Challenges for diagnosis and control of cystic hydatid disease

Discordance Therapeutic Protocol of Cystic Echinococcosis With WHO Guideline: A Descriptive Study Based on Liver Ultra-Sonographic Data in North Khorasan Province, Northeastern of Iran

BACKGROUND

Cystic echinococcosis (CE), a helminth-associated zoonosis caused by Echinococcus granulosus, poses a significant public health problem, particularly in pastoral-rearing regions. The lack of uniform guidelines led to variations in CE management. Based on ultrasound data, the World Health Organization Informal Working Group on Echinococcosis (WHO-IWGE) classification system categorizes cysts into active, transitional, and inactive groups. This study assesses whether the therapeutic approach from liver human operation cases in North Khorasan province aligns with the WHO-IWGE reference based on ultrasound data.

METHODS

The research is based on ultrasound data from liver CE human operation cases collected between 2018 and 2022. This retrospective study investigates the therapeutic protocol for (CE) in North Khorasan Province, Iran, comparing it with the WHO-IWGE guidelines. We collect data from previously registered patients' medical information from our studied area's main CE surgical hospital. Moreover, as the first hospitalized survey in Iran, this study reveals insights into patient demographics, cyst stage prevalence, and treatment modalities.

RESULTS

Notably, more than half of the patients were treated for CE1 stage cysts, and CE4 cases, which generally do not require surgery, underwent open surgery. The results suggest a need for adherence to the "watch-and-wait" approach in specific cases. All patients underwent successful surgeries, but we do not have access to follow-up data from patients after discharge.

CONCLUSIONS

This descriptive study contributes to understanding the implementation of WHO guidelines in a regional context, shedding light on the challenges and variations in CE management. It seems, retraining courses for surgeons are required to update their knowledge of standard CE diagnostic and treatment methods.

Challenges and Prospective of Enhancing Hydatid Cyst Chemotherapy by Nanotechnology and the Future of Nanobiosensors for Diagnosis

Hydatid cysts have been widely recognized for decades as a common medical problem that affects millions of people. A revolution in medical treatment may be on the prospect of nanotechnology enhancing chemotherapy against hydatid cysts. An overview of nanotechnology's impact on chemotherapeutics is presented in the current review. It discusses some of the challenges as well as some of the opportunities. The application of nanotechnology to enhance chemotherapy against hydatid cysts is what this review will explore. Nanotechnology is a critical component of delivering therapeutic agents with greater precision and efficiency and targeting hydatid cysts with better efficacy, and minimizing interference with surrounding tissue. However, there are biodistribution challenges, toxicity, and resistance problems associated with nanotherapeutics. Additionally, nanobiosensors are being investigated to enable the early diagnosis of hydatid cysts. A nanobiosensor can detect hydatid cysts by catching them early, non-invasively, rapidly, and accurately. The sensitivity and specificity of diagnostic tests can be enhanced with nanobiosensors because they take advantage of the unique properties of nanomaterials. By providing more precise and customized treatment options for hydatid cysts, nanotechnology may improve therapeutic options and strategies for diagnosing the disease. In conclusion, treatment with nanotechnology to treat hydatid cysts is potentially effective but presents many obstacles. Furthermore, nanobiosensors are being integrated into diagnostic techniques, as well as helping to diagnose patients earlier and more accurately.

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.

Proteomics investigation of human sera for determination of postoperative indicators of pulmonary cystic echinococcosis

BACKGROUND

Cystic echinococcosis (CE)/hydatidosis is an important zoonotic parasitic disease caused by the larval stage of Echinococcus granulosus. The disease is a major health problem all over the world. Finding specific and sensitive biomarkers for follow-up of CE in patients after surgery is essential. Using proteomics methods, the present study aimed to evaluate post-surgical treatment by finding probable biomarker/s in the serum of human lungs CE.

METHODS

A total of 24 human sera were tested. These sera included eight confirmed lung/s CE patients sera before surgery (BS), eight sera 12 months post-surgery (12MPS) as well as eight control sera from healthy people. Proteomics methods including 2DE and LC-MS/MS were performed on the specimens followed by bioinformatics analysis. Differentially expressed proteins (DEP) were detected and, separately integrated with protein-protein interaction (PPI) data to construct the PPI network.

RESULTS

A total of 171 protein spots were detected in three groups including BS, 12MPS, and control groups; of which a total of 106 DEP have been expressed based on fold changes > = 2 and p-value < 0.05. More analysis was performed and a total of 10 protein spots were selected for identification by mass spectrometry showing the following proteins: APOA1, BGN, SPP2, EAF1, ACOXL, MRPL55, MCTP2, SEPTIN1, B4GALNT1, and ZNF843. Based on centrality parameters of the PPI network (degree and betweenness) five Hub-bottlenecks proteins with significant centrality values were found including APOA1, BGN, SPP2, EAF1, and ACOXL.

CONCLUSION

This study showed five proteins as hub-bottleneck proteins; of which APOA1 was more prominent. It can be concluded that a change in expression of this protein in patients' sera could be used as an indicator tool for the achievement of lungs CE surgical therapy.

Food-borne zoonotic echinococcosis: A review with special focus on epidemiology

Echinococcosis is a neglected, WHO-listed cyclozoonotic parasitic disease that is caused by a number of species belonging to the genus Echinococcus. This disease is widespread across the globe, resulting in heavy economic losses for farmers and cystic disease in aberrant human hosts. This review paper briefly discussed taxonomy, a brief history, the magnitude of economic losses, host spectrum and life cycle, risk factors, and clinical manifestations. Furthermore, the copro- and sero-ELISA-based prevalence of echinococcosis on different continents was summarized. Finally, the authors analyzed the frequency and use of molecular epidemiology in the taxonomy of Echinococcus species based on molecular markers. This review will serve as a quick reference to Echinococcus.

Africa-wide meta-analysis on the prevalence and distribution of human cystic echinococcosis and canine Echinococcus granulosus infections

BACKGROUND

Echinococcosis is a neglected zoonosis of increasing public health concern worldwide. According to the World Health Organization, 19,300 lives and 871,000 disability-adjusted life-years are lost globally each year because of cystic echinococcosis. Annual costs associated with cystic echinococcosis were estimated at US$ 3 billion because of treatment of cases and losses in the livestock industry.

METHODS

We performed the random-effects model of meta-analysis using 51-year (1970-2021) data available from AJOL, Google Scholar, PubMed, Science Direct, Scopus and Web of Science. We also applied the Joanna Briggs Institute critical appraisal instrument for studies reporting prevalence data, the Cochran's Q-test, Egger's regression test and the single study deletion technique to respectively examine within-study bias, heterogeneity, across-study bias and sensitivity.

RESULTS

Thirty-nine eligible studies on human cystic echinococcosis (HCE) from 13 countries across the five African sub-regions showed an overall prevalence of 1.7% (95% CI 1.1, 2.6) with a statistically significant (P < 0.001) sub-group range of 0.0% (95% CI 0.0, 14.1) to 11.0% (95% CI 7.6, 15.7). Highest prevalences were observed in Eastern Africa (2.7%; 95% CI 1.4, 5.4) by sub-region and Sudan (49.6%; 95% 41.2, 58.1) by country. Another set of 42 studies on Echinococcus granulosus infections (EGI) in dogs from 14 countries across the five African sub-regions revealed an overall prevalence of 16.9% (95% CI 12.7, 22.3) with a significant (P < 0.001) variation of 0.4 (95% CI 0.0, 5.9) to 35.8% (95% CI 25.4, 47.8) across sub-groups. Highest prevalences of E. granulosus were observed in North Africa (25.6%; 95% CI 20.4, 31.6) by sub-region and Libya (9.2%; 95% CI 5.7, 13.9) by country.

