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PubMed2001

Assessment of the epidemiological status of Echinococcus multilocularis in foxes in France using ELISA coprotests on fox faeces collected in the field.

The aim of this study was to estimate the relevance of Echinococcus multilocularis coproantigen detection in fox faeces collected in the field to identify different levels of endemicity for Echinococcus multilocularis on a large scale (n x 10 km(2)). Six study sites were selected in a high endemicity area and two study sites in a low endemicity area in eastern France on the basis of landscape composition. Sampling was undertaken in the winters of 1996-97, 1997-98 and 1998-99. At each site, (i) necropsy and intestine examination was undertaken on a sample of shot foxes (total number of foxes, 222), and (ii) fox faeces were collected in the field along road verges, and scored for degradation status (total number of faeces, 625). Fox faeces were also sampled in a control area (n=30) in western France in the summer of 1998. Intestines were examined according to the sedimentation method. Echinococcus multilocularis coproantigens were detected by using two ELISA tests: EM-ELISA and EmA9-ELISA. The necropsy prevalence in high and low endemicity areas was 63.3% and 19.4%, respectively, and the distribution of adult worms in the fox population was highly overdispersed (75.5% of the total biomass was harboured by 11.6% of foxes). Using the two ELISA tests, there was no difference in the detection of E. multilocularis coproantigens in field faeces, regardless of the degradation status. The medians of EM- and EmA9-ELISA OD values of field faeces in high endemicity area were significantly higher than in low endemicity area (P<0.001 for both ELISA). The distribution of EM-ELISA OD values in low endemicity area was significantly higher (P=0.002) than in the control area. Moreover, for the two ELISA, the observed ELISA OD value distributions in high endemicity area, low endemicity area and control area seemed representative of the distribution of adult worms in fox populations. These results indicate that E. multilocularis coproantigen detection in field faeces could serve for large-scale surveillance, as an alternative to necropsy.

Animals↗
PubMed2003

Identification and characterisation of two distinct Smad proteins from the fox-tapeworm Echinococcus multilocularis.

Members of the transforming growth factor-beta (TGF-beta) family of cytokines and their corresponding receptors regulate cellular key processes such as proliferation and differentiation, and could be involved in communication mechanisms between parasitic helminths and their hosts. A pivotal role in intracellular TGF-beta signalling is played by Smad factors which directly transmit incoming signals from the cell surface receptors to the nucleus. In this study, we have identified and characterised two novel members of the Smad family, EmSmadA and EmSmadB, which are expressed by the human parasite Echinococcus multilocularis. Based on amino acid sequence comparisons, both echinococcal Smad homologues could be classified as members of the R-Smad subfamily. EmSmadB showed a typical domain structure consisting of conserved MH1 and MH2 domains separated by a proline-rich linker region. EmSmadA, on the other hand, lacked an MH1 region and merely contained an MH2 domain, a feature which has so far not been described for R-Smads. Based on the structures of the corresponding chromosomal loci and on sequence features of the conserved L3 loop regions, EmSmadA and EmSmadB are most likely involved in the transmission of TGF-beta- and bone morphogenetic protein (BMP) signals, respectively. Yeast two-hybrid analyses revealed that both Echinococcus Smads are capable of homo- and heterodimer formations. However, while the formation of homodimers for EmSmadB required previous activation of the protein at the C-terminal SSVS motif, EmSmadA homodimers were already formed in the basal state of the factor. Upon expression of the Echinococcus Smads in human cells, EmSmadA, but not EmSmadB, was phosphorylated by the human TGF-beta type I receptor. Furthermore, both factors functionally interacted with human BMP receptors. By reverse transcriptase-PCR experiments, the encoding genes, emsmadA and emsmadB, were shown to be expressed in the larval stages metacestode and protoscolex during an infection of the intermediate host. Taken together, our data suggest an involvement of EmSmadA and EmSmadB in echinococcal developmental processes during natural infections and provide a solid basis for further investigations on TGF-beta signalling mechanisms in cestodes.

