Letter to Dr Ludlam from J Craske re suspect batches of Edinburgh Factor VIII and Factor IX Possible risk of infection with HTLV-3 with subsequent development of AIDS. The study aims to assess the risk to patients who received suspect batches of Factor VIII that are infected with HIV of developing AIDS. Details the methods of investigation which include identifying all patients who have received suspect batches and; following up these patients at four monthly intervals for 6 years. Record forms were devised to help with the study including Form JC1 about patient data and clinical features; Form JC2 laboratory investigations for haematology and immunology and; Form JC3 laboratory investigations for virology. The letter also says that the patient should ideally be told about the infection, but this will depend on the amount of anxiety concerning AIDS. The letter also deals with ethical problems associates with HTLV-3 infection in Haemophiliacs.