CONCLUSION

Human cystic echinococcosis and EGI are respectively prevalent among Africans and African dogs. We recommend a holistic control approach that targets humans, livestock, dogs and the environment, which all play roles in disease transmission. This approach should involve strategic use of anthelminthics in animals, standardized veterinary meat inspection in abattoirs, control of stray dogs to reduce environmental contamination and proper environmental sanitation. Mass screening of humans in hyper-endemic regions will also encourage early detection and treatment.

Turkish HPB Surgery Association consensus report on hepatic cystic Echinococcosis (HCE)

OBJECTIVES

Cystic Echinococcosis (CE) is one of the important problems of the Eurasian region. We aimed to prepare a consensus report in order to update the treatment approaches of this disease. This study was conducted by Turkish HPB Surgery Association.

MATERIAL AND METHODS

This study was conducted with the modified Delphi model. For this purpose, we conducted a three-stage consensus-building approach.

RESULTS

Six topics, including diagnosis, medical treatment, percutaneous treatment, surgical treatment, management of complications and posttreatment follow-up and recurrences in HCE were discussed.

CONCLUSION

The expert panel made recommendations for every topic.

Autoimmunity in human CE: Correlative with the fertility status of the CE cyst

Cystic echinococcosis is speculated to exert several immune-evasion strategies involving autoimmune-phenomena. We evaluated the hypothesizes that the prevalence of autoantibodies increases in the sera of CE patients that may evidence the association between the parasite and autoimmune diseases. Sera from 63 subjects at distinct types of CE cyst fertility were investigated for antinuclear antibodies (ANA), and anti-CCP antibodies. Plasma levels and cellular production of IL-17A cytokine were specifically defined as being assumed to prime for autoimmunity. Healthy-controls were age and gender-matched to test sera. ANA expressions inside the surgically removed metacestode and adventitial layer were also assayed. Out of 63 patients, 35 % had fertile highly viable cysts (group-1), 41 % had fertile low viable cysts (group-2) and 24 % had non-fertile cysts (group-3). A four-fold increase in ANA sera-levels was detected in group-1 compared with their controls (p-value 0.001) while anti-CCP levels were of insignificant differences. In group-2 and group-3, no significant differences were detected between ANA and anti-CCP sera-levels in CE patients and their controls. IL-17A sera-levels in group-1 and group- 2 were significantly higher than their healthy-controls while being of insignificant differences in group-3, p-value= 0.300. No association was detected between sera-levels of IL-17A and ANA as well as anti-CCP antibodies. Interestingly, relative IL-17A cellular expression associated positive ANA deposition in the parasite cells and adventitial layer. Collectively, based on the parasite fertility, IL-17A and ANA seemed to be involved in the host immune defenses against CE. There is no association between CE and anti-CCP antibodies.

Development of Loop-Mediated Isothermal Amplification Combined with Lateral Flow Dipstick Assay for a Rapid and Sensitive Detection of Cystic Echinococcosis in Livestock in Kenya

Background

Cystic echinococcosis is a zoonotic disease caused by the metacestode stage of Echinococcus granulosus and occurs worldwide, causing considerable economic losses and public health problems. The currently available methods for the diagnosis of animal hydatidosis are time-consuming and require well-equipped laboratories which make them incompatible with testing in resource-poor settings. This study developed and evaluated a rapid, more sensitive, and specific loop-mediated isothermal amplification combined with a lateral flow dipstick assay for the rapid and sensitive detection of cystic echinococcosis.

Results

In this study, a specific primer set and FITC-labeled probe targeting the conserved region of the NADH-1 gene were designed. The LAMP reaction was performed at 60°C for 40 minutes, and the amplification products were successfully visualized by LFD strips. The analytical sensitivity of LAMP-LFD was determined using 10-fold serial dilutions of E. granulosus DNA. The minimal concentration detected was 10 fg/μl, and no cross-reactivity was observed with DNA extracted from Taenia solium, Taenia saginata, and Fasciola hepatica. The ability of the developed LAMP-LFD assay to detect cystic echinococcosis was further evaluated with 62 cyst samples from slaughtered cattle in Juja Abattoir, Kiambu County, Kenya. The LAMP-LFD was able to detect 59/62 (95.2%, 95% CI 0.87–0.98) as positive samples of E. granulosus compared to 53/62 (85.5%, 95% CI 0.75–0.92) by nested PCR assay.

Conclusion

Our results indicated that the developed LAMP-LFD technique was more sensitive than the nested PCR assay, rapid, and easy to perform with a simple visual detection of products. Therefore, it could be an important point-of-care diagnostic tool for cystic echinococcosis.

The Epidemiology, Clinical Manifestations, Radiology, Microbiology, Treatment, and Prognosis of Echinococcosis: Results of NENEHATUN Study

Aim: Echinococcosis, caused by Echinococcus species, is an important zoonotic disease causing major health problems in humans and animals. Herein, we aimed to evaluate the epidemiology, clinical and laboratory parameters, radiological, serological, pathological, and treatment protocols of followed-up cases of hydatidosis. Methods: A total of 550 patients diagnosed with hydatid cyst disease were included in this study. Patients who were positive for one or more of the enzyme-linked immunosorbent assay or indirect hemagglutination test, pathological results, or radiological findings were examined. The data analyzed were collected from nine centers between 2008 and 2020. Records were examined retrospectively. Results: Among the patients, 292 (53.1%) were women and 258 (46.9%) were men. The patients' mean age was 44.4 ± 17.4 years. A history of living in rural areas was recorded in 57.4% of the patients. A total of 435 (79.1%) patients were symptomatic. The most common symptoms were abdominal pain in 277 (50.4%), listlessness in 244 (44.4%), and cough in 140 (25.5%) patients. Hepatomegaly was found in 147 (26.7%), and decreased breath sounds were observed in 124 (22.5%) patients. Radiological examination was performed in all cases and serological methods were also applied to 428 (77.8%) patients. The most frequently applied serological test was IHA (37.8%). A single cyst has been found in 66% patients. Hepatic involvement occurred in 327 (59.4%), pulmonary involvement was found in 128 (23.3%), whereas both of them were recorded in 43 (7.8%) patients. Splenic involvement was only detected in nine (1.6%) patients. Echinococcus granulosus (72.5%) was most frequently detected. Cyst diameters of 56.9% of the patients were in the range of 5-10 cm. A total of 414 (75.2%) patients received albendazole as an antiparasitic. Mortality was noted in nine (1.6%) patients. Conclusion: Echinococcosis is an important public health problem in Turkey. It can affect the social, economic, and political structures of the community. Public education and awareness are extremely important.

