The immunodiagnosis of Echinococcus multilocularis infection

Molecular phylodiagnosis of Echinococcus multilocularis and Echinococcus granulosus among canids in Guilan province, northern Iran

Canine-transmitted worms and an uncontrolled deworming program of stray dogs have caused that accurate diagnosis of zoonotic parasites received notable attention in endemic regions. This study aimed to assess the presence of E. multilocularis and E. granulosus infections in canids from Guilan province, northern Iran. A total of 272 fecal samples from carnivores were collected across 24 different regions in Guilan province between 2023 and 2024. All fecal specimens were observed following concentration and flotation techniques. DNAs of taeniid eggs were extracted, amplified, and sequenced targeting of specific mitochondrial Cox1 gene for E. granulosus and NAD 1 gene for E. multilocularis. On the base of molecular and phylogenetic analysis 1.47 % (in jackal) and 25 % (in dogs and jackal) of samples were positive for E. multilocularis and E. granulosus sensu strico G1 genotype, respectively. Molecular technique was found to be more sensitive in detecting infection in comparison with conventional techniques. Sequence analysis of Cox1 indicated a high genetic diversity (Haplotype diversity; 0.933; Number of haplotypes, h: 7) in E. granulosus G1. Current findings show that canids particularly jackals play potential role of definitive host in maintenance and transmission dynamic of E. multilocularis and E. granulosus in northern Iran. The presence of these infections is of particular concern in Guilan province due to the high influx of tourists, increasing the risk of transmission to humans. Therefore, the implementation of preventive programs is warranted to apply hygienic practices and adjusting deworming programs for the canids and at-risk individuals in the region.

Immunoprotective effect and mechanism of rEg.P29 against CD4 + T cell-deficient mice with Echinococcus multilocularis infection

Alveolar echinococcosis (AE) is a zoonotic parasitic disease caused by infection with the larval stage of Echinococcus multilocularis and a major challenge to human public health. Vaccines are the most effective way to prevent and control infectious diseases. We previously revealed that the Echinocuccus granulosus recombinant protein P29 is a good vaccine candidate against E. granulosus. However, the protective and immunological mechanism of rEg.P29 against E. multilocularis remain unclear. In this study, CD4 + T cell-deficient mice are transferred with spleen CD4 + T cells isolated from wild-type mice and subjected to rEg.P29 immunization, and then these immunized mice are infected with E. multilocularis. The cyst inhibition rate is calculated by weighing the body and cyst weights. The level of antibody is detected by ELISA. Flow cytometry is used to detect the level of IFN-γ production by CD4 + T and CD8 + T cells. The cytokines in culture supernatant are detected by ELISA. The expressions of CD44 and CD62L on memory T cells are determined by flow cytometry. The results show the cyst inhibition rate is 41.52% after adoptive transfer of CD4 + T cells. Furthermore, the levels of IgG, IgM, IgA and IgE in serum are significantly increased compared with those in the PBS group. The IFN-γ-secretion by CD8 + T cells and the level of IFN-γ in culture supernatant are obviously increased; and the number of CD4 + T cells is increased, but the number of IFN-γ producing CD4 + T cells has no significant difference compared with PBS group. In addition, the number of CD44 +CD62L ‒CD8 + memory T cells in the spleen is significantly increased, while the number of CD44 ‒CD62L + CD8 + memory T cells is not significantly altered. Collectively, rEg.P29 can alleviate E. multilocularis infection by inducing humoral immune responses and CD8 + T cell responses.

China's prevention and control experience of echinococcosis: A 19-year retrospective

Echinococcosis poses a significant threat to public health. The Chinese government has implemented prevention and control measures to mitigate the impact of the disease. By analyzing data from the Chinese Center for Disease Control and Prevention and the State Council of the People's Republic of China, we found that implementation of these measures has reduced the infection rate by nearly 50% between 2004 to 2022 (from 0.3975 to 0.1944 per 100,000 person-years). Nonetheless, some regions still bear a significant disease burden, and lack of detailed information limites further evaluation of the effects on both alveolar and cystic echinococcosis. Our analysis supports the continuing implementation of these measures and suggests that enhanced wildlife management, case-based strategies, and surveillance systems will facilitate disease control.

Past and Present of Diagnosis of Echinococcosis: A Review (1999-2021)

The larval forms of taeniid cestodes belonging to the genus Echinococcus are the source of the zoonotic infection known as echinococcosis. Alveolar and cystic echinococcosis are caused by Echinococcus multilocularis and Echinococcus granulosus (s. s) respectively. It is endemic in several regions of the world. In this systematic review, we describe diagnosis, and the species (human, canids, livestock, and small rodents) affected by cystic (CE) and alveolar echinococcosis (AE). From 1999 to 2021, we searched the online directory through PubMed, SCOPUS, Web of Science, and google scholar. Among the 37,700 records found in the online databases, 187 publications met our eligibility requirements. The majority of investigations employed a range of diagnostic methods, such as ELISA, imaging, copro-PCR, necropsy or arecoline hydrobromide purgation, morphological cestode confirmation, and fecal sieving/flotation to detect and confirm Echinococcus infection. ELISA was the most commonly used method followed by PCR, and imaging. The research team retrieved data describing the incidence or assessment of the diagnostic test for E. multilocularis in humans (N = 99), canids (N = 63), small ruminants (N = 13), large ruminants (N= 3), camel (N= 2), pigs (N=2) and small mammals (N= 5). This study was conducted to explore the diagnostic tools applied to detect echinococcosis in humans as well as animals in prevalent countries, and to report the characteristic of new diagnostic tests for disease surveillance. This systematic review revealed that ELISA (alone or in combination) was the most common method used for disease diagnosis and diagnostic efficacy and prevalence rate increased when recombinant antigens were used. It is highly recommended to use combination protcols such as serological with molecular and imaging technique to diagnose disease. Our study identified scarcity of data of reporting echinococcosis in humans/ animals in low-income or developing countries particularly central Asian countries. Study reports in small rodents indicate their role in disease dissemination but real situation in these host is not refected due to limited number of studies. Even though echinococcosis affects both public health and the domestic animal sector, therefore, it is important to devise new and strengthe implementation of the existing monitoring, judging, and control measures in this estimate.

