Hepatitis A

Hepatitis A is a viral infection that causes inflammation of the liver. It is caused by the hepatitis A virus, also known as HAV. Hepatitis A is the most common form of viral hepatitis, with an estimated 1.4 million infections worldwide each year.

Hepatitis A is most common in developing areas including Central and South America, Africa, the Middle East and Asia. Whilst it used to be a common childhood infection in the United Kingdom, United States and other developed countries in the early 20th century, it is now infrequent due to improved sanitation and water treatment. In England and Wales, there were more than 7000 cases in the early 1990s, falling to just over 1000 in 2001. In the United States, about 7600 cases were reported in 2003. Because fewer people now become infected and gain immunity as children, more remain susceptible to hepatitis A as adults.¹