What is hepatitis B?
Having hepatitis means that your liver has become inflamed. Hepatitis can be caused by a number of things including:
There are a number of viruses that infect the liver. The best known are hepatitis A, B, C, D and E. The ways in which they are transmitted (spread or passed on), how they cause liver damage and the effects they can have on your health, are different. Only hepatitis B, C and D cause chronic or long term, disease.
Apart from hepatitis B, hepatitis A and C are the biggest problems for people in the UK.
Hepatitis B, sometimes called hep B or HBV, is a virus that is carried in the blood which infects and damages the liver. A virus is a tiny particle that needs to infect and control the cells of your body in order to live and reproduce ('replicate').
Hepatitis B is very infectious - 100 times more infectious than HIV. However, there is a simple test to find out whether you have the virus and an effective vaccine is available to protect you from it.
Where is hepatitis B common?
Hepatitis B is the most widespread form of hepatitis.
It is common in South-East Asia, the Middle and Far East, Southern Europe and Africa.
The World Health Organisation estimates that one third of the world's population has been infected at some time and that there are approximately 350 million people who are infected long term. In Europe, there are estimated to be one million people infected every year.
In the UK, approximately one in 1,000 people are thought to have the virus. In some inner-city areas with a high percentage of people from parts of the world where the virus is common, as many as one in 50 pregnant women may be infected.
How is hepatitis B passed on?
Blood
Hepatitis B is known as a 'blood-borne virus' (BBV) and is spread by blood to blood contact. Highest amounts of the virus are present in blood. Even a tiny amount of blood from someone who has the virus can pass on the infection if it gets into your bloodstream. This might be through an open wound, a cut or scratch, or from a contaminated needle.
People who use drugs and share injecting equipment have a high risk of infection. Having a tattoo or body-piercing or even acupuncture can pose a small risk if unsterile equipment is used.
The virus can also be passed on from medical and dental treatment in countries where equipment is not sterilised properly.
All blood donations in the UK are now tested for hepatitis B, but before testing was introduced in 1991 it was possible to become infected by receiving blood or blood products from an infected person. In countries where blood is not tested, blood transfusions may still be a cause of infection.
The virus is able to survive outside the body for at least a week. This means that you should take care not to share iems such as a razor or toothbrush which might be contaminated with dried blood.
Sex
Hepatitis B can be transmitted by having penetrative sex without a condom with an infected person. Even oral sex can pass on the virus. Sexually active young adults who do not use condoms have a high risk of getting hepatitis B.
Other body fluids
Although it is called a blood-borne virus, hepatitis B may be present in other body fluids such as saliva, semen and vaginal fluid, particularly if these have become contaminated with blood.
Small traces have been found in sweat, tears, breast milk and urine but these fluids are not regarded as infectious.
Some people transmit hepatitis B more easily than others because they have more of the virus in their bloodstream.
Mother to baby
Hepatitis B is usually transmitted to the baby during delivery, as the baby is exposed to the mother’s blood in the birth canal. Transmission to the unborn baby does not usually occur in the uterus (before birth). Infection at birth is called ‘perinatal transmission’ and is the most common way the virus is spread globally. Vaccination of the baby at birth prevents the majority of infections.
Although small amounts of the virus have been found in breast milk, the risk from breastfeeding is not fully known and is prevented by vaccination of the new born baby.
Since April 2000, all pregnant women in the UK are tested for hepatitis B. Pregnant women with high levels of the virus in their blood may be offered additional treatment including antiviral therapy.
Work and environment
Certain jobs can put people at risk from hepatitis because they may involve contact with infectious body fluids.
- Healthcare workers.
- Other workers who might come into contact with body fluids including morticians, sewage workers, those in emergency services and people in the fi tness industry.
- People who might have injuries and come into contact with others with injuries, such as people involved in contact sports or in the building industry.
- Foster carers and people who live or work in accommodation for people with severe learning disabilities.
- Prison staff and prison inmates are also at risk.
People who may be at increased risk because of their work or environment should be vaccinated against hepatitis B.
Travel
More than 10% of cases in the UK are thought to result from people travelling to and working in countries where there is increased risk of hepatitis B infection.
If you think you might have been exposed to hepatitis B, see your doctor immediately.
People who intend to stay in an area where hepatitis B is common, particularly if they are likely to need medical treatment such as dialysis, should get vaccinated.
It is important to remember that you are not naturally protected from infection with hepatitis B just because you are travelling to a country where you or your parents were born. Vaccination is strongly recommended for all travellers to countries where hepatitis B is common.
Hepatitis D
A few people with hepatitis B also have another virus called the delta virus or hepatitis D. This virus needs the hepatitis B virus to survive, which means that it is only possible to have hepatitis D if you have hepatitis B. Hepatitis D is also passed on in blood and is most common in injecting drug users, though it is not common in the UK overall. Being infected with both viruses can lead to more serious liver disease.
There is a separate publication on Hepatitis D available containing further information.