Trypanosoma brucei rhodesiense
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invertebrate host) takes a blood meal and injects the infective metacyclic invertebrate metacyclic trypomastigotes. (2) Injected metacyclic trypomastigotes transform into trypomastigotes and are carried to other sites via blood stream. ( 3) Trypomastigotes multiply by binary fission. (4) Trypomastigotes are found in blood extracellular extracellular.. ( 5) Trypomastigotes in the blood are ingested by tsetse fly and transform into procyclic trypomastigotes in the midgut of the fly (6 ). ). (7–8) Procyclic trypomastigotes transform into epimastigotes before transforming into metacyclic trypomastigotes in the fly’s salivary salivary gland. Modes of transmission are via bite of infected tsetse fly and congenital transmission. It is endemic in scattered foci in West West and Central Africa.
Pathogenesis and Clinical Features Trypanosoma brucei gambiense causes African trypanosomiasis (West African sleeping sickness). The illness is chronic and can persist for fo r many years. There is an initial period of parasitaemia, followed by localization of parasites in the lymph nodes. A painless chancre appears on the skin at the site of bite by tsetse fly, followed by fever, chills, rash, anaemia and weight loss. There is high levels of immunoglobulins mainly IgM. Patient presents with hepatosplenomegaly and lymphadenopathy, particularly in the posterior cervical region (Winterbottom’s sign). Invasion of CNS occurs after several months later and is marked by increasing headache, mental dullness, apathy and daytime sleepiness. The patient may fall into coma followed by death from other infections and physical weakness. Histopathology examination of the brain shows chronic meningoencephalitis. The meninges are heavily infiltrated with lymphocytes, plasma cells and morula cells (atypical plasma cells containing mulberry-shaped masses of IgA). Vessels in the brain show perivascular perivascular cuffing. There is cellular infiltration of the brain and spinal cord, neuronal degeneration and microglial proliferation. Intracranial pressure is raised and CSF shows sh ows pleocytosis with increased protein.
Antigenic Variation Trypanosomes exhibit antigenic variation of their glycoproteins. There is a cyclical fluctuation in the trypanosomes in the blood of infected vertebrates. Trypanosomes have many variant surface glycoprotein (VSG) genes that help to evade immune response.
Trypanosoma brucei rhodesiense Distribution It is found in Eastern and Central C entral Africa. Africa. The principal vectors are Glossina morsitans, Glossina palpalis and Glossina swynnertoni. It is a zoonotic disease, with the reservoir hosts being game and domestic animals. It is usually transmitted by the
Medical Parasitology
Rohela Mahmud Yvonne Yv onne Ai Lian Lim • Amirah Amir
Medical Parasitology A Text Textboo book k
Rohela Mahmud Fac. of Medicine, Dept. of Parasitology University of Malaya Kuala Lumpur, Malaysia
Yvonne Ai Lian Lim Fac. of Medicine, Dept. of Parasitology University of Malaya Kuala Lumpur, Malaysia
Amirah Amir Fac. of Medicine, Dept. of Parasitology University of Malaya Kuala Lumpur, Malaysia
ISBN 978-3-319-68794-0 ISBN 978-3-319-68795-7 https://doi.org/10.1007/978-3-319-68795-7
(eBook)
Library of Congress Control Number: 2017961316 © Springer International Publishing AG 2017 This work is subject to copyright. co pyright. All rights are reserved by the Publisher, Publish er, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, warranty, express or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. Printed on acid-free paper This Springer imprint is published by Springer Nature The registered company is Springer International Publishing AG The registered company address is: Gewerbestrasse 11, 6330 Cham, Switzerland
Foreword
My heartfelt congratulations congratulation s to the authors, Professor Dr. Rohela Mahmud, Professor Dr. Yvonne Ai-Lian Lim and Dr. Amirah Amir, for bringing out this textbook on medical parasitology. Why you may ask another textbook on medical parasitology when so many already exist? The answer is simple. Most of the textbooks until recently have been written by western authors on an academic slant without considering the actual reality and needs of students and researchers in endemic countries of Asia-Pacific or other regions. As the authors rightly point out, the study of medical parasitology is indeed daunting to the uninitiated, and this book aims to promote an easy yet comprehensive way of learning the subject. Like the authors, I have been teaching medical parasitology to medical and nonmedical students in Malaysia as well as in Southeast Asia for the past four decades, and there was no “one” reference book that I could recommend to students on issues related to parasitic infections in the Asia-Pacific Asia-Pacific and in particular the south-east region. This book—well written and comprehensive—fills that gap. It will be a useful book not just to medical students but to medical scientists, clinicians, veterinary scientists, biologists, researchers and public health workers in tropical trop ical medicine. This book integrates available information on parasitic diseases in the AsiaPacific region through reader-friendly illustrations, case reports, diagnostic methodologies, treatment and preventive methods. With the emphasis given on the global elimination of neglected tropical diseases (NTD) by the World Health Organization (WHO) which affects millions of people, especially the poor in the developing world, I hope this book will help to contribute knowledge towards prevention, control, treatment and elimination of parasitic diseases in this region as well as globally. Once again, my congratulations to the authors in bringing out this book at this timely moment. Emeritus Dato Dr. C.P. Ramachandran Academician Professor Retired Chief of Filariasis Research and Control World Health Organization Geneva, Genev a, Switzerland
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