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Philip S Craig - One of the best experts on this subject based on the ideXlab platform.
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echinococcus granulosus epidemiology and state of the art of diagnostics in animals
Veterinary Parasitology, 2015Co-Authors: Philip S Craig, Alexander Mastin, Freya Van Kesteren, Belgees BoufanaAbstract:Diagnosis and detection of Echinococcus granulosus (sensu lato) infection in animals is a prerequisite for epidemiological studies and surveillance of echinococcosis in endemic, re-emergent or emergent transmission zones. Advances in diagnostic approaches for definitive hosts and livestock, however, have not progressed equally over the last 20 years. Development of laboratory based diagnostics for canids using coproantigen ELISA and also coproPCR, have had a huge impact on epidemiological studies and more recently on surveillance during hydatid control programmes. In contrast, diagnosis of cystic echinococcosis (CE) in livestock still relies largely on conventional post-mortem inspection, despite a relatively low diagnostic sensitivity especially in early infections, as current serodiagnostics do not provide a sufficiently specific and sensitive practical pre-mortem alternative. As a result, testing of dog faecal samples by coproantigen ELISA, often combined with mass ultrasound screening programmes for human CE, has been the preferred approach for monitoring and surveillance in resource-poor endemic areas and during control schemes. In this article we review the current options and approaches for diagnosis of E. granulosus infection in definitive and animal intermediate hosts (including applications in non-domesticated species) and make conclusions and recommendations for further improvements in diagnosis for use in epidemiological studies and surveillance schemes.
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echinococcus granulosus infection in domestic dogs in urban and rural areas of the coquimbo region north central chile
Veterinary Parasitology, 2010Co-Authors: H Bradshaw, Gerardo Acostajamett, Sarah Cleaveland, Barend Dec M Bronsvoort, Andrew A Cunningham, Philip S CraigAbstract:Hydatidosis is a zoonotic disease caused by the cystic stage of the cestode parasite Echinoccocus granulosus, in which the definitive hosts are mainly domestic dogs. This parasite is regarded mainly as a rural disease, where man is exposed through contact with eggs excreted by definitive hosts; however, some studies have shown that domestic dogs can get infected within urban areas. This study was conducted to assess differences in prevalence of E. granulosus in urban and rural sites in Coquimbo region of Chile. From 2005 to 2006 a cross-sectional household questionnaire survey was conducted in Coquimbo and Ovalle cities, in three towns and in rural sites along two transects from these cities to the Fray Jorge NP in the Coquimbo region. Faecal samples were collected from dogs during the questionnaire survey and tested for Echinococcus Coproantigens. Positive dogs were found in urban areas. Analysis of risk factors indicated that dogs inhabiting the borders of urban areas were at greater risk of being coproantigen positive than those in the centre of these areas. These results are likely to be related to the custom of slaughtering livestock at home in urban areas during local celebrations, which could favour the importation of E. granulosus to urban areas by acquiring livestock contaminated with cysts from rural sites. This study shows that surveillance and control measures in livestock and domestic dogs need to be introduced in urban areas as well as rural areas of the Coquimbo region to reduce the public health risk of hydatid disease.
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Development of a Species-Specific Coproantigen ELISA for Human Taenia solium Taeniasis
The American Journal of Tropical Medicine and Hygiene, 2009Co-Authors: Maria Claudia Guezala, J. C. Allan, Silvia Rodriguez, Humberto Zamora, Alice Tembo, Philip S CraigAbstract:Taenia solium causes human neurocysticercosis and is endemic in underdeveloped countries where backyard pig keeping is common. Microscopic fecal diagnostic methods for human T. solium taeniasis are not very sensitive, and Taenia saginata and Taenia solium eggs are indistinguishable under the light microscope. Coproantigen (CoAg) ELISA methods are very sensitive, but currently only genus (Taenia) specific. This paper describes the development of a highly species-specific coproantigen ELISA test to detect T. solium intestinal taeniasis. Sensitivity was maintained using a capture antibody of rabbit IgG against T. solium adult whole worm somatic extract, whereas species specificity was achieved by utilization of an enzyme-conjugated rabbit IgG against T. solium adult excretory-secretory (ES) antigen. A known panel of positive and negative human fecal samples was tested with this hybrid sandwich ELISA. The ELISA test gave 100% specificity and 96.4% sensitivity for T. solium tapeworm carriers (N = 28), with a J index of 0.96. This simple ELISA incorporating anti-adult somatic and anti-adult ES antibodies provides the first potentially species-specific coproantigen test for human T. solium taeniasis.