Flexible Fibreoptic Bronchoscopy and Bronchoalveolar Lavage for Confirmation of Pulmonary Hydatid Disease in Children: A Case Series

Hydatid disease of the lungs is common in endemic regions. It can be suspected clinically by non-specific respiratory symptoms in children living in endemic regions, especially when they are close to sheep or dogs. Chest imaging X-ray or computed tomography may show characteristic cysts in some cases, but typical findings are absent in many children. Hydatid serology may contribute to the diagnosis, but does not have sufficient sensitivity for pulmonary cysts. Thus, there is no confirmatory diagnostic test, other than surgical excision and histopathologic examination. Hence, there is a need for more reliable diagnostic tests. We present a series of children, both with and without suspected pulmonary hydatid, wherein flexible fibreoptic bronchoscopy (FFOB) performed under conscious sedation, revealed hydatid membranes in the airways. Bronchoalveolar lavage (BAL) analysis revealed hydatid in most of them. Thus the diagnosis could be confirmed even before surgical excision of cysts was performed. We propose that FFOB with BAL could be useful to confirm the diagnosis of pulmonary hydatid in children. This will be particularly helpful in children without characteristic radiological or serological findings. To the best of our knowledge, this is a completely novel approach to the condition with potential to alter the diagnostic paradigm Lay summary Hydatid disease of the lungs is commonly encountered in endemic regions. However, there is no confirmatory diagnostic test for pulmonary hydatid cyst, other than surgical excision and histopathologic examination. Imaging including chest X-ray and computed tomography may not be typical, especially in complicated cysts and hydatid serology does not have a satisfactory sensitivity for diagnosing lung cysts. Thus, there is a need for more reliable diagnostic tests. We present a series of children, both with and without suspected pulmonary hydatid, wherein flexible fibreoptic bronchoscopy (FFOB) under conscious sedation, revealed hydatid membranes in the airways. Bronchoalveolar lavage (BAL) analysis confirmed hydatid in most of them. We propose FFOB with BAL as a useful diagnostic modality to confirm pulmonary hydatid in children, prior to surgical excision. To the best of our knowledge, this is a completely novel approach to the condition with potential to alter the diagnostic paradigm.

Cystic Echinococcosis: Clinical, Immunological, and Biomolecular Evaluation of Patients from Sardinia (Italy)

Cystic echinococcosis (CE), a zoonotic disease caused by the larval stage of the tapeworm Echinococcus granulosus sensu lato (s.l.), is a worldwide public health problem. Echinococcus granulosus sensu stricto (s.s.), associated with G1 and G3 genotypes, is endemic with high prevalence in the Mediterranean basin. The parasite's life cycle comprises definitive hosts (canids) and intermediate hosts (ruminants) and can occasionally involve humans. The main aim of this research was to confirm the diagnosis of 13 patients suspected of CE who presented different complications and needed the surgical removal of the cysts. We also wanted to understand and clarify more the diagnosis of echinococcosis in humans. For this purpose, the patients first underwent cyst evaluation by ultrasound (US), immunological analysis, and then total pericystectomy, followed by parasitological, histopathological, and molecular biology examinations of the cysts. US stadiated one CE1, one CE2, eight CE3b, one CE4, and two CE5; immunology evidenced nine positives; histopathology confirmed 11 CE cysts, of which 8 fertile presenting protoscoleces were identified as E. granulosus s.s. by molecular biology, genotyped as three G1 and four G3 by neighbor-joining (NJ) phylogenetic tree. In conclusion, the results showed that 11 patients were affected by E. granulosus s.s. G1 orG3, and 2 cystic neoformations were of non-parasitic origin.

Progress on the national echinococcosis control programme in China: analysis of humans and dogs population intervention during 2004-2014

Background

A national control program for echinococcosis has been in effect since 2005 in China. This program has applied a comprehensive strategy, and good control results have been achieved. Human echinococcosis prevalence rate decrease from 1.08% in 2004 to 0.24% in 2012. The objective of this study is focusing on assessment of the programme with two indices, including patient treatment and registered dogs deworming, in endemic areas of echincoccosis control over the period of 10 years (2004–2014) in China.

Methods

We established the database including demography at county and township levels with coverage for ten provinces and autonomous regions of China in this study. We using methods of epidemiological descriptive, instead the expectation-maximization for missing value filling for grouping available patients into those subjected to surgery and those receiving drug treatment after population screening and the dogs population after registered by deworming. We performed Microsoft Excel software and SPSS software on the results as percentages with the corresponding 95% confidence intervals (95% CIs). We also statistically analyzed the economics data on patient treatment and dogs deworming after the corresponding discount with annual bank interest rates (USD 1 = CNY 6.5, bank discount average changes of 2.3–3.3%).

Results

During 2004–2014, the grant total average rate of surgical patient (after surgical operation) treatment had increased with 32.4% and with 81.3% for medical treatment with albendazole. Meanwhile, it increased by 58.6% for the deworming of registered dog since 2007. The accumulated costs amounted to USD 27.03 million after discount for patients and registered dog treatment, which is 1/4 of the total accumulated financial inputs (USD 110.67 million from the Chinese Government). Since the implementation of the national program, it has increased 57 times with respect to the annual financial inputs (costs) and 368 times with respect to all accumulated financial inputs (costs).

Conclusions

This study showed that in endemic areas, patient diagnosis and management, dog management and treatment over this period helped reduce the parasite load to control the disease. More attention should be paid to controlling wild canines during the ongoing program period and sustainable follow-up evaluations are crucial for success and continued implementation of the national program.

Human cystic echinococcosis: Serological diagnosis by indirect hemagglutination test, enzyme-linked immunosorbent assay, immunoelectrophoresis, and immunoblotting in surgically confirmed patients versus cases diagnosed by imaging techniques

INTRODUCTION

Human cystic echinococcosis (CE) diagnosis is based on imaging findings and serology. Serology is the first-line test followed by imaging tests.

MATERIALS AND METHODS

A total of 268 serum samples from CE patients were included in this study. The serodiagnosis was made simultaneously by indirect hemagglutination assay (IHA), enzyme-linked immunosorbent assay (ELISA), immunoblotting test (IB), and immunoelectrophoresis (IEP).

RESULTS

In serum samples belonging to surgically confirmed CE patients, we observed a percentage of positivity of 83.7% [77.2%-89.0%] and 80.7% [73.9%-86.4%] for IHA and IgG-ELISA, respectively. IgG-IB was associated with a higher positivity rate than IEP with 81.3% [74.6%-86.9%] and 62.0% [54.2%-69.5%], respectively. IHA and ELISA results were analyzed using cut-off generated by receiver operating curves. The best diagnostic performances were achieved by IHA (cut-off ≥1/128) and ELISA (>1.16 index). Sensitivities reported in patients with suggestive imaging findings and positive Echinococcus IB were 86.2% [78.0%-92.2%], 72.5% [62.8%-80.9%], 49.0% [39.0%-59.1%] for IHA, IgG-ELISA, and IEP, respectively. All tests gave false negative results in the confirmed CE group. Overall, 18.6% of negative results were obtained by IgG-IB test. Cross-reactivities with non-hydatid serum samples were observed in all tests. Only one patient carrying Taenia saginata serum cross-reacted with 8/12 kDa band by IB. We observed specificity at 73% [63.2%-81.4%], 87% [78.8%-92.9%], 99% [94.6%-100.0%], and 99% [94.6%-100.0%] with IHA, IgG-ELISA, IEP, and IgG-IB, respectively. Serology was less sensitive (74%) in lung cysts. Sensitivity was better in liver cysts, especially by IgG-IB (96%).

