Evaluation of purified antigen fraction in the immunodiagnosis of cystic echinococcosis

Echinococcus granulosus antigen B fraction (AgB) was evaluated for its prognostic value in the serological follow-up of cystic echinococcosis (CE), compared to crude hydatid fluid (HF) as well as soluble somatic Echinococcus multilocularis antigen (Em). The sensitivity and specificity of enzyme-linked immunosorbent assays (ELISA) were compared examining 177 sera from patients with different clinical courses and outcome of CE and with other parasitic infections. AgB-ELISA in comparison to confirmed cystic echinococcosis has 96.4 % sensitivity and 97.2 % specificity, with 93.1 % positive predictive value and 98.6 % negative predictive value. The HF-ELISA was more sensitive than the AgB-ELISA, but its specificity was lower. Our results indicate that AgB-ELISA was more satisfactory for seroconfirmation of acute echinococcosis than HF-ELISA. Moreover, the AgB-ELISA has a potential key role in control measures implemented in patients undergoing surgery. In sera of patients more than 3 months after the treatment, no antibody response to antigen B was detected; however, with conventionally used HF-ELISA, they were still positive. The AgB is recommended for the confirmatory diagnosis. AgB-WB allocated low background with typical “triplet” bands at 8-12-16 kDa.     

Cystic Echinococcosis

Echinococcosis is one of the 17 neglected tropical diseases (NTDs) recognized by the World Health Organization. The two major species of medical importance are Echinococcus granulosus and Echinococcus multilocularis. E. granulosus affects over 1 million people and is responsible for over $3 billion in expenses every year. In this minireview, we discuss aspects of the epidemiology, clinical manifestations, and diagnosis of cystic echinococcosis or cystic hydatid disease caused by E. granulosus.     

Usefulness of Hydatid Cyst Fluid of Echinococcus granulosus Developed in Mice with Secondary Infection for Serodiagnosis of Cystic Echinococcosis in Humans

The aim of this work was to assess the usefulness of hydatid cyst fluid (HCF) of Echinococcus granulosus, obtained from mice experimentally infected with hydatid cyst tissue homogenates, for the serodiagnosis of cystic echinococcosis (CE) in humans. The sensitivity and specificity of HCF obtained from mice for the detection of immunoglobulin G (IgG) antibodies in the sera of CE patients were compared with those of HCF from sheep and/or from a human CE patient by using immunoblotting (IB) and an enzyme-linked immunosorbent assay (ELISA). HCFs obtained from three different host species all were highly useful for immunoblotting, and sera from 19 (95%) of 20 CE patients equally recognized the antigen B subunit (approximately 8 kDa). HCF from mice showed a cross-reaction with 9 of 20 alveolar echinococcosis (AE) sera (45%), whereas HCFs from two other host species cross-reacted with 14 of the AE sera (70%). Although 2 (10%) of 20 sera from neurocysticercosis (NCC) patients were false positive with HCF from both sheep and humans, none of these sera showed a positive reaction with HCF from mouse origin. ELISAs with HCFs from both mouse and sheep origins detected all 20 CE and AE sera; however, these ELISAs showed 45% (9 of 20) and 60% (12 of 20) false-positive reactions with 20 NCC sera, respectively. The presence of nonspecific human IgG in HCF obtained from a CE patient prevented us from applying it to the ELISA. HCF of E. granulosus, obtained from laboratory mice with a secondary infection with hydatid cyst tissue homogenates, appears to be highly useful for the serodiagnosis of CE in humans and may be useful in domestic animals.     

Development of an immunochromatographic test to detect antibodies against recombinant Em18 for diagnosis of alveolar echinococcosis

An immunochromatographic test (ICT) for the rapid detection of antibodies to Echinococcus multilocularis was developed. The ICT showed a sensitivity of 94% and a specificity of 95.4%. High degrees of agreement were observed between the ICT and an enzyme-linked immunosorbent assay (κ = 0.93) and between the ICT and immunoblot analysis (κ = 0.97). It is expected that the ICT developed in this study will be useful for the serodiagnosis of alveolar echinococcosis.     

