Hepatitis B is a virus that causes inflammation of the liver. Chronic (long-lasting) hepatitis B can cause liver cell damage, which can lead to cirrhosis (scarring of the liver) and cancer. It is estimated that 5,000 people die each year in the United States due to the complications of cirrhosis and liver cancer as a result of hepatitis B virus (HBV).
According to Centers for Disease Control and Prevention (CDC), it is estimated that between 800,000 and 1.4 million people in the United States have chronic hepatitis B. There were an estimated 38,000 new HBV infections in the United States in 2009.