Amino Acid Sequence↗
PubMed1998

Dideoxy fingerprinting: application to the genotyping of Echinococcus.

Dideoxy fingerprinting is an efficient method for the detection of sequence variation in PCR-amplified DNA segments. It is a hybrid between single-strand conformation polymorphism and dideoxy sequencing, employing only one dideoxynucleotide in the sequencing reaction. Herein, we report the application of dideoxy fingerprinting to genetically type cestodes of the genus Echinococcus, utilising the mitochondrial cytochrome c oxidase subunit I as the gene sequence for analysis. All of the seven genotypes (G1, G4, G6, G8, O, V and M2) examined could be readily differentiated from one another by their characteristic and reproducible dideoxy fingerprinting profiles. Only subtle variation in profiles was detected among some of the eight isolates representing genotype G1, and no variation was detected between two samples of genotype G4 and of genotype M2. The capacity of dideoxy fingerprinting to detect all nucleotide variations over 150-250bp fragments indicates that it should be possible to distinguish among all of the genotypes of Echinococcus thus far described. Although employed herein to display sequence variation in the cytochrome c oxidase subunit I of Echinococcus, dideoxy fingerprinting could be used for the high-resolution analysis of nucleotide variations in other parasite genes, without the need for DNA sequencing. This has important implications for studying the genetic structure of parasite populations.

Animals↗
PubMed2002

Identification of Echinococcus granulosus eggs.

The eggs from Echinococcus granulosus contaminate the environment spreading out the disease among the herbivorous. The differential diagnosis of the embriophores recovered from the soil is very difficult by morphologic and immunologic methods. In this paper we evaluate the EgO/DNA-IM1 for identification of E. granulosus oncosphere DNA and differentiation of eggs from other Taeniid. The positive result of the PCR technique shows an amplification fragment of the expected size (285 bp) corresponding to the partial sequence of the mitochondrial gene of the cytochrome oxidase CO1 from E. granulosus (391 bp). The fragment is not present in the DNA from Echinococcus multilocularis, Taenia hydatigena, Taenia saginata, Diphyll-obothrium latum, and Hymenolepis nana. It could be useful to rule out Taenia taeniformis, Taenia solium, Taenia pisiformis, and Taenia crassiceps, which sequences do not belong to the primer. We concluded that the PCR amplification employing the EgO/DNA-IM1 primer set showed high sensitivity and specificity for the identification of Echinococcus granulosus eggs.

Animals↗
PubMed2002

Towards a taxonomic revision of the genus Echinococcus.

Echinococcus remains a significant public health problem worldwide and, in several regions, the aetiological agents of cystic hydatid disease/echinococcosis are extending their range. The taxonomy of Echinococcus has been a controversial issue for decades, but the outcome of recent molecular epidemiological studies has served to reinforce proposals made ten years ago to revise the taxonomy of Echinococcus. A formal nomenclature is essential for effective communication, and provides the stability that underpins epidemiological investigations. It will also serve to recognize the contribution of early taxonomists.

Animals↗
PubMed1991

Release and survival of Echinococcus eggs in different environments in Turkana, and their possible impact on the incidence of hydatidosis in man and livestock.