Optimization of single-tube nested PCR for the detection of Echinococcus spp

Echinococcosis is a serious zoonotic life-threatening parasitic disease caused by metacestodes of Echinococcus spp., and appropriate sensitive diagnosis and genotyping techniques are required to detect infections and study the genetic characterization of Echinococcus spp. isolates. In this study, a single-tube nested PCR (STNPCR) method was developed and evaluated for the detection of Echinococcus spp. DNA based on the COI gene. STNPCR was 100 times more sensitive than conventional PCR and showed the same sensitivity to common nested PCR (NPCR); but with a lower risk of cross-contamination. The limit of detection of the developed STNPCR method was estimated to be 10 copies/μL of the recombinant standard plasmids of Echinococcus spp. COI gene. In clinical application, 8 cyst tissue samples and 12 calcification tissue samples were analysed by conventional PCR with outer and inner primers and resulted in 100.00% (8/8) and 8.33% (1/12), 100.00% (8/8) and 16.67% (2/12) positive reactions, respectively, while STNPCR and NPCR were all able to identify the presence of genomic DNA in 100.00% (8/8) and 83.33% (10/12) of the same samples. Due to its high sensitivity combined with the potential for the elimination of cross-contamination, the STNPCR method was suitable for epidemiological investigations and characteristic genetic studies of Echinococcus spp. tissue samples. The STNPCR method can effectively amplify low concentrations of genomic DNA from calcification samples and cyst residues infected with Echinococcus spp. Subsequently, the sequences of positive PCR products were obtained, which were useful for haplotype analysis, genetic diversity, and evolution studies of Echinococcus spp., and understanding of Echinococcus spp. dissemination and transmission among the hosts.

Basic Operative Tactics for Pulmonary Echinococcosis in the Era of Endostaplers and Energy Devices

Human echinococcosis is a zoonotic infection caused by the larvae of the tapeworm species Echinococcus. The liver is the most common location for a primary echinococcosis. However, the parasite may bypass or spread from the liver to the lungs, causing primary or secondary pulmonary echinococcosis, respectively. Pulmonary echinococcosis is a clinically challenging condition in which anthelminthic regiments are important, but surgery has the central role in removing the cysts and preventing recurrences. Surgical treatment may involve cystotomy, enucleation, capitonnage, or atypical resections, which occasionally are in combination with hepatic procedures. The utilization of modern devices is greatly underdescribed in surgery for thoracic infections, even though these facilitate much of the work. Therefore, this article aims to describe pulmonary echinococcosis and the role of modern surgical devices in the treatment process. Furthermore, we report surgical treatment of three different cases of pulmonary echinococcosis. Surgeries of uncomplicated and ruptured hepatic or pulmonary cysts are described. Simple small pulmonary echinococcal lesions can be excised by endostaplers both for diagnostic and curative reasons. Larger cysts can be removed by energy devices unless large bronchial air leaks occur. Complicated cysts require treatment by more extensive techniques. Inexperienced surgeons should not abstain but should carefully decide preoperatively how to proceed.

Alveolar and neotropical echinococcosis

The urgency of the problem of human alveolar and neotropic echinococcosis is due to polymorphism and the severity of clinical manifestations. The purpose and result of the work is to summarize the data available in the literature on the etiology, epidemiology, clinic, diagnosis, treatment, prevention of alveolar and neotropic echinococcosis in humans. Conclusion. The causative agent of human alveolar echinococcosis is E. multilocularis, neotropic – E. vogeli, E. oligarthra. The liver and lungs are most often affected, less often other organs of the abdominal cavity, bones, brain, spinal cord, eyes, etc. Diagnostics is carried out on the basis of a complex of clinical, instrumental, serological, molecular genetic studies. Treatment includes surgical removal of parasitic cysts and drug therapy.

Genetic diversity of Echinococcus spp. in wild carnivorous animals in Kazakhstan

Background and Aim:

The study of Echinococcus infection among farm animals in Kazakhstan was carried out to monitor the invasion among livestock and map the data obtained. Unfortunately, there are only partial data on the study of echinococcosis among wild carnivores in Kazakhstan, which makes it difficult to conduct a comparative analysis of the epidemiological situation among wild animals. The present study aimed to estimate the genetic diversity of Echinococcus spp. (Leuckart, 1863) in Kazakhstan based on sequence analysis of cytochrome c oxidase subunit 1 (cox1) and dehydrogenase subunit 1 (nad1) of worms isolated from wild carnivorous animals wolf (Canis lupus), red fox (Vulpes vulpes) and corsac (Vulpes corsac).

Materials and Methods:

DNA from parasite tissue was used as a template for the amplification of the two mitochondrial genes cox1 and nad1. Sequencing was performed according to the manual for the Seq Studio Genetic Analyzer. The multiple alignments of obtained sequences were performed using the ClustalW algorithm in Mega (v.11) software. Alignments were exported as a Nexus extension and used as input for TCS v1.21 for the identification of haplotypes. The phylogenetic analysis was constructed according to the neighbor-joining method using Mega (v.11) software.

Results:

Analysis of the extensiveness of echinococcosis invasion showed that 6.3% were wolves, 18.2% were corsacs, and 85% were foxes. In total, 159 adults of Echinococcus spp. from the three species of animals in different parts of Kazakhstan were analyzed, and 17 individual biological samples were successfully sequenced. Sequence analysis of cox1 and nad1 genes revealed two types of echinococcosis – Echinococcus granulosus in red foxes and wolves, and Echinococcus multilocularis in corsacs. Sequencing of a portion of the mitochondrial genome made it possible to determine seven haplotypes of the pathogen in the studied samples of E. granulosus. Molecular analysis of cox1 and nad1 genes of E. multilocularis revealed three new haplotypes, which have significant variability compared with other studied Asian haplotypes.

