Schistosomiasis Vel Bilharziasis

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.

According to the author, the book addresses to all the scientists and not only to immunologists or biologists of European countries who are engaged in developing a vaccine, or a diagnostic kit or a new drug against the infection or on schistosome evolution. Even these scientists have to visit endemic countries for field trials or ask their counterparts to collect field data (which this book addresses ). Thus this book is not on molecular fundamentals but on the infection itself; how schistosome species are responding to the drug ; sensitivity and specificity of immunodiagnostic kits, antigen molecules; snail compatibility, production losses; schistosome evolution; schistosome outbreaks; complexities where more than two schistosome species are existing; problem of human schistosomiasis in South Asia etc In fact , all the topics of great interest to international scientists and scientists of endemic countries.

Human schistosomes (blood flukes) are digenetic trematodes that spend the adult part of their life cycle in humans and a further part in aquatic snails. Despite advances in chemotherapy, schistosomiasis is still a significant infection in the populations of several countries in the tropics. This book replaces a previous volume Schistosomiasis: Epidemiology, Treatment and Control (Heinemann, 1982) by Jordan and Webbe. All chapters have been rewritten by internationally renowned workers. Ultrasound, expected to aid identification of early disease in the field and increase our understanding of its evolution, is discussed in a new chapter. Others, each with an extensive bibliography, review the parasites and their snail intermediate hosts, epidemiology, clinical manifestations and pathology, diagnosis, immunology, drugs and patient management and control. Limitations of the role of chemotherapy in morbidity control are discussed and the need for flexibility in control interventions in the varied epidemiological situations is stressed. An interdisciplinary approach may be necessary to reduce transmission by appropriate measures against the snail intermediate host, and to implement public health measures, including the provision of safe water (with many other medical and social benefits) and health education. This comprehensive volume is for public health workers involved in the prevention and control of the disease, for physicians, and for students and teachers of many disciplines. It also provides a reference book for health planners, social anthropologists, health educators, water and sanitary engineers and others engaged in improving health in the tropics. Physicians in temperate countries will also find it a useful reference book as schistosomiasis, often acute, is being diagnosed more frequently in those returning from holidays in endemic areas.

This work provides a unique, comprehensive, and up-to-date review of the biology of the parasitic flatworm, Schistosoma, which is responsible for one of the world's most pervasive infectious diseases, Schistisomiasis. The unusual characteristics of the organism, and the immediacy of its effect on human health, have combined to bring the schistosomes under considerable scrutiny in the field of parasitology. As parasites living within the circulatory systems of their vertebrate hosts, adult schistosomes face problems of reproduction and egg dispersal far beyond those of most animals. Yet despite their many apparent frailties, these organisms have developed mechanisms not only to survive, but to prevail and evolve into dangerous pathogens. This book concentrates on development and reproduction, since they are key to the parasite's existence and are particularly important because the disease in humans is induced by the worms' eggs rather than the organisms themselves. The book will aid those investigators who wish to apply advanced techniques to schistosomes, but who lack familiarity with their fundamental biology. It draws together findings on the main features of schistosome biology, pointing out areas of controversy and special significance, and topics in need of further work. The author is a recognized authority on schistosomiasis. His book will be an invaluable aid to all those involved in studying and treating the disease, including parasitologists, immunologists, molecular biologists, and public health specialists.