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screening for echinococcus granulosus in dogs comparison between arecoline purgation coproelisa and copropcr with necropsy in pre patent infections
Veterinary Parasitology, 2007Co-Authors: H Bradshaw, S Lahmar, Belgees Boufana, Philip S CraigAbstract:Echinococcus granulosus is an important zoonotic infection of dogs. The purpose of the present study assessed the performance of two laboratory diagnostic methods with arecoline purgation and necropsy in infected dogs. In total 65 dogs were successfully experimentally infected with protoscoleces of E. granulosus from ovine infection. At 14–34 days post-infection groups of dogs were purged with arecoline hydrobromide and then necropsied. Faecal samples were tested at weekly intervals by coproantigen ELISA and coproPCR. The necropsy infection rate with E. granulosus was 89.2%. Only 43% of dogs were successfully purged after one arecoline dose; this percentage increased to 76.9% for two doses of arecoline purgation. E. granulosus coproantigen was detected by coproELISA in 82.8% of faeces. The positive and negative predictive values for coproantigen ELISA were 96 and 44.4% respectively. E. granulosus DNA was detected in pre-patent faecal samples by coproPCR in 25.9% of dogs. These results indicate that coproELISA is more sensitive than arecoline purgation for the detection of pre-patent E. granulosus infection in dogs. CoproPCR detected E. granulosus DNA in dog faeces by 21 days post-infection before egg production.
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Coproantigens in taeniasis and echinococcosis
Parasitology International, 2006Co-Authors: J. C. Allan, Philip S CraigAbstract:The application of modern immunodiagnostic or molecular diagnostic techniques has improved the diagnosis of the taeniid cestode infections, echinococcosis and taeniasis. One particularly promising approach is the detection of parasite-specific antigens in faeces (Coproantigens). This approach has been applied to both Echinoccocus and Taenia species and it has gained increasingly widespread use. Taeniid coproantigen tests are based on either monoclonal or polyclonal antibodies raised against adult tapeworm antigens. These tests have the following common characteristics; they are largely genus-specific, specificity is high (>95%), parasite antigen can be detected in faeces weeks prior to patency, levels of coproantigen are independent of egg output, coproantigen is stable for days at a range of temperatures (-80 degrees C to 35 degrees C), for several months in formalin-fixed faecal samples, and coproantigen levels drop rapidly (1-5 days) following successful treatment. In the genus Taenia, most work has been done on Taenia solium and coproantigen tests have reliably detected many more tapeworm carriers than microscopy. For Echinococcus species, there is a broad positive correlation between test sensitivity and worm burden with a reliable threshold level for the test of >50 worms. Characterisation of taeniid Coproantigens in order to further improve the tests is ongoing. Studies indicate taeniid Coproantigens to include high molecular weight (>150 kDa), heavily glycosylated molecules with carbohydrate moieties contributing substantially to the levels of antigen detected in faeces. Application of the existing coproantigen tests in epidemiological and control programmes for Echinococcus and Taenia species infection has begun to contribute to an improved understanding of transmission and of surveillance of these important zoonotic cestodes.
Gerardo Acostajamett - One of the best experts on this subject based on the ideXlab platform.
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echinococcus granulosus infection in domestic dogs in urban and rural areas of the coquimbo region north central chile
Veterinary Parasitology, 2010Co-Authors: H Bradshaw, Gerardo Acostajamett, Sarah Cleaveland, Barend Dec M Bronsvoort, Andrew A Cunningham, Philip S CraigAbstract:Hydatidosis is a zoonotic disease caused by the cystic stage of the cestode parasite Echinoccocus granulosus, in which the definitive hosts are mainly domestic dogs. This parasite is regarded mainly as a rural disease, where man is exposed through contact with eggs excreted by definitive hosts; however, some studies have shown that domestic dogs can get infected within urban areas. This study was conducted to assess differences in prevalence of E. granulosus in urban and rural sites in Coquimbo region of Chile. From 2005 to 2006 a cross-sectional household questionnaire survey was conducted in Coquimbo and Ovalle cities, in three towns and in rural sites along two transects from these cities to the Fray Jorge NP in the Coquimbo region. Faecal samples were collected from dogs during the questionnaire survey and tested for Echinococcus Coproantigens. Positive dogs were found in urban areas. Analysis of risk factors indicated that dogs inhabiting the borders of urban areas were at greater risk of being coproantigen positive than those in the centre of these areas. These results are likely to be related to the custom of slaughtering livestock at home in urban areas during local celebrations, which could favour the importation of E. granulosus to urban areas by acquiring livestock contaminated with cysts from rural sites. This study shows that surveillance and control measures in livestock and domestic dogs need to be introduced in urban areas as well as rural areas of the Coquimbo region to reduce the public health risk of hydatid disease.
