Serological differentiation between Echinococcus granulosus and E. multilocularis infections in man.
TL;DR: An enzyme-linked immunosorbent assay (ELISA) was adapted for the serological differential diagnosis of cystic or alveolar echinococcosis in man caused by Echinococcus granulosus or E. multilocularis respectively.
Abstract: An enzyme-linked immunosorbent assay (ELISA) was adapted for the serological differential diagnosis of cystic or alveolar echinococcosis in man caused by Echinococcus granulosus or E. multilocularis respectively. By affinity chromatography using rabbit anti hydatid fluid IgG coupled covalently to CNBr-Sepharose 4B a protein fraction (Em 1) containing shared antigens of both parasites could be isolated from an extract of E. multilocularis metacestode tissue. From the same source another antigen fraction (Em 2) with a high degree of specificity for E. multilocularis was prepared by immunosorption. Antigen Em 1 was equally sensitive for the detection of antibodies against E. granulosus and E. multilocularis, whereas antigen fraction Em 2 appeared to be more specific for E. multilocularis. A correct serological differential diagnosis was achieved in 95% of 57 confirmed cases of human cystic or alveolar echinococcosis by the simultaneous use of both antigen fractions in the ELISA and by comparison of their reactivities.
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TL;DR: The biology of Echinococcus, the causative agent of echinococcosis (hydatid disease) is reviewed with emphasis on the developmental biology of the adult and metacestode stages of the parasite.
Abstract: The biology of Echinococcus, the causative agent of echinococcosis (hydatid disease) is reviewed with emphasis on the developmental biology of the adult and metacestode stages of the parasite. Major advances include determining the origin, structure and functional activities of the laminated layer and its relationship with the germinal layer; and the isolation, in vitro establishment and characterization of the multipotential germinal cells. Future challenges are to identify the mechanisms that provide Echinococcus with its unique developmental plasticity and the nature of activities at the parasite-host interface, particularly in the definitive host. The revised taxonomy of Echinococcus is presented and the solid nomenclature it provides will be essential in understanding the epidemiology of echinococcosis.
298 citations
TL;DR: The chapter addresses the problem of neurocysticercosis and epilepsy in developing countries particularly Latin America and its public health consequences in the USA and elsewhere.
Abstract: Publisher Summary This chapter focuses on the public health importance of taeniid cestode zoonoses especially cystic echinococcosis, alveolar echinococcosis and T. solium cysticercosis. The chapter addresses the problem of neurocysticercosis and epilepsy in developing countries particularly Latin America and its public health consequences in the USA and elsewhere. E. multilocularis , which is the cause of one of the most pathogenic of all human parasitic infections, appears to be spreading in parts of western Europe, USA, and Japan. The remarkable development in the past 20 years or so of high resolution imaging technologies, such as computerized tomography (CT) scan and ultrasound have enabled precision detection of taeniid larval cystic infection in humans. Coupled with improvements in immunodiagnostic test sensitivity and antigen specificity, diagnosis of cestode zoonoses is now more accurate than ever before. Although further developments in immunodiagnosis are required, laboratory tests have provided improved capability for screening populations in both epidemiological and community studies. Parallel and recent development of genus specific coproantigen tests for human taeniasis and canine echinococcosis have also provided major new tools for epidemiological and surveillance programs.
213 citations
TL;DR: Serologic and eosinophil counts decreased after therapy, suggesting that they may be useful markers of treatment success, and the sensitivity of the CDC Strongyloides EIA was determined.
Abstract: Strongyloidiasis is a chronic infection that may result in significant morbidity; however, diagnosis and management remain problematic. The objective of this study was to 1) evaluate the demographic, clinical, and laboratory features of 76 consecutive individuals who had Strongyloides stercoralis larvae identified in their fecal specimens; 2) determine the sensitivity of the Centers for Disease Control and Prevention (CDC) enzyme immunoassay (EIA) for detecting antibodies to Strongyloides in those with confirmed infection; and 3) assess the serologic responses and changes in eosinophil counts following treatment. Most (96%) cases occurred in immigrants, but some patients had immigrated as long as 40 years earlier. The CDC Strongyloides EIA had a sensitivity of 94.6% (95% confidence interval = 92.0-97.2%) in this patient population with proven infection. Serologic and eosinophil counts decreased after therapy, suggesting that they may be useful markers of treatment success.
198 citations
TL;DR: The nature, extent, and significance of variation particularly, below the species level, in the causative agent of hydatid disease, Echinococcus is discussed.
