Echinococcus vogeli in immigrant from Suriname to the Netherlands

Monoclonal antibody-based localization of major diagnostic antigens in metacestode tissue, excretory/secretory products, and extracellular vesicles of Echinococcus species

Alveolar (AE) and cystic echinococcosis (CE) are severe parasitic zoonoses caused by the larval stages of Echinococcus multilocularis and E. granulosus sensu lato, respectively. A panel of 7 monoclonal antibodies (mAbs) was selected against major diagnostic epitopes of both species. The binding capacity of the mAbs to Echinococcus spp. excretory/secretory products (ESP) was analyzed by sandwich-ELISA, where mAb Em2G11 and mAb EmG3 detected in vitro extravesicular ESP of both E. multilocularis and E. granulosus s.s. These findings were subsequently confirmed by the detection of circulating ESP in a subset of serum samples from infected hosts including humans. Extracellular vesicles (EVs) were purified, and the binding to mAbs was analyzed by sandwich-ELISA. Transmission electron microscopy (TEM) was used to confirm the binding of mAb EmG3 to EVs from intravesicular fluid of Echinococcus spp. vesicles. The specificity of the mAbs in ELISA corresponded to the immunohistochemical staining (IHC-S) patterns performed on human AE and CE liver sections. Antigenic small particles designated as ''spems'' for E. multilocularis and ''spegs'' for E. granulosus s.l. were stained by the mAb EmG3IgM, mAb EmG3IgG1, mAb AgB, and mAb 2B2, while mAb Em2G11 reacted with spems and mAb Eg2 with spegs only. The laminated layer (LL) of both species was strongly visualized by using mAb EmG3IgM, mAb EmG3IgG1, mAb AgB, and mAb 2B2. The LL was specifically stained by mAb Em2G11 in E. multilocularis and by mAb Eg2 in E. granulosus s.l. In the germinal layer (GL), including the protoscoleces, a wide staining pattern with all structures of both species was observed with mAb EmG3IgG1, mAb EmG3IgM, mAb AgB, mAb 2B2, and mAb Em18. In the GL and protoscoleces, the mAb Eg2 displayed a strong E. granulosus s.l. specific binding, while mAb Em2G11 exhibited a weak granular E. multilocularis specific reaction. The most notable staining pattern in IHC-S was found with mAb Em18, which solely bound to the GL and protoscoleces of Echinococcus species and potentially to primary cells. To conclude, mAbs represent valuable tools for the visualization of major antigens in the most important Echinococcus species, as well as providing insights into parasite-host interactions and pathogenesis.

Update of Cestodes Parasitizing Neotropical Hystricomorphic Rodent

This review aims at identifying cestodes that are present in hunted rodent species in the neo-tropical region. The rodent species that was investigated were the capybara (Hydrochoerus hydrochaeris, Linnaeus, 1766), lappe (Cuniculus paca, Linnaeus, 1766), agouti (Dasyprocta leporina, Linnaeus, 1758), chinchilla (Chinchilla chinchilla, Lichtenstein, 1829), Trinidad spiny rat (Proehimys trinitatus, Allen and Chapman, 1893), nutria (Myocastor coypus, Molina, 1782), and vizcacha (Lagostomus maximus, Desmarest, 1817). These rodent species are utilized for their meats in many rural communities in the Caribbean and South America. These rodents belong to the hystricomorphic group. Raillietina demerariensis Daniels, 1895 was commonly found in the gastrointestinal tract of D. leporina, C. paca and P. trinitatus. Similarly, in the liver, muscle and subcutaneous tissue the metacestodes on Echinococcus vogeli Daniels, 1895 and Echinococcus oligarthrus was found in the lappe and agouti. The capybara was found to have the most species of cestodes in its gastrointestinal tract when compared to the agouti and lappe. However, metacestodes were not recorded in the tissues of the capybara. This surprising feature shows the effect of the difference in feeding habits between the capybara and the agouti and lappe. The literature reviewed in this study includes scientific publications on cestodes and metacestodes of Hystricomorphic rodents. An exhaustive search was performed using the digital repositories in Google Scholar, Scielo, Redalyc, Scopus and Pubmed. Literature searched spanned the years 1970-2021. Cestodes of zoonotic significance were E. vogeli and E. oligarthrus, with humans becoming infected when consuming eggs of contaminated food and water. The agouti and lappe act as intermediate host in the life cycle of E. vogeli and E. oligarthrus, the definitive host (canids and felids) become infected by consuming of tissue infected with metacestodes. Humans become infected through the ingestion of eggs from the definitive host where cystic lesions develop in the liver, lungs and other abdominal organs.

