V E T E R I N A R Y V I R O L O G Y Third Edition This Page Intentionally Left Blank VETERINARY VIROLOGY Third Edition Frederick A. Murphy School of Veterinary Medicine University of California, Davis Davis, California E. Paul J. Gibbs College of Veterinary Medicine University of Florida Gainesville, Florida Marian C. Horzinek Faculty of Veterinary Medicine Utrecht University Utrecht, The Netherlands Michael J. Studdert School of Veterinary Science University of Melbourne Melbourne, Victoria, Australia An Imprint of Elsevier San Diego London Boston New York Sydney Tokyo Toronto Cover illustration: Rabies encephalitis. Two hallmarks of street rabies virus infection are minimal cytopathology of infected neurons and minimal inflammatory infiltration into the neuropil. Here, in a thin section of part of the cytoplasm of a neuron in the hippocampus of a hamster inoculated intracerebrally 6 days earlier with a street rabies virus, the architecture of cellular organelles appears nonlaal, but some of the cytosol has been displaced by aggregated viral nucleocapsids (smoothly granular areas; seen by light microscopy as Negri bodies). Large numbers of bullet-shaped virions are evident budding from adjacent endoplasmic reticulum membranes. Thin-section electron microscopy; uranyl acetate and lead citrate stain; magnification X 25,000. This book is printed on acid-free paper. ~) All Rights Reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic, or mechanical, including photocopy, recording, or any information storage and retreival system, without permission in writing from the publisher. Permissions may be sought directly from Elsevier'sS cience & TechnologyR ights Department in Oxford, UK; phone: (44) 1865 843830, fax: (44) 1865 853333, email: [email protected]. You may also complete your request on-line via the Elsevier homepage: http://www.elsevier.com,b y selecting "Customer Support" and then "Obtaining Permissions". Academic Press An Imprint of Elsevier 525 B Street, Suite 1900, San Diego, California 92101-4495, USA http://www.academicpress.com Academic Press Harcourt Place, 32 Jamestown Road, London NWl 7BY, UK http://www, academicpress.com Library of Congress Catalog, Card Number: 99-60582 ISBN-13:978-0-12-511340-3 ISBN-10:0-12-511340-4 PRINTED IN THE UNITED STATES OF AMERICA 06 07 08 QW 9 8 7 6 This book is dedicated to our dear friends, Frank J. Fenner and David O. White, the founders of the series of books that now includes three editions of this book and four editions of "Medical Virology." They set a standard of scholarship that is impossible to match and a joie de vivre that made the Writing and editing almost fun. They taught us that the subject of virology must be seen within the context of society as a whole as well as within the context of science. They envisioned virology as being so broad as to extend from its roots as a microbiological science, a molecular and cell biological science, an infectious disease science, to become a major contributor to the overall advance of human and animal well-being. All this as a single seamless cloth. We hope our students will come to understand the "big picture" of veterinary and medical virology as well as Frank and David have throughout their amazing careers. We would also like to dedicate this book to our families, our teachers and mentors, and our students, all of whom have shaped our thinking and provided our inspiration over the years in so many ways. Frederick A. Murphy E. Paul J. Gibbs Marian C. Horzinek Michael J. Studdert This Page Intentionally Left Blank CONTENTS Dedication V Preface ix II PART I: PRINCIPLES oF VIROLOGY 1. The Nature of Viruses as Etiologic Agents of Veterinary and Zoonotic Diseases 2. Viral Taxonomy and Nomenclature 23 3. Viral Replication 43 4. Viral Genetics and Evolution 61 5. Virus-Cell Interactions 81 6. Mechanisms of Infection and Viral Spread through the Body 93 7. Determinants of Viral Virulence and Host Resistance / Susceptibility 111 8. Immune Response to Viral Infections 127 9. Pathogenesis of Viral Diseases" Viral Strategies and Host Defense Mechanisms 145 10. Pathogenesis of Viral Diseases" Representative Model Diseases 161 11. Mechanisms of Viral Oncogenesis 177 12. Laboratory Diagnosis of Viral Diseases 193 13. Vaccination against Viral Diseases 225 14. Epidemiology of Viral Diseases 245 15. Surveillance, Prevention, Control, and Eradication of Viral Diseases 259 PART II: VETERINARY AND ZOONOTIC VIRAL DISEASES 16. Poxviridae 277 17. Asfarviridae and Iridoviridae 293 18. Herpesviridae 301 19. Adenoviridae 327 20. Papovaviridae 335 21. Parvoviridae 343 vii viii Contents 22 Circoviridae 357 23 Retroviridae 363 24 Reoviridae 391 25 Birnaviridae 405 26 Paramyxoviridae 411 27 Rhabdoviridae 429 28. Filoviridae 447 29. Bornaviridae 455 30. Orthomyxoviridae 459 31. Bunyaviridae 469 32. Arenaviridae 485 33. Coronaviridae 495 34. Arteriviridae 509 35. Picornaviridae 517 36. Caliciviridae 533 37. Astroviridae 543 38. Togaviridae 547 39. Flaviviridae 555 40. Prions" Agents of Transmissible Spongiform Encephalopathies 