Abstract: Publisher Summary This chapter discusses the nature, extent, and significance of variation particularly, below the species level, in the causative agent of hydatid disease, Echinococcus. An application of current taxonomic procedures to the classification of a group of organisms in Echinococcus ensures an important role for the explanatory and predictive value of taxonomic determinations in studies on the epidemiology and control of hydatid disease. Despite increasing access to highly discriminatory differential criteria and a more flexible taxonomic approach, problems of nomenclature are likely to remain. Many genetically distinct populations within the recognized species of Echinococcus cannot be adequately allocated to a formal taxonomic category. However, in parasitic organisms the recognition of variation may be of great medical and agricultural significance and it is for this reason that the term “strain” has been widely used to describe intraspecific variants in Echinococcus and other parasites. It is essential that strains are indentified and characterized in each endemic area if effective control programs are to be instituted. Future research should aim to develop even more reliable and practically applicable differential criteria for this purpose. Biochemical and molecular dissection of the parasite in a quest toward this end may also unravel the functional nature of strain variation and provide direction for the development of chemotherapeutic agents.
192 citations
TL;DR: The purpose should be to update what is known about the nature and extent of variation in Echinococcus to provide a sound basis for a phylogenetic analysis, and there is an urgent need for the molecular characterization of strains of E. multilocularis as well as strains in lions and cervid so that this taxonomic revision can be completed.
Abstract: Publisher Summary Hydatid disease (echinococcosis) is one of the most important parasitic zoonoses and remains a public health and economic problem of global proportions. There are currently four recognized species in the genus Echinococcus : E.granulosus , E.multilocularis , E.oligarthrus , and E.vogeli . Because of the extensive variation in Echinococcus, it is very important to characterize the aetiological agents in different endemic areas to determine transmission patterns, particularly where there is the possibility of interaction between cycles. The first step in a taxonomic revision of the genus Echinococcus is to establish an appropriate species concept. Therefore, the purpose should be to update what is known about the nature and extent of variation in Echinococcus to provide a sound basis for a phylogenetic analysis. The current classification within the genus Echinococcus is not compatible with historical relationships between taxa. Phylogenetic analysis of DNA sequence data provides no support for the concept that E.grunulosus is a monophyletic group and it cannot be considered an evolutionary species. There is an urgent need for the molecular characterization of strains of E. multilocularis as well as strains of Echinococcus in lions and cervids, so that this taxonomic revision can be completed.
162 citations
References
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TL;DR: In this paper, the specificity of the DNP system was assessed by inhibition with hapten, and the reaction of immune serum against DNP with DNP-protein, adsorbed to the tubes, was completely inhibited by haptens in solution.
3,349 citations
Journal Article•
TL;DR: In the DNP system, the specificity of the reaction was assessed by inhibition with hapten, and the reaction of immune serum against DNP with DNP-protein, adsorbed to the tubes, was completely inhibited by haptens in solution.
Abstract: In the DNP system, the specificity of the reaction was assessed by inhibition with hapten. The reaction of immune serum against DNP with DNP-protein, adsorbed to the tubes, was completely inhibited by hapten in solution.
3,109 citations
Journal Article•
131 citations
TL;DR: Concern is expressed that previous taxonomic considerations of Echinococcus have not taken into account the nature of its reproductive mechanism which defies the application of traditional taxonomic concepts and definitions derived from dioecious cross-fertilising organisms.
Abstract: The taxonomy ofEchinococcus is reviewed and consideration given to speciation within the genus. The morphological and other biological characteristics of all species and subspecies so far described are given, and evidence for the existence of other intraspecific variants is presented. A total of 16 species have been described but only four have well-defined characteristics and are generally accepted as being taxonomically valid;E. granulosus, E. multilocularis, E. oligarthrus andE. vogeli. The taxonomic status of intraspecific variants is uncertain. Some authorities consider that the majority of described subspecies are invalid taxonomically. However, concern is expressed that previous taxonomic considerations ofEchinococcus have not taken into account the nature of its reproductive mechanism which, like that of most cestodes, defies the application of traditional taxonomic concepts and definitions derived from dioecious cross-fertilising organisms. At the present time intraspecific variants ofEchinococcus are referred to as strains. The existence of such strains, particularly ofE. granulosus, in different parts of the world is firmly established. Their importance in the epidemiology of hydatidosis has high-lighted the needed to establish criteria for their differentiation and characterisation. The limitations of morphology as a sole differential criterion are emphasised. Attention is given to recent studies on strain variation which have demonstrated the value of applying several different criteria in which the developmental, physiological and biochemical characteristics of different strains are compared in conjunction with morphological investigations.
72 citations
TL;DR: Using immunoelectrophoresis or double diffusion tests with E. granulosus antigens, the Echinococcus-specific arc 5 was demonstrated in 11 of 21 hydatidosis sera and in 1 of 20 cysticercosisSera.
Abstract: Serum specimens from persons with pathologically confirmed Echinococcus granulosus hydatidosis and Taenia solium cysticercosis were tested in indirect hemagglutination tests using both Echinococcus and Taenia antigens. There were cross-reactions with most sera, and it was not possible to distinguish specific reactions by comparing titers with the homologous or heterologous antigens. Using immunoelectrophoresis or double diffusion tests with E. granulosus antigens, the Echinococcus-specific arc 5 was demonstrated in 11 of 21 hydatidosis sera and in 1 of 20 cysticercosis sera.
66 citations