Serological differentiation betweenEchinococcus granulosus andE. multilocularis infections in man

An enzyme-linked immunosorbent assay (ELISA) was adapted for the serological differential diagnosis of cystic or alveolar echinococcosis in man caused byEchinococcus granulosus orE. 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 ofE. multilocularis metacestode tissue. From the same source another antigen fraction (Em 2) with a high degree of specificity forE. multilocularis was prepared by immunosorption. Antigen Em 1 was equally sensitive for the detection of antibodies againstE. granulosus andE. multilocularis, whereas antigen fraction Em 2 appeared to be more specific forE. 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.     

Concepts in immunology and diagnosis of hydatid disease

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.     

Immunodiagnosis of alveolar echinococcosis by enzyme-linked immunosorbent assay using a partially purified Em18/16 enriched fraction.

An improved enzyme-linked immunosorbent assay (ELISA) system using partially purified Eml8/16 enriched fraction (PP-Em18/16) prepared by isoelectric focusing was evaluated for serodiagnosis of alveolar echinococcosis (AE). The PP-Em18/16-ELISA was compared with Em2plus-ELISA by using sera from AE and cystic echinococcosis (CE) patients in China, where both AE and CE are endemic; sera from CE patients in Australia, where only CE exists; and sera from patients with cysticercosis, paragonimiasis, or sparganosis in Korea, where no indigenous AE or CE exists. We used Em2plus-ELISA as a standard ELISA and found 24.6% (17 of 69 specimens) cross-reactivity with sera from CE. Furthermore, some of the sera from paragonimiasis, sparganosis, and cysticercosis patients were also cross-reactive in the Em2plus-ELISA. When we tested for similar cross-reactivity in the same sera from CE patients by PP-Em18/16-ELISA (23.2%, 16 of 69), it became evident that the specificity of the PP-Em18/16-ELISA was better than that of the Em2plus-ELISA, since no sera from patients with the examined parasitic diseases except CE showed cross-reactivity. Some CE patients from China showed exceptionally high levels of antibody in comparison with those of CE patients from Australia, where no AE occurs. It is speculated that these patients with strongly positive cases of CE from China may have been exposed to both species of Echinococcus.     

In vitro efficacy of triclabendazole and clorsulon against the larval stage of Echinococcus multilocularis

Alveolar echinococcosis (AE) caused by the cestode Echinococcus multilocularis (E. multilocularis) is endemic in wide areas of the Northern hemisphere. Untreated AE progresses and leads to death in more than 90 % of cases. Until the advent of benzimidazoles, no antihelminthic drugs were available to cure AE. Benzimidazoles have greatly improved the prognosis of patients with AE. However, benzimidazoles have only a parasitostatic effect on E. multilocularis. Albendazole (ABZ) must sometimes be withdrawn because of adverse events. Alternative drugs are urgently needed. The antihelminthic triclabendazole (TCZ) and clorsulon (CLS) are more effective than ABZ to cure infections by the liver flukes Fasciola spp. The efficacy of TCZ and CLS was investigated on an in vitro culture of E. multilocularis larval tissue. E. multilocularis vesicles were evaluated for their morphology before and after adding TCZ, TCZ sulfoxide (TCZSX) and CLS to the larval tissue culture. TCZ at the concentrations of 20 μg/ml culture solution led to maximum vesicle damage within 12 days and of 25 μg/ml within 13 days, and TCZSX at the concentrations of 20 μg/ml within 20 days and of 25 μg/ml within 14 days. Contrary, CLS added at 5, 10 and 15 μg/ml to culture solution did not lead to any vesicle damage. TCZ is a promising further candidate drug for the treatment of AE.     

Echinococcus multilocularis in south-eastern Europe (Romania)

Echinococcus multilocularis, the causative agent of alveolar echinococcosis (AE) in humans, has been found in 4.8% of 561 red foxes originating from various regions of Romania. Infected foxes were identified in 8 of 15 counties with average prevalence rates between 1.7% and 14.6%. In previous studies, E. multilocularis was not found in 535 foxes from three counties, but larval stages (metacestodes) were present in four species of rodents. Furthermore, AE was diagnosed in two patients. Experiences from other European regions indicate that several factors (such as increasing fox populations with higher parasite prevalences and urban cycles of the parasite) may result in an increased infection risk for humans.     

