《医学寄生虫学（英文改编版，第2版）》邀请境内外60多位专家教授参与了《医学寄生虫学（英文改编版，第2版）》的改编工作。绝大多数编委都有境外学习进修和工作的经历，他们既有扎实的专业知识，又有较好的英文阅读理解和写作能力，以及丰富的一线教学经验。《医学寄生虫学（英文改编版，第2版）》以麦格劳-希尔教育出版公司授权的“Foundation of Parasitology”第9版为蓝本，结合国内医学教学的实际情况加以改编。《医学寄生虫学（英文改编版，第2版）》包括总论、原虫学、吸虫学、绦虫学、线虫学和节肢动物学共41章。

Chapter 1 Introduction to Parasitology
Few people realize that there are far more kinds of parasitic than nonparasitic organisms in the world. Even if we exclude viruses and rickettsias， which are all parasitic， and the many kinds of parasitic bacteria and fungi， parasites are still in the majority. Organisms that are not parasites are usually hosts. Humans， for example， can be infected with more than a hundred kinds of flagellates， amebas， ciliates， worms， lice， fleas， ticks， and mites. It is unusual to examine a domestic or wild animal without finding at least one species of parasite on or within it. Even animals reared under strict laboratory conditions are commonly infected with protozoa and other parasites. The relationships between parasites and hosts are typically quite intimate， biochemically speaking. It is no wonder that the science of parasitology has developed out of efforts to understand parasites and their relationships with their hosts.
1 RELATIONSHIP OF PARASITOLOGY TO OTHER SCIENCES
The first and most obvious stage in the development of parasitology was the discovery of parasites themselves. Descriptive parasitology probably began in prehistory. Taxonomy as a formal science， however， started with Linnaeus’s publication of the 10th edition of Systema Naturae in 1758. Linnaeus himself is credited with the description of the sheep liver fluke， Fasciola hepatica， and over the next 100 years many common parasites， as well as their developmental stages， were described. The discovery and description of new parasite species continues today， just as does the description of new species in almost every group of organisms. Although biologists have a massive “catalog” of Earth’s biota， this list is far from complete.
Today systematists rely on published species descriptions， as well as on studies of DNA， proteins， ecology， and geographical distribution， to develop phylogenies (singular， phylogeny)， or evolutionary histories， of parasites. On the practical side， an epidemiologist may need to understand sociological and political factors， climate， local traditions， and global economics， as well as pharmacology， pathology， biochemistry， and clinical medicine， to devise a scheme for controlling parasitic infections.
When people became aware that parasites were troublesome and even serious agents of disease， they began an ongoing effort to heal the infected and elim-inate the parasites. Curiosity about routes of infection led to studies of parasite life cycles; thus it became generally understood in the last part of the 19th century that certain animals—for example， ticks and mosquitoes—could serve as vectors that transmitted parasites to humans and their domestic animals. Parasite biology does not differ fundamentally from biology of free-living organisms， and parasite systems have provided outstanding models in studies of basic biological phenomena. In the 19th century van Beneden described meiosis and Boveri demonstrated the continuity of chromosomes， both in parasitic nematodes. In the 20th century refined techniques in physics and chemistry applied to parasites have added to our understanding of basic biological principles and mechanisms. For example， Keilin discovered cytochrome and the electron transport system during his investigations of parasitic worms and insects. Today biochemical techniques are widely used in studies of parasite metabolism， immunology， and chemotherapy. Use of the electron microscope resulted in many new discoveries at the subcellular level. The techniques of modern molecular biology have contributed new diagnostic methods and new knowledge of relationships between parasites， and they offer much hope in the development of new vaccines. Certain parasitic protozoa (for example， trypanosomes) today serve as models for some of the most exciting research in molecular genetics and gene expression.
