Hepatitis is an inflammation of the liver, most commonly caused by a viral infection. There are five main hepatitis viruses, referred to as types A, B, C, D and E. Types B and C lead to chronic disease in hundreds of millions of people and, together, are the most common cause of liver cirrhosis and cancer.
Hepatitis A and E are typically caused by ingestion of contaminated food or water. Hepatitis B, C and D usually occur as a result of parenteral contact with infected body fluids. Common modes of transmission for these viruses include contaminated blood or blood products, invasive medical procedures using contaminated equipment, and for hepatitis B transmission from mother to baby at birth, from family member to child, and also by sexual contact.
Acute infection may occur with limited or no symptoms, or may include symptoms such as jaundice (yellowing of the skin and eyes), dark urine, extreme fatigue, nausea, vomiting and abdominal pain.
Member States of the Western Pacific Region are committed to preventing mother-to-child transmission of hepatitis B virus through vaccination, and have adopted a Regional goal to reduce chronic hepatitis B infection among children to lower than 2% by 2012.
In May 2012, China was officially verified as having exceeded this goal by reducing chronic hepatitis B infection in children <5 years from 9.7% in 1992 to 1.0% in 2006.