Hepatitis B

Hepatitis B is the most common serious liver infection in the world. It is thought to be the leading cause of liver cancer.

The World Health Organization estimates that hepatitis B infections lead to more than one million deaths every year.

What causes hepatitis B?

The disease is caused by the hepatitis B virus (HBV) that attacks the liver.

The virus is transmitted through blood and bodily fluids that contain blood.

This can occur through direct blood-to-blood contact, unprotected sex, and illicit drug use.

It can also be passed from an infected woman to her new-born during the delivery process.

Does the virus always pose a health threat?

It is thought that about one in three of the world's population is infected by HBV.

However, about 50% of those who carry the virus never develop any symptoms.

About nine out of ten people infected with HBV will eventually clear the virus from their bodies. But about 5-10% of infected adults will become chronic hepatitis B carriers, often without even knowing it.

What are the symptoms?

The virus can cause a range of problems, including fever, fatigue, muscle or joint pain, loss of appetite, nausea and vomiting.

Chronic carriers have an increased risk of developing liver disease such as cirrhosis or liver cancer, because the hepatitis B virus steadily attacks the liver.

Chronic carriers will usually have on going inflammation of the liver and may eventually develop cirrhosis and liver cancer.

About 1% of people who are infected develop an extreme form of disease called acute fulminant hepatitis.

This condition can be fatal if not treated quickly. Sufferers may collapse with fatigue, have yellowing of the skin and eyes (jaundice) and develop swelling in their abdomen.

How is it treated?

There are several drug treatments available to treat hepatitis B.

Patients may be put on a four month course of injections of the drug interferon.

An alternative treatment is a drug called lamivudine which is taken orally once a day. Treatment is usually for one year. Sometimes lamivudine is combined with interferon.

Chronic patients may require a liver transplant.

Can it be prevented?

Yes, by the use of a safe and effective vaccine.

However, for the 400 million people world-wide who are already carriers of HBV, the vaccine is of no use.