Hepatitis B is a liver disease that results from infection with the hepatitis B virus (HBV) and is transmitted through contact with infected body fluids or blood products. After an acute infection with HBV, some people develop a chronic infection.

Hepatitis B occurs worldwide. The burden of hepatitis B infection is highest in the Western Pacific region (China, Philippines, Cambodia, Vietnam, New Zealand, Australia) and Africa, where 116 million and 81 million people are chronically infected, respectively. Europe has 14 million infected people and the Americas five million.

Humans represent the only relevant pathogen reservoir.

Transmission occurs primarily through non-sterile instruments (needles, syringes) and through mother-to-child transmission (perinatal). Transmission is also possible via contaminated blood, semen/cervical secretions (sexual), and saliva (oral).

Sexual transmission and drug use via needles are currently the most common routes of transmission in Europe. Worldwide, perinatal transmission, from mother to child during birth, remains one of the most important routes of transmission.

Most individuals do not exhibit symptoms during the acute infection. If symptoms do occur during the acute infection phase, they manifest as fatigue, loss of appetite, abdominal discomfort, nausea, vomiting, and fever. Whether a chronic HBV infection develops is related to the age of the infected person. Up to 90% of children develop chronic infection, while it develops in less than 5% of adults. Individuals with chronic HBV infection have an increased risk of developing liver cirrhosis and liver carcinoma. Furthermore, they can transmit the virus to other people.

There is no specific treatment for acute hepatitis B virus infection. The use of drugs that are metabolized by the liver (e.g. paracetamol) should be avoided. Chronic hepatitis B virus infections can be treated with antiviral agents. This therapy can slow the development of liver cirrhosis, reduce the risk of liver cancer, and improve life expectancy.

Safe and effective hepatitis B vaccines are available that provide a high level of protection. In Austria, vaccination against hepatitis B is included in the free vaccination program.

In 2022, 875 hepatitis B cases were reported in Austria. The rate of hepatitis B virus infections decreased from 16.2 to 10.2 per 100,000 population:in between 2017 and 2021

Ministry of Health: Annual reports of notifiable infectious diseases

Clinically, it is not possible to distinguish hepatitis B infection from other hepatitis infections. Therefore, laboratory confirmation of the diagnosis is essential.

Basically, the diagnosis of acute hepatitis B virus infection is based on serological detection of HBsAg, anti-HBc (total, if positive complementary anti-HBc-IgM) and, if required, HBeAg and anti-HBe. A positive anti-HBs level does not represent general evidence of acute infection, as low levels may also occur in relapses of chronic hepatitis-B. In contrast, very high levels of anti-HBc IgM that decrease over time are indicative of acute infection. Observation of HBsAg and/or HBV DNA concentrations may help in equivocal cases.

Diagnosis of chronic HBV infection is based on detection of HBsAg and anti-HBc (total), as well as HBV DNA (quantitative) and anti-HBe/HBeAg (in pregnant women or before planned therapy).

WHO recommends that all blood donations be tested for hepatitis B to ensure blood safety and avoid accidental transmission.