Echinococcus multilocularis infection presenting clinically as cholangiocarcinoma

Cases of alveolar echinococcosis (liver cyst) caused by Echinococcus multilocularis are rare in the UK, but are increasing secondary to migration and travel. We report a case of alveolar echinococcosis that presented clinically as a cholangiocarcinoma. At histology, vesicles unusually contained protoscoleces, a feature more commonly seen in cases of Echinococcus granulosus. PCR confirmed the organism as E. multilocularis, avoiding misdiagnosis and subsequent mismanagement.     

Specific IgG Responses to Recombinant Antigen B and Em18 in Cystic and Alveolar Echinococcosis in China

An understanding of the correlation of the specific antibody responses and the disease phase is essential in evaluating diagnostic values of immunological tests in human echinococcosis. In this study, 422 echinococcosis patients diagnosed by ultrasonography, including 246 with cystic echinococcosis (CE), 173 with alveolar echinococcosis (AE), and 3 with dual infection, were tested for specific IgG in sera against recombinant AgB (rAgB) and recombinant Em18 (rEm18) in an enzyme-linked immunosorbent assay. As a result, rAgB-specific antibody was detected in 77.6% of CE and 86.1% of AE patients, while rEm18-specific antibody was present in 28.9% of CE and 87.3% of AE patients. Additionally, all three patients with dual infection exhibited specific antibodies responding to rAgB and rEm18. Further analysis revealed that rAgB-specific antibody was elevated in a significantly greater proportion (87.3%) of CE patients with cysts at active or transitional stages (CE1, CE2, or CE3), compared to 54.8% of other patients with cysts at an early or an inactive stage (CL or CE4 or CE5). Furthermore, rAgB-specific antibody was detected in 95.6% of CE2 cases, which was statistically greater than that (73.7%) in CE1 patients. Although rEm18-specific antibody was elevated in 28.9% of CE patients, the positive reaction was much weaker in CE than in AE cases. Serum levels and concentrations of rEm18-specific antibody were further indicated to be strongly disease phase correlated in AE patients, with positive rates of 97.4% in cases with alveolar lesions containing central necrosis and 66.7% in patients with early alveolar lesions that measured ≤5 cm.Humans acquire the infection of echinococcosis by accidental ingestion of eggs excreted with feces of carnivores harboring the adult worms of Echinococcus spp. The eggs hatch in the small intestine of humans, releasing the oncosphere, which migrates via the portal system into various organs and then develops into the metacestode stage. The larval parasite can establish itself in any part of the human body but most frequently does so in the liver (32). Diagnosis of human echinococcosis is primarily based on the pathognomonic features in images obtained using imaging techniques including ultrasonography, computed tomography (CT), and magnetic resonance imaging (MRI). Of these techniques, B-ultrasound is much more widely applied, as CT and MRI are too expensive and largely inaccessible in most areas where echinococcosis is endemic. Criteria for classification of cystic echinococcosis (CE) and alveolar echinococcosis (AE) have been proposed based on stage-specific ultrasound images (20, 36). Briefly, on the basis of conformational features of cysts, CE lesions are differentiated into six types: CL, CE1, CE2, CE3, CE4, and CE5. The CL type refers to a cystic lesion of a parasite origin and without a clear rim, indicating the parasite is at a very early stage of development. The CE1 type describes a unilocular simple cyst with uniform anechoic content and, importantly, with a visible wall, while the CE2 type is characterized by multivesicular, multiseptated cysts in which daughter cysts may partially or completely fill the unilocular mother cyst. The presence of CE1 or CE2 cysts is indicative of an active stage of the disease. The CE3 type is distinguished by detachment of the cyst membrane and/or partial degeneration of cyst content, suggestive of a transitional parasite. A CE4 or CE5 type of cyst shows an involution, with a necrotic or inactive parasite, with the features of complete degeneration of cyst content for CE4 and a calcified cyst wall for CE5 (36). In contrast, AE lesions are characterized by a nonhomogenous hyperechoic tumor-like structure with a poorly defined verge and containing scattered calcifications and/or a central necrotic cavity (1), and they are further differentiated into three types and eight subtypes based on the features and sizes of lesions, including AE1, AE2, and AE3 (20). In detail, AE1 refers to alveolar lesions measuring ≤5 cm, normally without central necrosis detected, and the type is differentiated further as AE1s (single lesion) and AE1m (multiple lesion) subtypes and indicates an early stage of the disease. Alveolar lesions that measure >5 cm and ≤10 cm are classified as AE2 and include three subtypes, recorded as AE2s (single lesion), AE2m (multiple lesions), and AE2f (presence of central necrotic fluid, regardless of the number of lesions), suggestive of a developing parasite, while AE lesions that measure >10 cm in diameter are confirmed as AE3, indicative of an advanced stage of the disease; this type includes three subtypes, i.e., AE3s (single lesion), AE3m (multiple lesions), and AE3f (presence of central necrotic fluid).Meanwhile, several antigens, such as antigen B (AgB) (15, 23, 24, 26) for cystic echinococcosis and for Echinococcus multilocularis Em2a (8), II/3 (34), II/3-10 (27), EM10 (5), EM4 (9), and Em18 (12, 30), have been confirmed to be of potential use in serodiagnosis of human echinococcosis. However, relatively little information about the correlation between the specific antibody levels in humans and disease pathology or stage is available (29).In this study, serum levels and concentrations of specific IgG antibodies in human CE and AE patients at different stages were determined by enzyme-linked immunosorbent assay (ELISA) using recombinant antigen B (rAgB) and recombinant Em18 (rEm18) as antigens.     