571 41. Other Viruses" Hepadnaviridae, Deltavirus 581 42. Viral Diseases by Animal Species 585 Glossary 601 Index 615 PREFACE The aim of "Veterinary Virology" is to present thology and immunity, their laboratory diagnosis, and the fundamental principles of virology to students of their epidemiology, prevention, and control. veterinary medicine and related medical, biomedical, In order to focus on major virologic concepts and ecological, environmental, and comparative medical sci- mechanisms that form the bases for our understanding ences. It will also serve as a useful resource for clinicians, of specific clinical diseases, minutiae have been omitted teachers, and those involved in research in many related and much of the factual information is consolidated into fields of comparative medicine. The pace of change since tables and figures. Likewise, statements are not individu- the previous edition has been so great that the book ally supported by citation of research papers; however, has been completely rewritten and greatly expanded. selective lists of authoritative books, reviews, and some Coverage of zoonotic viruses and the diseases they cause key recent papers are provided at the end of each chapter has been expanded as has coverage of the viruses and to simplify the reader's entry into the virologic and infec- viral diseases of laboratory animals, poultry, fish, and tious disease literature. wildlife. We have tried to weave the concept of new, The pattern of producing "Veterinary Virology" emerging, and reemerging viral diseases into the fabric and its companion volume "Medical Virology" involves of the book, reflecting the new perspective this concept alternating research, writing and editing between the has brought to veterinary and zoonotic virology and two, with the authors' sense of the advances in the related fields. science pertaining to veterinary medicine being incor- The arrangement of the previous editions has been porated into one volume and at the same time into retained, but our account of the molecular biology of the files from which the next volume pertaining to viral infections is much more detailed and more thor- human medicine is initiated; and, then, vice versa. Of oughly integrated into the overall subject. Similarly, our course, this system pertains mostly to Part I and to account of viral genetics, phylogeny, and evolution has the first part of each chapter in Part II of each book. been expanded and has become a more integral part of We believe that this cross-fertilization between the the book. This, of course, is built on accurate and up- veterinary and human medical sciences is a valuable to-date viral taxonomic usage. The classification and and unique aspect of these volumes and a useful nomenclature decisions of the International Committee foundation for the concept of comparative medicine. on Taxonomy of Viruses, to May 1998, have been incor- Comparative medicine, in our view, is a powerful porated in this new edition. impetus in advancing both human and animal health. Part I presents an overview of the principles of Thus, this book has as its base the fourth edition of animal virology, starting with the viruses themselves and "Medical Virology" published in 1994. In turn, this progressing to the infections they cause at the level of volume will serve as a foundation for the fifth edition the cell, the individual animal host, and the host popula- of "Medical Virology." tion. The emphasis is on pathogenesis, that is the events We would like to acknowledge the help of the in the war between virus and host that we see as acute, many colleagues who in so many ways have helped us chronic-persistent, and more subtle forms of disease. Our in preparing this book: this has ranged from discussions focus on pathogenesis naturally leads to emphasis on on the qualities and shortcomings of the earlier editions subjects pertaining to the host response to infection and and expectations for this edition, to the provision of new to the means of intervening in the course of infection: information from ongoing research work, to insights immunology, diagnostics, vaccinology, epidemiology, into the future of the science and its integration into prevention, and control. clinical practice. We also acknowledge the help of many Part II is arranged by virus family, with major colleagues with the illustrations used throughout this subsections in each chapter providing more specific in- book. Without all this help we would not have had the formation about the viruses, their classification, their incentive to revise the book to the extent that we hope molecular properties and their replication, and on the is evident. In this regard, we would also like to acknowl- important veterinary and zoonotic diseases caused by edge the help of Our teachers and our students who specific viruses. The diseases are covered from the per- in their own ways have provided life-long incentives. spective of their clinical features, their pathogenesis, pa- Veterinary students, graduate students, and postdoctoral /x