In Turkana, Kenya, a prevalence of hydatidosis of nearly 10% has been recorded among the pastoralists yet their livestock have a much lower prevalence of the disease. The present study investigated the release from dogs and subsequent survival of Echinococcus eggs in Turkana huts, water-holes and in the semi-arid environment. The results were compared with the survival of eggs of Taenia hydatigena and T. saginata. The study was repeated under the cooler and moister conditions found in Maasailand where livestock have a greater incidence of hydatid disease than in Turkana but where the incidence in man is ten times lower. The average number of Echinococcus eggs per proglottid is 823. Nine percent of these remain in proglottids 15 minutes after release from a dog and the released eggs lose their viability in less than two, 48 and 300 hours in the sun, huts and water in Turkana respectively: the major influencing factor being temperature. The greater survival of eggs in the houses, coupled with the fact that dogs congregate for most of the day in the small houses facilitating a close man:dog contact, provide ideal conditions for the transmission of the parasite to man. The hostile environmental conditions and lack of contact between dogs and livestock contributes to the lower infection rate in livestock. Conversely in Maasailand, Echinococcus eggs survive in the environment for longer than three weeks and in addition, dogs are used for herding. This partly explains the higher infection rate among Maasai livestock but the low human infection rate remains arcane and requires further study.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed2004

Echinococcus granulosus strain differentiation based on sequence heterogeneity in mitochondrial genes of cytochrome c oxidase-1 and NADH dehydrogenase-1.

Genetic analyses of Echinococcus granulosus isolates from different intermediate host species have demonstrated substantial levels of variation for some genotype (strain) clusters. To determine the range of genetic variability within and between genotypes we amplified and cloned partial cox1 and nadh1 genes from 16 isolates of E. granulosus from 4 continents. Furthermore, we sequenced different clones from a PCR product to analyse the intra-individual genetic variance. The findings showed a moderate degree of variance within single isolates and a significant degree of variance between the cluster of genotypes G1-G3 (sheep, Tasmanian sheep and buffalo strain), genotypes G4 (horse strain) and G5 (cattle strain) and the cluster of the genotypes G6 (camel strain) and G7 (pig strain). The variance of up to 2.2% within genotypes was relatively low compared with that of 4.3-15.7% among genotypes. The present results indicate that a re-examination of the classification of 5 genotypes of Echinococcus is warranted. Hence, our data highly support a re-evaluation of the taxonomy of the clades G1-G3, G4, G5, G6/7 and G8 (cervid strain) within the genus Echinococcus.

Animals↗
PubMed1985

Hydatid disease in the Turkana District of Kenya, IV. The prevalence of Echinococcus granulosus infections in dogs, and observations on the role of the dog in the lifestyle of the Turkana.

The prevalence of Echinococcus granulosus in dogs in the Turkana District of Kenya was 39.4% of 695 examined. Of these, 98 (35.8%) had heavy Echinococcus worm burdens (10(3)-5 X 10(4) ), while 54 (19.7%) and 122 (44.5%) had medium (201-1000) and light (1-200) burdens. The possible sources of these infections are discussed. The prevalence rate differed in various parts of the district, ranging from 63.5% in the northwest, where the highest incidence of human hydatidosis also occurs, to nil along the shores of Lake Turkana. Infection rates of 32.0% and 16.7% were recorded at Lokitaung (north-east) and Lodwar (central), while in the south 48.9% of dogs harboured Echinococcus. This latter figure is surprising as the area has a low incidence of human hydatidosis. The Turkana keep a large number of dogs, and the reasons for this and the social role of the dog in the district is discussed. No difference in susceptibility was found between Turkana-type dogs and those of mixed breeds from Nairobi when they were experimentally infected with hydatid protoscolices from man, camels, cattle, sheep and goats. However, it proved difficult to infect the Turkana-type of dogs with viable protoscolices of cattle origin. The reasons for this and its epidemiological implications remain unclear. It is suggested that droughts, which affect Turkana every six to ten years, may play an important role in the perpetuation of hydatid disease in the area.

Animals↗
PubMedDate not supplied

Echinococcus granulosus in wildlife in and around the Kosciuszko National Park, south-eastern Australia.