Species and genotypes belonging to Echinococcus granulosus sensu lato complex causing human cystic echinococcosis in Europe (2000-2021): a systematic review

BACKGROUND

This study aimed to fill a gap of knowledge by providing a quantitative measure of molecularly identified species and genotypes belonging to Echinococcus granulosus sensu lato (s.l.) causing human cystic echinococcosis (CE) in Europe during the period 2000-2021. As these species and genotypes are characterized by genetic, animal host and geographical differences, studying the E. granulosus s.l. complex is epidemiologically relevant.

METHODS

A systematic review (SR) was conducted on the basis of both scientific and grey literature considering primary studies between 2000 and 2021 in four databases. From a total of 1643 scientific papers, 51 records were included in the SR. The main inclusion criterion for this study was the molecular confirmation of E. granulosus s.l. at the genotype/species level as a causative agent of human CE cases in selected European countries.

RESULTS

Relevant data were obtained from 29 out of 39 eligible European countries. This SR identified 599 human molecularly confirmed echinococcal cysts: 460 (76.8%) identified as E. granulosus sensu stricto (s.s.), 130 (21.7%) as E. canadensis cluster (G6/7 and G10), 7 (1.2%) as E. ortleppi (G5), and 2 as E. vogeli (0.3%). Three geographical hotspots of human CE caused by different species of the E. granulosus s.l. complex were identified: (1) E. granulosus s.s. in Southern and South-eastern Europe (European-Mediterranean and Balkan countries); (2) E. canadensis (G6/7) in Central and Eastern Europe; (3) E. ortleppi in Central and Western Europe. This SR also identified data gaps that prevented a better definition of the geographical distribution of the Echinococcus granulosus s.l. species complex in Europe: western Balkan countries, part of Central Europe, and Baltic countries.

CONCLUSIONS

These results mandate longitudinal, multi-centre, intersectoral and transdisciplinary studies which consider both molecular and clinical epidemiology in animals and humans. Such studies would be valuable for a better understanding of the transmission of the E. granulosus s.l. species complex and their potential clinical impact on humans.

Morphological Characteristics of Alveolar and Cystic Echinococcosis Lesions in Human Liver and Bone

Among echinococcoses diseases of human interest, two have a global public health impact: cystic and alveolar echinococcosis caused by Echinococcus granulosus sensu lato and Echinococcus multilocularis, respectively. Cystic and alveolar echinococcosis are neglected infectious diseases epidemiologically and are clinically vastly different with distinct microscopic features. Because of the rareness of these zoonotic diseases, pathologists have limited diagnostic experience in the analysis of the lesions caused by Echinococcus tapeworms. Here, we describe the main microscopic features to be considered to characterize these lesions: laminated layer, central necrosis, growth pattern, and delineation from adjacent tissue. Moreover, immunohistology using monoclonal antibodies is of great diagnostic help in reaching a definitive diagnosis by identifying the laminated body and small particles of E. multilocularis (spems) and small particles of E. granulosus (spegs).

Percutaneous Versus Surgical Interventions for Hepatic Cystic Echinococcosis: A Systematic Review and Meta-Analysis

Purpose

This systematic review and meta-analysis summarises the current literature on invasive treatment options of cystic hepatic echinococcosis (CE), comparing percutaneous radiological interventions to surgery, still the cornerstone of treatment in many countries.

Methods

A literature search was conducted in Medline and EMBASE databases (PROSPERO registration number: CRD42019126150). The primary outcome was recurrence of cysts after treatment. Secondary outcomes were complications, duration of hospitalisation, mortality and treatment conversion.

