Methods for the accurate diagnosis of BSE and other animal TSEs which could be applied on a large scale to examine animals during life or after slaughter are urgently required and could have major epidemiological implications in minimising the risk to other animals or to human populations through food or other routes of exposure, including exposure via bovine derived materials used in the production of medicinal products. Similar epidemiological considerations apply to scrapie. Likewise, the accurate diagnosis of CJD and nvCJD remains problematic.
Methods based on histopathology of post-mortem specimens are currently the most useful indicators.
A reliable diagnostic method for Creutzfeldt-Jakob diseases using easily accessible samples, such as serum, would be invaluable and there is a great deal of scientific activity in this area. A number of promising approaches have been described and novel antibodies and new applications of existing technologies have been developed in the field of diagnostic procedures for TSEs. These are at a relatively early stage of development and the need for global standardization is becoming clear. Panels of reference materials of various kinds for comparison of methods and results, and the establishment of an international forum to discuss the assays available and to coordinate future collaborative studies would be of great value. Therefore, a meeting of scientists active in relevant aspects of TSE research has been proposed to evaluate progress so far, to assess future needs for standardization and to plan further WHO activities in order to facilitate development of various kinds of reference materials and reagents.