Evaluation of an enzyme-linked immunosorbent assay (ELISA) with affinity-purified Em18 and an ELISA with recombinant Em18 for differential diagnosis of alveolar echinococcosis: results of a blind test

Alveolar echinococcosis (AE) is the most potentially lethal parasitic zoonosis of the nontropical areas in the northern hemisphere, where cystic echinococcosis (CE) is also endemic. Both AE and CE are highly endemic in China, and both serologic detection of echinococcosis, either AE or CE, and differentiation of AE from CE are crucial problems. Evaluation of Western blot analysis (WB) and enzyme-linked immunosorbent assay (ELISA) for the Em18 antigen, using affinity-purified and recombinant Em18, was carried out "blindly" using 60 human sera from patients diagnosed in France. The results were compared with those obtained using a commercially available Echinococcus WB immunoglobulin G (IgG) kit developed in France. The Em18 WB and Echinococcus WB IgG showed very similar results for detection of AE. Both affinity-purified Em18 or a recombinant Em18 WB and Echinococcus WB IgG seem useful for identification of AE, and the latter seems appropriate for both AE and CE, whereas affinity-purified Em18 ELISA and the newly developed recombinant Em18 ELISA appear to be suitable for detection of AE, especially for epidemiological surveys.     

Distinctive cytokine,chemokine, and antibody responses in Echinococcus multilocularis-infected patients with cured,stable, or progressive disease

Metacestode larvae of the tapeworm Echinococcus multilocularis can cause alveolar echinococcosis (AE), a severe parasitic disease in man, which, if it remains untreated, may cause organ failure and death. Spontaneous and parasite antigen-induced cellular responses were studied in patients with cured, stable, and progressive AE to differentiate the response profiles between the distinct states of infection. Antibody reactivity was evaluated in AE patients with cured, stable, and progressive disease. The spontaneous cellular release of pro-inflammatory IL-31 and IL-33 was clearly depressed in all AE patients, while regulatory IL-27, anti-inflammatory SDF-1/CXCL12, and eosinophil granulocyte attracting Eotaxin-1, Eotaxin-2, and Eotaxin-3 (CCL11, CCL24, CCL26) were enhanced with disease progression. Such distinctive response profiles could be applied for monitoring of AE disease progression or regression. E. multilocularis metacestode (Em) antigens (entire metacestode EmAg as well as EmVesicles) stimulated in vitro IL-31, IL-33, Eotaxin-1, Eotaxin-3, and CXCL12 cytokine and chemokine responses, which were similarly present in all AE patient groups, while regulatory IL-27 was suppressed and pro-inflammatory Eotaxin-2 was enhanced. E. multilocularis metacestode-specific IgG1, IgG3, and IgE responses progressively diminished with regression from active to stable and cured AE. IgG2 and IgG4 reactivity remained similarly high in stable and progressive cases, and lessened only with cured AE. Antibody reactivity against E. multilocularis vesicle antigen distinctively separated between cured, stable, or progressive AE, with the exception of IgG4. In sum, the combined and longitudinal study of several cytokines and chemokines, together with the evaluation of E. multilocularis vesicle-specific antibody responses, should provide a better understanding of the immune response during progression and regression of AE, and may help to improve the staging of AE patients.     

