Advances in PARASITOLOGY VOLUME 27 Editorial Board W. H. R. Lumsden University of Dundee Animal Services Unit, Ninewells Hospital and Medical School, P.O. Box 120, Dundee DDI 9SY, UK P. Wenk Tropenmedizinisches Institut, Universitat Tubingen, D7400 Tubingen 1, Wilhelmstrasse 3 1, Federal Republic of Germany C. Bryant Department of Zoology, Australian National University, G.P.O. Box 4, Canberra, A.C.T. 2600, Australia E. J. L. Soulsby Department of Clinical Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 OES, UK K. S. Warren Director for Health Sciences, The Rockefeller Foundation, 1133 Avenue of the Americas, New York, N.Y. 10036, USA J. P. Kreier Department of Microbiology, College of Biological Sciences, Ohio State University, 484 West 12th Avenue, Columbus, Ohio 43210-1292, USA M. Yokogawa Department of Parasitology, School of Medicine, Chiba University, Chiba, Japan Advances in PARASITOLOGY Edited by J. R. BAKER Cambridge, England and R. MULLER Commonwealth Institute of Parasitology St. Albans, England VOLUME 27 1988 ACADEMIC PRESS Harcourt Brace Jovanovich, Publishers London San Diego New York Boston Sydney Tokyo Toronto ACADEMIC PRESS LIMITED 24/28 Oval Road LONDON NW 1 7DX United States Edition published by ACADEMIC PRESS INC. San Diego, CA 92101 Copyright 0 1988, by ACADEMIC PRESS LIMITED All Rights Reserved No part of this book may be reproduced in any form by photostat, microfilm, or any other means, without written permission from the publishers British Library Cataloguing in Publication Data Advances in parasitology.-Vol. 27 1. Veterinary parasitology 591.2'3 SF810.A3 ISBN Cb12-031727-3 ISSN 0065-308X Typeset by Latimer Trend and Company Ltd, Plymouth, England Printed in Great Britain by Galliard (Printers) Ltd, Great Yarmouth CONTRIBUTORS TO VOLUME 27 B. FRIED,Department of Biology, Lafayette College, Easton, Pennsylvania 18042, USA M. A. HASEEB,Department of Microbiology and Immunology, State Univer- sity of New York Health Science Center, Brooklyn, New York 11203, USA R. W. LEID,Laboratory of Molecular and Biochemical Inflammation, Depart- ment of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA 99164-7040, USA A. J. LYMBERY,Division of Veterinary Biology, School of Veterinary Studies, Murdoch University, Murdoch, Western Australia 6150 J. F. G. M. MEIS,Department of Medical Parasitology, St RadboudHospital, University of Nijmegen. Nijmegen, The Netherlands R. C. A. THOMPSON,Division of Veterinary Biology, School of Veterinary Studies, Murdoch University, Murdoch, Western Australia 6150 S. TZIPORI,Department of Microbiology, Royal Children’s Hospital, Mel- bourne 3052, Australia J. P. VERHAVE,Department of Medical Parasitology, St Radboud Hospital, University of Nijmegen, Nijmegen, The Netherlands This Page Intentionally Left Blank PREFACE In this volume, as in others, we hope that there will be something to interest everyone. The volume starts with two reviews concerning protozoa; that by Dr Meis and Dr Verhave, distinguished by its superb electron micrographs, presents a very full picture (literally) of the erstwhile “cryptic” exoerythro- cytic schizont of Plasmodium. Dr Tzipori’s contribution is particularly timely because of the recent surge of interest in Cryptosporidium as an “opportun- . istic” parasite of immunocompromized persons, including those unfortunate enough to be infected with human immunodeficiency virus. Then follow two chapters of more general interest, though with a leaning towards helmintho- logy-that by Dr Leid on the interaction between parasites and their hosts’ complement system, and that by Dr Haseeb and Dr Fried dealing with the problems of chemical communication between parasitic worms. Finally, there is Dr Thompson’s and Dr Lymbery’s contribution on a rather more restricted, though no less interesting, subject-subspecific variation in Echinococcus. This is a topic of growing interest with many parasitic genera, helminths and protozoa, because of the availability now of a range of new techniques of what is rather loosely referred to as “molecular taxonomy”. These techniques are introducing a whole new dimension into parasite taxonomy, and it seems likely that this will not be the last contribution concerning this subject to appear in Advances in Parasitology. 1987 J. R. BAKER R. MULLER This Page Intentionally Left Blank CONTENTS CONTRIBUTORSTO VOLUME27.. v PREFACE... vii Exoerythrocytic Development of Malarial Parasites J. F. G. M. MEIS AND J. P. VERHAVE I. Introduction.. 1 11. Historical Survey.. 4 111. Morphology of Exoerythrocytic Development . 7 IV. Metabolism of Exoerythrocytic Forms.. 39 V. Culture of Exoerythrocytic Forms in vitro.. 43 VI. Final Remarks.. .......... , ........... ..... 47 Acknowledgements.. 49 . ... ... ... .. .... .. .. 