Conclusion:

This study made it possible to fill the gaps in understanding the localization of the foci of the spread of the echinococcosis pathogen among the main wild carnivores and to determine the species reservoir of the pathogen in the greater territory of Kazakhstan.

Echinococcus granulosus Protoscolex DM9 Protein Shows High Potential for Serodiagnosis of Alveolar Echinococcosis

Alveolar echinococcosis (AE) caused by infection with E. multilocularis metacestode, represents one of the most fatal helminthic diseases. AE is principally manifested with infiltrative, proliferating hepatic mass, resembling primary hepatocellular carcinoma. Sometimes metastatic lesions are found in nearby or remote tissue. AE diagnosis largely depends on imaging studies, but atypical findings of imaging features frequently require differential diagnosis from other hepatic lesions. Serological tests may provide further evidence, while obtaining reliable AE materials is not easy. In this study, alternative antigens, specific to AE were identified by analyzing E. granulosus protoscolex proteins. An immunoblot analysis of E. granulosus protoscolex showed that a group of low-molecular-weight proteins in the range from 14 kDa to 16 kDa exhibited a sensitive and specific immune response to AE patient sera. Partial purification and proteomic analysis indicated that this protein group contained myosin, tubulin polymerization promoting protein, fatty-acid binding protein, uncharacterized DM9, heat shock protein 90 cochaperone tebp P-23, and antigen S. When the serological applicability of recombinant forms of these proteins was assessed using enzyme-linked immunosorbent assay, DM9 protein (rEgDM9) showed 90.1% sensitivity (73/81 sera tested) and 94.5% specificity (172/181 sera tested), respectively. rEgDM9 showed weak cross-reactions with patient sera from the transitional and chronic stages of cystic echinococcosis (3 to 5 stages). rEgDM9 would serve as a useful alternative antigen for serodiagnosis of both early- and advanced-stage AE cases.

Hepatic Alveolar Echinococcosis

Hepatic alveolar echinococcosis (HAE) is a rare but severe zoonosis caused by the pseudotumoral intrahepatic development of the larval stage of the tapeworm Echinococcus multilocularis. HAE is present only in the Northern Hemisphere, predominantly in China. Currently, there is a significant resurgence of cases in historically endemic areas associated with emergence of HAE in countries not previously concerned. Today, in European countries, HAE is often discovered by chance; however, clinicians should be made aware of opportunistic infections that progressively emerged recently as a result of therapeutic or pathological immunosuppression. Ultrasonography is the key first-line diagnostic procedure, with specific serology providing confirmation in 95% of the cases. Albendazole, only parasitostatic, is the mainstay for treatment. Surgical resection, if feasible, is the gold standard for treatment, and more patients are currently eligible for this option because of an earlier diagnosis. The prognosis has considerably improved but remains poor in countries where access to care is less favorable.

Seroprevalence of human cystic echinococcosis in South Kashmir, India

Cystic echinococcosis is a zoonotic disease that causes economic losses and public health problems throughout the globe. Present study was undertaken to estimate the seroprevalence of cystic echinococcosis in humans of South Kashmir and to determine the risk factors associated with this disease. The present study was carried out from April 2017 to March 2018, during which 458 blood samples (from 222 males and 236 females) were collected from selected subjects from 12 villages of four districts along with demographic characteristics. Samples were analyzed by an Enzyme-linked Immunosorbent Assay (ELISA) (commercially prepared kit) for detection of immunoglobulin IgG against cystic echinococcosis. Out of 458 samples, 20(4.36%) samples were found positive. Results implied that the seroprevalence of cystic echinococcosis in South Kashmir had significant relationship with age, gender and occupation (P < .05). Seroprevalence for cystic echinococcosis was significantly higher among males, children, and illiterate persons.

A rare case of the simultaneous location of Echinococcus multilocularis in the liver and the head of the pancreas: case report analysis and review of literature

Background

Echinococcosis multilocularis (Hydatid Disease - HD) is a zoonotic disease caused by the larval form of Echinococcus multilocularis (EM). The main sites for this zoonosis are the Middle East, China, India, Alaska, and Siberia. It is rather rare in Europe. In Poland, the Warmian-Masurian Province is the endemic region for Echinococcus multilocularis. The clinical manifestation of the disease is dependent on the location, the size of the cyst and the development stage of the parasite. Considering the uncommon character of echinococcosis in Central Europe, especially such located in the areas outside the liver and lungs, the authors would like to present a case of coexistence in one patient of two EM foci in the liver and the head of the pancreas.

Case presentation

We present a clinical case of a 32-year-old man who was diagnosed with a cystic lesion with septa and calcification in the sixth segment of the liver and a suspicious change in the head of the pancreas. ELISA Em 2 plus test was positive, Western Blot method - the P-5 pattern showed an image that is characteristic of an EM infection. The sixth liver segment with a tumour and a tumour from the head of pancreas were excised by means of laparotomy. On the 6th day after the surgery the patient was discharged from hospital without complications and in good condition. Currently, he is under the control of a parasitic and zoonotic clinic. He takes an 800 mg daily dosage of Albendazole.

Conclusions

The presented clinical case shows that if we have a patient with cystic / tumour change in the pancreas and positive immunological tests, CT and MRI of the abdominal cavity are usually sufficient in order to fully diagnose and to qualify such a person for surgery. The most effective treatment is surgical treatment supplemented with pre- and postsurgical treatment with Albendazole.