Control of cystic echinococcosis: Background and prospects

Cystic echinococcosis (CE), caused by Echinococcus granulosus, is a chronic and debilitating zoonotic larval cestode infection in humans, which is principally transmitted between dogs and domestic livestock, particularly sheep. Human CE occurs in almost all pastoral communities and rangeland areas of the underdeveloped and developed world. Control programmes against CE have been implemented in several endemic countries to reduce or eliminate the disease. New Zealand and Tasmania are examples of some of the first programmes to be undertaken (in insular territories) and which were very successful in the elimination of CE. The advent and proven effectiveness of praziquantel, plus the experience of insular models, produced high expectations for rapid advances in a second generation of control programmes undertaken in continental areas (Argentina, Uruguay and Chile). Nevertheless, only moderate gains in CE control have been made and the impact on prevalence among humans has been slight. A major impediment to the adoption of procedures that were successful in New Zealand and Tasmania has been the requirement to administer praziquantel to dogs in rural areas eight times per year over numerous years. In addition, there have been clear technological improvements made in the diagnosis of canine echinococcosis for surveillance, the genetic characterization of parasite strains and in vaccination against CE infection in livestock. In order to establish new paradigms and appropriate combinations of control strategies, we have carried out a review and discussion of the available control tools and control models. Control strategies must be suitable and sustainable to benefit the Echinococcosis-endemic areas primarily, which at the same time are the poorest regions of the world.

Molecular phylodiagnosis of Echinococcus granulosus sensu lato and Taenia hydatigena determined by mitochondrial Cox1 and SSU-rDNA markers in Iranian dogs: Indicating the first record of pig strain (G7) in definitive host in the Middle East

Unawareness of canine parasitic diseases among at-risk hosts and an uncontrolled program of stray dog population have caused that zoonotic parasites received great attention in endemic regions of the Middle East. A total of 552 faecal samples were collected between December 2016 to January 2018 from stray (n = 408) and domestic (n = 144) dogs of Iran. All specimens were coproscopically observed following concentration and flotation techniques. Subsequently, the DNAs of taeniid eggs were extracted, amplified, and sequenced by targeting of mitochondrial cytochrome oxidase subunit 1 and small-subunit ribosomal DNA markers. The overall prevalence of canine intestinal parasites found 53.6%. The following parasites and their total frequencies were identified: taeniid (10.5%), Dicrocoelium dendriticum (0.7%), Trichuris vulpis (1.2%), Capillaria spp. (2.3%), Blastocystis spp. (5.2%), Ancylostoma spp. (2%), Eimeria spp. (13.2%), Dipylidium caninum (2.3%), Toxocara canis (3.8%), Giardia spp. (8.5%), and Toxascaris leonina (3.6%). Stray dogs were characterized more likely to be poliparasitized and indicated a higher prevalence of taeniid (10.9%), T. canis (4.4%) Giardia spp. (10.1%) than domestic dogs (P > 0.05). Phylogenetic and sequence analysis of Cox1 and SSU-rDNA indicated a low genetic diversity (Haplotype diversity; 0 to 0.495) in E. granulosus sensu lato G1, G3, G7 genotypes, and Taenia hydatigena. The pairwise sequence distances between G7 isolates showed an intra-diversity of 0.7%-1.5% and identity of 98.5%-100%. The first occurrence of pig strain (G7) from Iranian dogs might have substantial implications in the drug treatment of infected dogs due to the shorter maturation time of G7 compared with G1 genotype. Thus, the preventive strategies should be noticed to determine the risk factors, the importance of applying the hygienic practices, and well adjusting deworming programs for the Iranian dogs and at-risk individuals.

Validation of a one-step PCR assay for the molecular identification of Echinococcus granulosus sensu stricto G1-G3 genotype

The Italian National Reference Center for Echinococcosis (CeNRE, Sassari, Italy) set up a diagnostic protocol of "one-step-PCR" useful for the detection of E. granulosus sensu stricto (E.g.s.s.) and the identification of its genotype (G1-G3). The purpose of this work was to perform the validation of the "PCR E.g.s.s." method. The procedures were performed employing the criteria of the World Organization for Animal Health as well as of the Italian Accreditation Body (ACCREDIA) based on the Regulation UNI CEI EN ISO/IEC 17025. Positive DNA samples belonging to E. granulosus, E. ortleppi, E. multilocularis, E. canadensis species were used for the experiments. Analytical specificity evidenced primer pairs Cal (Calreticulin l gene of 1001 bp) with an specificity higher respect to Ef1 (Elongation-Factor 1 Alpha gene of 706 bp) and NAD (Dehydrogenase-subunit 1 gene of 219 bp). The analytical sensitivity presented the capability to detect a very low amount of parasite DNA corresponding to a concentration of 12.5 pg/µl; accuracy and precision related to the operator performance, along with repeatability and reproducibility, evidenced high concordance among results and demonstrated an excellent κ values of Cohen. According to the good performance related to the evaluated parameters, the method "PCR E.g.s.s." was suitable for the validation procedure, and consequently, to be undergone to the accreditation process. In conclusion, the results demonstrated an elevated robustness and reliable features of the "PCR E.g.s.s." able to perform a rapid diagnosis of E. granulosus in only "one step", hence, it is likely to avoid the sequencing step.

Studies on the specific immunodiagnosis of cystic echinococcosis in camels using enzyme-linked immunosorbent assay

Cystic echinococcosis (CE) is of increasing public health and socio-economic concern because of the large morbidity rates and produced high economic losses in the livestock industry. The objective of the current research was to study the reliability of indirect ELISA in detecting CE, based on two dif-ferent types of crude antigens of camel origin; protoscolex and germinal layer antigens from hydatid cyst. Blood samples were collected from 284 (125 slaughtered and 159 live camels). Out of 125 slaughtered camels examined visually, 55 (44%) were found to have hydatid cysts. Of them, 52/125 (41.6%) and 3/125 (2.4%) harboured hydatid cysts in lungs and livers respectively. Fertile lung cysts were 32.8%; 26.9% were sterile, while 40.3% of lung and liver cysts were calcified. The sensitivity of ELISA was 83% and 46.5% when protoscolex and germinal layer antigens were used, respectively. The respective specificity of antigens of protoscolex and germinal layer was 70.3% and 41.7%. The protoscolex antigen showed higher accuracy (73.6%) compared to the germinal layer antigen (52.8%). The cross reactivity of these antigens were evaluated with antigens and hyperimmune sera of CE and Fasciola spp. and Haemonchus contortus using ELISA. The results showed also weak immunogenic potency of each antigen with Fasciola spp. hyperimmune sera at dilution 1:50 while hyperimmune sera of Haemonchus contortus did not bind any antigen.

Innovative tools for the diagnosis of Echinococcus granulosus in definitive hosts

The aim of this study was to develop and validate an innovative protocol for the diagnosis of Echinococcus granulosus and other Taeniidae in dogs. For this purpose, three experiments were performed, using faecal samples from naturally infected dogs. Firstly, the FLOTAC technique was calibrated with five flotation solutions: saturated sodium chloride (specific gravity, s.g. = 1.20), zinc sulphate (s.g. = 1.35), zinc chloride (s.g. = 1.45), Breza (s.g. = 1.30) and modified Breza (s.g. = 1.40). Then, FLOTAC was compared with four techniques of flotation in centrifuge using: zinc sulphate (s.g. = 1.20), Breza (s.g. = 1.30), modified Breza (s.g. = 1.40), and zinc chloride (s.g. = 1.45). Finally, four different protocols of DNA extraction were compared for Taeniidae identification: QIAamp Tissue Kit and QIAamp Stool from eggs; QIAamp Stool and Wizard Magnetic Purification System for Food from faeces. FLOTAC with zinc sulphate was the most efficient method to detect Taeniidae eggs, showing highest mean of eggs per gram (EPG) of faeces. The QIAamp Stool, using eggs concentrated by FLOTAC, was the best method for DNA extraction. The combination of these protocols provided the highest number of positive samples with PCR, i.e., 47/50 (94.0%). The three negative samples showed a low faecal egg count (2 EPG) below the detection limit (4 EPG) of the protocol. From sequencing of the 47 positive samples: 6 samples were identified as E. granulosus sensu stricto (s.s.), 28 as Taenia hydatigena and 6 as T. pisiformis. A co-infection between different genera of Taeniidae was found in 7 samples.

