World Class Parasites – serie

Human schistosomiasis is a disease with a rich and well-documented past, and every expectation of an unfortunately long future. These infections were known to the ancient Egyptians and their transmission shows little evidence of slowing down, globally. The good news is that field applicable, and increasingly affordable, chemotherapy has been available for almost 25 years. Using chemotherapy and other means of control, some countries have decreased transmission and made excellent headway against morbidity. The bad news is that the public health problems caused by schistosomiasis are still with us, with the estimated number of cases of schistosomiasis, while shifting geographically, remaining approximately 200 million for the last 30 years. In fact, with the development of field usable ultrasound technology and meta-analyses performed on existing data, there is a new appreciation for the extent of non-lethal morbidity associated with these infections. While the percentage of individuals with severe hepatosplenic disease remains below 10%, recent reassessments of morbidity associated with schistosomiasis indicate that the prevelance of symptoms and the cost in diability-adjusted life years is much greater than was previously, commonly appreciated (Van der Werf, M. J. , et al. 2003, Acta Tropica 86:125-139; Charles H. King, personnel communication). Strong impetus for addressing these issues is provided by the World Health Assembly’s recently passed Resolution 54. 19, which calls for efforts to reduce morbidity caused by schistosomiasis and soil-transmitted helminths in school-aged children, largely through chemotherapy campaigns.

Humans suffer from numerous parasitic foodborne zoonoses, many of which are caused by helminths. The helminth zoonoses of concern in this book are normally limited to diseases of animals which have now become transmissible to humans. In the past these diseases were limited to populations living in low- and middle-income countries, but the geographical limits and populations at risk are expanding and changing because of growing international markets , improved transportation systems, and demographic changes (such as population movements). The World Health Organization (WHO) has estimated that the number of people currently infected with food borne trematodes alone exceeds 41 million, but worldwide the number of people at risk, including those in developed countries, is 750 million. The increasing recognition of the public health significance of these zoonoses, especially their complicated epidemiologies, and their links to poverty, intensification of agriculture, environmental degradation, and lack of tools for control- has been welcome. However, the development of priorities for a national public health system is often a competitive exercise, and the argument for devoting appropriate attention and resources to foodborne parasitic zoonoses is generally handicapped by the lack of good health and economic impact data. The genesis of this book was a desire to draw attention to the problem of these zoonoses and to hopefully, inspire greater efforts to acquire a reliable global impact assessment and therefore a basis for improved prevention and control actions for these zoonoses. This book reviews not only the prevalence and distribution of these zoonoses, including available health and economic impact data, but will highlight gaps in knowledge that must be filled in order to gain the assessment needed to depict the overall importance of a particular zoonosis. This is critical for comparisons to other pressing public health and development needs in resource allocations. The topics on epidemiology, diagnosis, and clinical aspects emphasize the knowledge gaps that limit a full understanding of these zoonoses, and target where greater research investments on these parasitic diseases should be focused.

African trypanosomes are tsetse-transmitted protozoa that inhabit the extracellular compartment of host blood. They cause fatal sleeping sickness in people, and Nagana, a wasting and generally fatal disease, in cattle. While trypanosomes are most common to Africa (about 30% of Africa's cattle graze on the fringe of the tsetse habitat), some species have spread beyond its boarders to Asia, the Middle East and South America. This text, volume one of "World Class Parasites", is written for researchers, students and scholars who enjoy reading research that has a major impact on human health, or agricultural productivity, and against which we have no satisfactory defense. It is intended to supplement more formal texts that cover taxonomy, life cycles, morphology, vector distribution, symptoms and treatment. It integrates vector, pathogen and host biology and celebrate the diversity of approach that comprises modern parasitological research.

The soil-transmitted nematode parasites, or geohelminths, are so called because they have a direct life cycle, which involves no intermediate hosts or vectors, and are transmitted by faecal contamination of soil, foodstuffs and water supplies. They all inhabit the intestine in their adult stages but most species also have tissue-migratory juvenile stages, so the disease manifestations they cause can therefore be both local and systemic. The geohelminths together present an enormous infection burden on humanity. Those which cause the most disease in humans are divided into three main groupings, Ascaris lumbricoides (the large roundworm), Trichuris trichiura (whipworm), and the blood-feeding hookworms (Ancylostoma duodenale and Necator americanus ). This text is written for researchers, students and scholars who enjoy reading research that has a major impact on human health, or agricultural productivity, and against which we have no satisfactory defense. It is intended to supplement more formal texts that cover taxonomy, life cycles, morphology, vector distribution, symptoms and treatment.It integrates vector, pathogen and host biology and celebrates the diversity of approach that comprises modern parasitological research.

