Third Annual Report on Project No J/S240/78/7 - Preliminary Results. Studies of the epidemiology and chronic sequelae of factor VIII and IX associated hepatitis in the UK. The aim of the study is twofold firstly, to study the incidence and types of factor VIII and IX related hepatitis in the UK by requesting the Directors of Haemophilia Centres to report cases as soon as they occur to the Oxford Haemophilia Centre, secondly, to assess the incidence of chronic liver disease due to factor VIII and IX associated hepatitis by following up patients who have received known infected batches of concentrate.