Echinococcus Granulosus Infection in Two Free-Ranging Lumholtz's Tree-Kangaroo (Dendrolagus lumholtzi) from the Atherton Tablelands, Queensland

Infection with the larval stage of the cestode, Echinococcus granulosus sensu lato (s.l.), causes hydatid disease (hydatidosis) in a range of hosts, including macropods and other marsupials, cattle, and humans. Wild macropods are an important sylvatic reservoir for the life cycle of E. granulosus (s.l.) in Australia, and so provide a conduit for transmission of hydatid disease to domestic animals and humans. Two Lumholtz's tree-kangaroos (Dendrolagus lumholtzi) from the Atherton Tablelands of Far North Queensland were recently found to have hydatid cysts in both liver and lung tissues. Tree-kangaroos may travel across the ground between patches of forest but are primarily arboreal leaf-eating macropods. The finding of hydatid cysts in an arboreal folivore may indicate that the area has a high level of contamination with eggs of E. granulosus (s.l.). This finding may be of significance to human health as well as indicating the need for further investigation into the prevalence of hydatid disease in domestic stock, wildlife and humans living in this rapidly urbanizing region.

Prevalence of Echinococcus infection in dogs in Akola district of Maharashtra (India) by Copro- PCR

A study on prevalence of Echinococcus infection in dogs was carried out in Akola district of Maharashtra state in India. Total 289 fresh fecal samples of dogs (stray and domesticated) from seven tahsils of Akola district were collected and were analyzed by conventional floatation method as well as by PCR. The overall prevalence of E. granulosus infection in dogs was found to be 6.57%. Numerically higher prevalence was observed by PCR method (6.57%) compared to conventional floatation methods (2.77%) indicating PCR is more specific techniques for Echinococcus infection in dog's fecal samples. The numerically higher prevalence was recorded in Akola tahsil (9.84%) followed by Akot (9.30%), Patur (8.82%), Telhara (6.25%), Barshi Takli (4%), Balapur (3.85%) and Murtijapur (2.38%). It was observed those dogs around the slaughter houses and in rural areas was more prevalent compared to domesticated and in resided in town. It is thus concluded that Echinococcal infection is prevalent in Akola district of Maharashtra.

Expression, Tissue Localization and Serodiagnostic Potential of Echinococcus granulosus Leucine Aminopeptidase

Echinococcus granulosus is the causative agent of cystic echinococcosis (CE), a widespread parasitic zoonosis. Leucine aminopeptidases (LAPs) of the M17 peptidase family have important functions in regulating the balance of catabolism and anabolism, cell maintenance, growth and defense. In this study, we presented a bioinformatic characterization and experimentally determined the tissue distribution characteristics of E. granulosus LAP (Eg-LAP), and explored its potential value for diagnosis of CE in sheep based on indirect ELISA. Through fluorescence immunohistochemistry, we found that Eg-LAP was present in the tegument and hooks of PSCs, the whole germinal layer and adult worm parenchymatous tissue. Western blotting results revealed that the recombinant protein could be identified using E. granulosus-infected sheep serum. The diagnostic value of this recombinant protein was assessed by indirect ELISA, and compared with indirect ELISA based on hydatid fluid antigen. The sensitivity and specificity rEgLAP-ELISA were 95.8% (23/24) and 79.09% (87/110), respectively, while using hydatid fluid as antigen showed the values 41.7% (10/24) and 65.45% (72/110). This is the first report concerning leucine aminopeptidase from E. granulosus, and the results showed that Eg-LAP belong to M17 peptidase families, and that it is involved in important biological function of E. granulosus. Furthermore, rEg-LAP is appropriate for diagnosing and monitoring CE in sheep in field. Development of a rapid test using rEg-LAP to diagnose sheep CE deserves further study.

Prevalence of Selected Zoonotic and Vector-Borne Agents in Dogs and Cats on the Pine Ridge Reservation

The prevalence of intestinal parasites and vector-borne agents of dogs and cats in the Pine Ridge Reservation, South Dakota were determined. Fecal samples (84 dogs, 9 cats) were examined by centrifugal floatation and by immunofluorescence assay (FA) for Giardia and Cryptosporidium. PCR was performed on Giardia [beta-giardin (bg), triose phosphate isomerase (tpi), glutamate dehydrogenase genes (gdh)] and Cryptosporidium [heat shock protein-70 gene (hsp)] FA positive samples. Cat sera (n = 32) were tested for antibodies against Bartonella spp., Toxoplasma gondii, and FIV, and antigens of FeLV and Dirofilaria immitis. Dog sera (n = 82) were tested for antibodies against T. gondii, Borrelia burgdorferi, Ehrlichia canis, and Anaplasma phagocytophilum and D. immitis antigen. Blood samples (92 dogs, 39 cats) were assessed by PCR for amplification of DNA of Bartonella spp., Ehrlichia spp., Anaplasma spp., haemoplasmas, and Babesia spp. (dogs only). The most significant results were Giardia spp. (32% by FA), Taenia spp. (17.8%) and Cryptosporidium spp. (7.1%). The Giardia isolates typed as the dog-specific assemblages C or D and four Cryptosporidium isolates typed as C. canis. Antibodies against T. gondii were detected in 15% of the dogs. Antibodies against Bartonella spp. and against T. gondii were detected in 37.5% and 6% of the cats respectively. FeLV antigen was detected in 10% of the cats.

Prevalence of cystic echinococcosis in Iran: a systematic review and meta-analysis

As a significant zoonosis, cystic echinococcosis (CE) is endemic in some parts of the world, such as the Middle East. There are studies on the prevalence of this infection in animal and human reservoirs in Iran; hence, we conducted this meta-analysis to elucidate the prevalence of CE in Iran. English (PubMed, Scopus, Web of Science, Science Direct and Google Scholar) and Persian (Magiran, Iran Medex, Iran Doc and SID) databases were explored. In the case of definitive, animal and human intermediate hosts, 37, 90 and 33 studies, respectively, have been included in the current review from January 1990 to December 2015. According to outcomes of the heterogeneity test, either Der Simonian and Laird's random-effects method or Mantel–Haenszel's fixed-effects method were employed to pool the estimations. The pooled prevalence ofEchinococcus granulosusinfection in definitive hosts was calculated as 23.6% (95% confidence interval (CI) = 17.6–30.1%). The weighted prevalence of animal and human hydatidosis was calculated as 15.6% (95% CI = 14.2–17.1%) and 4.2% (95% CI = 3.0–5.5%), respectively. Meanwhile, most cases of human hydatidosis were in southern Iran, with a prevalence of 5.8% (3.2–9.2%). In terms of human hydatidosis, more infections were found in rural regions, and mostly in female individuals. Egger's regression test revealed publication bias, with a remarkable impact on total prevalence of the infection in animal intermediate hosts (P< 0.001), while it was not significant in human hosts (P= 0.4) and definitive hosts (P= 0.3). According to the weighted estimated prevalence of cystic echinococcosis and its financial burden, implementing appropriate control programmes should be compulsory to decrease the burden of the disease in Iran.