Peter Deplazes - One of the best experts on this subject based on the ideXlab platform.
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spatial and temporal aspects of urban transmission of echinococcus multilocularis
Parasitology, 2002Co-Authors: C Stieger, Daniel Hegglin, G Schwarzenbach, Alexander Mathis, Peter DeplazesAbstract:High prevalences of Echinococcus multilocularis have been reported from foxes of the city of Zurich, Switzerland. In order to characterize transmission in urban areas, a coproantigen ELISA was evaluated for diagnosing the infection in fox faecal samples collected in the environment. In addition, trapped rodents were investigated for the presence of metacestodes. Faecal samples could reliably be classified as being of fox origin by assessing physical properties as shown by the different parasite spectra of putative fox and dog faecal specimens. From the total of 604 tested putative fox faecal samples 156 (25.8%) were positive in the ELISA with a distinct increase in the proportion of positive samples from the urban to the periurban zone. Furthermore, samples collected in the border zone had significantly more coproantigen-positive results during winter. Prevalence of E. multilocularis in rodents was 9.1% (81/889) for Arvicola terrestris (with 3.5% of the animals harbouring between 14 and 244400 protoscoleces) and 2.4% (2/83) for Clethrionomys glareolus. E. multilocularis-infected A. terrestris were found in 9 of 10 trapping sites in the border zone. The high infection pressure in the periphery of urban areas might pose a risk for infection with E. multilocularis for both domestic carnivores as well as for urban inhabitants. Interventions into the cycle aiming at reducing the infection pressure should therefore focus on these areas.
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screening of dogs for echinococcus granulosus coproantigen in a low endemic situation in cyprus
Veterinary Parasitology, 2002Co-Authors: G Christofi, Peter Deplazes, N Christofi, I Tanner, P Economides, Johannes EckertAbstract:In the framework of an echinococcosis surveillance and control programme in Cyprus, a commercial enzyme-linked immunosorbent assay (ELISA) (CHEKIT ECHINOTEST) designed for the detection of Echinococcus granulosus and E. multilocularis Coproantigens was used in 1997-2000 for the investigation of large numbers of dogs. Most of the animals originated from areas where approximately 0.2% of the dogs had been found to be infected with E. granulosus in previous (1993-1996) arecoline surveys. The sensitivity of the coproantigen test was 83%, as determined in 35 dogs naturally infected with this cestode species. The specificity was 98% in 97 randomly selected dogs from Cyprus, but it was reduced to 80% in a group of 50 dogs, infected with Taenia spp. A total of 6551 dogs (mainly of rural origin) was examined, including three large groups (N: 2928, 1761 and 1800) from the Government Control Area (GCA) in southern Cyprus and a small group (N: 62) from the Non-Government Control Area (NonGCA) in the northern part of the island. Among the dogs from the GCA, 184 (2.8%) tested positive for coproantigen; coproantigen prevalences were 2.6, 4.9 and 1.1% in these three groups, and of 62 dogs from the NonGCA 8.1% were positive. The calculated true prevalences of E. granulosus in the dog population of the GCA ranged between 0.0 and 3.58%. The predictive values of the test, based on a 0.2% prevalence, was >99.9% for negative results, but very low (7%) for coproantigen-positive results. However, the relatively small number of coproantigen-positive dogs can be treated with praziquantel or the results can further be confirmed by arecoline purging.
