Advances in PARASITOLOGY VOLUME 41 Editorial Board C. Bryant Division of Biochemistry and Molecular Biology, The Australian National University, Canberra, ACT 0200, Australia M. Coluzzi Director, Istituto di Parassitologia, Universita Degli Studi di Roma “La Sapienza”, P. le A. Moro 5, 00185 Roma, Italy C. Combes Laboratoire de Biologie Animale, Universite de Perpignan, Centre de Biologie et d’Ecologie Tropicale et Mediterrankenne, Avenue de Villeneuve, 66860 Perpignan Cedex, France S.L. James Chief, Parasitology and Tropical Diseases Branch, Division of Microbiology and Infectious Diseases, National Institute for Allergy and Infectious Diseases, Bethesda, MD 20892-7630, USA W.H.R. Lumsden 16A Merchiston Crescent, Edinburgh EHlO 5AX, UK Lord Soulsby of Swaffham Prior Department of Clinical Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 OES, UK K. Tanabe Laboratory of Biology, Osaka Institute of Technology, 5-16-1 Ohmiya, Asahi-Ku, Osaka 535, Japan P. Wenk Falkenweg 69, D-72076 Tubingen, Germany Advances in PARASITOLOGY Edited by J.R. BAKER Royal Society of Tropical Medicine and Hygiene, London, England R. MULLER International Institute of Parasitology, St Albans, England and D. ROLLINSON The Natural History Museum, London, England VOLUME 41 ACADEMIC PRESS San Diego London Boston New York Sydney Tokyo Toronto ACADEMIC PRESS 525 B Street, Suite 1900, San Diego, California 92101495, USA http://www.apnet.com ACADEMIC PRESS 24-28 Oval Road LONDON NWI 7DX http://www.hbuk.co.uWap/ Copyright 0 1998, by ACADEMIC PRESS 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 retrieval system, without permission in writing from the publisher A catalogue record for this book is available from the British Library ISBN 0-12-031741-9 Typeset by J&L Composition Ltd, Filey, North Yorkshire Printed in Great Britain by MPG, Bodmin, Cornwall 98 99 00 01 02 03 MP 9 8 7 6 5 4 3 2 1 CONTRIBUTORS TO VOLUME 41 T.J.C. ANDERSON, Wellcome Trust Centre for Epidemiology of Infectious Disease, Department of Zoology, South Parks Road, Oxford, OX1 3PS, UK R.M. BEECH, Institute for Parasitology, 21111 Lakeshore Road, Ste-Anne de Bellevue, Quebec, H9X 3 V9, Canada R.G. BELL, James A. Baker Institute for Animal Health, College of Veter- inary Medicine, Cornell University, Ithaca, N Y 14853, USA M.S. BLOUIN, Department of Zoology, Cordley Hall 3029, Oregon State University, Corvallis, OR 97331-2714, USA D.W.T. CROMPTON, WHO Collaborating Centre for Soil-transmitted Helminthiases, University of Glasgow, Glasgow, GI2 8QQ, Scotland, UK J. DE BOW, Department of Parasitology, Faculty of Veterinary Medicine, University of Gent, Salisburylaan 133, 9820 Merelbeke, Belgium Y. NAKAMURA, Department of Tumor Biology, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108, Japan W. PETERS, CABI Bioscience, Tropical Parasitic Diseases Unit, 395a Hatjield Road, St Albans, Herflordshire, AL4 OXU UK J. VERCRUYSSE, Department of Parasitology, Faculty of Veterinary Medicine, University of Gent, Salisburylaan 133, 9820 Merelbeke, Belgium M. WADA, Department of Tumor Biology, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108, Japan PENG WEIDONG, Department of Parasitology, Jiangxi Medical College, Nanchang, Jiangxi 330006, People’s Republic of China ZHOU XIANMIN, Department of Parasitology, Jiangxi Medical College, Nanchang, Jiangxi 330006, People’s Republic of China This Page Intentionally Left Blank This volume commences with a review of the current situation concerning drug-resistant malaria by Wallace Peters, currently working in the Tropical Parasitic Diseases Unit of CAB1 Bioscience in St Albans, UK (formerly the Institute of Parasitology). Professor Peters is universally acknowledged to be one of the, if not the, world expert(s) on this topic, and his monograph Chemotherapy and Drug Resistance in Malaria (published by Academic Press in 1970 and, as the revised second edition, again in 1987) is the malaria chemotherapists’ ‘bible’. In the first edition, Peters cited Paul Ehrlich’s warning that trypanosomes would probably become resistant to any new drug and presciently predicted that ‘The same maxim may equally well be applied to the malaria parasite.’ This prediction has proved only too true, and it is entirely appropriate that Peters should bring malariol- ogists up to date with this scholarly and wide-ranging review of the current situation which includes among its many references several dated 1997 and even, in the addendum, one published in 1998. The author concludes that ‘The goal of eradicating malaria is probably no longer realistic . . . all we can do is to try to keep one step ahead of the parasites.’ This review should contribute to the realization of that hope. The second review in this volume, by Yoshikazu Nakamura and Miki Wada of the Tokyo University Institute of Medical Science, deals with that still rather enigmatic organism, Pneumocystis carinii. Propelled, sad to say, in the course of a decade or two into the front rank of pathogenic micro- organisms by the advent of the AIDS pandemic, P. carinii remains taxo- nomically somewhere in limbo between protista and fungi, being probably (as Nakamura and Wada argue) ‘much more closely related’ to the latter. The review covers all aspects of the molecular biology of the organism, to our knowledge of which the authors have made very considerable contri- butions, with emphasis on the surface glycoproteins and the genes control- ling their production. l? carinii was originally thought by Carlos Chagas to be a stage in the life cycle of the trypanosomes subsequently named after him, and it is perhaps ironic that the parasite shares with some other species of trypanosomes the ability to switch these antigens and thus, to some extent, escape the host’s immune response (a feature not known in other fungi). The authors predict rapid advances in our understanding of ... Vlll PREFACE this and other aspects of the pathobiology of the parasite in the not-too- distant future as a result of the hoped-for achievement of a reliable in vitro culture system and the sequencing of the organism’s entire genome. China has about one-quarter of the world’s population but little is known about the present status of ascariasis in the country. This is due to two reasons: the first in that until recently there were considered to be more important priorities in health care; the second is that all the literature has been in Chinese. This review by Peng Weidong and Zhou Xianmin (Jianxi Medical College, China) and David Crompton (University of Glas- gow, UK) attempts to answer the questions of what is the scale of disease in China, how is it distributed geographically and demographically, what is the pattern of infection and whether it follows that in other countries. Most of the literature cited is in Chinese. More that half the population is estimated to be infected, mostly in rural populations and particularly in the south-east. There is a close relationship with pigs in China and the possible degree of cross-infection is discussed. The need for a test to identify the source of eggs in the soil is stressed. There have been numerous studies on immunity to Trichinella spiralis in laboratory rodents and this field is comprehensively reviewed by Robin Bell (Cornell University, USA). He separates immunological work into two broadly defined periods, that before 1970 and the wealth of more recent studies. However, as he points out, some of the earlier work was virtually ignored until rediscovered later. The most recent researches have concen- trated particularly on helping to explain the basic immunological precepts governing the Thl and Th2 models of CD4 cell function. Antibody responses, which have been neglected in recent years, are now being given the most important role in protection. The author believes that there is a need to define the novel parasite-specific mechanisms of protection by investigating the parasite’s biology and host responsiveness, rather than relying completely on basic immunological knowledge and applying it to immunoparasitology. Drawing on their extensive experience of animal parasitic nematodes, Tim Anderson (Wellcome Trust Centre for Epidemiology of Infectious Disease, Oxford, UK), Michael Blouin (Oregon State University, USA) and Robin Beech (Institute of Parasitology, Quebec, Canada) consider the use of genetic markers to unravel the population biology of parasitic nematodes. This is an area of parasitology where there has been consider- able progress in recent years. The authors first pose the question: How variable are nematode parasites? The answer can be found by comparing patterns of variation in different genes and by making comparisons with other groups of organisms. The population structure of nematode popula- tions has wide implications concerning the epidemiology of disease and interesting insights are presented into aspects of transmission and mating PREFACE ix systems. Further sections deal with the use of genetic markers in the study of sibling species, host affiliation and hybridization and the ways in which genetic markers can contribute to the unravelling of parasite life cycles. The uses of genetic markers in the study of drug resistance are carefully reviewed and emphasis given to the monitoring of drug resistance in populations. Finally research areas, such as antigen evolution and intra- host dynamics, have been identified which are likely to benefit from increas- ing genetic analysis in future years. The final chapter in this volume is a comprehensive review of cattle schistosomiasis by Jan De Bont and Jozef Vercruysse (Faculty of Veter- inary Medicine, University of Gent, Belgium). Both authors are well quali- fied to review this topic and the chapter reflects their extensive field and laboratory experience in relation to cattle schistosomes. It is difficult to quantify losses caused by cattle schistosomiasis, but it is well recognized that the disease can be of veterinary significance in certain parts of the world and there are problems in terms of treatment and control. The authors consider many aspects of the biology and epidemiology of cattle schistosomiasis, the pathology and pathophysiology of infection, diagnosis, and treatment and control. It is increasingly being realized that cattle schistosomiasis may provide a natural animal model for the study of immunity against human schistosome infection and the dynamics of trans- mission, and this contribution should be of value to all workers on schis- tosomiasis. J.R. Baker R. Muller D. Rollinson