WHO Guidelines on Tissue Infectivity Distribution in Transmissible Spongiform Encephalopathies

WHO guidelines on tissue infectivity distribution in transmissible spongiform encephalopathies. 1.Creutzfeldt-Jakob syndrome – pathogenicity. 2.Creutzfeldt-Jakob syndrome – diagnosis. 3.Encephalopathy, Bovine spongiform – transmission. 4.Encephalopathy, Bovine spongiform – pathogenicity. 5.Prion diseases. 6.Blood transfusion. 7. Th e designations employed and the presentation of the material in this publication do not imply the expression of any opinion whatsoever on the part of the World Health Organization concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. Dotted lines on maps represent approximate border lines for which there may not yet be full agreement. Th e mention of specifi c companies or of certain manufacturers' products does not imply that they are endorsed or recommended by the World Health Organization in preference to others of a similar nature that are not mentioned. Errors and omissions excepted, the names of proprietary products are distinguished by initial capital letters. All reasonable precautions have been taken by the World Health Organization to verify the information contained in this publication. However, the published material is being distributed without warranty of any kind, either expressed or implied. Th e responsibility for the interpretation and use of the material lies with the reader. In no event shall the World Health Organization be liable for damages arising from its use. iii CONTENTS EXECUTIVE SUMMARY v INTRODUCTION 1 REVIEW OF SCIENTIFIC DEVELOPMENTS 2 Epidemiology, clinical features and diagnostic criteria of Creutzfeldt-Jakob disease (CJD) 2 Bovine spongiform encephalopathy (BSE) and scrapie 3 Diagnosis 4 Risk of transmitting Creutzfeldt-Jakob disease (CJD) and variant CJD (vCJD) by human blood and blood products 5 RECOMMENDATIONS 7 Tissue infectivity 7 Measures to minimize risks to humans from biological and pharmaceutical products in which ruminant materials are used during manufacture 7 Source of starting materials 8 Tissue removal and processing 8 Production systems 9 Vaccines 9 Recombinant DNA Products 10 Other medicinal products 10 Measures to minimize risks to humans from human-derived materials 11 The risk of transmitting variant CJD (vCJD) by blood and blood products 11 Risk assessment 12 Risk-reducing measures 13 Product retrieval and market withdrawal 13 Donor deferral 13 Deferral of transfusion recipients as blood donors 14 Plasma products 14 Appropriate blood usage 14 Other measures 14 Future developments 15 The risk of transmitting vCJD by human cells, tissue and tissue-derived products 15 Annex 1: Major categories of infectivity (human TSEs, …