INTRODUCTION
1.1 INTRODUCTION TO HEPATITIS B
Viral hepatitis is a disease as old as the history of Medicine. Hepatitis was described in the Babylonian Talmud in the fifty century BC, and was referred to by Hippocratic over 2000 years ago. Despite this ancient knowledge, it was not until 1963, that the first human Repetitious virus was isolated, Hepatitis B. This was followed quickly by the purification of Hepatitis A in 1973, and more recently by the isolation of viruses C, D, E and G. These viruses are known to infect the human liver (Anderson et al; 2001).
However, there are more than twenty other viruses, which infect the human liver. These are not considered “Repatitis viruses” as these other viruses tend to infect organs other than the liver more seriously’. These include common viruses such as Cytomegalovirus (CMV), Mumps, Rubella, Epstein-Barr virus (EBV) as well as rare ones such as Rassa fever and yellow fever viruses.
Any infection that results in inflammation of the liver is called Repatitis (Greek Repaticus, liver). Incidentally, not all “hepatitis” is caused by viruses. “HEPATITIS” means “inflammation of the liver”, and can be caused also by other types of infection (bacteria fungi etc); toxic drugs; poisons; alcoholism and so on (Drexott etal; 2005).
But of interest is one Repatitis virus – one of the most common infections diseases, causing an estimated 1.5millon deaths world wide each year – Hepatitis B. Hepatitis B is caused by the Repatitis B virus (HBV), a double – stranded circular DNA virus of complex structure. Hbv is class ivied as an orthoropadnavirus within the family hepadnaviridae. HBV was originally