OBJECTIVE: To investigate the distribution of Echinococcus granulosus in wild dogs and foxes and hydatidosis in wildlife coexisting with foxes and wild dogs in and around Kosciuszko National Park. DESIGN: Prospective and ad hoc surveys by necropsy of definitive and intermediate hosts. PROCEDURE: Wild dogs and foxes were trapped at one location in the Kosciuszko National Park and at 7 locations around the periphery of the Park. Feral pigs, macropodid marsupials, wombats, and feral goats were collected at some of the same locations. The animals were humanely killed, their small intestines removed in the field, the contents collected, preserved and examined microscopically. All internal organs of intermediate hosts were examined for hydatid cysts. Unidentified lesions were examined histologically. RESULTS: Echinococcus granulosus tapeworms were found in wild dogs from all locations. Prevalence ranged up to 100% with worm burdens up to 300,000 worms. Prevalence in foxes ranged up to 50% in animals recovered from 5 locations. The worm burdens were usually less than 50 E. granulosus per fox. Hydatid cysts were found in all macropodid species. Prevalence (69%) and cyst fertility (100%) were highest in swamp wallabies (Wallabia bicolour). Prevalence of cysts in feral pigs ranged up to 49%. Less than 22% of the cysts were fertile. No cysts were found in any of the wombats or feral goats. CONCLUSION: Echinococcus granulosus occurs commonly in wildlife in and around the Kosciuszko National Park. High numbers of fertile cysts in swamp wallabies, a favoured dietary item for wild dogs in this region, suggests swamp wallabies are pivotal in maintaining transmission. Physical contact with wild dogs and foxes or accidental contact with wild canid faeces is a public health risk.

Animals↗
PubMedDate not supplied

Detection of Echinococcus granulosus coproantigens in faeces from naturally infected rural domestic dogs in south eastern Australia.

OBJECTIVE: To investigate the occurrence of Echinococcus granulosus in rural domestic dogs in farming areas around Yass, New South Wales, and Mansfield and Whitfield, Victoria. DESIGN: Faeces were collected per-rectally from farm dogs voluntarily presented by their owners in four farming districts in New South Wales and two in Victoria. PROCEDURE: Faeces were collected in the field, an extract prepared from each sample and E granulosus coproantigens detected in an ELISA. Farmers were also questioned about their dog feeding and worming practices. RESULTS: Echinococcus granulosus coproantigens were detected in 99 of 344 dogs (29%) from 95 farms in south eastern New South Wales and 38 of 217 dogs (17.5%) from 43 farms in Victoria. Cross-reactions between E granulosus coproantigen trapping antibody and coproantigens in faeces from dogs monospecifically infected with other species of intestinal helminthes (Taenia ovis, T hydatigena, T pisiformis, Spirometra ericacei, Dipylidium caninum, hookworm, Toxocara canis, Trichuris vulpis) were not evident. Dietary and worming data revealed many owners fed raw meat and occasionally offal from domestic livestock and wildlife to their dogs and few owners wormed their dogs frequently enough to preclude the chance of patent E granulosus being present in their dogs. CONCLUSION: Echinococcus granulosus occurs commonly in rural dogs in south eastern Australia and an education program promoting the public health importance of responsible management of rural dogs is urgently needed.

Animals↗
PubMedDate not supplied

Aspiration cytology of echinococcus oligarthrus. A case report.

BACKGROUND: Fine needle aspiration cytology is a useful technique in the diagnosis of several parasitic infections. The present case highlights the aspiration cytology findings in a case of Echinococcus oligarthrus infection, a rare variant of the Echinococcus species affecting humans. To the best of our knowledge, this is the first case report on the cytology of E oligarthrus in English. CASE: A submandibular swelling developed in a 14-year-old male. A mistaken diagnosis of Cysticercus cellulosae was made on the first aspirate and of a hydatid cyst (Echinococcus granulosus) on the second aspirate. A diagnosis of E oligarthrus was made on subsequent histopathologic examination of the excised lesion. CONCLUSION: This seems to be the first case report in English of the cytomorphology of E oligarthrus on fine needle aspiration cytology with histopathologic confirmation.