Results

The number of eligible prospective studies, in particular RCTs, was limited. In the four included studies, only conventional surgery is compared directly to percutaneous techniques. From the available data, in terms of recurrence, percutaneous treatment of hydatid cysts is non-inferior to open surgery. With regard to complications and length of hospital stay, outcomes favour percutaneous therapy.

Conclusion

Although evidence from prospective research is small, percutaneous treatment in CE is an effective, safe and less invasive alternative to surgery.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00270-021-02911-4.

Pathology of Echinococcosis: A Morphologic and Immunohistochemical Study on 138 Specimens With Focus on the Differential Diagnosis Between Cystic and Alveolar Echinococcosis

Infection of humans by the larval stage of the tapeworms Echinococcus granulosus sensu lato or Echinococcus multilocularis causes the life-threatening zoonoses cystic echinococcosis (CE) and alveolar echinococcosis (AE). Although cystic liver lesions are a hallmark of both diseases, course, prognosis, and patients' management decisively differ between the two. The wide and overlapping spectrum of morphologies and the limited availability of ancillary tools are challenges for pathologists to reliably diagnose and subtype echinococcosis. Here, we systematically and quantitatively recorded the pathologic spectrum in a clinically and molecularly defined echinococcosis cohort (138 specimens from 112 patients). Immunohistochemistry using a novel monoclonal antibody (mAbEmG3) was implemented, including its combined application with the mAbEm2G11. Six morphologic criteria sufficiently discriminated between CE and AE: size of smallest (CE/AE: >2/≤2 mm) and largest cyst (CE/AE: >25/≤25 mm), thickness of laminated layer (CE/AE: >0.15/≤0.15 mm) and pericystic fibrosis (CE/AE: >0.6/≤0.6 mm), striation of laminated layer (CE/AE: moderate-strong/weak), and number of cysts (CE/AE: ≤9/>9). Combined immunohistochemistry with mAbEm2G11 (E. multilocularis specific) and mAbEmG3 (reactive in AE and CE) was equally specific as and occasionally more sensitive than polymerase chain reaction. On the basis of these findings, we developed a diagnostic algorithm for the differential diagnosis of echinococcosis. In summary, we have not only identified the means to diagnose echinococcosis with greater certainty, but also defined morphologic criteria, which robustly discriminate between CE and AE. We expect our findings to improve echinococcosis diagnostics, especially of challenging cases, beneficially impacting the management of echinococcosis patients.

Genetic diversity of Echinococcus vogeli in the western Brazilian Amazon

Human polycystic echinococcosis is a parasitic infection caused by the larval stage of Echinococcus vogeli, which occurs in rural areas of Central and South America. Until now, little information on the genetic variability of E. vogeli is available. Here, 32 samples from human-excised E. vogeli cysts had a 396-bp sequence of the mitochondrial cytochrome oxidase I (COI) gene sequenced and compared to another 17 COI sequences representing nine Echinococcus species. A Bayesian COI tree revealed that all E. vogeli sequences formed a monophyletic and well-supported clade with an E. vogeli reference sequence. The occurrence of geographically restricted E. vogeli COI haplotypes suggests retention of ancestral polymorphisms with little migration in Acre, Brazil.

First parasitological, histopathological and molecular characterization of Echinococcus vogeli Rausch and Bernstein, 1972 from Cuniculus paca Linnaeus, 1766 in the Cerrado biome (Mato Grosso do Sul, Brazil)