50 Cryptosporidiosis in Perspective S. TZIPORI I. Introduction . .. .... .. 63 . 64 111. Life-cycle and Ultrastructure . 67 IV. The Infection in Humans ........................................ 82 V. The Infection in Other Animals.. 99 VI. Laboratory Investigation. ... .. 110 VII. Treatment and Control . .. ... ......... 117 VIII. Summary and Conclusions . ........... ......... 118 Acknowledgements. 120 References. .... 120 Parasites and Complement R. W. LEID I. Introduction.. 131 11. The Complement Cascade.. 133 111. Classical Pathway.. 133 X CONTENTS IV. Alternative Pathway.. ........................................... 134 V. Parasites and Complement ....................................... 135 VI. Conclusions .................................................... 157 Acknowledgements. ............................................. 158 References. ..................................................... 158 Chemical Communication in Helminths M. A. HASEEB AND B. FRIED I. Introduction ....................... 11. Terminology. ............... ............... 172 111. Chemoattraction Bioassays. .. ...................... 173 IV. Chemical Nature of Helminth Pheromones. ............... 180 V. Structures Involved in the Production and Release of Pheromones. ... 183 VI . Receptors and Chemoreception ... ............ VII. Specific Organisms .............................. VIII. Site-finding Behavior ............................ IX . Analytical Techniques Used in Studies of Chemical Communication. 194 X. Concluding Remarks and Future Prospects . ........................... The Nature, Extent and Significance of Variation Within the Genus Echinococcus R. C. A. THOMPSON AND A. J. LYMBERY ................................................. 210 11. Taxonomy.. ...................... 111. Beyond Taxonomy: Variation Within IV. Intraspecific Variation and Speciation ............................. 23 1 f Strain Variation ................ VI. Conclusion ........................................... 247 .......... ...... ............... 248 References. ........................... 248 INDEX ............................................................ 259 Exoerythrocytic Development of Malarial Parasites* J. F. G. M. MEIS AND J. P. VERHAVE Department of Medical Parasitology, St Radboud Hospital, University of Nijmegen, Nijmegen. The Netherlands I. Introduction.. ........................................... 1 11. Historical Survey. ....................................................... 4 111. Morphology of Exoerythrocytic Development .............................. 7 A. Avian Malaria.. ................................................ 7 B. Rodent Malaria ...................................................... 9 C. Primate Malaria ...................................................... 34 1V. Metabolism of Exoerythrocytic Forms. .................................... 39 V. Culture of Exoerythrocytic Forms in vitro.. ... .... 43 A. Avian Malaria ........................................................ 43 B. Rodent Malaria ................................................ 43 C. Primate Malaria.. .................................................... 46 VI. Final Remarks .......................................................... 41 Acknowledgements ... 49 References. ............................................................. 50 I. INTRODUCTION The life-cycle of Plasmodium species is completed when, in the stomach of the insect vector, a uninucleate zygote is formed from male and female gametes present in the bloodmeal. The insect vector is normally a female mosquito (many species of Anopheles and, for lizard and bird malaria, culicine mosquitoes). The zygote, now called an ookinete, is active and moves through the stomach or midgut wall. The parasite becomes localized under the lining of the gut and transforms into an oocyst. This multiplication stage produces thousands of infective sporozoites which become concentrated in the salivary glands and so are in a favourable position to enter the vertebrate host when the mosquito takes a new *Dedicated to P. C. C. Garnham FRS, Emeritus Professor of Medical Protozoology in the University of London. ADVANCES IN PARASITOLOGY VOL. 27 Cupvrighr 0 1988 Aca&mic Press Limired ISBN &124)31727-3 A// rights of repprodurtiun in any form reserved. 2 J. F. G. M. MEIS AND J. P. VERHAVE bloodmeal. After introduction of the sporozoites into the bloodstream, a series of cycles begins that involves different cells and tissues depending on the parasite species and host. The mammalian malaria parasites may enter various tissue cells, but develop solely in liver parenchymal cells, whereas the sporozoites of avian species develop in fixed macrophages. It is now recognized that sporozoites of mammalian