Therapy is only possible to a limited extent. The best protection against infection is to use condoms during sexual intercourse and to avoid transmission routes via bodily fluids (e.g. sharing spraying equipment).
Hepatitis D is a viral infectious disease of the liver (in Greek, "hepar" means liver and the suffix "-itis" means inflammation). It is caused by a defective RNA virus (RNA refers to ribonucleic acid), which can only be transmitted in combination with the hepatitis B virus.
Therapy is only possible to a limited extent. The best protection against infection is to use condoms during sexual intercourse and to avoid transmission routes via bodily fluids (e.g. sharing spraying equipment).
Hepatitis generally refers to an inflammation of the liver. In addition to medication, alcohol and other triggers, various viruses can also lead to liver inflammation. Due to a defect – the missing envelope around the RNA strand – the hepatitis D virus nests in the envelope of the hepatitis B virus. This is the only way it can be infectious. Therefore, infection with hepatitis D can only occur if an affected person comes into contact with the hepatitis B virus and is not vaccinated. Vaccination against hepatitis B therefore also offers protection against the hepatitis D virus. In addition to general symptoms such as tiredness and fatigue, gastrointestinal complaints also occur and urine and stool change color. In a chronic course, a hepatitis D co-infection may lead to liver cirrhosis and liver cancer.
Hepatitis D infection occurs mainly in the Mediterranean region, North Africa and South America. Globally, five percent of people infected with hepatitis B are co-infected with hepatitis D. In our latitude, infection with HDV is rare. The possibility of being vaccinated against hepatitis B, in combination with preventive measures, makes infection with hepatitis D very unlikely in this country. There is no mandatory reporting requirement for hepatitis D in Switzerland, but since hepatitis B infection must be reported, people infected with hepatitis D are also automatically recorded.
The gene structure and the type of replication (multiplication) is a special feature of the hepatitis D virus. As a virusoid (defective virus), the hepatitis D virus consists only of a highly tangled RNA ring without its own envelope. The envelope proteins (proteins) of the hepatitis B virus are bound and the hepatitis B virus is used as a means of transportation. Humans are the only natural host of the hepatitis D virus. It is transmitted through bodily fluids such as blood or semen. Most infections occur through sexual intercourse or the use of infected needles (in the case of drug use or tattoo needles). The risk of transmission through an infected blood product is very low due to the strict controls we have in place.
Hepatitis D is contracted at the same time as hepatitis B, which is why it is referred to as a co-infection or simultaneous infection. The incubation period (period from infection to the first symptoms) is three to seven weeks. However, it is also possible that the onset of hepatitis D is delayed. This is called superinfection. The incubation period here is 50 to 180 days.
In the early course of a hepatitis D infection, rather unspecific symptoms usually develop, which lead to a general feeling of malaise. These include:
As the disease progresses, other symptoms such as
As the early symptoms of the disease can indicate a variety of illnesses, in most cases we will not initially suspect hepatitis. A detailed medical history and information about stays abroad in risk areas provide initial indications. In addition, the living conditions of those affected (e.g. drug addiction or unprotected sexual intercourse with frequently changing sexual partners) can be an indication. If we suspect that symptoms are occurring that indicate a liver problem, we will arrange for a blood test to be carried out, which will also test for hepatitis viruses. In most cases, this is done by means of an antibody test. In rare cases, even the hepatitis D virus itself can be detected in the blood. However, this is not a mandatory requirement for a diagnosis.
The laboratory of the Immunology Clinic at the USZ supports the diagnosis with precise and recognized analyses.
In addition to the analysis of blood values, which is informative in most cases, the liver can also be biopsied. A tissue sample is taken from the liver under local anesthesia using a thin needle. The material obtained can be analyzed for viral material (hepatitis D antigen and RNA).
The most effective prevention against hepatitis D infection is vaccination against hepatitis B, as this prevents the transport route for the hepatitis D virus. Vaccination against hepatitis B has been a standard vaccination since the 1990s. It is usually integrated into the so-called six-vaccination package. This is already carried out in the first months of life. Adults at increased risk who have not received such a vaccination should have it carried out. The risk groups include:
Up to ten percent of those vaccinated do not develop sufficient protection or no protection at all. Successful immunization must therefore be verified. Other preventive measures against hepatitis D are
If those affected act quickly and ask a doctor for an appropriate examination, even in the case of minor general symptoms, the chances of early detection are high.
Co-infection with hepatitis B and D viruses often leads to a severe course of the disease. Severe acute courses often result in liver cirrhosis and liver cancer. In the case of a superinfection, i.e. the delayed onset of hepatitis D after existing hepatitis B, chronic courses are very likely, which can cause severe liver damage and also lead to liver cirrhosis and liver cancer.
The exchange with people who are affected by the same disease can be a great support in coping with the disease. Advice on finding a suitable self-help group is available from Selbsthilfe Zürich. Self-Help Zurich and the University Hospital Zurich are cooperation partners in the national project “Health literacy thanks to self-help-friendly hospitals”.
Unfortunately, there is currently no effective treatment for hepatitis D infection. Although the hepatitis D virus only survives with the hepatitis B virus, a drug-controlled hepatitis B infection has no effect on hepatitis D infection. There are individual drugs that show efficacy against the hepatitis D virus (e.g. interferon-alpha, peginterferon-alpha), the therapy must be carried out in high doses and lasts up to a year, but the exact duration of therapy is uncertain.
Experimental therapies are also being discussed in specialist circles. If treatment is required, the case is discussed on an interdisciplinary basis with staff from the Infectious Diseases Clinic and colleagues from the Hepatology Department in order to find a customized treatment for the person concerned.