Causes of hepatitis B.

Causes of Hepatitis B Infection

The hepatitis B is an inflammatory disease of the liverthat through the Hepatitis B. Virus (HBV) is triggered. The virus belongs to the group of Hepadnaviruses and is a covered, double-stranded one Dna virus.

The hepatitis B virus is transmitted parenterally (literally translated: past the intestine), i.e. via blood and other body fluids.

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Infections are therefore particularly common in certain risk groups: Medical staff or nursing staff who deal with infected people, for example, have the risk of coming into contact with the blood of sick people via needlestick injuries and thus becoming infected. Drug addicts who consume drugs such as heroin, who have to be injected into the blood, who share syringes, run a high risk of infection. Infections are also conceivable through other contaminated sharp objects such as piercing devices or tattoo needles.

Sexual transmission

The hepatitis B virus is found in various body fluids in infected people. This mainly includes blood, semen and vaginal secretions. During unprotected intercourse, these fluids come into contact with the partner's genital mucosa. Since the mucous membrane in this area is very well supplied with blood and small tears very often occur during intercourse, the viruses can enter the partner's bloodstream and infect them.

Therefore, sexual intercourse with someone with hepatitis B should be carried out with a condom. It is also important to note that the risk of infection increases with the number of viruses in the blood. This is usually very high at the beginning of the infection, which means that the risk of infection is at its peak in the early phase of the disease.

Transmission through other body fluids

The saliva is produced by the salivary glands in the head and consists mainly of salts and water. Very few viruses enter the saliva as it is produced. The small number is usually not enough to infect a person. Other body fluids such as urine, tear secretion or breast milk also contain virus particles, but only in very few patients in sufficient quantities to cause infection.

Transmission through kissing

When kissing someone with hepatitis B, the patient's saliva comes into contact with the lining of the mouth. However, since there are very few virus particles in the saliva, there is no need to be afraid of becoming infected. In addition, the oral mucosa is strong, but not as well supplied with blood as the genital mucosa during sexual intercourse. Caution should only be used with very large open wounds.

Transmission via blood contact or blood reserves

Since the hepatitis B virus can be present in high numbers in the blood, especially at the beginning of the disease, hepatitis B can be transmitted through blood contact. The infected person's blood must come into direct contact with the other person's bloodstream. This can be transmitted through wounds or needlestick injuries, where the disease is passed through a needle prick to draw blood from a sick person.

Blood transfusions also result in direct contact between the blood of two people. In the past, people who received a blood transfusion would occasionally become infected with hepatitis B. Today, however, each donor sample is carefully screened for many diseases, including hepatitis B. Therefore blood transfusions are no longer a cause of infection with hepatitis B in Germany. The same applies to the transplantation of liver (parts).

Drug addiction as a cause

Drug addiction can also be a cause of hepatitis B infection in some cases. Whenever the blood of one sick person comes into direct contact with the bloodstream of another, the disease can be transmitted. This often happens with drug addicts who inject drugs into their blood with used needles. Since the risk of infection is so high, there are more infected people in these circles, which in turn increases the risk of infection through shared needle use. When sharing a joint or the like, however, as with saliva, there is no risk of becoming infected with hepatitis B.

Transfer via tattoo needles

There is also a low risk of infection with tattoo needles that have come into contact with the blood of a person suffering from hepatitis B and have not been hygienically cleaned. However, these needles are not designed to pierce blood vessels. They only penetrate into the layers of the skin and therefore do not have direct blood contact.

In addition, they usually take more time to be used again than with needles used to inject drugs, which means that the hepatitis B virus is less able to survive on the surface of the needle anyway. The same applies to piercing devices.

Transmission through dialysis

An infection with the hepatitis B virus would theoretically be possible through dialysis. However, it no longer occurs if the current hygiene and precautionary measures are observed.

Transmission through breast milk

Since components of the hepatitis B virus can be found in breast milk, infection while breastfeeding is a theoretical thought. However, it has not yet been proven in any study that this route of infection can occur. In addition, breast milk contains many components that are very important for building up the child's immune system and thus protecting it from infections. To be absolutely sure that the child is not exposed to any danger, the breast milk can be examined for virus components. This is especially recommended for a mother with hepatitis C.

Transmission during pregnancy and delivery

Transmission from an infected mother to her child is also possible both during pregnancy and during delivery, whereby the infection occurs more frequently during delivery and also represents the largest number of new infections worldwide.

Mechanism of inflammation

It has not yet been fully clarified which mechanism actually leads to the inflammatory reaction in the liver, but it is assumed that certain factors are under the influence of the virus cytotoxic Defense cells (lymphocytes) are formed (i.e., causing cell death), which ultimately ensure that more liver cells die.

This then ensures the typical symptoms of hepatitis, which result from the impaired functionality of the liver, in later stages especially jaundice (Jaundice).