Hepatitis D or delta hepatitis is a virus causing liver inflammation in patients
who are already infected with hepatitis B virus. The delta virus is unable to
infect cells by itself and requires the presence of hepatitis B in order to
multiply. It is associated with severe liver inflammation in patients with hepatitis
B; the liver inflammation tends to be more severe in patients who acquire delta
virus after infection with hepatitis B, compared to patients who acquire both
viruses at the same time.
Mode of Transmission
Hepatitis D is transmitted in a similar way to hepatitis B, that is via contact
with blood or body fluids, particularly on shared needles, and through sex.
Hepatitis D is found world-wide, although its prevalence varies widely. It
is common in hepatitis B infected individuals in southern Italy and the Mediterranean,
North Africa and South America. The prevalence of hepatitis D virus is low in
the United Kingdom except for in particular risk groups, such as intravenous
drug users, haemophiliacs and male homosexuals.
As hepatitis D virus cannot exist without hepatitis B infection, infection
can be prevented by taking measures to avoid hepatitis B infection. If a patient
is hepatitis B positive, they must avoid further exposure to blood products
and body fluids, for example by avoiding needle sharing and unprotected sex.
Symptoms and Signs
Hepatitis D can cause acute or chronic exacerbations of liver inflammation
due to hepatitis B, depending on the timing of infection with the 2 viruses.
If an individual acquires both viruses together, they may develop a severe acute
hepatitis with jaundice and higher mortality than with acute hepatitis B infection
alone. When an individual with chronic hepatitis B infection acquires hepatitis
D virus, this can result in an acute exacerbation of liver inflammation, or
chronic hepatitis D infection with more rapid progression to cirrhosis and liver
Infection with hepatitis D virus is diagnosed by detecting antibodies to the
virus in the blood stream. The virus itself can be detected in blood samples
during acute infection.
There is no specific treatment for delta hepatitis. Treatment of acute infection
is supportive. Interferon alpha is used to treat patients with chronic hepatitis
B and hepatitis D infection. Some studies have suggested that a dose higher
than that usually used for hepatitis B infection may be beneficial.
Complications and Outcome
Acute infection with both hepatitis B and hepatitis D viruses causes severe
liver inflammation and has a higher risk of mortality compared to acute hepatitis
B infection alone (5% compared to 1%). However if the patient recovers, they
usually clear both viruses completely. In patients with chronic hepatitis B
infection who acquire hepatitis D virus, again they may develop acute liver
inflammation. Hepatitis D infection in this setting is more likely to become
chronic, with more rapid progression of liver inflammation and damage, leading
By Dr Ann Chapman