P. Doherty...VB Introduction D. Dobbelaere and D. McKeever...IX Theileria Development and Host Cell Invasion Michael K. Shaw...1 Genomic Polymorphism, Sexual Recombination and Molecular Epidemiology af Theileria Parva R. Bishop, D. Geysen, R. Skilton, D. Odongo, V. Nene, B. Allsopp, S. Mbogo, P. Spooner and S. Morzaria...23 Epidemiological Significance of Strain-Specific Immunity to Theileria Parva D. J. McKeever and W. I. Morrison...41 Virulence and Attenuation in Theileria Annulata R. Adamson and R. Hall...55 Theileria Survival Strategies and Host Cell Transformation V. T. Heussler...69 Genomics of Theileria Parva V. Nene, R. Bishop, J. Quackenbush, M. Pertea, S. L. Salzberg, E. Taracha, S. Morzaria, C. M. Fraser and M. Gardner...85 Non-Transforming Theileria Parasites of Ruminants C. Sugimoto and K. Fujisaki 93 Index...107 FOREWORD The apicomplexan protozoal parasites continue to provide major challenges for human and animal health. While most of us have some familiarity with the ravages of malaria, there is relatively little awareness of diseases caused by parasites of the Theileria species.The reason is that these tick-borne organisms are problematic only in cattle and small ruminants. This does not mean, however, that the various manifestations of Theileriosis are of little interest to those concerned principally with human health. The economic loss and diminished food production associated with East Coast Fever (ECF, caused by T. parva) continues to be a major problem in East Africa.

Leishmania parasites cause a diverse group of diseases endemic to many tropical and subtropical regions of the world. This volume seeks to bring together recent research on cell and molecular biology of Leishmania with chapters on the host response to infection, the current epidemiology of leishmaniasis, explanations of the many different species, vector control, and strategies for vaccine development and drug treatment. "Leishmania", volume four of "World Class Parasites", is written for researchers, students and scholars who enjoy reading research that has a major impact on human health, or agricultural productivity, and against which we have no satisfactory defense. It is intended to supplement more formal texts that cover taxonomy, life cycles, morphology, vector distribution, symptoms and treatment. It integrates vector, pathogen and host biology and celebrates the diversity of approach that comprises modern parasitological research.

Filarial nematodes constitute and important group of human pathogens in tropical regions of the world. Diseases associated with these worms are generally separated into two categories: filariasis, caused by infections of lymphatic dwelling parasites and onchocerciasis, or river blindness, caused by infections of Onchocerca volvulus. Other filariae specifically infect humans and it is likely that zoonotic filarial infections may alter the outcome of infections with human parasites. The chapters in this book will cover concepts that, in most instances, overlap all of these parasites as well as focus on new and emerging ideas.The Filaria, volume five of World Class Parasites, is written for researchers, students and scholars who enjoy reading research that has a major impact on human health, or agricultural productivity, and against which we have no satisfactory defense. It is intended to supplement more formal texts that cover taxonomy, life cycles, morphology, vector distribution, symptoms and treatment. It integrates vector, pathogen and host biology and celebrates the diversity of approach that comprises modern parasitological research.

North American Parasitic Zoonoses provides a concise and useful review of essential information about parasitic zoonotic diseases. North American Parasitic Zoonoses, volume six of "World Class Parasites", is written for researchers, students, veterinarians, physicians and scholars who enjoy reading research that has a major impact on human health, or agricultural productivity, and against which we have no satisfactory defense. It is intended to supplement more formal texts that cover taxonomy, life cycles, morphology, vector distribution, symptoms and treatment. It integrates vector, pathogen and host biology and celebrates the diversity of approach that comprises modern parasitological research.

