Introduction

Hepatitis currently represents an enormous public health problem. Viral hepatitis is a group of infectious diseases of the liver linked to the presence of a proliferation of at least five different viruses. These viruses can produce acute symptoms and can spread in epidemic proportions. At present, at least six different viruses are known to cause viral hepatitis, and it is probable that current research will identify others.

300 million people worldwide are estimated to be infected with hepatitis B. This viral infection is thought to be responsible for two million deaths each year, affecting around 5% of the population of the world. The oldest known description of the 'jaundice epidemic' dates from the time of Hippocrates. However, until the 1940's, it was not known that there are several forms of hepatitis and several different viruses causing it.

Hepatitis B is especially frequent in Africa, South-East Asia and China. There are around 100,000 new infections per year. It is a serious disease caused by a virus that attacks the liver. This organ is found beneath the lower right ribs and in the upper right abdomen. It has many functions, including the breakdown of unwanted substances and the production of proteins.