Hepatitis B is…
…an infection of the liver caused by the hepatitis B virus (HBV).

Symptoms
People with hepatitis B have either an acute infection—those who have recently caught the infection for the first time—or chronic infection—those who have had hepatitis B infection for more than six months. The symptoms of hepatitis B can vary greatly and many cases never develop any symptoms at all. Those who do get symptoms (somewhere between 30 and 50% of cases) usually suffer from symptoms like tiredness, loss of appetite, abdominal discomfort, nausea, vomiting and fever. The vast majority of healthy adults who get acute hepatitis B will recover in 4—12 weeks when they develop antibodies which will fight off hepatitis B. Chronic infection is most likely to develop in young babies.

Complications
Chronic infection can lead to inflammation of the liver, liver damage (called cirrhosis) and cancer.

Ways to catch hepatitis B
Hepatitis B is spread through contact with infected body fluids. Most infections occur by coming into contact with infected blood but semen, saliva and cervical secretions can also be infectious. Most infections occur sexually or through injected drug use. Tattooing and body piercing can also be sources of the infection. The virus can live on surfaces for at least seven days and so it could also be caught from objects that have been contaminated with infected body fluids (e.g. used hypodermic needles).

People most at risk
Hepatitis B occurs all over the world. Many developed counties have relatively low rates of incidence of hepatitis B and most infections occur in adults in high-risk groups. These groups include the following: injecting drug users; those who change sexual partners frequently; babies born to infected mothers; household contacts; sexual partners of people who are infected; healthcare workers who have contact with infected body fluids; people who received blood or blood product transfusions; and some patients having blood dialysis (although such nosocomial infections have become extremely rare in Europe after the introduction of HBV tests for all blood products). The most affected groups are those aged 15—24 followed by 25—44-year-olds. Men are more likely to be affected than women.

Diagnosis
The clinical symptoms of hepatitis B are the same as other forms of viral hepatitis; therefore, laboratory tests on a blood sample are necessary to confirm hepatitis B.

Treatment
Acute hepatitis B is treated by relieving the symptoms as there is no specific treatment and most people will clear the infection themselves. People who do not clear it and develop chronic infection should be monitored, but do not need treatment unless they start to develop liver disease. Those who require it can be given antiviral treatment.

How to avoid getting hepatitis B
Hepatitis B is one of the major diseases that can be prevented by vaccination. Safe and effective vaccines are available that offer high levels of protection to children and adults. The vaccine can be given after people have been exposed to hepatitis B to prevent the disease from developing or reduce its severity. Promoting safe sex, needle exchange programmes for drug users and screening high-risk groups for hepatitis B are all important ways of reducing the spread of the infection. Testing pregnant women for hepatitis B allows action to be taken to protect the baby against infection.

Note: The information contained in this factsheet is intended for the purpose of general information and should not be used as a substitute for the individual expertise and judgement of healthcare professionals.