Coprodiagnosis of Echinococcus granulosus infection in dogs from Ankara, Turkey

The present study were undertaken to compare two isolation techniques (centrifugal flotation and sedimentation) for recovering taeniid eggs from faecal samples, to identify E. granulosus DNA from taeniid eggs by PCR, and to determine the prevalence of E. granulosus in dogs in villages. Faecal samples were collected from 100 dogs in Ankara province. Taenia spp. eggs were found in 27% of dogs faeces. Echinococcus granulosus-specific PCR was obtained in 14 (51.85%) of the taeniid eggs-positive samples. As well as finding Taenia eggs in dogs' faeces, we also found eggs of some helminthic parasites; such as Dipylidium caninum, Toxocara canis, Toxascaris leonina, Trichuris sp., Capillaria sp., Filaroides sp., Dioctophyme renale, Linguatula serrata, hookworm, Dicrocoelium sp., Fasciola sp. and Ascaridia galli. Significantly, more dogs excreting taeniid eggs were diagnosed with the sedimentation method (n=27) as compared to the flotation method (n=10).

Echinococcus granulosus ss in dog - A report in center-northern Portugal

Routine parasitic control and health care of the dog is lacking in many Portuguese rural communities. Freely roaming and stray dogs are responsible for the maintenance of a permanent parasitic infection pressure, namely of zoonotic importance. Therefore, a good understanding of the epidemiology of Echinococcus granulosus including the transmission to man is of great significance to further the awareness within the rural populations and the local health authorities of this zoonotic parasite. This report aims at a better understanding of the epidemiology of Echinococcus granulosus in the Cantanhede region, located in the Central region of Portugal, through the necropsy of stray dogs. At the Official Veterinary Kennel of this Municipality, 105 stray dogs were studied for the presence of Echinococcus granulosus following the adult cestode recovery with necropsy procedure of the first third part of the small intestine. One dog revealed to be positive (1.05%) and the sampled Echinococcus were genotyped and identified as E. granulosus ss. As this genotype is widely spread and has been reported in different parts of the world, further work is necessary to be conducted in this and other regions of Portugal for a better understanding of E. granulosus epidemiology within the typical small rural farms where pig rearing plays an important economic role.

Molecular Characteristics and Serodiagnostic Potential of Dihydrofolate Reductase from Echinococcus granulosus

The larval stage of Echinococcus granulosus causes cystic echinococcosis (CE), a neglected tropical disease that leads to morbidity and mortality in humans and livestock worldwide. Here, we identified and characterized dihydrofolate reductase (Eg-DHFR) from E. granulosus, and evaluated its potential as a diagnostic antigen for sheep CE. Comparison between mammalian (host) DHFR and Eg-DHFR indicates that 45.7% of the 35 active site residues are different. Immunolocalisation analysis showed that native Eg-DHFR was widely distributed in all life-cycle stages of E. granulosus. Recombinant Eg-DHFR (rEg-DHFR) showed typical DHFR enzymatic parameters towards substrate, and was very sensitive to inhibition by methotrexate (IC₅₀ = 27.75 ± 1.03 nM) and aminopterin (IC₅₀ = 63.67 ± 6.76 nM). However, inhibition of DHFR exhibited little protoscolicidal effect in vitro. As there is no reliable method to monitor sheep CE, the immunogenicity of rEg-DHFR was detected, and we developed an indirect ELISA (iELISA) for CE serodiagnosis. The iELISA exhibited diagnostic specificity of 89.58%, diagnostic sensitivity of 95.83%, and the diagnostic accuracy was 91.67% compared with necropsy. Cross-reactivity assay showed analytical specificity of 85.7%. These suggest that rEg-DHFR is an effective antigen for the diagnosis of sheep CE.

Molecular identification of Echinococcus granulosus strain in stray dogs from Northeastern Iran

Canine echinococcosis, caused by the adult form of taeniid cestodes of the genus Echinococcus is zoonotic and has an epidemiologically worldwide distribution. Dogs infected with E. granulosus are the main source of human hydatidosis, however, there is little information on molecular epidemiology of adult Echinococcus spp. in stray dogs. In the present study, 100 stray dogs (48 males and 52 females, 72 adults and 28 juveniles) were collected from Khorasan Razavi province in Northeastern Iran during October 2013 to December 2014. Thirty-eight (21 males and 17 females, 3 juveniles and 35 adults) out of 100 dogs were infected with E. granulosus. There were no significant differences in prevalence observed between females (43.5%) and males (34.4%), however, the prevalence of E. granulosus, showed a significant increasing trend with increasing host age (p<0.05). Thirty-eight isolated parasites from 38 stray dogs (one parasite per dog) were used for PCR-RFLP analysis of the ITS1 gene. PCR-RFLP analysis showed that all the 38 parasites were E. granulosus G1 genotype (common sheep strain). Five PCR products were sent for sequencing. The results of sequencing were similar to those reported by PCR-RFLP analysis and the presence of E. granulosus G1 genotype (sheep strain) as dominant genotype in dogs were emphasized. The results of this study suggest that the sheep strain occurs in definitive host in Northeastern Iran. Data presented here are expected to be useful for health and educational authorities responsible for designing and implementing effective measures for disease control.

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.

Reprint of "Survey and first molecular characterization of Echinococcus granulosus sensu stricto (G1) in Pampas fox (Lycalopex gymnocercus) in Buenos Aires province, Argentina"

Echinococcosis is a zoonosis caused by tapeworms of the genus Echinococcus. Echinococcus granulosus sensu lato (s. l.) has a world-wide distribution and its transmission is primarily maintained in a synanthropic cycle with dogs as definitive hosts and livestock species as intermediate hosts. However, many wild canids also function as definitive hosts for E. granulosus s. l. Echinococcosis in humans is mainly caused by E. granulosus sensu stricto (s. s.) G1 genotype. In the present work, we expanded the epidemiological study on echinococcosis reported cases in Pampas fox (Lycalopex gymnocercus) to provide a prevalence estimate for rural areas of southern Buenos Aires province, Argentina. Ninety-five whole intestines were analyzed using the sedimentation and counting technique with a result of 83 foxes (87.37%) harboring at least one helminth species. E. granulosus s. l. adults were found in one Pampas fox (1.05%). These adult helminthes were E. granulosus s. s. (G1) according to the genotyping analysis of a 450-bp region of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene.

Echinococcus granulosus infection in dogs in Sidi Kacem Province (North-West Morocco)

This study was undertaken in the Province of Sidi Kacem in northwest Morocco between April 2010 and March 2011. The main objective of the study was to determine the prevalence of Echinococcus granulosus (Eg) infection in owned dogs. This province was selected as a case study because of the social conditions, geographic and climatic diversity making it a model representative of many parts of Morocco. The survey was carried out in 23 rural communes and in the 5 municipalities (urban districts) of the Province and sampling was undertaken in randomly selected households. A total of 273 owned dogs comprising 232 from the 23 rural communes (rural dogs) and 41 from the 5 municipalities (urban dogs) were tested. Arecoline hydrobromide purgation was selected as the diagnostic method of choice to enable visualisation of expelled worms by dog owners, thereby imparting messages on the transmission mode of Eg to humans and farm animals. Of the 273 dogs tested, purgation was effective in a total of 224 dogs (82.1%). The overall estimated prevalence of Eg infection was 35.3% (79/224, 95% CI 22.3-47.0%). Dogs inhabiting rural communes were at greater risk of infection (38.0%, 95% CI 31.1-45.3%) than dogs roaming in municipalities or urban areas (18.8%, 95% CI 7.2-36.4%) and the prevalence of infection was higher in those inhabiting rural communes with slaughterhouses (62.7%, 95% CI 48.1-75.9%) than in communes without (29.1%, 95% CI 21.7-37.2%). This first assessment of Eg infection in Sidi Kacem Province indicates a key role of rural slaughterhouses in parasite transmission to dogs.