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echinococcus multilocularis coproantigen detection by enzyme linked immunosorbent assay in fox dog and cat populations
Journal of Parasitology, 1999Co-Authors: Peter Deplazes, I Tanner, P Alther, R C A Thompson, Johannes EckertAbstract:A sandwich enzyme-linked immunosorbent assay (ELISA) for the detection of Echinococcus multilocularis Coproantigens (EM-ELISA) was developed with polyclonal rabbit (solid phase) and chicken egg (catching) antibodies that were directed against E. multilocularis Coproantigens and somatic worm antigens, respectively. In experimentally infected dogs and cats, Coproantigens were first detectable 6-17 days postinfection (PI) in samples of 8 dogs (worm burdens at necropsy: 6,330-43,200) and from 11 days PI onward in samples of 5 cats infected with 20-6,833 worms. After anthelmintic treatment of 4 dogs and 5 cats at day 20 PI, coproantigen excretion disappeared within 3-5 days. The sensitivity of the ELISA was 83.6% in 55 foxes infected with 4-60,000 E. multilocularis, but reached 93.3% in the 45 foxes harboring more than 20 worms. The EM-ELISA was used in surveys of "normal" dog and cat populations in Switzerland. Among 660 dogs and 263 cats, 5 dogs and 2 cats exhibited a positive reaction. In 2 of these dogs (0.30%) and 1 cat (0.38%), intestinal E. multilocularis infections were confirmed by necropsy, polymerase chain reaction PCR, or both. The specificites of the ELISA in these groups were found to be 99.5% and 99.6%, respectively, if positive ELISA results that could not be confirmed by other methods were classified as "false positive" reactions.
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detection of echinococcus Coproantigens in stray dogs of northern spain
Applied parasitology, 1994Co-Authors: Peter Deplazes, S Jimenezpalacios, Bruno Gottstein, J Skaggs, Johannes EckertAbstract:An enzyme-linked immunosorbent assay (ELISA) was assessed for its suitability to diagnostically detect Echinococcus Coproantigens in fecal samples of dogs infected with E. granulosus. The specificity of the test was determined by investigating fecal samples from 177 Echinococcus-free dogs infected with Taenia spp., 41 dogs with non-taeniid helminths and 24 dogs free of helminth infections. An overall specificity of 97% was determined. The diagnostic sensitivity was in close association to the worm burden of infected individuals: when dogs harboured less than 100 worms, six from 21 samples (29%) were found to be positive in coproantigen ELISA, whereas sensitivity was much higher (23 ELISA-positive from 25 samples = 92%) when dogs had more than 100 worms. Despite the relatively low average sensitivity (63%), the test enabled detection of more than 90% of the biomass of adult Echinococcus present in the respective dog populations. Conclusively, coproantigen detection allows diagnosis of most individual intestinal Echinococcus infections relevant for the egg contamination of the environment and is therefore a valuable tool to determine the relative prevalence of adult stage E. granulosus prevalence in a given endemic area.
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detection of echinococcus Coproantigens by enzyme linked immunosorbent assay in dogs dingoes and foxes
Parasitology Research, 1992Co-Authors: Peter Deplazes, David Jenkins, Johannes Eckert, Bruno Gottstein, D Ewald, S JimenezpalaciosAbstract:An enzyme-linked immunosorbent assay (ELISA) was developed for the detection ofEchinococcus Coproantigens in fecal samples from dogs, dingoes or foxes infected with eitherE. granulosus orE. multilocularis. The ELISA was based on protein-A-purified polyclonal antibodies [anti-E. granulosus excretory/secretory (E/S) antigens]. The specificity of the assay as determined in 155 samples derived from carnivores that were free of helminth infection (n=37) or infected with non-Echinococcus cestodes (n=76) or with various nematodes (n=42) was found to be 98% overall. The diagnostic sensitivity was strongly dependent on the homologous worm burden. All 13 samples from foxes harboring >1,000E. multilocularis worms and 13 of 15 (87%) samples from dogs or dingoes containing >200E. granulosus worms were ELISA-positive, whereas 34 of 46 samples from foxes harboring 1,000E. granulosus each; a low worm burden (<1,000 tapeworms/animal) resulted in ELISA positivity in only 2 of 3 animals at 30 days post-infection at the earliest. All five dogs that had been experimentally infected withE. multilocularis tested positive in the coproantigen ELISA as early as on day 5 post-infection.
