For Medical Laboratory Technology Students

[Pages:284]LECTURE NOTES

For Medical Laboratory Technology Students

Parasitology

Girma Mekete Mohamed Awole Adem

Jimma University

In collaboration with the Ethiopia Public Health Training Initiative, The Carter Center, the Ethiopia Ministry of Health, and the Ethiopia Ministry of Education

January 2003

Funded under USAID Cooperative Agreement No. 663-A-00-00-0358-00.

Produced in collaboration with the Ethiopia Public Health Training Initiative, The Carter Center, the Ethiopia Ministry of Health, and the Ethiopia Ministry of Education.

Important Guidelines for Printing and Photocopying Limited permission is granted free of charge to print or photocopy all pages of this publication for educational, not-for-profit use by health care workers, students or faculty. All copies must retain all author credits and copyright notices included in the original document. Under no circumstances is it permissible to sell or distribute on a commercial basis, or to claim authorship of, copies of material reproduced from this publication. ?2003 by Girma Mekete and Mohamed Awole Adem All rights reserved. Except as expressly provided above, no part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without written permission of the author or authors.

This material is intended for educational use only by practicing health care workers or students and faculty in a health care field.

Parasitology

1

Preface

The problem faced today in the learning and teaching of Parasitology for laboratory technicians in universities, colleges, health institutions, training health centers and hospitals emanates primarily from the unavailability of textbooks that focus on the needs of Ethiopian students. This lecture note has been prepared with the primary aim of alleviating the problems encountered in the teaching of Medical Parasitology course and in minimizing discrepancies prevailing among the different teaching and training health institutions. It can also be used in teaching any introductory course on medical parasitology and as a reference material.

This lecture note is devoted to providing general aspects of parasitology in addition to covering human parasites in two major groups -the protozoa and helminths- including their distribution, habitat, morphology, life cycle, pathogenicity, prevention and control, laboratory diagnosis and their relevance to Ethiopia. It has also appendices, which discuss the collection of laboratory specimens, preservatives of stool sample, frequently used parasitological diagnostic methods and reagent preparation. Finally, it contains a glossary, which summarizes important terminologies used in the text. Each chapter begins by specific learning objectives and after each objective and after each class of parasites review questions are also included.

No systemic study has been conducted on the prevalence of human parasites in different ecological zones of Ethiopia but past surveys indicate the presence of all parasites except some that are found in the Far East, South East Asian and Latin American countries and which require specific intermediate hosts. This lecture note tries as far as possible to summarize local literatures that deal with parasite prevalence

Parasitology

2

in Ethiopia so that it may address itself particularly to the needs of Ethiopian students.

We welcoming the reviewers and users input regarding this edition so that future editions will be better.

Parasitology

3

Acknowledgments

We would like to acknowledge The Carter Center for its initiative, financial, material and logistic supports for the preparation of this teaching material. We are indebted to The Jimma University and other institutions that support directly or indirectly for the visibility of this lecture note preparation.

Our deepest gratitude to Professor Dennis Carlson with out whom these lectures note preparation is not visible. We greatly thank him for his attitude, knowledge, and practice and above all his commitment, concern and dedication toward solving the health problem of Ethiopia.

We extend our appreciation to the reviewers and teaching staffs in the different institution for their unreserved contribution for the materialization of this lecture note preparation.

Parasitology

4

Contents

I. Preface II. Acknowledgement III. Overview III. General objectives

i ii

iii v

CHAPTER ONE - INTRODUCTION

1

1.1 Definition of terms used in parasitology1

1.2 Sources of exposure to

parasitic infections

5

1.3 Mode of transmission

6

1.3.1 Direct mode of transmission 6

1.3.2 Indirect mode of transmission 7

1.4

Route of transmission

7

1.5

Host parasite relationship

8

1.5.1 Effects of parasites on

there hosts

8

1.5.2 Host susceptibility factors

8

1.5.3 Escape mechanism of the parasite

from the immune system

1.6 General life cycle of parasites

9 1.6.1

Direct life cycle

9

1.6.2 Indirect life cycle

9

1.7 Types of specimen used for

parasitological examination

9

1.8 Classification of Parasites

10

1.9 Major differences between parasitic

Parasitology

protozoa and metazoa

11

CHAPTER TWO - MEDICAL PROTOZOOLOGY13

2.1 Class- Rhizopoda ( Amoebae)

2.1.1Free living amoeba

11

Free living pathogenic amoebae 28

2.2 Class - Zoomastigophora ( Flagellates)32

2.2.1 The Oro-intestinal and Urogenital

flagellates

32

2.2.2 The Haemo-Somatic Flagellates 45

2.3. Class -Telosporidia

63

2.3.1 Intestinal and tissue

Coccidian Parasite

64

2.3.2 Haemosporidia

72

2.4 Class -Ciliatea ( Ciliates)

87

CHAPTER THREE -MEDICAL

HELMINTHOLOGY

91

3.1 Platyhelminths

92

3.1.1 Class cestoda (tapeworm)

92

3.1.2 Class trematodes(flukes)

3.1.2.1 Blood Flukes

(Schistosmes)

115

3.1.2.2 Liver Flukes

131

3.2.2.3 Intestinal Flukes 139

3.2.2.4Lung Flukes

142

3.2. Nemathelminths

145

3.3.1. Class Nematoda

145

3.3.1.1Intestinal nematodes 145

5

2.1.2

Parasitology

6

3.3.1.2. Tissue nematodes

168

Appendix I

- Laboratory Examination of

Specimens

191

A. Stool

193

B. Urine

206

C. Vaginal and urethral discharge

208

D. Blood

209

E. Skin

216

F. The Gram scotch

217

Appendix II - Preservatives of specimens

219

Glossary

228

Bibliography

241

 ................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download