Field evaluation of an immunochromatographic test for diagnosis of cystic and alveolar echinococcosis

Background

The larval stages of the tapeworms Echinocoocus granulosus and Echinococcus multilocularis are the causative agents of human cystic echinococcosis (CE) and human alveolar echinococcosis (AE), respectively. Both CE and AE are chronic diseases characterised by long asymptomatic periods of many years. However, early diagnosis of the disease is important if treatment and management of echinococcosis patients are to be successful.

Methods

A previously developed rapid diagnostic test (RDT) for the differential detection of CE and AE was evaluated under field conditions with finger prick blood samples taken from 1502 people living in the Ganzi Tibetan Autonomous Prefecture, China, a region with a high prevalence for both forms of human echinococcosis. The results were compared with simultaneously obtained abdominal ultrasonographic scans of the individuals.

Results

Using the ultrasonography as the gold standard, sensitivity and specificity, and the diagnostic accuracy of the RDT were determined to be greater than 94% for both CE and AE. For CE cases, high detection rates (95.6–98.8%) were found with patients having active cysts while lower detection rates (40.0–68.8%) were obtained with patients having transient or inactive cysts. In contrast, detection rates in AE patients were independent of the lesion type. The positive likelihood ratio of the RDT for CE and AE was greater than 20 and thus fairly high, indicating that a patient with a positive test result has a high probability of having echinococcosis.

Conclusions

The results suggest that our previously developed RDT is suitable as a screening tool for the early detection of human echinococcosis in endemic areas.

Large-scale evaluation of a rapid diagnostic test for human cystic echinococcosis

Cystic echinococcosis (CE) is a neglected zoonotic disease, diagnosed through clinical findings, imaging techniques, and serology, for which many serological tests are available. Here we report a rapid unit assay, the immunochromatographic VIRapid® HYDATIDOSIS test (Vircell, Granada, Spain), potentially suitable for laboratories in low-prevalence or poorly equipped areas. This test was evaluated with a large retrospective cohort (224 sera), including patients suffering from CE or from other parasitic or liver diseases. The test was also assessed in routine conditions with a prospective cohort (115 sera) in areas where both cystic and alveolar echinococcoses have been diagnosed. Its performance (in terms of sensitivity, specificity, and both positive and negative likelihood ratios) was similar to an ELISA based on a crude antigen. Our study shows that this test performs adequately in the diagnostic process, when used with caution, especially regarding cross-reactivity with other parasitic diseases.

Laboratory Diagnosis of Echinococcus spp. in Human Patients and Infected Animals

Among the species composing the genus Echinococcus, four species are of human clinical interest. The most prevalent species are Echinococcus granulosus and Echinococcus multilocularis, followed by Echinococcus vogeli and Echinococcus oligarthrus. The first two species cause cystic echinococcosis (CE) and alveolar echinococcosis (AE) respectively. Both diseases have a complex clinical management, in which laboratory diagnosis could be an adjunctive to the imaging techniques. To date, several approaches have been described for the laboratory diagnosis and followup of CE and AE, including antibody, antigen and cytokine detection. All of these approaches are far from being optimal as adjunctive diagnosis particularly for CE, since they do not reach enough sensitivity and/or specificity. A combination of several methods (e.g., antibody and antigen detection) or of several (recombinant) antigens could improve the performance of the adjunctive laboratory methods, although the complexity of echinococcosis and heterogeneity of clinical cases make necessary a deep understanding of the host-parasite relationships and the parasite phenotype at different developmental stages to reach the best diagnostic tool and to make it accepted in clinical practice. Standardization approaches and a deep understanding of the performance of each of the available antigens in the diagnosis of echinococcosis for the different clinical pictures are also needed. The detection of the parasite in definitive hosts is also reviewed in this chapter. Finally, the different methods for the detection of parasite DNA in different analytes and matrices are also reviewed.

Biochemical Characterization of Echinococcus multilocularis Antigen B3 Reveals Insight into Adaptation and Maintenance of Parasitic Homeostasis at the Host-Parasite Interface

Alveolar echinococcosis (AE) caused by Echinococcus multilocularis metacestode is frequently associated with deleterious zoonotic helminthiasis. The growth patterns and morphological features of AE, such as invasion of the liver parenchyme and multiplication into multivesiculated masses, are similar to those of malignant tumors. AE has been increasingly detected in several regions of Europe, North America, Central Asia, and northwestern China. An isoform of E. multilocularis antigen B3 (EmAgB3) shows a specific immunoreactivity against patient sera of active-stage AE, suggesting that EmAgB3 might play important roles during adaptation of the parasite to hosts. However, expression patterns and biochemical properties of EmAgB3 remained elusive. The protein profile and nature of component proteins of E. multilocularis hydatid fluid (EmHF) have never been addressed. In this study, we conducted proteome analysis of EmHF of AE cysts harvested from immunocompetent mice. We observed the molecular and biochemical properties of EmAgB3, including differential transcription patterns of paralogous genes, macromolecular protein status by self-assembly, distinct oligomeric states according to individual anatomical compartments of the worm, and hydrophobic ligand-binding protein activity. We also demonstrated tissue expression patterns of EmAgB3 transcript and protein. EmAgB3 might participate in immune response and recruitment of essential host lipids at the host-parasite interface. Our results might contribute to an in depth understanding of the biophysical and biological features of EmAgB3, thus providing insights into the design of novel targets to control AE.

Investigation of the use of serology and ultrasonography to detect hepatic cystic echinococcosis in Heilongjiang, China, using a Bayesian framework

BACKGROUND

Cystic echinococcosis (CE) is a public health problem in China. However, the prevalence and incidence of CE in Heilongjiang province is still poorly understood. Because there is no perfect gold standard, evaluation of ultrasound (US) and serological methods have been limited. This study evaluated the use of these two diagnostic methods for the diagnosis of CE in suspected cases.

METHODS

A total of 522 suspected hepatic CE patients, as well as their demographic and clinical features were collected and detected by immunoglobulin (IgG)-ELISA and US. The marginal posterior densities of sensitivity and specificity for both tests, and the prevalence of hepatic CE amongst participants, were estimated from the product of the likelihood function of observed and latent data by a Bayesian framework.