J. C. Allan - One of the best experts on this subject based on the ideXlab platform.
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Development of a Species-Specific Coproantigen ELISA for Human Taenia solium Taeniasis
The American Journal of Tropical Medicine and Hygiene, 2009Co-Authors: Maria Claudia Guezala, J. C. Allan, Silvia Rodriguez, Humberto Zamora, Alice Tembo, Philip S CraigAbstract:Taenia solium causes human neurocysticercosis and is endemic in underdeveloped countries where backyard pig keeping is common. Microscopic fecal diagnostic methods for human T. solium taeniasis are not very sensitive, and Taenia saginata and Taenia solium eggs are indistinguishable under the light microscope. Coproantigen (CoAg) ELISA methods are very sensitive, but currently only genus (Taenia) specific. This paper describes the development of a highly species-specific coproantigen ELISA test to detect T. solium intestinal taeniasis. Sensitivity was maintained using a capture antibody of rabbit IgG against T. solium adult whole worm somatic extract, whereas species specificity was achieved by utilization of an enzyme-conjugated rabbit IgG against T. solium adult excretory-secretory (ES) antigen. A known panel of positive and negative human fecal samples was tested with this hybrid sandwich ELISA. The ELISA test gave 100% specificity and 96.4% sensitivity for T. solium tapeworm carriers (N = 28), with a J index of 0.96. This simple ELISA incorporating anti-adult somatic and anti-adult ES antibodies provides the first potentially species-specific coproantigen test for human T. solium taeniasis.
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Coproantigens in taeniasis and echinococcosis
Parasitology International, 2006Co-Authors: J. C. Allan, Philip S CraigAbstract:The application of modern immunodiagnostic or molecular diagnostic techniques has improved the diagnosis of the taeniid cestode infections, echinococcosis and taeniasis. One particularly promising approach is the detection of parasite-specific antigens in faeces (Coproantigens). This approach has been applied to both Echinoccocus and Taenia species and it has gained increasingly widespread use. Taeniid coproantigen tests are based on either monoclonal or polyclonal antibodies raised against adult tapeworm antigens. These tests have the following common characteristics; they are largely genus-specific, specificity is high (>95%), parasite antigen can be detected in faeces weeks prior to patency, levels of coproantigen are independent of egg output, coproantigen is stable for days at a range of temperatures (-80 degrees C to 35 degrees C), for several months in formalin-fixed faecal samples, and coproantigen levels drop rapidly (1-5 days) following successful treatment. In the genus Taenia, most work has been done on Taenia solium and coproantigen tests have reliably detected many more tapeworm carriers than microscopy. For Echinococcus species, there is a broad positive correlation between test sensitivity and worm burden with a reliable threshold level for the test of >50 worms. Characterisation of taeniid Coproantigens in order to further improve the tests is ongoing. Studies indicate taeniid Coproantigens to include high molecular weight (>150 kDa), heavily glycosylated molecules with carbohydrate moieties contributing substantially to the levels of antigen detected in faeces. Application of the existing coproantigen tests in epidemiological and control programmes for Echinococcus and Taenia species infection has begun to contribute to an improved understanding of transmission and of surveillance of these important zoonotic cestodes.
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field trial of the coproantigen based diagnosis of taenia solium taeniasis by enzyme linked immunosorbent assay
American Journal of Tropical Medicine and Hygiene, 1996Co-Authors: J. C. Allan, Magda Velasqueztohom, Rodrigo Torresalvarez, Pablo Yurrita, Jose GarcianovalAbstract:A microplate-type enzyme-linked immunosorbent assay for the detection of Taenia species antigen in human feces was tested in field studies undertaken in two Guatemalan communities. The test was based on immunoglobulin G antibodies from a rabbit hyperimmunized to Taenia solium proglottides. Comparison was made with microscopy and patient interviews as a means of diagnosis. The coproantigen test result was positive in 79 of the 1,582 fecal samples examined. Parasitologic confirmation was made in 55 of these cases. The coproantigen test was the most sensitive technique used, detecting 2.6 times as many confirmed cases of taeniasis as microscopy, which diagnosed 21 cases. Only one case was detected by interviewing. Microscopy revealed on false-negative coproantigen result. Mass treatment of the population did not result in the detection of any additional cases. Twelve coproantigen-positive results were categorized as unconfirmed and an additional 12 as putative false-positive results, giving an overall specificity of 99.2% for the coproantigen test. Of the 34 taeniid tapeworms identified to the species level, all were T. solium. The practicalities of the use of such a test in epidemiologic studies on human taeniasis are discussed.