Historically centered on animal parasites of humans and domestic animals， the discipline of parasitology usually does not include a host of other parasitic organisms， such as viruses， bacteria， fungi， and nematode parasites of plants. Thus， parasitology has evolved separately from virology， bacteriology， mycology， and plant nematology. Medical entomology， too， has branched off as a separate discipline， but it remains a subject of paramount importance to parasitologists， who must understand the relationships between arthropods and the parasites they harbor and disperse.
2 SOME BASIC DEFINITIONS
Parasitology is largely a study of symbiosis， as originally proposed by the German scholar A. de Bary in 1879: Any two organisms living in close association， commonly one living in or on the body of the other， are symbiotic， as contrasted with free living.
2.1 Interactions of Symbionts
1. Phoresis
Phoresis exists when two symbionts are merely “traveling together，”and there is no physiological or biochemical dependence on the part of either particip

CONTENTS Chapter 1 Introduction to Parasitology 1 Chapter 2 Basic Principles and Concepts I: Parasite Systematic， Ecology，and Evolution 7 Chapter 3 Basic Principles and Concepts II: Immunologyand Pathology 17 Chapter 4 Parasitic Protozoa: Form， Function， and Classification 33 Chapter 5 Kinetoplasta: Trypanosomes and Their Kin 45 Chapter 6 Other Flagellated Protozoa 54 Chapter 7 The Amebas 63 Chapter 8 Phylum Apicomplexa: Gregarines， Coccidia，and Related Organisms 76 Chapter 9 Phylum Apicomplexa: Malaria Organisms and Piroplasms 98 Chapter 10 Phylum Ciliophora: Ciliated Protistan Parasites 122 Chapter 11 Microsporidia and Blastocystis Hominis 127 Chapter 12 The Mesozoa: Pioneers or Degenerates? 133 Chapter 13 Introduction to Phylum Platyhelminthes 138 Chapter 14 Trematoda: Aspidobothrea 142 Chapter 15 Trematoda: Form， Function， and Classification of Digeneans 146 Chapter 16 Digeneans: Strigeiformes 156 Chapter 17 Digeneans: Echinostomatiformes 168 Chapter 18 Digeneans: Plagiorchiformes and Opisthorchiformes 175 Chapter 19 Monogenoidea 185 Chapter 20 Cestoidea: Form， Function， and Classification of Tapeworms 189 Chapter 21 Tapeworms 198 Chapter 22 Phylum Nematoda: Form， Function， and Classification 218 Chapter 23 Nematodes: Trichinellida and Dioctophymatida，Enoplean Parasites 227 Chapter 24 Nematodes: Tylenchina， a Functionally Diverse Clade 234 Chapter 25 Nematodes: Rhabditomorpha， Bursate Roundworms 239 Chapter 26 Nematodes: Ascaridomorpha， Intestinal Large Roundworms 251 Chapter 27 Nematodes: Oxyuridomorpha， Pinworms 257 Chapter 28 Nematodes: Gnathostoma Spinigerum， Gongylonema Pulchrum and Thelazia Callipaeda 261 Chapter 29 Nematodes: Filarioidea—Filarial Worms 267 Chapter 30 Nematodes: Dracunculomorpha， Guinea Worms and Others 280 Chapter 31 Phylum Nematomorpha， Hairworms 286 Chapter 32 Phylum Acanthocephala: Thorny-Headed Worms 290 Chapter 33 Phylum Arthropoda: Form， Function， and Classification 296 Chapter 34 Parasitic Crustaceans 317 Chapter 35 Pentastomida: Tongue Worms 321 Chapter 36 Parasitic Insects: Phthiraptera， Chewing and Sucking Lice 323 Chapter 37 Parasitic Insects: Hemiptera， Bugs 332 Chapter 38 Parastic Insects: Fleas， Order Siphonaptera 337 Chapter 39 Parasitic Insects: Diptera， Flies 344 Chapter 40 Parastic Insects: Strepsiptera， Hymenoptera，and Others 358 Chapter 41 Parasitic Arachnids: Subclass Acari， Ticks and Mites 368 Glossary 381