RESULTS

Most of the patients were from rural areas. The most common symptom was upper abdominal pain. The antibody-positive proportion determined by IgG-ELISA was 24.33% (127/522), significantly higher than with US examination (17.24%, 90/522). Bayesian analysis indicated that the estimated prevalence of CE amongst suspected cases was 17.70% (95% credible interval: 14.23-21.54%). The sensitivity and specificity of the ELISA test were 92.63% and 90.37%, and that of US were 93.05% and 98.44%, respectively. Among US-confirmed hepatic CE cases, the male to female ratio was 0.46 and the peak age group was 40-49 years.

CONCLUSIONS

The results of the current study demonstrate that CE is present in Heilongjiang province. They also suggest that, whilst ultrasonography appears to be the detection modality of choice, serology may have a use for detection of infection in individuals suspected to be infected. This may have applications for surveillance within the province.

Spatiotemporal Expression Patterns and Antibody Reactivity of Taeniidae Endophilin B1

Larval Taeniidae, such as metacestodes of Taenia solium, Echinococcus granulosus, and Echinococcus multilocularis, produce chronic and fatal helminthic diseases. Proper identification of these zoonotic cestodiases is often challenging and is hampered in some clinical settings. Endophilin B1 plays critical roles in the maintenance of membrane contours and endocytosis. We isolated proteins homologous to endophilin B1 from T. solium, Taenia saginata, and Taenia asiatica The three Taeniidae endophilin B1 proteins shared 92.9 to 96.6% sequence identity. They harbored a Bin1/amphiphysin/Rvs (BAR) domain and residues for a dimeric interface but lacked a SRC homology 3 (SH3) domain. Endophilin B1 showed a unique immunological profile and was abundantly expressed in the tegumental syncytium of Taeniidae metacestodes and adults. Bacterially expressed recombinant T. solium endophilin B1 (rTsMEndoB1) demonstrated a sensitivity of 79.7% (345/433 cases) for serodiagnosis of larval Taeniidae infections. The protein showed strong immune recognition patterns against sera from patients with chronic neurocysticercosis, cystic echinococcosis, or advanced-stage alveolar echinococcosis. Adult Taeniidae infections exhibited moderate degrees of positive antibody responses (65.7% [23/35 samples]). rTsMEndoB1 showed some cross-reactivity with sera from patients infected with Diphyllobothriidae (23.6% [25/106 samples]) but not with sera from patients with other parasitic diseases or normal controls. The specificity was 91.7% (256/301 samples). The positive and negative predictive values were 93.6% and 73.4%, respectively. Our results demonstrate that Taeniidae endophilin B1 may be involved in the control of membrane dynamics, thus contributing to shaping and maintaining the tegumental curvature. rTsMEndoB1 may be useful for large-scale screening, as well as for individual diagnosis and follow-up surveillance of Taeniidae infections.

Evaluation of reactivity to Echinococcus spp. among rural inhabitants in Poland

A group of 172 rural inhabitants from eastern Poland (68 males and 104 females, mean age 49.0 ± 12.0 years) was examined for the presence of antibodies against Echinococcus granulosus and Echinococcus multilocularis. A population of 38 healthy urban dwellers from the city of Lublin (17 males and 21 females, mean age 36.2 ± 9.6 years) were examined as a control group. Sera of 22 rural inhabitants (12.8%) reacted positively to Echinococcus granulosus hydatid fluid antigen in the screening test. A cross-reactivity was observed with two serum samples that tested positive in ELISA for E. granulosus. Three serum samples were tested positive for E. multilocularis using the Em2plus ELISA assay and also positive for Western blot. None of the members of control group showed the presence of a seropositive reaction to Echinococcus spp. The reactivity to Echinococcus spp. among rural inhabitants decreased with age and this correlation was statistically significant (R = -0.197151, p = 0.009535). The percentage of positive findings was the highest (50.0%) in the youngest age group (14-20). No significant correlations were found between responses to interview questions (possession of domestic and farm animals, contact with wild animals, eating unwashed berries, drinking unboiled water) and the presence of seropositive reactions to Echinococcus spp. The presented results seem to indicate that echinococcosis is still a current problem in Poland that should not be neglected and, moreover, indicates the need for improvement in the routine laboratory diagnostics of Echinococcus spp. by standardizing the ELISA and Western blot tests.

An Echinococcus multilocularis Antigen B3 Proteoform That Shows Specific Antibody Responses to Active-Stage Alveolar Echinococcosis

Alveolar echinococcosis (AE), caused by the Echinococcus multilocularis metacestode, represents one of the most frequently fatal zoonoses. Early diagnosis significantly reduces morbidity and mortality associated with AE. Diagnosis of AE largely depends on a combination of imaging and serological tests due to its minimal clinical manifestations. Several antigens derived from the whole worm and protoscolex have been targeted for AE serodiagnosis, while the antigenic properties of E. multilocularis hydatid fluid (EmHF) are unclear. We observed two AE-specific 6- and 8-kDa antigen proteoforms through an immunoproteome array of the EmHF. We identified these proteins as representing an E. multilocularis antigen B3 (EmAgB3) isoform, and the proteins were shown to be encoded by the same gene. We cloned the gene and expressed the recombinant EmAgB3 protein (rEmAgB3) in Escherichia coli. rEmAgB3 exhibited sensitivity of 90.9% (80/88 cases) and specificity of 98.5% (597/606 samples) by immunoblotting. The positive and negative predictive values were 89.9% and 98.6%, respectively. The protein did not show antibody responses to 33 AE sera collected during posttreatment follow-up monitoring. Mouse sera experimentally infected with AE protoscoleces began to demonstrate specific antibody responses to native and recombinant EmAgB3 6 months after infection. At that stage, fully mature metacestode vesicles that harbored the brood capsule, primary cell, and protoscolex were observed within an AE mass(es). The response declined along with worm degeneration. Our results demonstrate that the immune responses to this EmAgB3 isoform were highly correlated with worm viability accompanied with AE progression. rEmAgB3 is a promising biomarker for serological assessment of AE patients.