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partial characterization and time course analysis of hymenolepis diminuta Coproantigens
Journal of Helminthology, 1994Co-Authors: J. C. Allan, Philip S CraigAbstract:An analysis of Hymenolepis diminuta specific antigens in infected rat faeces was carried out. Using a capture type antibody sandwich ELISA assay based on a hyperimmune rabbit anti-worm somatic antisera it was demonstrated that, although antigen was present in faeces before patency, the onset of egg production led to a sharp increase in the levels of parasite antigen in the faeces. Levels of antigen in host faeces were independent of worm burden. Parasite eggs did not contribute significantly to faecal antigen levels. Western blot analysis indicated a number of highly specific antigens at around M(r) 69,000, M(r) 37,000, M(r) 50,000 and M(r) 27,000 with a low molecular weight smear at between M(r) 30,000 and M(r) 34,000 present in the faeces of H. diminuta infected rats. Some cross reaction occurred with an antigen of around M(r) 66,000 in the faeces of non H. diminuta infected rodents. Antibody activity against this antigen was removed by affinity adsorption of the antibody solution against normal rat faeces.
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dipstick dot elisa for the detection of taenia Coproantigens in humans
Parasitology, 1993Co-Authors: J. C. Allan, Ana Flisser, F Mencos, J Garcianoval, Elsa Sarti, Yunhai Wang, D Liu, Philip S CraigAbstract:A dipstick dot ELISA for detection of Taenia-specific Coproantigens was developed. The test was based on a sandwich ELISA using antibodies raised against adult Taenia solium. Antibodies were absorbed to nitrocellulose paper previously adhered to acetate plastic to form dipsticks. Once blocked with 5% skimmed milk and dried the antibody-coated dipsticks were stable for several weeks at room temperature. Both micro and dot ELISA formats were genus specific although the dot ELISA was less sensitive than the micro ELISA based on the same antiserum. During field studies, in which the majority of samples were tested in rural villages soon after collection, 3728 samples were tested. All samples were also examined by microscopy using formol ether concentration and individuals questioned to determine whether they were aware of being infected. After the initial diagnostic work individuals were treated with taeniacidal drugs for worm recovery. Use of the coproantigen test significantly increased the number of cases diagnosed. Of the 41 cases diagnosed by the three diagnostic techniques combined 31 were detected by the dipstick assay making it the most sensitive technique employed. The specificity of the dipstick assay was 99.9% with a positive predictive value of 88.6%. The combined diagnostic approach did not, however, diagnose all cases. The coproantigen test was fast and easy to use. Further improvements may make the dipstick test suitable for wide-scale use in field studies and diagnostic laboratories.
Johannes Eckert - One of the best experts on this subject based on the ideXlab platform.
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screening of dogs for echinococcus granulosus coproantigen in a low endemic situation in cyprus
Veterinary Parasitology, 2002Co-Authors: G Christofi, Peter Deplazes, N Christofi, I Tanner, P Economides, Johannes EckertAbstract:In the framework of an echinococcosis surveillance and control programme in Cyprus, a commercial enzyme-linked immunosorbent assay (ELISA) (CHEKIT ECHINOTEST) designed for the detection of Echinococcus granulosus and E. multilocularis Coproantigens was used in 1997-2000 for the investigation of large numbers of dogs. Most of the animals originated from areas where approximately 0.2% of the dogs had been found to be infected with E. granulosus in previous (1993-1996) arecoline surveys. The sensitivity of the coproantigen test was 83%, as determined in 35 dogs naturally infected with this cestode species. The specificity was 98% in 97 randomly selected dogs from Cyprus, but it was reduced to 80% in a group of 50 dogs, infected with Taenia spp. A total of 6551 dogs (mainly of rural origin) was examined, including three large groups (N: 2928, 1761 and 1800) from the Government Control Area (GCA) in southern Cyprus and a small group (N: 62) from the Non-Government Control Area (NonGCA) in the northern part of the island. Among the dogs from the GCA, 184 (2.8%) tested positive for coproantigen; coproantigen prevalences were 2.6, 4.9 and 1.1% in these three groups, and of 62 dogs from the NonGCA 8.1% were positive. The calculated true prevalences of E. granulosus in the dog population of the GCA ranged between 0.0 and 3.58%. The predictive values of the test, based on a 0.2% prevalence, was >99.9% for negative results, but very low (7%) for coproantigen-positive results. However, the relatively small number of coproantigen-positive dogs can be treated with praziquantel or the results can further be confirmed by arecoline purging.