Evaluation of a New Immunochromatographic Test Using Recombinant Antigen B8/1 for Diagnosis of Cystic Echinococcosis

Diagnosis of cystic echinococcosis (CE) is based on the identification of the cyst(s) by imaging, using immunodiagnostic tests mainly as complementary tools in clinical settings. Among the antigens used for immunodiagnosis, previous studies described a good performance of the recombinant antigen B8/1 (rAgB) in an enzyme-linked immunosorbent assay (ELISA) format; however, in remote parts of areas where the disease is endemic, the implementation of an ELISA is difficult, so a more simple, rapid, and reliable method such as the immunochromatographic test (ICT) is required. In this study, using a set of 50 serum samples from patients with surgically confirmed CE, we compared the performance of an ICT and that of an ELISA using the rAgB. The overall sensitivities of ICT and ELISA were not statistically different (78% versus 72%; P = 0.36). The overall agreement between both tests was moderate (κ = 0.41; P < 0.01). Concordance between ICT and ELISA was substantial or almost perfect for patients with liver involvement (κ = 0.65; P < 0.001) and patients with more than one hydatid cyst (κ = 0.82; P < 0.001), respectively. Moreover, specificity analysis using a total of 88 serum samples from healthy individuals (n = 20) and patients (n = 68) with other parasitic infections revealed that ICT had a specificity of 89.8%. ICT and ELISA had similar performance for the detection of specific antibodies to E. granulosus, and ICT had a high specificity, opening the possibility of using ICT as a screening tool in rural settings.     

Epidemiology,clinical manifestations and diagnosis of zoonotic cestode infections: an update

This paper reviews the literature on zoonotic cestode infections with specific reference to the years 1999-2003. The sources and prevalence of various zoonotic tapeworm infections caused by adult and larval stages of the genera Taenia, Echinococcus, Diphyllobothrium, Hymenolepis and Dipylidium continue to be an important cause of morbidity and mortality, not only in most underdeveloped countries but also in industrialized countries, particularly in rural areas or among immigrant groups from endemic areas. The review gives a detailed report on recent molecular epidemiological studies on the taxonomy and phylogenetic variations in Echinococcus granulosus, immunological tests and imaging techniques used in epidemiological surveys and clinical investigations of important adult and larval tapeworm infections of animals and humans. Larval stages or metacestodes of Taenia solium, Echinococcus spp. and pseudophyllidean tapeworms (Spirometra syn. Diphyllobothrium spp.) may reside in various tissues of their intermediate hosts, including humans. In particular, Cysticercus cellulosae (T. solium) and the larvae of E. granulosus, and E. multilocularis, which are predominantly located in the liver, lungs and central nervous system forming various types of cysts, lead to a complex of systemic diseases such as cysticercosis, cystic echinococcosis and alveolar echinococcosis, respectively. Relatively rare clinical manifestations are seen in the muscles, subcutaneous tissue, spleen, kidneys, bones and body cavities.     

Immunodiagnosis of Echinococcus infections: confirmatory testing and species differentiation by a new commercial Western Blot

The Echinococcus Western Blot IgG (LDBIO Diagnostics, Lyon, France), using a whole larval antigen from Echinococcus multilocularis, was evaluated for serodiagnosis and differentiation between two human parasitic infections of worldwide importance: cystic echinococcosis, due to Echinococcus granulosus, and alveolar echinococcosis, due to E. multilocularis. Fifty and 61 serum samples from patients with cystic and alveolar echinococcosis, respectively, were used for assessing diagnostic sensitivity. The sensitivity of the assay was compared with those of screening tests used for these applications. Sera used for assessing cross-reactivities were from 154 patients with other diseases, either parasitic or not. The assay allowed the detection of serum immunoglobulin G antibodies in 97% of Echinococcus-infected patients. It had a higher sensitivity than screening assays for the detection for each echinococcosis. The assay allowed us to correctly distinguish between E. granulosus- and E. multilocularis-infected patients in 76% of cases. It did not allow us to distinguish active from inactive forms of both echinococcoses. The occurrence of cross-reactivities with neurocysticercosis indicates the necessity for retesting sera with species-specific antigens, for rare patients with neurologic disorders. This study shows the usefulness of the commercially available Echinococcus Western Blot IgG for the serological confirmation of human echinococcosis.     