Potential Risk Factors Associated with Human Cystic Echinococcosis: Systematic Review and Meta-analysis

Background

Scientific literature on cystic echinococcosis (CE) reporting data on risk factors is limited and to the best of our knowledge, no global evaluation of human CE risk factors has to date been performed. This systematic review (SR) summarizes available data on statistically relevant potential risk factors (PRFs) associated with human CE.

Methodology/Principal Findings

Database searches identified 1,367 papers, of which thirty-seven were eligible for inclusion. Of these, eight and twenty-nine were case-control and cross-sectional studies, respectively. Among the eligible papers, twenty-one were included in the meta-analyses. Pooled odds ratio (OR) were used as a measure of effect and separately analysed for the two study designs. PRFs derived from case-control studies that were significantly associated with higher odds of outcome were “dog free to roam” (OR 5.23; 95% CI 2.45–11.14), “feeding dogs with viscera” (OR 4.69; 95% CI 3.02–7.29), “slaughter at home” (OR 4.67; 95% CI 2.02–10.78) or at “slaughterhouses” (OR 2.7; 95% CI 1.15–6.3), “dog ownership” (OR 3.54; 95% CI 1.27–9.85), “living in rural areas” (OR 1.83; 95% CI 1.16–2.9) and “low income” (OR 1.68; 95% CI 1.02–2.76). Statistically significant PRFs from cross-sectional studies with higher odds of outcome were “age >16 years” (OR 6.08; 95% CI 4.05–9.13), “living in rural areas” (OR 2.26; 95% CI 1.41–3.61), “being female” (OR 1.38; 95% CI 1.06–1.8) and “dog ownership” (OR 1.37; 95% CI 1.01–1.86).

Conclusions/Significance

Living in endemic rural areas, in which free roaming dogs have access to offal and being a dog-owner, seem to be among the most significant PRFs for acquiring this parasitic infection. Results of data analysed here may contribute to our understanding of the PRFs for CE and may potentially be useful in planning community interventions aimed at controlling CE in endemic areas.

Cystic echinococcosis (CE) is a chronic zoonotic disease causing serious global socio-economic losses in human and animal hosts. Two main aspects make it extremely difficult to study risk factors associated with human CE, the parasite’s unknown and apparently long incubation period which may last for several years, and the predominantly fecal-oral transmission route. This systematic review (SR) summarizes findings from relevant publications on this topic and provides a detailed list of potential risk factors (PRFs) associated with CE infection in humans. Free dog roaming, dogs having access to offal, being a dog-owner and slaughtering at home or using inadequately supervised slaughterhouses have all been shown to be highly statistically significant PRFs associated with the perpetuation of the parasite life cycle in endemic areas. The effect of other risk factors identified in this SR can vary between geographically different areas and societies and could reflect socio-cultural determinants of infection.

Bayesian spatial analysis of the surgical incidence rate of human cystic echinococcosis in north-eastern Iran

BACKGROUND

Cystic echinococcosis (CE) is a zoonotic disease that presents a public health challenge and a socioeconomic burden on developing areas in the Middle East. This study used spatial methods to assess the distribution of surgically managed CE cases in an endemic region of north-eastern Iran.

METHODS

For the years 2001-2007, a case series of all 446 patients that were surgically treated for CE in a referral hospital in north-eastern Iran was evaluated. Patients seen at the referral hospital represent 35 counties in three provinces (Razavi Khorasan, North Khorasan, and South Khorasan). A Besag, York and Mollie (BYM) spatial model was used to produce smoothed standardized incidence ratios (SIRs) for surgically managed cases of CE for the 35 counties represented in this study.

RESULTS

Out of 446 surgically managed patients, 54% were male. County-level crude incidence rates ranged from 0 to 3.27 cases per 100,000 population. The highest smoothed SIR (3.46) was for Sarakhs County in the province of Razavi Khorasan, while the lowest smoothed SIR (0.05) was for Birjand County, located in the province of South Khorasan.

CONCLUSION

SIRs for CE were highest for the province of Razavi Khorasan, which has large ranching and agricultural industries. Additional studies are needed to better evaluate the role of climate, land cover, and livestock rearing on local Echinococcus granulosus transmission in Iran.

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.

Molecular characterization and serodiagnostic potential of a novel dithiol glutaredoxin 1 from Echinococcus granulosus

Background

The larval stage of Echinococcus granulosus is the etiological agent of cystic echinococcosis (CE), which causes serious morbidity and mortality in many areas. There is no reliable method to monitor sheep CE. Here, we characterize E. granulosus glutaredoxin 1 (Eg-Grx1) and report an improved immunodiagnostic method for CE.

Methods

We cloned and expressed recombinant Eg-Grx1 and generated antibodies. We analyzed the location of the protein in different parasite stages by fluorescence immunohistochemistry, detected the immunogenicity of recombinant Eg-Grx1, and developed an indirect ELISA (iELISA) for CE serodiagnosis.

Results

Eg-Grx1 is a classic dithiol Grx with several GSH-binding motifs. Native Eg-Grx1 protein was distributed in the tegument of protoscoleces, the whole germinal layer, and the parenchymatous tissue of adult worms. Recombinant Eg-Grx1 exhibited good immunoreactivity to CE-infected sheep serum. An iELISA using this antigen showed specificity of 64.3 % (9/14) and sensitivity of 1:3200, and the diagnostic accordance rate was 97.9 % (47/48) compared with the results of necropsy.

Conclusion

We characterized a novel Grx (Eg-Grx1) from a parasitic helminth and present a comprehensive analysis of the sequence and structure of this protein. The recombinant Eg-Grx1 protein showed good potential serodiagnostic performance, and we established an iELISA method, which may contribute to the surveillance of sheep CE in epidemic areas.

Immunoprotection of recombinant Eg.myophilin against Echinococcus granulosus infection in sheep

The aims of the present study were to investigate the immunoprotection of recombinant Echinococcus granulosus myophilin (rEg.myophilin) against the establishment of a challenge oral infection with E. granulosus eggs, as well as to determine the mechanisms underlying this protection. Sheep were subcutaneously immunized two times with rEg.myophilin, followed by the challenge with E. granulosus eggs orally. The animals were sacrificed 44 weeks after infection and the immunoglobulin (Ig) and cytokine levels were analyzed using ELISA. The results identified significant changes in several indexes of animal immune response subsequent to immunization with rEg.myophilin. These changes included reduced number of formed cysts, as well as elevated levels of IgG, IgA and cytokines. The present data suggest that immunization with rEg.myophilin in sheep can successfully reduce the formation of cysts caused by challenge E. granulosus infection and stimulate immune response, suggesting that rEg.myophilin a has potential value as a candidate vaccine against E. granulosus.

Survey and first molecular characterization of Echinococcus granulosus sensu stricto (G1) in Pampas fox (Lycalopex gymnocercus) in Buenos Aires province, Argentina

Echinococcosis is a zoonosis caused by tapeworms of the genus Echinococcus. Echinococcus granulosus sensu lato (s. l.) has a world-wide distribution and its transmission is primarily maintained in a synanthropic cycle with dogs as definitive hosts and livestock species as intermediate hosts. However, many wild canids also function as definitive hosts for E. granulosus s. l. Echinococcosis in humans is mainly caused by E. granulosus sensu stricto (s. s.) G1 genotype. In the present work, we expanded the epidemiological study on echinococcosis reported cases in Pampas fox (Lycalopex gymnocercus) to provide a prevalence estimate for rural areas of southern Buenos Aires province, Argentina. Ninety-five whole intestines were analyzed using the sedimentation and counting technique with a result of 83 foxes (87.37%) harboring at least one helminth species. E. granulosus s. l. adults were found in one Pampas fox (1.05%). These adult helminthes were E. granulosus s. s. (G1) according to the genotyping analysis of a 450-bp region of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene.

