Hepatitis B virus

Hepatitis B is caused by the Hepatitis B virus transmitted, which causes liver inflammation. The disease is usually transmitted through sexual or blood contact. The disease rarely manifests itself in its course through symptoms.

What is the hepatitis B virus?

Hepatitis B is an inflammation of the liver caused by the hepatitis B virus. In most patients, an acute course of the disease can be observed that heals on its own. In addition, serious dimensions associated with, for example, liver cancer, gastrointestinal bleeding or liver cirrhosis cannot be ruled out.

The disease can be chronic or acute. Liver inflammation is caused by damage to liver cells. These can limit the function of the organ. Hepatitis B is one of the most common infectious diseases. Globally, every third person is said to be infected.

Transmission during pregnancy means that the risk of infection is particularly high in some areas. If left untreated, the long-term consequences of a hepatitis B infection are particularly relevant. In order to avoid infection, a vaccination can be considered before a long-haul trip.

The individual hepatitis B virion is protected by a specific envelope. This contains various proteins, such as the membrane protein and the pre-S1 protein. The pre-S1 protein enables the virus to enter a host cell. Overall, the hepatitis B virus, with its 42nm diameter, is one of the smaller viruses.

Occurrence, Distribution & Properties

Hepatitis B is widespread around the world and therefore poses a risk of illness that must be considered when traveling long-distance. Chronic hepatitis B can be localized in areas near the Amazon and in Eastern and Central Europe. According to experts, up to 20 percent of the population in China and Central Africa should suffer from hepatitis B, in contrast to less than 1 percent in Western European and North American countries. A third of the world's population has suffered from hepatitis B infection. 780,000 people die every year as a result of acute or chronic hepatitis B infection.

The virus is transmitted through contact with all body fluids such as semen, saliva and blood. This means that those affected who have not been informed about their illness pose a particular risk of infection. In some regions, the virus is also transmitted through contaminated material during medical treatments. The virus is said to be 50 to 100 times more contagious than the one that leads to HIV.

Hepatitis B viruses only have about 3000 bases and are therefore a million times smaller than the human genome. Despite its unusual size and shape, the virus manages to spread efficiently. It can produce seven proteins from just four genes, which in turn can have different structures. The hepatitis B virus creates a DNA copy from a viral RNA and transports this out of the cell as packaged virions. The resulting envelope protects the viral genome from damage and helps transport the virus within the host.

Illnesses & ailments

Hepatitis B is caused by the hepatitis B virus. This is a virus with double-stranded DNA. Humans are the only possible host. Because many of the viruses are found in the blood, this in particular is considered to be contagious. Even drops of blood are sufficient for an infection. In other body fluids such as semen or saliva, the concentration of the virus turns out to be lower.

The incubation period for a hepatitis B virus is between one and six months. The incubation time is the time until the first symptoms appear after infection.

Overall, hepatitis B disease has a very different course. A third of all patients have no symptoms at all. That is why the disease is not recognized and those affected represent a particular risk for healthy people. If there are complaints, these are increasingly general symptoms that cannot always be assigned immediately. Those affected complain of tiredness, headaches, loss of appetite, weight loss, fatigue, muscle and joint problems and fever.

Once the cells in the liver have become damaged, other symptoms may appear: dark urine, light stools, discoloration of the skin and eyes. These specifically indicate an underlying jaundice. If the disease is left untreated, serious long-term consequences can occur. If in doubt, it makes sense to consult a doctor.

The severity of the hepatitis B illness depends on various factors. Above all, this includes the age and general health of the patient. In adults, the disease often heals on its own and has an overall favorable course. Small children and people with weakened immune systems, on the other hand, suffer more from the fact that the acute illness becomes chronic.

Chronic hepatitis B illness means that those affected may be permanently contagious. This condition is not always noticeable through corresponding symptoms. In addition, the liver values ​​are permanently increased and there may be serious consequential damage. These include, for example, liver cirrhosis and liver cancer. Liver cirrhosis is the end-stage of liver disease that has destroyed the structure of the organ. The tissue hardens, shrinks and is increasingly scarred. The function of the liver is further restricted, which can lead to life-threatening symptoms. Different medical approaches can improve the condition of the liver. In the case of advanced liver cirrhosis, however, often only a liver transplant will help.

In liver cancer, the time of diagnosis in particular determines the patient's prognosis. The earlier the tumor is noticed, the better the chances of survival. If surgery is necessary, the chances of surviving more than the first five years are 20 to 50 percent. However, liver cancer is diagnosed late in many people. A cure is then often no longer possible because the tumor has already spread metastases.

Hepatitis B can therefore lead to serious consequences. Vaccination efficiently prevents infection. The active ingredient is administered at two appointments, each two weeks apart, and is usually well tolerated. A third vaccination after six months is recommended for long-term protection. It is possible to have children vaccinated as early as infancy. A vaccination is also important for risk groups. This includes people with a weakened immune system, such as those infected with HIV, as well as people who have an increased risk of infection due to their work.