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Hepatitis D (delta hepatitis)

Page content: Victorian statutory requirement | Infectious agent | Identification | Incubation period | Public health significance & occurrence | Reservoir | Mode of transmission | Period of communicability | Susceptibility & resistance | Control measures | Outbreak measures

Victorian statutory requirement

Hepatitis D infection (Group B disease) must be notified in writing within five days of diagnosis.

School exclusion is not applicable.

Infectious agent

Hepatitis D virus (HDV) is a virus-like particle consisting of a coat of hepatitis B virus (HBV) surface antigen and a unique internal antigen, the delta antigen.

Identification

Clinical features
Onset of disease is usually abrupt, with signs and symptoms resembling those of hepatitis B infection. It may be severe and is always associated with a coexistent HBV infection. Co-infection (simultaneous infection with HBV and HDV) or superinfection (infection with HDV in a person who already has HBV) with HDV is usually more severe than HBV infection alone and more likely to result in fulminant disease. Co-infection has a lower risk of severe chronic disease than does superinfection.

Method of diagnosis
Serological diagnosis is made by:

  • detection of total antibody to HDV (anti-HDV). A positive HDV IgM result indicates ongoing replication
  • detection of HDV-specific RNA by polymerase chain reaction (PCR) testing. PCR is the most sensitive assay for assessing HDV viraemia.

Incubation period

Approximately two to eight weeks.

Public health significance & occurrence

Hepatitis D occurs worldwide and is most prevalent in countries that have a high incidence of hepatitis B. The highest incidence occurs in parts of Russia, Romania, southern Italy, Africa, pockets of South America and the islands of the Western Pacific.

Despite high rates of hepatitis B in Asian countries the incidence of hepatitis D is lower. Hepatitis D is uncommon in Australia. Three to twelve cases are reported per year in Victoria.

Reservoir

HDV is unable to infect a cell by itself and requires co-infection with HBV to undergo complete replication. Therefore humans with HBV infection act as reservoirs.

Mode of transmission

This virus is transmitted by the same methods as HBV: exposure to infected blood and serous body fluids, contaminated needles, syringes or blood and plasma product transfusions. Sexual transmission may also occur but is less common than with hepatitis B. Perinatal infection is rare. Infection may occur at the same time as a new HBV infection (co-infection) or after someone has been infected with HBV and become a chronic HBV carrier (super-infection).

Period of communicability

This is similar to that of HBV. Persons infected with the HDV are thought to be most infectious before the onset of symptoms. All persons with asymptomatic infection, persons with acute disease and those with chronic carriage of the virus are infectious to others.

Susceptibility & resistance

All people susceptible to hepatitis B infection or those who have chronic hepatitis B can be infected with HDV.

Control measures

Preventive measures
Prevention of hepatitis B infection with hepatitis B vaccine prevents infection with HDV. For persons with chronic hepatitis B infections, the only preventive measure is avoidance of exposure to potential sources of HDV. This means always using a new needle and syringe when injecting drugs and practising safe sex.

Control of case
There is no specific treatment for hepatitis D, although alpha-interferon has been shown to be of some benefit. Expert advice for ongoing management should be sought.

Isolation is not required.

Educate patient about safe injecting, safe sex and blood and body fluid precautions.

Control of contacts
Initiate contact tracing with patient.

Susceptible sexual, injecting and household contacts should be offered hepatitis B vaccine.

Vaccination against hepatitis B prevents HDV infection.

Control of environment
Not applicable.

Outbreak measures

Not applicable.