American trypanosomiasis, or Chagas disease, is caused by the protozoan parasite, Trypanosoma cruzi. Sixteen to 18 million people are currently infected with this organism, and 45,000 deaths are attributed to the disease each year. Infection with T. cruzi is life-long, and 10-30% of persons who harbour the parasite chronically develop cardiac and gastrointestinal problems associated with the parasitosis. Although major progress has been made in reducing vector-borne and transfusion-associated transmission of T. cruzi, the burden of disability and death in persons chronically infected with the organism continues to be enormous. Eight to 10 million persons born in countries in which Chagas disease is endemic currently reside in the United States, and epidemiologic and census data suggest that 50,000-100,000 are chronically infected with T. cruzi. The presence of these infected persons poses a risk of transmission of the parasite in the USA through blood transfusion and organ transplantation and several such cases have now been documented.This text, volume seven of "World Class Parasites" is written for students of tropical medicine, parasitology and public health, for researchers and practitioners alike who wish to bring themselves abreast of the status quo with respect to this disease. It is intended to supplement formal textbooks, in order to broaden and illuminate current areas of scientific and public health concern. Uniquely for T. cruzi, this book addresses parasite, vector and host biology, the pathogenesis of Chagas disease and prospective therapeutics and control strategies in a single volume.

Giardia duodenalis (=G. lamblia), Entamoeba histolytica, Cryptosporidium parvum and Cyclospora cayetanensis are more than just a mouthful for most who might encounter them. These protozoan parasitic agents contribute significantly to the staggering caseload of diarrheal disease morbidity encountered in developing world nations. Compounding the issue of their mere presence is the fact that standard ova and parasite exams frequently do not detect these infections. Detectable stages may be shed intermittently or require specialized staining procedures. Added to this is the often large number of asymptomatic carriers who serve as reservoirs for infecting others. These parasites are also not strangers to more developed nations, having responsibility for both small and large-scale disease outbreaks. In such settings they may be even more difficult to detect simply because they are frequently overlooked in the grand scheme of disease causing possibilities. They share common features; all are Protozoa, all possess trophic stages that inhabit the gastrointestinal tract, all have the ability to produce disease and in some instances death, and all produce environmentally stable cysts or oocysts, which ensure their transmissibility. In other ways, these organisms are profoundly different. Giardia is a flagellate that inhabits the gut lumen in close association with enterocytes. Entamoeba is an amoeba that preferentially inhabits the mucosal region of the gut lumen, but which may, under certain circumstances, become invasive. Cryptosporidium and Cyclospora are obligate intracellular coccidians, each taking up a unique niche within their respective host enterocytes.

Opportunistic Infections: Toxoplasma, Sarcocystis, and Microsporidia will focus on two important Genera of Apicomplexan parasites, Toxoplasma gondii and Sarcocystis species, and the medically important members of the Phylum Microsporida. We have been fortunate in obtaining excellent contributions from many experts in the field. Volumes in the "World Class Parasites" book series are written for researchers, students and scholars who enjoy reading about excellent research on problems of global significance. Each volume focuses on a parasite, or group of parasites, that has a major impact on human health, or agricultural productivity, and against which we have no satisfactory defense. The volumes are intended to supplement more formal texts that cover taxonomy, life cycles, morphology, vector distribution, symptoms and treatment. They integrate vector, pathogen and host biology and celebrate the diversity of approach that comprises modern parasitological research.

Human schistosomiasis is a disease with a rich and well-documented past, and every expectation of an unfortunately long future. These infections were known to the ancient Egyptians and their transmission shows little evidence of slowing down, globally. The good news is that field applicable, and increasingly affordable, chemotherapy has been available for almost 25 years. Using chemotherapy and other means of control, some countries have decreased transmission and made excellent headway against morbidity. The bad news is that the public health problems caused by schistosomiasis are still with us, with the estimated number of cases of schistosomiasis, while shifting geographically, remaining approximately 200 million for the last 30 years. In fact, with the development of field usable ultrasound technology and meta-analyses performed on existing data, there is a new appreciation for the extent of non-lethal morbidity associated with these infections. While the percentage of individuals with severe hepatosplenic disease remains below 10%, recent reassessments of morbidity associated with schistosomiasis indicate that the prevelance of symptoms and the cost in diability-adjusted life years is much greater than was previously, commonly appreciated (Van der Werf, M. J. , et al. 2003, Acta Tropica 86:125-139; Charles H. King, personnel communication). Strong impetus for addressing these issues is provided by the World Health Assembly’s recently passed Resolution 54. 19, which calls for efforts to reduce morbidity caused by schistosomiasis and soil-transmitted helminths in school-aged children, largely through chemotherapy campaigns.