Echinococcosis in wild carnivorous species: epidemiology, genotypic diversity, and implications for veterinary public health

Echinococcosis is a zoonosis caused by helminths of the genus Echinococcus. The infection, one of the 17 neglected tropical diseases listed by the World Health Organization, has a cosmopolitan distribution and can be transmitted through a variety of domestic, synanthropic, and sylvatic cycles. Wildlife has been increasingly regarded as a relevant source of infection to humans, as demonstrated by the fact that a significant proportion of human emerging infectious diseases have a wildlife origin. Based on available epidemiological and molecular evidence, of the nine Echinococcus species currently recognized as valid taxa, E. canadensis G8-G10, E. felidis, E. multilocularis, E. oligarthrus, E. shiquicus, and E. vogeli are primarily transmitted in the wild. E. canadensis G6-G7, E. equinus, E. granulosus s.s., and E. ortleppi are considered to be transmitted mainly through domestic cycles. We summarize here current knowledge on the global epidemiology, geographical distribution and genotype frequency of Echinococcus spp. in wild carnivorous species. Topics addressed include the significance of the wildlife/livestock/human interface, the sympatric occurrence of different Echinococcus species in a given epidemiological scenario, and the role of wildlife as natural reservoir of disease to human and domestic animal populations. We have also discussed the impact that human activity and intervention may cause in the transmission dynamics of echinococcosis, including the human population expansion an encroachment on shrinking natural habitats, the increasing urbanization of wildlife carnivorous species and the related establishment of synanthropic cycles of Echinococcus spp., the land use (e.g. deforestation and agricultural practices), and the unsupervised international trade and translocation of wildlife animals. Following the 'One Health' approach, we have also emphasized that successful veterinary public health interventions in the field of echinococcosis requires an holistic approach to integrate current knowledge on human medicine, veterinary medicine and environmental sciences.

Primary cerebral alveolar echinococcosis: mycology to the rescue

A case of primary cerebral alveolar echinococcosis with a favorable outcome is reported. A universal fungal PCR enabled this diagnosis, while the initial serological analysis remained noncontributive.

Canine echinococcosis: global epidemiology and genotypic diversity

Canine echinococcosis is a potential zoonotic infection caused by the adult form of several cestode species belonging to the genus Echinococcus, of which E. granulosus sensu lato and E. multilocularis are the most epidemiologically relevant. Dogs infected with E. granulosus and E. multilocularis are widely regarded as the main source of infection for human cystic and alveolar echinococcosis, diseases that cause substantial morbidity and socio-economic burden in several regions of the world. Following our previous review on the global situation of cystic echinococcosis in livestock species (Cardona and Carmena. Vet. Parasitol. 2013;192:10-32), we summarize here current knowledge on the global epidemiology, geographical distribution and molecular diversity of Echinococcus spp. infection in dogs. We address relevant topics including the implications of the increasing urbanization of wildlife species such as foxes, coyotes, and dingoes in the establishment of urban cycles of Echinococcus spp., or the rising concerns regarding the role of unsupervised translocation of infected dogs in spreading the infection to Echinococcus-free areas. The involvement of wildlife species as natural reservoirs of disease to domestic animals and humans and the epidemiological significance of the sympatric occurrence of different Echinococcus species in the same geographical region are also debated. Data presented are expected to be useful for policy makers, educational and health authorities responsible for designing and implementing effective measures for disease control and prevention.

Differential diagnosis of cystic and alveolar echinococcosis using an immunochromatographic test based on the detection of specific antibodies

Human cystic and alveolar echinococcoses are zoonotic diseases caused by the larval stages of Echinococcus granulosus and Echinococcus multilocularis, respectively. As the diseases are co-endemic in many areas of the world, a simple and rapid test for the differential diagnosis of cystic echinococcosis (CE) and alveolar echinocoocosis (AE) is needed. Here, we describe the development of an immunochromatographic test (ICT) using crude hydatid cyst fluid and a recombinant 18-kDa protein (rEm18) as antigens for the detection of E. granulosus and E. multilocularis antibodies in serum samples. The ICT was evaluated with serum samples from 195 echinococcosis patients from different endemic areas in northwestern China. These included 144 from CE patients, 51 from AE patients, 67 from patients with other parasitic diseases, 13 from patients with serous hepatic cysts, and 60 from healthy individuals. The sensitivity and specificity of the ICT for CE were 91.0 and 96.9% and for AE were 98.0 and 99.3% with diagnostic efficiencies of 94.1 and 99.1%, respectively. No significant differences and high degrees of agreement were found between the ICT and an enzyme-linked immunosorbent assay for both CE and AE. Five serum samples from cysticercosis patients and one serum sample from a healthy control were found positive for CE with the ICT. These findings indicate that this test allows for discrimination between both forms of human echinococcosis. In conclusion, the ICT developed in this study is a promising tool for the simultaneous detection and discrimination of CE and AE. This test will be useful for serodiagnosis of CE and AE in clinical settings and screening programs.

Molecular identification of Echinococcus multilocularis infection in small mammals from Northeast, Iran

BACKGROUND

Alveolar echinococcosis is a zoonotic disease caused by the metacestode of Echinococcus multilocularis. Many species of small mammals, including arvicolid rodents or Ochotona spp., are natural intermediate hosts of the cestode. The main aim of this study was to identify natural intermediate hosts of E. multilocularis in Chenaran County, Razavi Khorasan Province, northeastern Iran, where the prevalence of infected wild and domestic carnivores is high.