Adolescent↗
PubMed2001

Elevated carbohydrate antigen 19-9 (CA 19-9) in patients with Echinococcus infection.

The carbohydrate antigen 19-9 (CA 19-9), a determinant (sialylated lacto-N-fucopentaose 119) of a circulating oligosaccharide antigen, is a frequently used tumor marker. Echinococcus spp. infects humans throughout the world and may be able to synthesize closely related molecules which could interfere with the measurement and interpretation of CA 19-9 concentration. The main objective of the present study was to determine the range of CA 19-9 levels in the sera of patients infected by E. granulosus (cystic hydatide disease; CYSHD) or E. multilocularis (alveolar hydatide disease; ALVHD). Serum samples were collected from patients (aged 10-85 years) over a period of 5 years: from 19 patients with CYSHD and from 20 patients with ALVHD. Infection was confirmed by positive Echinococcus serology and clinical evidence provided by imaging and/or histopathological findings. CA 19-9 was detectable in 13 patients with CYSHD (13.5 +/- 8.5 kU/l) and 13 patients with ALVHD (30.0 +/- 21 kU/l; p < 0.05). Thus ALVHD patients exhibited a significantly higher plasma level of CA 19-9 than CYSHD patients. The serum level of CA 19-9 assessed with an increased cut-off value (> 22 kU/l) was elevated in nine (45%) of 20 ALVHD patients compared to two (11%) of 19 CYSHD patients (p < 0.05). Sera from patients with Echinococcus multilocularis infection contain substances which cross-react with CA 19-9. These substances originate either from the parasite or are synthesized by the host in response to the infection, and possibly bear the Lewis-a antigen or closely related structures which are recognized by anti-CA 19-9 antibodies. Our findings are relevant to the investigation of patients presenting with cystic lesions for which the differential diagnosis includes an infectious or neoplastic origin.

Adolescent↗
PubMed1986

The identification of eggs of Echinococcus by immunofluorescence using a specific anti-oncospheral monoclonal antibody.

A relatively simple and specific test has been developed to distinguish eggs of Echinococcus from those of other morphologically identical taeniid species. A specific anti-Echinococcus oncosphere monoclonal antibody was produced which binds in an indirect immunofluorescence test to egg-derived oncospheres of E. granulosus but not to those of other taeniid species, such as Taenia hydatigena, T. saginata, T. pisiformis, T. ovis, T. multiceps, or T. taeniaeformis. Specific fluorescence was obtained with oncospheres of E. granulosus derived from either hatch/activated viable eggs using artificial intestinal fluid or from hypochlorite/detergent treated eggs. The potential use of this test in the study of the transmission of Echinococcus in Turkana, Kenya, is discussed.

Animals↗
PubMed1989

A specific diagnostic antigen of Echinococcus granulosus with an apparent molecular weight of 8 kDA.

An echinococcus antigen with an apparent molecular weight of 8 kDa was identified as diagnostically important. An immunoblot assay using this antigen was 91% sensitive for surgically confirmed Echinococcus granulosus hydatid disease of the liver. Specificity was 100% for echinococcosis. Marked cross-reactivity was observed with serum specimens from patients with E. multilocularis and E. vogeli infections. The 8 kDa component was not related to the widely recognized echinococcus antigen 5.

Animals↗
PubMed1995

Immunodiagnosis of polycystic hydatid disease/polycystic echinococcosis due to Echinococcus vogeli.

A crude antigenic metacestode extract from Echinococcus vogeli was assessed by enzyme-linked immunosorbent assay (ELISA) and showed strong binding activity with serum antibodies from patients with polycystic echinococcosis. Major cross-reactions occurred with serum antibodies from patients with cystic and alveolar echinococcosis and from patients infected with other species of helminths. An E. vogeli antigen fraction, Ev2, was subsequently purified by immunosorption. The respective Ev2 ELISA demonstrated improved specificity, allowing discrimination of non-Echinococcus infections from polycystic echinococcosis. Based upon the calculation of a comparative (Ev-crude ELISA versus Ev2 ELISA) reactivity index, it became possible to discriminate all cystic echinococcosis cases, but only some alveolar echinococcosis cases, from polycystic echinococcosis. Immunoblot analyses revealed an antibody banding pattern highly conserved among polycystic, cystic, and alveolar echinococcosis. However, immunoblotting reliably distinguished between echinococcosis and all non-Echinococcus infections.

