There is now wide agreement in the clinical and biomedical science communities that helminthiasis has greater public health significance than was previously thought and that action to relieve and reduce its debilitating effects on the health and livelihoods of millions of poor people deserves high priority. We have written this book to support all who are concerned to confront and overcome helminthiasis. Although we may enjoy explaining how helminths travel from host to host and we may marvel at how these remarkable animals obtain food and shelter in an immunocompetent environment, we have sought to concentrate on the fact that helminths are agents of human disease.