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echinococcus multilocularis coproantigen detection by enzyme linked immunosorbent assay in fox dog and cat populations
Journal of Parasitology, 1999Co-Authors: Peter Deplazes, I Tanner, P Alther, R C A Thompson, Johannes EckertAbstract:A sandwich enzyme-linked immunosorbent assay (ELISA) for the detection of Echinococcus multilocularis Coproantigens (EM-ELISA) was developed with polyclonal rabbit (solid phase) and chicken egg (catching) antibodies that were directed against E. multilocularis Coproantigens and somatic worm antigens, respectively. In experimentally infected dogs and cats, Coproantigens were first detectable 6-17 days postinfection (PI) in samples of 8 dogs (worm burdens at necropsy: 6,330-43,200) and from 11 days PI onward in samples of 5 cats infected with 20-6,833 worms. After anthelmintic treatment of 4 dogs and 5 cats at day 20 PI, coproantigen excretion disappeared within 3-5 days. The sensitivity of the ELISA was 83.6% in 55 foxes infected with 4-60,000 E. multilocularis, but reached 93.3% in the 45 foxes harboring more than 20 worms. The EM-ELISA was used in surveys of "normal" dog and cat populations in Switzerland. Among 660 dogs and 263 cats, 5 dogs and 2 cats exhibited a positive reaction. In 2 of these dogs (0.30%) and 1 cat (0.38%), intestinal E. multilocularis infections were confirmed by necropsy, polymerase chain reaction PCR, or both. The specificites of the ELISA in these groups were found to be 99.5% and 99.6%, respectively, if positive ELISA results that could not be confirmed by other methods were classified as "false positive" reactions.
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detection of echinococcus Coproantigens in stray dogs of northern spain
Applied parasitology, 1994Co-Authors: Peter Deplazes, S Jimenezpalacios, Bruno Gottstein, J Skaggs, Johannes EckertAbstract:An enzyme-linked immunosorbent assay (ELISA) was assessed for its suitability to diagnostically detect Echinococcus Coproantigens in fecal samples of dogs infected with E. granulosus. The specificity of the test was determined by investigating fecal samples from 177 Echinococcus-free dogs infected with Taenia spp., 41 dogs with non-taeniid helminths and 24 dogs free of helminth infections. An overall specificity of 97% was determined. The diagnostic sensitivity was in close association to the worm burden of infected individuals: when dogs harboured less than 100 worms, six from 21 samples (29%) were found to be positive in coproantigen ELISA, whereas sensitivity was much higher (23 ELISA-positive from 25 samples = 92%) when dogs had more than 100 worms. Despite the relatively low average sensitivity (63%), the test enabled detection of more than 90% of the biomass of adult Echinococcus present in the respective dog populations. Conclusively, coproantigen detection allows diagnosis of most individual intestinal Echinococcus infections relevant for the egg contamination of the environment and is therefore a valuable tool to determine the relative prevalence of adult stage E. granulosus prevalence in a given endemic area.
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detection of echinococcus Coproantigens by enzyme linked immunosorbent assay in dogs dingoes and foxes
Parasitology Research, 1992Co-Authors: Peter Deplazes, David Jenkins, Johannes Eckert, Bruno Gottstein, D Ewald, S JimenezpalaciosAbstract:An enzyme-linked immunosorbent assay (ELISA) was developed for the detection ofEchinococcus Coproantigens in fecal samples from dogs, dingoes or foxes infected with eitherE. granulosus orE. multilocularis. The ELISA was based on protein-A-purified polyclonal antibodies [anti-E. granulosus excretory/secretory (E/S) antigens]. The specificity of the assay as determined in 155 samples derived from carnivores that were free of helminth infection (n=37) or infected with non-Echinococcus cestodes (n=76) or with various nematodes (n=42) was found to be 98% overall. The diagnostic sensitivity was strongly dependent on the homologous worm burden. All 13 samples from foxes harboring >1,000E. multilocularis worms and 13 of 15 (87%) samples from dogs or dingoes containing >200E. granulosus worms were ELISA-positive, whereas 34 of 46 samples from foxes harboring 1,000E. granulosus each; a low worm burden (<1,000 tapeworms/animal) resulted in ELISA positivity in only 2 of 3 animals at 30 days post-infection at the earliest. All five dogs that had been experimentally infected withE. multilocularis tested positive in the coproantigen ELISA as early as on day 5 post-infection.