P. Craig – författare

Parasitic worms (helminths) are a diverse and geographically widespread group of organisms which are responsible for infecting millions of people throughout the world. Many of these parasitic helminths are either zoonoses (disease agents naturally transmitted between vertebrate animals and man) or have evolved from animal parasites. Helminthic parasitism may be responsible for asymptomatic, mild, severe and even lethal infections in humans and some vertebrate animals. Many of these helminth species are primarily resticted to tropical and subtropical areas and others have greater prevalence in warm climates. In Africa, parasitic helminths, many of which are zoonoses, are of significant public health importance, are responsible for economic losses, may hamper rural development programmes and generally slow down the pace of economic development. Human migration and movements due to the ever expanding population, wars, famine or modiciation of the environment, and the increased proximity of people to areas inhabited by a great diversity of wildlife species, make zoonoses of special interest in Africa.Patterns of transmissions of helminth parasites (in Africa) are highly influenced by social and cultural interactions and by the unique variety of wildlife and habitats. It is not surprising therefore that approaches to the study and control of parasitic zoonoses usually requires a complex intersectorial co-operation between medical and veterinary experts, parasitologists, biologists, zoologists, demographers, anthropologists and engineers. This book is a selective, rather than a comprehensive, compilation on parasitic helminths, with some emphasis on helminth zoonoses, particularly those which are important in the context of Africa. Furthermore, the importance of animal models has been highlighted for some helminth parasites. The title of this book strongly reflects the three areas, ie. parasitic worms, zoonoses and Africa, in which the work of one man, Professor George Stanley Nelson, has made a major impact over a 40 year period. This volume was conceived with George Nelson Nelson very much in mind and is dedicated to him on his retirement.The subject of the chapters strongly reflect areas where he contributed directly or indirectly, and all the authors have worked with him or been influenced by him.

Helminths include one of the most diverse and geographically widespread groups of parasites which infect humans and animals. About 100 species have been reported from humans, usually producing asymptomatic infection or mild symptoms. However, about 20 species are of public health importance causing severe or even fatal infections. In many parts of Africa parasitic helminths are responsible for enormous economic losses, hampering rural development programmes and reducing the pace of economic growth. Many parasitic helminths are either zoonoses (diseases naturally transmitted between vertebrate animals and man) or have evolved from animal parasites. The modification of the environment through wars, famine and the ever expanding and increasingly mobile human population brings people into close contact with new environments and wildlife species which makes the study and control of zoonoses of special interest and complexity. In Africa, the transmission of helminth parasites is highly influenced by the ever changing social and cultural differences between diverse groups of peoples and their interaction with wild and domestic animals. It is not surprising, therefore, that approaches to the study and control of parasitic zoonoses require intersectoral cooperation between physicians, veterinarians, parasitologists, zoologists, demographers, anthropologists, engineers and economists to provide the breadth of knowledge and expertise required to develop our understanding of these diseases and to devise methods for their control. This book provides a selective compilation of parasitic helminths, many of which are zoonoses which create important economic and public health problems in Africa.