In hepatitis B (synonyms: HBV; hepatitis B virus; viral hepatitis B; ICD-10-GM B16.-: Acute viral hepatitis B) is an inflammation of the liver caused by the hepatitis B virus. The hepatitis B virus is a partially double-stranded DNA virus and belongs to the Hepadnaviridae family. The disease belongs to the sexually transmitted diseases (STD) or STI (sexually transmitted infections). Humans are currently the only relevant reservoir of the pathogen. Occurrence: Infection is common in central and northern Africa, China, the Middle East, and eastern and southern Europe. It is often brought back from travels in these countries. Contagiousness (infectiousness or transmissibility of the pathogen) is high. The virus is found in blood, body fluids such as semen, breast milk, saliva, and tear fluid. The virus can be found in all body fluids. In most cases, transmission of the pathogen (route of infection) occurs through parenteral infections:
- Through sexual transmission (including 40% homosexual contact); for this reason, hepatitis B is categorized as a sexually transmitted disease (STD); 49% of cases.
- Contaminated injection needles (intravenous drug use), contaminated blood, contaminated instruments in the context of tattoos and piercings; 17% of cases.
In 24% of cases, the pathogen is found in residential communities with HepB virus carriers. In countries with a high incidence of virus carriers, transmission of the pathogen often occurs perinatally (around birth or during childbirth) from mother to unborn/newborn. The entry of the pathogen into the body is parenterally (the pathogen does not penetrate through the intestine, but enters the blood through the skin (percutaneous infection), through the mucous membranes (permucous infection), through the genitals (genital infection); the risk of infection from a needlestick injury (NSV, NSTV) with virus-positive blood is up to 30%. The incubation period (time from infection to onset of disease) is usually about 30-180 days. A distinction is made between an acute and a chronic form (approx. 5-10 %). The acute form can in turn be divided into a benign (benign) and a malignant (malignant) form (see below “Course and prognosis”). Gender ratio: Men are affected significantly more frequently than women. The peak incidence for women is 10 years before that of men:
- For men: age group of 30 to 39 years.
- For women: Age group of 20- to 29-year-olds
The prevalence (disease incidence) is 0.6% in Germany. In Central Africa and China, the prevalence is > 8%, in the Middle East, North Africa and Eastern / Southern Europe 2-7% and in other areas < 2%. Approximately 400 million people worldwide have chronic disease. The prevalence in developing countries is up to 80%.The prevalence of chronic hepatitis B in pregnancy is 0.7-0.9%. The incidence (frequency of new cases) is about 35 cases per 100,000 inhabitants per year (in Germany). The disease leaves a lifelong immunity. Course and prognosis: Hepatitis B is asymptomatic (“without symptoms”) in 65 % of cases, symptomatic in 35 % and fulminant (sudden, rapid and severe) in 1 %. Acute hepatitis B leads to spontaneous (“on its own”) recovery in 90% of cases. However, the acute form of hepatitis B can become chronic in 5-10% of cases. Of these, about 70-90% are clinically healthy (= chronic inactive hepatitis) and in about 10-30% of cases the disease is chronically active. Patients with chronic active hepatitis often complain of fatigue and loss of appetite. A typical long-term complication of chronically active cases is liver cirrhosis (irreversible (non-reversible) damage to the liver and a pronounced remodeling of the liver tissue) in 15-20 % of cases, and of these, hepatocellular carcinoma (HCC; liver cell cancer) is a further complication in about 15 % of cases. The “cure” of chronic hepatitis B (= low viral load, i.e. < 300 copies of HBV DNA/ml) under therapy is up to 70 %. Vaccination: Vaccination against hepatitis B is available. Due to the possibility of vaccination, the number of affected persons in industrialized nations will probably decrease. Vaccination is recommended especially when traveling to risk areas.Employees in the medical sector, in emergency services and mentally disabled persons in homes also have a higher risk of infection and should be vaccinated. Hepatitis B immunoglobulin is available for hepatitis B postexposure prophylaxis (passive immunization; to prevent disease in persons who are not protected against hepatitis B by vaccination but have been exposed to it). In Germany, the disease is notifiable according to the Infection Protection Act (IfSG). Notification must be made by name in cases of suspected disease, illness, and death.
