Viral hepatitis.

The list of hepatitis viruses is increasing over the years. Now the viruses range from A to G. Hepatitis A virus is a short incubation RNA virus which is transmitted oro-faecally. It does not cause chronic illness but may be fatal in a few cases especially in pregnancy. It can now be prevented by vaccination. Hepatitis B virus is a long incubation DNA virus which is transmitted mainly through blood and blood products. It causes chronic illness and can lead to liver cancer in some cases. It can be prevented by vaccination and WHO is now recommending global vaccination of all infants irrespective of endemicity of hepatitis B virus. Hepatitis C virus is an RNA virus which used to be known as parenterally transmitted non A non-B virus. It leads to chronic illness and can lead to liver cancer. It is now responsible for most cases of post transfusion hepatitis in Europe, North America and Asia. Hepatitis Delta virus is a defective virus which requires hepatitis B virus for its existence. Thus it affects only those who have hepatitis B virus. Hepatitis E virus used to be known as the enterically transmitted non-A non-B virus. It is transmitted oro-faecally and seems not to lead to chronic illness. It is endemic in some areas like Middle East and parts of Africa. Hepatitis G virus is just being described. More information about it will soon be available.