Production and immunoanalytical application of 32 monoclonal antibodies against metacestode somatic antigens of Echinococcus multilocularis

Alveolar echinococcosis is a rare but potentially fatal disease. Immunodiagnosis based on antibodies or antigens plays an important role in its diagnosis. In this study, metacestode somatic antigens of Echinococcus multilocularis were used to immunize BALB/c mice, and hybridomas were formed by cell fusion. Making use of the inherent effect of monoclonal antibody techniques to isolate different epitopes, we obtained a repertoire of 32 monoclonal antibodies against the metacestode somatic antigens. These monoclonal antibodies were used to investigate the specificity and localization of the metacestode antigens by enzyme-linked immunosorbent assay and immunohistochemistry, respectively. Nine antibodies specifically reacted with E. multilocularis, while 14 and ten cross-reacted with Echinococcus granulosus and Taenia saginata, respectively. Twenty-five antibodies stained the laminated layer. Eight reacted with the tegument of the protoscolex. Fourteen antibodies recognized the germinal layer. Most of the monoclonal antibodies can react with the antigen Em2. One antibody can react with antigen Em2 and Em10. One antibody that cross-reacted with T. saginata stained the germinal layer and protoscolex, especially its hooklets and suckers, but could not react with Em2 and Em10 antigens. It detected protein bands at 26 and 52 kDa. Two E. multilocularis-specific monoclonal antibodies stained both the germinal and laminated layers and could be used not only to purify specific antigens but also for immunohistochemical studies of E. multilocularis. In summary, these 32 monoclonal antibodies could have potential applications as useful tools in further studies of E. multilocularis antigen profiles.     

Molecular characterization of Echinococcus granulosus in south-eastern Romania: evidence of G1–G3 and G6–G10 complexes in humans

Echinococcus granulosus is the aetiological agent of cystic echinococcosis (CE), which is a public health problem in many eastern European countries, particularly in Romania, where the infection causes a high number of human and animal cases. To shed light on the transmission patterns of the parasite, we performed a genotyping analysis on 60 cyst samples obtained from patients who live in south-eastern Romania and who underwent surgery for liver or lung CE. DNA was extracted from the endocysts or the cyst fluids, and fragments of cytochrome c oxidase subunit 1 and NADH dehydrogenase subunit 1 mitochondrial genes (cox1 and nd1, respectively) were amplified by PCR and sequenced. We found that most of the samples analysed (59/60) belonged to the G1–G3 complex (E. granulosus sensu stricto), which contains the most widespread and infective strains of the parasite. We also identified the first human patient infected by a non-G1–G3 genotype of E. granulosus in this country. As the DNA sequence of this cyst sample showed maximum homology with the G6–G10 complex (Echinococcus canadensis), this is, in all likelihood, a G7 genotype, which is often found in pigs and dogs in most countries of eastern and south-eastern Europe.     

Prevalence survey and first molecular characterization of Echinococcus granulosus in France

Human cystic echinococcosis (hydatid disease) caused by the Echinococcus granulosus tapeworm continues to be a substantial cause of morbidity and mortality in many parts of the world. France is still considered as endemic area, but the current infestation by E. granulosus of intermediate hosts in France remains currently unknown due to the absence of official data reporting for the last 20 years. A 1-year prevalence survey was conducted in the 24 slaughterhouses of ten departments of the South of France. We demonstrate that the E. granulosus parasite is still currently present at low prevalence at slaughterhouses in the study area (4 cases for 100,000 sheep and 3 cases for 100,000 cattle). In addition, we assess the presence of genotype G1 in infected animals and identify for the first time in France genotypes G2 and G3 of E. granulosus sensu stricto.