Infection
Infection with the hepatitis B virus (HBV) usually occurs through blood contact or other body fluids (urine, saliva, tears, semen, breast milk). The hepatitis B virus usually enters the body via very small injuries to the skin and mucous membranes. In the early stages of an infection, a small amount of blood is often sufficient to transmit the virus from an infected person to a non-infected person.
The risk of infection via other body fluids is much lower. In Germany, transmission occurs in 40-70% of cases via sexual contacts, with homosexually active men or prostitutes (frequently changing sexual partners) being particularly frequently affected. Unprotected sexual intercourse with a hepatitis B infected person is considered a high risk factor for such an infection.In addition, the use of contaminated tattoo needles or syringes (eg in the drug milieu) carries particular risks of contracting hepatitis B infection.
The risk of infection via blood or blood products is still present despite improved testing for hepatitis B viruses (Hbs antigen testing/HBV DNA testing/anti-Hbc testing) prior to blood donation or blood transfusion, but is extremely low in countries with very good hygienic standards, such as Germany. The situation is different in nations with lower hygiene standards; here the risk of acquiring an infection this way (via blood preserves) is much higher. Another not negligible route of infection is the injury of persons employed in the health care system (doctors, nurses, cleaning staff, etc.)
with possibly infected material. In general, medical or dental personnel are exposed to a much higher risk of becoming infected through needlestick injuries or similar procedures. Since (also in Germany) hepatitis B is a disease that affects a relatively large number of people (sometimes without knowing it themselves), special attention must be paid to a possible infection with hepatitis B after a needlestick injury or comparable incident.
It is therefore advisable for health care workers to ensure adequate protection and to undergo a booster vaccination if necessary. Hepatitis B is a contagious and also sexually transmitted disease. The infection occurs from person to person.
How contagious an infected person is depends on specific serological factors. Both newly infected and certain chronically ill people can transmit the pathogen. The pathogen is present in blood, semen, vaginal secretion, menstrual blood, tear fluid, saliva and breast milk, whereby the concentration in blood is by far the highest.
The danger of infection usually exists before symptoms appear. The risk of infection depends largely on how many pathogens are present in the blood and how the infection is transmitted. Hepatitis B is most frequently transmitted through sexual contact.
People with intravenous drug use who swap injecting equipment are also considered a high-risk group. But hepatitis B also plays a role in the health care system. Therefore, all healthcare professionals should be vaccinated against hepatitis B.
Hepatitis B can also be transmitted through improper tattooing or piercing or in community facilities if hygiene measures are not followed. Importantly, hepatitis B can also be transmitted by pregnant mothers to their unborn children. The transmission occurs during the birth process.
Therefore, newborns of mothers at risk must receive a prophylactic vaccination immediately after birth. The hepatitis B virus is found in large numbers in the blood of newly infected or certain chronically infected persons. But they are also present in smaller quantities in the saliva.
The amount of the pathogen is here by a factor of 1000 to 10,000 less than in the blood. So far, there is no reliable evidence that hepatitis B can be transmitted by kissing. However, during closer sexual contacts it is essential to ensure protected sexual intercourse, hepatitis B is one of the sexually transmitted diseases.
