Hepatitis is an inflammation of the liver. The condition can be self-limiting or can progress to fibrosis (scarring), cirrhosis or liver cancer. Hepatitis viruses are the most common cause of hepatitis in the world but other infections, toxic substances (e.g. alcohol, certain drugs), and autoimmune diseases can also cause hepatitis.

There are five main hepatitis viruses, referred to as types A, B, C, D and E. These 5 five types are of greatest concern because of the burden of illness and death they cause and the potential for outbreaks and epidemic spread. Hepatitis B and C infections are the most common causes of liver disease, and they lead to more than 380,000 cancer-related deaths in China each year.

There are 87 million people who are chronic carriers of the hepatitis B virus in China, accounting for about one-third of all hepatitis B virus chronic carriers in the world. An estimated 7.6 million people in China are living with chronic hepatitis C.