Humans suffer from numerous parasitic foodborne zoonoses, many of which are caused by helminths. The helminth zoonoses of concern in this book are normally limited to diseases of animals which have now become transmissible to humans. In the past these diseases were limited to populations living in low- and middle-income countries, but the geographical limits and populations at risk are expanding and changing because of growing international markets , improved transportation systems, and demographic changes (such as population movements). The World Health Organization (WHO) has estimated that the number of people currently infected with food borne trematodes alone exceeds 41 million, but worldwide the number of people at risk, including those in developed countries, is 750 million. The increasing recognition of the public health significance of these zoonoses, especially their complicated epidemiologies, and their links to poverty, intensification of agriculture, environmental degradation, and lack of tools for control- has been welcome. However, the development of priorities for a national public health system is often a competitive exercise, and the argument for devoting appropriate attention and resources to foodborne parasitic zoonoses is generally handicapped by the lack of good health and economic impact data. The genesis of this book was a desire to draw attention to the problem of these zoonoses and to hopefully, inspire greater efforts to acquire a reliable global impact assessment and therefore a basis for improved prevention and control actions for these zoonoses. This book reviews not only the prevalence and distribution of these zoonoses, including available health and economic impact data, but will highlight gaps in knowledge that must be filled in order to gain the assessment needed to depict the overall importance of a particular zoonosis. This is critical for comparisons to other pressing public health and development needs in resource allocations. The topics on epidemiology, diagnosis, and clinical aspects emphasize the knowledge gaps that limit a full understanding of these zoonoses, and target where greater research investments on these parasitic diseases should be focused.

The soil-transmitted nematode parasites, or geohelminths, are - called because they have a direct life cycle, which involves no intermediate hosts or vectors, and are transmitted by faecal contamination of soil, foodstuffs and water supplies. They all inhabit the intestine in their adult stages but most species also have tissue-migratoryjuvenile stages, so the disease manifestations they cause can therefore be both local and systemic. The geohelminths together present an enormous infection burden on humanity. Those which cause the most disease in humans are divided into three main groupings, Ascaris lumbricoides (the large roundworm), Trichuris trichiura (whipworm), and the blood-feeding hookworms (Ancylostoma duodenale and Necator americanus ), and this book concentrates on these. These intestinal parasites are highly prevalent worldwide, A. lumbricoides is estimated to infect 1471 million (over a quarter ofthe world’s population), hookworms 1277 million, and T. trichiura 1049 million. The highly pathogenic Strongyloides species might also be classified as geohelminths, but they are not dealt with here because the understanding of their epidemiology, immunology and genetics has not advanced as rapidly as for the others. This is primarily because of the often covert nature of the infections, with consequent difficulties for analysis. If there is ever a second edition of this book, then there will hopefully be much to say about this infection.

Opportunistic Infections: Toxoplasma, Sarcocystis, and Microsporidia will focus on two important Genera of Apicomplexan parasites, Toxoplasma gondii and Sarcocystis species, and the medically important members of the Phylum Microsporida. We have been fortunate in obtaining excellent contributions from many experts in the field. Volumes in the "World Class Parasites" book series are written for researchers, students and scholars who enjoy reading about excellent research on problems of global significance. Each volume focuses on a parasite, or group of parasites, that has a major impact on human health, or agricultural productivity, and against which we have no satisfactory defense. The volumes are intended to supplement more formal texts that cover taxonomy, life cycles, morphology, vector distribution, symptoms and treatment. They integrate vector, pathogen and host biology and celebrate the diversity of approach that comprises modern parasitological research.

American trypanosomiasis, or Chagas disease, is caused by the protozoan parasite, Trypanosoma cruzi. Sixteen to eighteen million people are currently infected with this organism, and 45,000 deaths are attributed to the disease each year. Infection with T. cruzi is life-long, and 10-30% of persons who harbor the parasite chronically develop cardiac and gastrointestinal problems associated with the parasitosis. Although major progress has been made in recent years in reducing vector-borne and transfusion-associated transmission of T. cruzi, the burden of disability and death in persons chronically infected with the organism continues to be enormous. Eight to ten million persons born in countries in which Chagas disease is endemic currently reside in the United States, and epidemiologic and census data suggest that 50,000-100,000 are chronically infected with T. cruzi. The presence of these infected persons poses a risk of transmission of the parasite in the USA through blood transfusion and organ transplantation and several such cases have now been documented.American Trypanosomiasis, volume seven of World Class Parasites is written for students of tropical medicine, parasitology and public health, for researchers and practitioners alike who wish to bring themselves abreast of the status quo with respect to this disease. It is intended to supplement formal textbooks, in order to broaden and illuminate current areas of scientific and public health concern. Uniquely for T. cruzi, this book addresses parasite, vector and host biology, the pathogenesis of Chagas disease and current and prospective therapeutics and control strategies in a single volume.