METHODOLOGY/PRINCIPAL FINDINGS

A program of trapping was carried out in five villages in which this cestode was reported in carnivores. The livers of 85 small mammals were investigated for the presence of E. multilocularis infection using multiplex PCR of mitochondrial genes. Infections were identified in 30 specimens: 23 Microtus transcaspicus, three Ochotona rufescens, two Mus musculus, one Crocidura gmelini, and one Apodemus witherbyi.

CONCLUSIONS/SIGNIFICANCE

A range of small mammals therefore act as natural intermediate hosts for the transmission of E. multilocularis in Chenaran County, and the prevalence suggested that E. multilocularis infection is endemic in this region. The existence of the life cycle of this potentially lethal cestode in the vicinity of human habitats provides a significant risk of human infection.

Hydatid cyst of spleen: a diagnostic challenge

Although splenic involvement alone in hydatid disease is very rare, spleen is the third most common organ involved in hydatid disease. The rarity of splenic hydatid disease poses a diagnostic challenge for clinicians, particularly in non-endemic areas. As the hydatid cyst can present as a simple cyst without having the classic serological and imaging features, and later can lead to life-threatening complications like anaphylaxis, hydatid disease of spleen should be considered in differential in every patient in endemic areas with cystic lesion of spleen until proved otherwise. The author used the keyword “splenic hydatid cyst” in PubMed and reviewed the scientific literatures published from January 1965 to June 2012. The present review is to accentuate the incidence, classification, clinical and pathophysiological features, differential diagnosis, diagnostic modalities, and treatment choices of hydatid cyst of spleen along with follow-up strategy and newer treatment approaches.

Detection of Echinococcus multilocularis in carnivores in Razavi Khorasan province, Iran using mitochondrial DNA

Background

Echinococcus multilocularis is the source of alveolar echinococcosis, a potentially fatal zoonotic disease. This investigation assessed the presence of E. multilocularis infection in definitive hosts in the Chenaran region of Razavi Khorasan Province, northeastern Iran.

Methodology/Principal Findings

Fecal samples from 77 domestic and stray dogs and 14 wild carnivores were examined using the flotation/sieving method followed by multiplex PCR of mitochondrial genes. The intestinal scraping technique (IST) and the sedimentation and counting technique (SCT) revealed adult Echinococcus in the intestines of five of 10 jackals and of the single wolf examined. Three jackals were infected only with E. multilocularis but two, and the wolf, were infected with both E. multilocularis and E. granulosus. Multiplex PCR revealed E. multilocularis, E. granulosus, and Taenia spp. in 19, 24, and 28 fecal samples, respectively. Echinococcus multilocularis infection was detected in the feces of all wild carnivores sampled including nine jackals, three foxes, one wolf, one hyena, and five dogs (6.5%). Echinococcus granulosus was found in the fecal samples of 16.9% of dogs, 66.7% of jackals, and all of the foxes, the wolf, and the hyena. The feces of 16 (21.8%) dogs, 7 of 9 (77.8%) jackals, and all three foxes, one wolf and one hyena were infected with Taenia spp.

Conclusions/Significance

The prevalence of E. multilocularis in wild carnivores of rural areas of the Chenaran region is high, indicating that the life cycle is being maintained in northeastern Iran with the red fox, jackal, wolf, hyena, and dog as definitive hosts.

Echinococcus multilocularis causes alveolar echinococcosis, a serious zoonotic disease present in many areas of the world. The parasite is maintained in nature through a life cycle in which adult worms in the intestine of carnivores transmit infection to small mammals, predominantly rodents, via eggs in the feces. Humans may accidentally ingest eggs of E. multilocularis through contact with the definitive host or by direct ingestion of contaminated water or foods, causing development of a multivesicular cyst in the viscera, especially liver and lung. We found adult E. multilocularis in the intestine and/or eggs in feces of all wild carnivores examined and in some stray and domestic dogs in villages of Chenaran region, northeastern Iran. The life cycle of E. multilocularis is being maintained in this area by wild carnivores, and the local population and visitors are at risk of infection with alveolar echinococcosis. Intensive health initiatives for control of the parasite and diagnosis of this potentially fatal disease in humans, in this area of Iran, are needed.

Immunochromatographic test with recombinant Em18 antigen for the follow-up study of alveolar echinococcosis

The performance of a rapid and simple immunochromatographic test (ICT) with recombinant Em18 (rEm18) antigen for serological follow-up of Echinococcus multilocularis infection was evaluated by comparison with that of an enzyme-linked immunosorbent assay (ELISA) with rEm18, using serum samples from patients who underwent surgery and/or received antiparasitic chemotherapy. The degree of Em18-band intensity on the ICT correlated highly with the absorbance value obtained by the ELISA. The kinetics of antibody levels obtained by the ICT paralleled those of the ELISA. These data suggest that the ICT has high potential as an easy-to-handle, fast, and reliable follow-up tool to monitor the status of alveolar echinococcosis in different stages.

Primary extrahepatic alveolar echinococcosis of the lumbar spine and the psoas muscle

Alveolar echinococcosis (AE) of human being caused by Echinococcus multilocularis is a rare but important zoonosis especially in tempered zones of middle Europe and Northern America with endemic character in many countries. Due to the long incubation period, various clinical manifestations, critical prognosis, and outcome AE presents a serious and severe disease. The primary focus of infection is usually the liver. Although secondary affection of visceral organs is possible extrahepatic AE is highly uncommon. Moreover, the involvement of bone and muscle presents with an even lower incidence. In the literature numerous cases on hepatic AE have been reported. However, extrahepatic AE involving bones and/or muscles was described very rarely. We report a case of an 80-year-old man with primary extrahepatic alveolar Echinococcosis of the lumbar spine and the psoas muscle. The etiology, diagnosis, differential diagnoses, treatment options and outcome of this rare disease are discussed in context with the current literature.