Animals↗
PubMedDate not supplied

The role of foxes Vulpes vulpes in the epidemiology of Echinococcus granulosus in urban environments.

OBJECTIVE: To survey the prevalence of intestinal worms, particularly Echinococcus granulosus, in foxes in Canberra. DESIGN: The locations of foxes seen in Canberra during this study were recorded. Foxes and macropod marsupials killed on the roads of Canberra were collected and examined for the presence of intestinal helminths and hydatid cysts respectively. METHOD: The intestinal contents of the foxes were washed through a fine sieve and examined microscopically. All helminths recovered were collected and identified. All the internal organs of the macropods were examined for any cystic lesions. RESULTS: Forty-five foxes and 44 macropods were examined. Echinococcus granulosus was found in three of the foxes (7%). Hydatid cysts were not found in the internal organs of any of the macropods examined. CONCLUSIONS: Echinococcus granulosus is present in the urban fox population of Canberra. This hitherto unreported aspect of the epidemiology of E. granulosus in Australia could be a potential public health risk to urban populations.

Animals↗
PubMed1998

[A survey of Echinococcus granulosus infection in Camelus bactrianus in north Xinjiang].

AIM: To determine the situation and characteristics of Echinococcus granulosus infection in camels (Camelus bacterianus) in our country. METHODS: The camels slaughtered in abattoir were examined for visceral infection of larval cestode of Echinococcus. The number and diameter of cysts were recorded and the content of cysts were examined microscopically to detect the protoscoleces. RESULTS: 185 out of 375 camels were positive, the infection rate was 49.3%. The metacestodes parasitized mainly in the liver and lung, the ratio between liver and lung involved was 1:0.64. The fertile cyst rate was 39.2%, the fertile cyst-carrying rate of camels was 34.8%, the cyst index was 7.53. The cyst wall was relatively thin and the cysts located singly on the surface of liver. There was no daughter cyst seen in fertile cysts. The average diameter of fertile cysts was 5.6 +/- 2.65 cm in liver and 4.83 +/- 2.03 cm in lung. The percentage of animals harboring calcified cysts was 64.3%. CONCLUSION: The infection rate of metacestodes of Echinococcus granulosus in Bactrian camel was very high in north Xinjiang and the characteristics of infection differ in some aspects from the local sheep and cattle and from dromedaries in Africa as well. Further study is needed to elucidate the significance of the infection of E. granulosus in Bactrian camels.

Animals↗
PubMedDate not supplied

[Echinococcus multilocularis in red foxes in Saxony-Anhalt: identification of areas of increased risk of infestation and association of the infestation probability with the average annual maximum temperature].

Between 1998 and 2004 1341 Red Foxes from 611 locations were examined parasitologically for Echinococcus multilocularis at the State Office of Consumer Protection Saxony-Anhalt. Examination was carried out in parallel to rabies monitoring. A period-prevalence of 9.2% of infestation was found. Employing a Scan Statistic a large area in the southwest of the federal state and two smaller areas of increased risk with respect to infestation with Echinococcus multilocularis were identified. The hypothesis of a negative association of the probability of infestation with the average annual maximum temperature of the location where the foxes were shot was supported by logistic regression analysis. A decreased probability of inactivation of Echinococcus multilocularis-oncospheres through heat and desiccation in areas of lower average annual maximum temperature seems to be likely.Thus, the infection pressure increases with reduced temperatures.

Animals↗