis D is a liver disease.
> Delta agent is a type of virus called hepatitis D that causes symptoms only in people    who have a hepatitis B infection.
> The hepatitis D virus (also called delta virus) is a small circular RNA virus.
> Hepatitis D virus (HDV) is found in nature only as a coinfection with HBV.
> HDV is considered to be a subviral satellite because it can propagate only in the    presence of another virus, the hepatitis B virus (HBV).
> The hepatitis D virus is replication defective and therefore cannot propagate in the    absence of another virus.
> In humans, hepatitis D virus infection only occurs in the presence of hepatitis B    infection.
Symptoms-
      Jaundice
      Nausea
      Vomiting
      Fatigue
      Abdominal pain
      Loss of appetite
      Joint pain
      Dark-colored urine
      Scleral icterus
      Petechia with bruising (rare)
Causes/Transmossion-
> Because HDV exist only in association with HBV, it can be transmitted by the same    route of HBV.
> The risk factors for infection are similar to those for hepatitis B virus infection
> Transmission of HDV can occur either via simultaneous infection with HBV    (coinfection) or via    infection of an individual previously infected with HBV    (superinfection).
> Hepatitis D virus infection is transmitted by blood and blood products. The hepatitis D    virus most often infects intravenous drug users.
Risk factors-
> Use of needles and syringes contaminated with infected blood.
> Through needle sharing.
> Through mother to child.
> Unprotected sex with infected partner.
> Blood transfusion.
> Re-use of contaminated needle and syringe
Diagnosis-
> Type D hepatitis should be considered in individuals who are HBsAg positive or who    have evidence of recent HBV infection.
> Hepatitis D infection may be diagnosed by detecting the antibody against the virus.    Measuring antibodies to delta antigen using enzyme-linked immunosorbent assay    (ELISA) can make the diagnosis.
> Liver enzymes are higher than normal.
> Anti-delta agent antibody is positive for HDV.
> Liver biopsy shows liver inflammation (hepatitis).
> To monitor ongoing HDV infection, reverse transcriptase-polymerase chain reaction    (RT-PCR) should be used. RT-PCR can detect 10 to 100 copies of the HDV genome in    infected blood serum.
> The current and preferred diagnostic test of choice is the detection of viral RNA in    the serum using a reverse transcriptase polymerase chain reaction (PCR).
> This test is very sensitive in detecting infection and its absence almost certainly    reflects absence of the virus.
Treatment-
> Currently there is no effective antiviral therapy available for treatment of acute or    chronic type D hepatitis.
> Most people with acute viral hepatitis experience a self-limited illness (one that runs a    defined, limited course) and go on to recover completely. There is no accepted    therapy, nor restrictions on diet or activity.
> Delta hepatitis can be prevented by vaccination against hepatitis B.
> Delta hepatitis can be treated with high-dose interferon.
> Persons with long-term HDV infection may receive a medicine called alpha interferon    or a liver transplant.