We will study what has happened to people, mainly Maori, found to be infected with Hepatitis B virus (HBV) 27 years ago, and in particular, whether there is chronic hepatitis, severe liver scarring (cirrhosis), or liver cancer. Our aim is to determine how ongoing surveillance to prevent liver disease in those with HBV can be improved. We will use initial blood samples from 1984 to determine whether there are markers which predict disease 27 years later. Current recommendations in New Zealand are that patients with HBV should be monitored with blood tests every six months. Anyone with abnormal liver tests is referred for assessment and consideration for antiviral treatment. The information gained from this study will enable physicians to predict who with HBV is at greater risk of developing liver disease and for the Hepatitis Foundation to refine its surveillance programme for such patients. This will be achieved within 5 years.