P. Doherty...VB Introduction D. Dobbelaere and D. McKeever...IX Theileria Development and Host Cell Invasion Michael K. Shaw...1 Genomic Polymorphism, Sexual Recombination and Molecular Epidemiology af Theileria Parva R. Bishop, D. Geysen, R. Skilton, D. Odongo, V. Nene, B. Allsopp, S. Mbogo, P. Spooner and S. Morzaria...23 Epidemiological Significance of Strain-Specific Immunity to Theileria Parva D. J. McKeever and W. I. Morrison...41 Virulence and Attenuation in Theileria Annulata R. Adamson and R. Hall...55 Theileria Survival Strategies and Host Cell Transformation V. T. Heussler...69 Genomics of Theileria Parva V. Nene, R. Bishop, J. Quackenbush, M. Pertea, S. L. Salzberg, E. Taracha, S. Morzaria, C. M. Fraser and M. Gardner...85 Non-Transforming Theileria Parasites of Ruminants C. Sugimoto and K. Fujisaki 93 Index...107 FOREWORD The apicomplexan protozoal parasites continue to provide major challenges for human and animal health. While most of us have some familiarity with the ravages of malaria, there is relatively little awareness of diseases caused by parasites of the Theileria species.The reason is that these tick-borne organisms are problematic only in cattle and small ruminants. This does not mean, however, that the various manifestations of Theileriosis are of little interest to those concerned principally with human health. The economic loss and diminished food production associated with East Coast Fever (ECF, caused by T. parva) continues to be a major problem in East Africa.

Leishmania parasites cause a diverse group of diseases endemic to many tropical and subtropical regions of the world. This volume seeks to bring together recent research on cell and molecular biology of Leishmania with chapters on the host response to infection, the current epidemiology of leishmaniasis, explanations of the many different species, vector control, and strategies for vaccine development and drug treatment.Leishmania, volume four of World Class Parasites, is written for researchers, students and scholars who enjoy reading research that has a major impact on human health, or agricultural productivity, and against which we have no satisfactory defense. It is intended to supplement more formal texts that cover taxonomy, life cycles, morphology, vector distribution, symptoms and treatment. It integrates vector, pathogen and host biology and celebrates the diversity of approach that comprises modern parasitological research.

North American Parasitic Zoonoses provides a concise and useful review of essential information about parasitic zoonotic diseases. North American Parasitic Zoonoses, volume six of "World Class Parasites", is written for researchers, students, veterinarians, physicians and scholars who enjoy reading research that has a major impact on human health, or agricultural productivity, and against which we have no satisfactory defense. It is intended to supplement more formal texts that cover taxonomy, life cycles, morphology, vector distribution, symptoms and treatment. It integrates vector, pathogen and host biology and celebrates the diversity of approach that comprises modern parasitological research.

The African Trypanosomes, volume one of World Class Parasites, is written for researchers, students and scholars who enjoy reading research that has a major impact on human health, or agricultural productivity, and against which we have no satisfactory defense.

Filarial nematodes constitute and important group of human pathogens in tropical regions of the world. Diseases associated with these worms are generally separated into two categories: filariasis, caused by infections of lymphatic dwelling parasites and onchocerciasis, or river blindness, caused by infections of Onchocerca volvulus. Other filariae specifically infect humans and it is likely that zoonotic filarial infections may alter the outcome of infections with human parasites. The chapters in this book will cover concepts that, in most instances, overlap all of these parasites as well as focus on new and emerging ideas.The Filaria, volume five of World Class Parasites, is written for researchers, students and scholars who enjoy reading research that has a major impact on human health, or agricultural productivity, and against which we have no satisfactory defense. It is intended to supplement more formal texts that cover taxonomy, life cycles, morphology, vector distribution, symptoms and treatment. It integrates vector, pathogen and host biology and celebrates the diversity of approach that comprises modern parasitological research.