Delta hepatitis is an infection and inflammation of the liver caused by the hepatitis D virus. It is one of several types of hepatitis. The hepatitis D virus (also called delta virus) is a small circular RNA virus. The hepatitis D virus is replication defective and therefore cannot reproduce in the absence of another virus. In humans, hepatitis D virus infection only occurs in the presence of hepatitis B infection. In 1977, a previously unrecognized nuclear antigen was detected in hepatocytes of patients with chronic hepatitis B.
The antigen resembled hepatitis B core antigen (HBcAg) in its subcellular localization. Its presence was always associated with hepatitis B virus (HBV) infection, but it rarely co-existed with HBcAg. It was termed “delta antigen”. Patients with delta antigen develop anti-delta antibodies. In 1980, the delta antigen was recognized to be the component of a novel virus that was defective and required coinfection with HBV to reproduce.
The hepatitis delta virus (HDV) was shown to rely on HBV for transmission because it used the hepatitis B surface antigen (HBsAg) as its own virion coat. The virus like delta agent was subsequently shown to be associated with the most severe forms of acute and chronic hepatitis in many HBsAg-positive patients. Hepatitis D or delta hepatitis is caused by the hepatitis delta virus (HDV), a defective RNA virus. HDV requires the help of a hepadnavirus like hepatitis B virus (HBV) to reproduce. Delta hepatitis is an infection of humans.
The viruses have been found in blood, saliva, semen, and vaginal secretions of infected individuals. Acute delta hepatitis infection may be followed by recovery but usually becomes chronic and causes symptoms for years. An infected person with no symptoms can still spread delta hepatitis to others. They can be spread through sexual contact with an infected person, passed on to a newborn from an infected mother during childbirth, or transmitted by contact with infected blood or bodily fluids.
Routes of transmission of hepatitis D are similar to those of hepatitis B. For this reason, it is seen in individuals who have received a blood transfusion or who have shared needles during drug abuse. Chronic liver disease, which may occur with hepatitis D, often has minimal symptoms. At times there may be mild flare-ups with jaundice (yellowing of the skin and whites of the eyes, accompanied by darkened urine), nausea, fatigue, and weight loss. Symptoms that are similar to hepatitis B but there are those with no symptoms at all.
Hepatitis D virus infection is often severe if it occurs in someone who already has chronic hepatitis B. This acute fulminant form of hepatitis involves severe liver cell destruction and loss of liver function. It can be fatal. Symptoms include: an enlarged, painful liver, enlarged spleen, severe jaundice, susceptibility to bleeding, encephalopathy – a disorder in the functioning of the brain, aplastic anemia in rare cases. Aplastic anemia is a condition in which the bone marrow cannot make enough red and white blood cells.
Chronic HBV carriers are at risk for infection with HDV, especially as they participate in activities which put them at risk of repeated exposure to hepatitis D (e. g. , intravenous drug abuse, and unsafe sex, especially among homosexuals). Individuals who are not infected with HBV, and have not been immunized against HBV, are at risk of infection with HBV with simultaneous or subsequent infection with HDV. Since HDV absolutely requires the support of a hepadnavirus to reproduce itself, inoculations with HDV in the absence of HBV will not cause hepatitis D.
Alone, the viral genome indeed replicates in a helper-independent manner, but virus particles are not released. The healthcare provider may suspect hepatitis D after doing a physical examination and checking liver function tests. Another blood test, often drawn at the same time as the liver function tests, can confirm that hepatitis D is the cause of the symptoms. Chronic hepatitis can be diagnosed with a liver biopsy. Liver biopsy specimens can be graded in terms of severity. Liver biopsies may have to be done repeatedly to detect progression of the disease or response to therapy.
There are no special medicines or antibiotics that can be used to treat individuals with hepatitis D. Hepatitis D is a viral disease, and as such, antibiotics are of no value in the treatment of the infection. There is no hyperimmune D globulin available for pre- or postexposure prophylaxis. Disease conditions may occasionally improve with administration of the antiviral drug alpha interferon, which can help if not that fatal. It is more effective in the early stage of the disease.
Some people with severe hepatitis or end-stage liver disease may need a liver transplant, it can reappear in the transplanted liver, but it is rare. The hepatitis delta virus is present worldwide and in all age groups. Its distribution parallels that of HBV infection, although with different rates (highest in parts of Russia, Romania, Southern Italy and the Mediterranean countries, Africa and South America). In some HBV-prevalent countries such as China, HDV infection is disproportionately low. Delta hepatitis is rare in the U. S.
Washington State averages less than one case a year. Since delta hepatitis is dependent on hepatitis B infection, preventing hepatitis B infections will prevent delta hepatitis infections. Vaccinating people against hepatitis B can do this or by reducing transmission of hepatitis B. Infected persons can prevent the spread of delta hepatitis by not sharing any blood testing devices, needles, or other drug equipment. No donating of blood or organs, no sharing of razors, toothbrushes, nail care devices, or any other personal items that might have their blood on them.
Let health care professionals who may be exposed to their blood know that they have delta hepatitis. Recommend that any regular sexual partner be vaccinated for hepatitis B. Although sexual transmission appears to be low, inform sexual partners that you have delta hepatitis, and consider using condoms and barriers. Cover cuts or open sores on skin. There is no special medicine for HDV, but living a clean and healthy life makes a person disease free.
REFERENCE
M. D. Achord, J. L. (2002). “Understanding Hepatitis. ” Mississippi: University Press of Mississippi.