Cystic pulmonary hydatidosis

Cystic echinococcosis (CE) is a zoonotic parasitic disease caused by the larval stages of the cestode Echinococcus granulosus. Worldwide, pulmonary hydatid cyst is a significant problem medically, socially, and economically. Surgery is the definitive therapy of pulmonary hydatidosis. Benzimidazoles may be considered in patients with a surgical contraindication. This review will focus on pathogenesis, lifecycle, clinical features, and management of pulmonary hydatid disease.

[Study of infestation of dogs with Echinococcus granulosus in the province of La Rioja, Argentina]

This work was conducted in the province of La Rioja, located in northwestern Argentina. The aim of this study was to estimate the percentage of dog feces showing the presence of antigens of Echinococcus sp. in different regions of the province. A total of 269 samples of dried canine stool were taken, which were analyzed by the copro-ELISA technique. The most affected area was zone IV, which had 30.5% of positive samples. Zone I corresponding to the Capital Department of the province had 12% of positivity. In other areas, the percentages ranged between 11.4% and 14.8%. This is the first study in the province of La Rioja on the existence of this disease in dogs. The lack of control strategies has allowed the spread of echinococcosis.

Major Parasitic Zoonoses Associated with Dogs and Cats in Europe

Some of the most important zoonotic infectious diseases are associated with parasites transmitted from companion animals to man. This review describes the main parasitic zoonoses in Europe related to dogs and cats, with particular emphasis on their current epidemiology. Toxoplasmosis, leishmaniosis, giardiosis, echinococcosis, dirofilariosis and toxocariosis are described from the animal, as well as from the human host perspectives, with an emphasis on parasite life cycle, transmission, pathogenicity, prevention and identification of knowledge gaps. In addition, priorities for research and intervention in order to decrease the risks and burden of these diseases are presented. Preventing zoonotic parasitic infections requires an integrated multidisciplinary 'One Health' approach involving collaboration between veterinary and medical scientists, policy makers and public health officials.

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.

Serological Diagnosis and Follow-Up of Human Cystic Echinococcosis: A New Hope for the Future?

Cystic echinococcosis (CE) is an important helminthic zoonotic disease caused by the Echinococcus granulosus complex. In humans, CE is a chronic disease driven by the growth of echinococcal cysts in different organs. Prognosis of this disease depends on multiple factors, including location, number, size, and stage of the cysts, making CE a disease of complex management. CE is usually asymptomatic for years and attracts limited attention from funding organizations and health authorities. For this reason, only experts' recommendations are available but no evidence-based conclusions have been drawn for CE clinical management. One of those pitfalls refers to the lack of evidence to support the use of serological tools for the diagnosis and follow-up of CE patients. In this respect, crude antigens are used to detect specific antibodies in patients, giving rise to false positive results. The advent of molecular techniques allowing the production of recombinant proteins has provided a number of candidate antigens that could overcome the problems associated with the use of crude parasite extracts in the serological assays. In this review, we present the last advances in this field, proposing the use of serology to support cyst stage-specific diagnosis and follow-up.

Echinococcus granulosus: Epidemiology and state-of-the-art of diagnostics in animals. Vet Parasitol. 2015;213:132-148. [PMID: 26321135 DOI: 10.1016/j.vetpar.2015.07.028]

Diagnosis and detection of Echinococcus granulosus (sensu lato) infection in animals is a prerequisite for epidemiological studies and surveillance of echinococcosis in endemic, re-emergent or emergent transmission zones. Advances in diagnostic approaches for definitive hosts and livestock, however, have not progressed equally over the last 20 years. Development of laboratory based diagnostics for canids using coproantigen ELISA and also coproPCR, have had a huge impact on epidemiological studies and more recently on surveillance during hydatid control programmes. In contrast, diagnosis of cystic echinococcosis (CE) in livestock still relies largely on conventional post-mortem inspection, despite a relatively low diagnostic sensitivity especially in early infections, as current serodiagnostics do not provide a sufficiently specific and sensitive practical pre-mortem alternative. As a result, testing of dog faecal samples by coproantigen ELISA, often combined with mass ultrasound screening programmes for human CE, has been the preferred approach for monitoring and surveillance in resource-poor endemic areas and during control schemes. In this article we review the current options and approaches for diagnosis of E. granulosus infection in definitive and animal intermediate hosts (including applications in non-domesticated species) and make conclusions and recommendations for further improvements in diagnosis for use in epidemiological studies and surveillance schemes.

Independent evaluation of a canine Echinococcosis Control Programme in Hobukesar County, Xinjiang, China

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Xinjiang is one of the most important foci of human cystic echinococcosis in the world.

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A control programme, including PZQ dosing of dogs, began in Xinjiang in 2010.

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The control programme was evaluated using LQAS sampling, dog necropsies and questionnaires.

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The control programme did not meet our evaluation criteria in most communities studied.

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Other measures should be considered to improve Echinococcus spp. control in Xinjiang.

The Xinjiang Uyghur Autonomous Region in northwest China is one of the world's most important foci for cystic echinococcosis. Domestic dogs are the main source for human infection, and previous studies in Xinjiang have found a canine Echinococcus spp. coproELISA prevalence of between 36% and 41%. In 2010 the Chinese National Echinococcosis Control Programme was implemented in Xinjiang, and includes regular dosing of domestic dogs with praziquantel. Six communities in Hobukesar County, northwest Xinjiang were assessed in relation to the impact of this control programme through dog necropsies, dog Echinococcus spp. coproantigen surveys based on Lot Quality Assurance Sampling (LQAS) and dog owner questionnaires. We found that 42.1% of necropsied dogs were infected with Echinococcus granulosus, and coproELISA prevalences were between 15% and 70% in the communities. Although approximately half of all dog owners reported dosing their dogs within the 12 months prior to sampling, coproELISA prevalence remained high. Regular praziquantel dosing of owned dogs in remote and semi-nomadic communities such as those in Hobukesar County is logistically very difficult and additional measures should be considered to reduce canine echinococcosis.

Infection of dogs with Echinococcus granulosus: causes and consequences in an hyperendemic area

Background

Tunisia is a hyper endemic country for human echinococcosis. The infection is transmitted via the eggs of Echinococcus granulosus which are passed in the faeces of the definitive canid host.

Methods

This study evaluated the contamination rate of the dog faeces in different climatic conditions at eight different geographic regions throughout Tunisia. Dog faecal samples were collected from the soil and the Echinococcus eggs were identified using microscopic and molecular (Eg1121/1122 PCR, Egss1 PCR and Nad1 PCR-RFLP) tools.

Results

The contamination index of dog faeces by E. granulosus eggs ranged from 8.3% to 41.3% depending on the region. Comparisons of the dog faecal contamination rate against human incidence found them to be independent. Neither human prevalence nor dog contamination index appeared to be related to climatic conditions or geographic characteristics. The genetic variability of E. granulosus samples was different within each region but was not related to geographic distance which is indicative of local divergent evolutions rather than isolation by distance.

Conclusions

A high environmental dog contamination index does not necessarily correspond to high prevalence in humans as transmission is strongly linked to human behavior and hygiene.