Emerging and established parasitic lung infestations

Many lung infestations from established and newly emerging parasites have been reported as a result of the emergence of HIV/AIDS, the increasing use of immunosuppressive drugs, increasing organ transplantations, the increase in global travel, and climate change. A renewed interest in parasitic lung infections has been observed recently because many protozoal and helminthic parasites cause clinically significant lung diseases. The diseases caused by these parasites may mimic common and complicated lung diseases ranging from asymptomatic disease to acute respiratory distress syndrome requiring critical care management. The availability of new molecular diagnostic methods and antiparasitic drugs enables early diagnosis and prompt treatment to avoid the morbidity and mortality associated with these infestations. Good hygiene practices, improvement in socioeconomic conditions, vector control measures, and consumption of hygienically prepared and properly cooked food are essential to reduce the occurrence of parasitic infestations.

Diagnosis of parasitic diseases: old and new approaches

Methods for the diagnosis of infectious diseases have stagnated in the last 20–30 years. Few major advances in clinical diagnostic testing have been made since the introduction of PCR, although new technologies are being investigated. Many tests that form the backbone of the “modern” microbiology laboratory are based on very old and labour-intensive technologies such as microscopy for malaria. Pressing needs include more rapid tests without sacrificing sensitivity, value-added tests, and point-of-care tests for both high- and low-resource settings. In recent years, research has been focused on alternative methods to improve the diagnosis of parasitic diseases. These include immunoassays, molecular-based approaches, and proteomics using mass spectrometry platforms technology. This review summarizes the progress in new approaches in parasite diagnosis and discusses some of the merits and disadvantages of these tests.

Echinococcus multilocularis: Proteomic analysis of the protoscoleces by two-dimensional electrophoresis and mass spectrometry

Echinococcus multilocularis is an important parasite that causes human alveolar echinococcosis. Identification and characterization of the proteins encoded by E. multilocularis metacestode might help to understand the complexity of the parasites and their interactions with the host, and to identify new candidates for immunodiagnosis and vaccine development. Here we present a proteomic analysis of E. multilocularis protoscolex (PSC) proteins. The proteins were resolved by 2-DE (pH range 3.5-10), followed by MALDI-TOF MS analysis. Fourteen known Echinococcus proteins were identified, including cytoskeletal proteins, heat shock proteins, metabolic enzymes, 14-3-3 protein, antigen P-29 and calreticulin. To construct a systematic reference map of the immunogenic proteins from E. multilocularis PSC, immunoblot analysis of PSC 2-DE maps was performed. Over 50 proteins spots were detected on immunoblots as antigens and 15 of them were defined. The results showed that cytoskeletal proteins and heat shock proteins were immunodominant antigens in alveolar echinococcosis.

Surgical management of splenic echinococcal disease

Background

Infection of the spleen with echinococcus is a rare clinical entity. Because the diagnosis of a splenic infestation with echinococcus is sometimes delayed, large hydatid cysts or pseudotumors may develop, demanding a differential surgical approach to cure the disease.

Methods

In a retrospective study 10 patients out of 250 with abdominal echinococcosis (4%) were identified to have splenic infestation, either limited to the spleen (n = 4) or with synchronous involvement of the liver (n = 4), major omentum (n = 1), or the liver and lung (n = 1). Only one patient had alveolar echinococcosis whereas the others showed hydatid cysts of the spleen. Surgical therapy included splenectomy in 7 patients or partial cyst excision combined with omentoplasty in 3 patients. In case of liver involvement, pericystectomy was carried out simultaneously.

Results

There was no mortality. Postoperative complications were observed in 4 patients. Hospital stay and morbidity were not influenced when splenic procedures were combined with pericystectomies of the liver. Mean follow- up was 8.8 years and all of the patients are free of recurrence at this time.

Conclusions

Splenectomy should be the preferred treatment of hydatid cysts but partial cystectomy is suitable when the cysts are located at the margins of the spleen. Due to low morbidity rates, simultaneous treatment of splenic and liver hydatid cysts is recom mended.

Echinococcosis: diagnosis and diagnostic interpretation in population studies

Diagnosis is a basic component of population studies on echinococcosis. Other than careful necropsy in animals, there is no perfect gold standard. In the definitive host, techniques for direct parasite identification include copro-antigen and copro-DNA detection. In intermediate hosts, necropsy is typically used. In humans, diagnostic imaging and serology are both widely employed. The use of multiple parallel testing or an additional confirmatory test (or tests) in a diagnostic strategy can overcome the lack of a perfect gold standard. This will yield valuable information at population and individual levels, providing the study is well designed and any shortcomings of the tests are incorporated into the analysis. Here, we discuss analytical approaches to population studies of echinococcosis.

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 (kappa = 0.93) and between the ICT and immunoblot analysis (kappa = 0.97). It is expected that the ICT developed in this study will be useful for the serodiagnosis of alveolar echinococcosis.

Zoonotic helminth infections of humans: echinococcosis, cysticercosis and fascioliasis

PURPOSE OF REVIEW

Tissue parasites of humans are still prevalent in most regions of the world, and are also seen more frequently in developed countries due to increasing travel patterns. In particular, Echinococcus infections still account for hepatic and pulmonary pathology, cysticercosis is a major cause of seizures and epilepsy, and fascioliasis also causes significant liver pathology. This review summarizes current knowledge on clinical and epidemiologic aspects of zoonotic disease caused by tissue helminths.

RECENT FINDINGS

Tissue helminth infections remain as a public health concern. Recent research has provided new insights into clinical disease in humans and improved methods for diagnosis, treatment and control, arising mostly from the application of new techniques for immune and molecular diagnosis, availability of data from controlled trials, and development of new vaccines. Specific antiparasitic therapies are now better characterized, and new control tools are available.

SUMMARY

Recent research has provided new diagnostic technologies applicable to diagnosis, treatment and control, but effective interventions to reduce transmission are rarely applied. Despite some progress in their control, these zoonoses continue to be a major public health problem in many regions both in developing countries and in some more developed ones.