Hepatitis is an infectious disease caused by viruses. The whole body is affected by the viral infection which leads to systematic illness, and the liver is particularly susceptible to damage. Hepatitis is classified according to its cause. In Hong Kong, viral hepatitis is more common. To date, at least six hepatitis viruses have been identified. They are hepatitis A, B, C, D, E, and G viruses.
Hepatitis A: a type of viral hepatitis that usually leads to acute hepatitis and jaundice. While most patients have a complete recovery, it can progress to liver failure or even death in a very small number of cases.
Hepatitis B: a type of viral hepatitis that leads to acute and chronic hepatitis. It can be followed by chronic liver damage, including cirrhosis and liver cancer.
Hepatitis C: an RNA virus that causes liver damage. Like hepatitis B, some hepatitis C carriers develop liver scarring or even liver cancer due to chronic hepatitis.
Hepatitis D: a virus that cannot propagate on its own and needs hepatitis B virus for replication in human cells. Therefore, hepatitis D is limited to people with hepatitis B. Hepatitis D is transmitted in the same way as hepatitis B. The infection can occur either simultaneously or after the patient has become a hepatitis B carrier. People with both hepatitis B and D are at higher risk of chronic hepatitis and cirrhosis.
Hepatitis E: a form of viral hepatitis caused by hepatitis E virus, affecting adults mostly. Pregnant women, however, are more vulnerable to serious complications from the disease.
Hepatitis G: a newly discovered virus. We are not yet able to assess how severe hepatitis G is in Hong Kong.