Echinococcosis is a cosmopolitan zoonosis caused by adult or larval stages of cestodes belonging to the genus Echinococcus (family Taeniidae). The two major species of medical and public health importance are Echinococcus granulosus and E. multilocularis, which cause cystic echinococcosis (CE) and alveolar echinococcosis (AE), respectively. Both CE and AE are both serious diseases, the latter especially so, with a high fatality rate and poor prognosis if managed inappropriately. This review discusses new concepts and approaches in the immunology and diagnosis of CE, but comparative reference has also been made to AE infection and to earlier pivotal studies of both diseases. The review considers immunity to infection in the intermediate and definitive hosts, innate resistance, evasion of the immune system, and vaccination of intermediate and definitive hosts, and it particularly emphasizes procedures for diagnosis of CE and AE, including the value of immunodiagnostic approaches. There is also discussion of the new advances in recombinant and related DNA technologies, especially application of PCR, that are providing powerful tools in the fields of vaccinology and molecular diagnosis of echinococcosis

The cestodes, or tapeworms, are a group of parasitic worms many species of which cause serious, often fatal, diseases in man and domestic animals throughout the world. This book is an updated and expanded version of Professor Smyth's The Physiology of Cestodes (1969). The text has now been entirely rewritten, taking into account advances in investigative techniques such as immunocytochemistry, in vitro culture and scanning electron microscopy, which have immensely increased our understanding of these organisms. The biochemical coverage now includes the spectacular advances in molecular biology that have occured. The book also shows how cestodes are increasingly being recognized as valuable models for investigating fundamental biological phenomena such as membrane transport and asexual/sexual differentiation. Students of medicine, veterinary medicine, parasitology and zoology will find this book invaluable. Its high research content and extensive references also make it an essential reference book for researchers in these fields.

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Three nucleotide data sets, two mitochondrial (COI and ND1) and one nuclear (ribosomal ITS1), have been investigated in order to resolve relationships among species and strains of the genus Echinococcus. The data have some unusual properties in that mitochondrial heteroplasmy was detected in one strain of E. granulosus, and more than one class of ITS1 sequence variant can occur in a single isolate. The data failed to support the hypothesis that E. granulosus, as it is currently viewed, is a single valid species. Rather, the strains of E. granulosus seem to comprise at least three evolutionarily diverse groups, the sheep strain group, bovine strain group and horse strain group. Molecular distances between them are comparable to, or greater than, molecular evolutionary distances observed between recognized species. The affinities of the cervid strain of E. granulosus are unclear because of ambiguous data, but this strain does not appear to be ancestral to others. E. multilocularis may not be distinct from E. granulosus. However, the remaining two species. E. vogeli and E. oligarthrus appear distinct and rather distant from the first two. Based on the results presented here, taxonomic revision of the genus is clearly warranted.

Schistosomiasis japonica is an endemic, zoonotic disease of major public health importance in China where water buffaloes account for approximately 75% of disease transmission. Interventions that reduce schistosome infection in water buffaloes will enhance their health simultaneously reducing disease transmission to humans. While chemotherapy has proved successful, it requires continued time consuming and expensive mass treatments. A more sustainable option would be development of vaccines that reduce transmission of S. japonicum from bovines to replace bovine chemotherapy. We performed two randomized double blind trials in water buffaloes to determine if DNA vaccines encoding triose-phosphate isomerase (SjCTPI), or the tetraspanin 23 kDa integral membrane protein (SjC23), alone or fused to bovine heat shock protein 70 (Hsp70) could induce a level of immunity conducive to long-term sustainable control. Groups of water buffaloes (15/group) received three intramuscular injections, 4 weeks apart. Booster immunizations were co-administered with a plasmid DNA encoding IL-12. Four weeks after the last injection, water buffaloes were challenged with 1000 cercariae, and vaccine efficacy analyzed 8 weeks later. Water buffaloes vaccinated with SjCTPI-Hsp70 or SjCTPI plasmids had worm burdens reduced by 51.2% and 41.5%, respectively. Importantly, fecal miracidial hatching was reduced by 52.1% and 33.2% respectively compared to control vaccinated water buffaloes. Vaccination with SjC23-Hsp70 and SjC23 plasmids reduced worm burdens by 50.9% and 45.5%, respectively, and fecal miracidial hatching by 52.0% and 47.4%. A mathematical model of schistosome transmission predicts that schistosome vaccines capable of reducing water buffaloes' fecal egg output by 45%, alone or in conjunction with praziquantel treatment, will lead to a significant reduction in transmission of schistosomiasis. Both DNA vaccines tested here exceed this hypothetical level. Indeed, mathematical modeling of SjCTPI-Hsp70 and SjC23-Hsp70 alone and in conjunction with human chemotherapy showed a significant reduction in transmission almost to the point of elimination.

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Abstract. We hypothesize that bovine infections are responsible for the persistence of human schistosomiasis transmission in the Yangtze marshlands of China. To test this hypothesis, we are carrying out a comparative intervention among four administrative villages in the Poyang Lake region, Jiangxi Province, two of which are experimental and two are control. The primary design involves treating, at the onset of the study, all the inhabitants in all four villages with praziquantel and all the bovines in two villages (the experimental or intervention villages). Following treatment, rates of reinfection in people of all villages, and in bovines in the experimental villages, will be assessed as will the ongoing prevalence of infection in bovines in the control villages. Before treatment, the prevalence and intensity of infection among humans and bovines was ascertained in the four villages. Our study design and baseline information are presented here, along with a description of the ecology of the study villages.