1. It had been recognised since 1972 that hepatitis B and non-A, non-B hepatitis could be transmitted by clotting factor concentrates'6. With the recognition that concentrate transmitted HIV infection to haemophilia patients, efforts to produce virally inactivated concentrates were intensified.3' These have culminated in the production of a generation of products which are safe and free from lipid-coated viruses. Some products have undergone double viral inactivation steps - for example, dry heating or ultrafiltration may be combined with a chemical inactivation step such as the use of solvent detergent processes or sodium thiocyanate'1. Thanks to these measures there have been no cases of seroconversion from HIV, hepatitis B or C recorded in the UK since 1986. Despite this significant achievement, caution is warranted because documented transmission ofhepatitis A and parvovirus B 19 have occurred in Europe39'40 and this indicates that non-lipid coated viruses can escape inactivation procedures
2. Haemophilia, with special reference to the Talmud. Heb Med J';Katznelson, J.L.;1956
3. An account of haemorrhagic disposition existing in certain families;Otto, J.C.;Med Repos
4. Contribution to the pathogenesis of haemophilia;Pavlovsky, A.;Blood,1947
5. Plasma thromboplastin component (PTC) deficiency: a new;Aggeler, P.M.; White, S.G.; Glendenning, M.B.