Polycystic echinococcosis (PE) is caused by Echinococcus vogeli metacestodes (larval stage) in Neotropical countries. E. vogeli is trophically-transmitted between predators bush dogs (Speothos venaticus) and prey pacas (Cuniculus paca). In Brazil, reported PE cases are restricted to the Amazon biome. In this study, metacestodes from a paca hunted in Mato Grosso do Sul state (Cerrado biome) were identified morphological and histopathological techniques and further confirmed by molecular testing (sequencing of cytochrome C oxidase subunit I (cox1) gene) for the first time. Images of the whole liver showed superficial bubble-like hepatic masses. The parasitological analysis revealed large hooks (41.3 ± 1.2 μm length/12.8 ± 0.8 μm width) and small hooks (33.0 ± 1.5 μm length/11.1 ± 1.2 μm width), consistent with E. vogeli. Microscopically, the liver showed protoscoleces, a thick laminated layer, fibrosis, and inflammatory infiltrate in the adventitial layer. The DNA sequencing confirmed E. vogeli with 99% homology with sequences deposited in the GenBank. In addition, this finding greatly extends the geographic range of animal polycystic echinococcosis into the Cerrado. It is likely to occur in new biomes, where bush dogs and pacas share a given area in a trophic relationship.

The echinococcoses in Asia: The present situation

Human alveolar and cystic echinococcosis, caused by the accidental ingestion of eggs of the tapeworms Echinococcus multilocularis and Echinococcus granulosus sensu lato, respectively, are endemic in Asia. Various Echinococcus species are maintained in domesticated and/or wild mammals through predator-prey interactions. Molecular analysis is used to help differentiate infecting parasite species and genotypes, with the goal of better understanding parasite life cycles in order to aid in the planning and implementation of control programs. This paper discusses the various echinococcoses in Asia, with limited reference to neighboring areas, including parts of Central Asia, Russia, Europe and North America.

The Echinococcoses: Diagnosis, Clinical Management and Burden of Disease

The echinococcoses are chronic, parasitic diseases that are acquired after ingestion of infective taeniid tapeworm eggs from certain species of the genus Echinococcus. Cystic echinococcosis (CE) occurs worldwide, whereas, alveolar echinococcosis (AE) is restricted to the northern hemisphere, and neotropical echinococcosis (NE) has only been identified in Central and South America. Clinical manifestations and disease courses vary profoundly for the different species of Echinococcus. CE presents as small to large cysts, and has commonly been referred to as 'hydatid disease', or 'hydatidosis'. A structured stage-specific approach to CE management, based on the World Health Organization (WHO) ultrasound classification of liver cysts, is now recommended. Management options include percutaneous sterilization techniques, surgery, drug treatment, a 'watch-and-wait' approach or combinations thereof. In contrast, clinical manifestations associated with AE resemble those of a 'malignant', silently-progressing liver disease, with local tissue infiltration and metastases. Structured care is important for AE management and includes WHO staging, drug therapy and long-term follow-up for at least a decade. NE presents as polycystic or unicystic disease. Clinical characteristics resemble those of AE, and management needs to be structured accordingly. However, to date, only a few hundreds of cases have been reported in the literature. The echinococcoses are often expensive and complicated to treat, and prospective clinical studies are needed to better inform case management decisions.

Efficacy of ultrasound-guided core-needle biopsy in the diagnosis of hepatic alveolar echinococcosis: a retrospective analysis

Background: This study retrospectively analyzed the clinical data, laboratory results, imaging findings, and histopathological features of 28 patients who underwent ultrasound-guided core-needle biopsy from a hepatic lesion and were diagnosed with alveolar echinococcosis. Results: Among 28 patients included in the study, 16 were females and 12 were males. The mean age of the studied population was 53 ± 16 years, and the age range was 18–79 years. The most common presenting symptom was abdominal pain, which was observed in 14 patients. A total of 36 lesions were detected in the patients’ livers, out of which 7 had a cystic appearance. Hepatic vascular involvement, bile duct involvement, and other organ involvement were depicted in 14, 5, and 7 patients, respectively. The average number of cores taken from the lesions was 2.7, ranging between 2 and 5. In histopathological evaluation, PAS+ parasitic membrane structures were visualized on a necrotic background in all cases. Regarding seven patients, who were operated, the pathological findings of preoperative percutaneous biopsies were in perfect agreement with the pathological examinations after surgical resections. None of the patients developed major complications after biopsy. Conclusion: Ultrasound-guided core-needle biopsy is a minimally invasive, reliable, and effective diagnostic tool for the definitive diagnosis of hepatic alveolar echinococcosis.