Echinococcosis: Control and Prevention

Evaluation of knowledge, attitude and practice towards cystic echinococcosis among undergraduate students in China

BACKGROUND

Cystic echinococcosis (CE), a zoonosis caused by Echinococcus granulosus sensu lato (EG), is a major public health burden in western China. The study aimed to evaluate the current status of KAP about CE among undergraduate students from western areas of China, and to provide a basis for developing health education strategies for college students on the prevention of CE.

METHODS

A cross-sectional study was conducted from September 2023 to April 2024 in China. A cluster sampling method was used to enroll participants of undergraduate students. The Cronbach's alpha coefficient of the questionnaire, the χ2 test for comparing rates, the independent sample T test for KAP scores, and linear regression analyses were conducted in the study.

RESULTS

A total of 724 students were included in the study. Approximately 65% (471) of the participants were female students and 35% (253) were male students, and most of them were non-medical (90%) students and from rural areas (60%). The total score of KAP was from 21 to 57, and the mean score of KAP was 41.92±5.78, and less than one fifth of undergraduate students had higher level knowledge (14.8%), positive attitudes (15.5%), and low-risk practices (8.6%). The education level was a significant factor in predicting knowledge, and upper-year students (junior/senior) had a higher level of knowledge about CE than lower-year students (OR = 1.59, p = 0.01). Both residence (OR = 0.57, p < 0.05) and knowledge (OR = 2.26, p<0.05) were significant predicting attitude factors, and students with more knowledge had a positive attitude. But the significant predictors of practice were gender (OR = 3.26, p < 0.05), education level (OR = 0.75, p < 0.05) and attitude (OR = 2.25, p = 0.05).

CONCLUSION

The KAP level and pass rate for knowledge of CE among Chinese students in western areas is low, and most participants showed insufficient or poor CE knowledge. It is necessary to strengthen the health education in school or by multimedia communication platforms on CE for college students in western areas and those with identified related factors.

Evaluation of the prevalence of Echinococcus multilocularis in free-roaming dogs in the human alveolar echinococcosis endemic region of Turkey

As free-roaming dogs may play a pivotal role in the transmission of alveolar echinococcosis (AE) to humans, the detection of the parasite in dogs is important for the control of the disease. The objective of this study was to ascertain the current situation of E. multilocularis in free-roaming dogs in the northeastern region of Türkiye which is endemic for human AE. The study area comprises the provinces of Ağrı, Ardahan, Bayburt, Erzincan, Erzurum, Iğdır and Kars. Between 2019 and 2020, 1069 individual fecal samples collected from free-roaming dogs were analyzed by sequential flotation/sieving method. Each taeniid egg-positive sample was then subjected to PCR for the amplification of partial fragments of 12S rRNA and NAD1 of E. multilocularis. The regional prevalence of E. multilocularis was 8.7 % (93/1069), while the rates of provinces were as follows: Bayburt [14.4 % (15/104)], Iğdır [13.2 % (14/106)], Kars [10.4 % (12/115)], Erzurum [8.3 % (35/420)], Erzincan [6.9 % (7/101)], Ağrı [6.9 % (8/116)] and Ardahan [1.9 % (2/107)]. This study demonstrates the high burden of E. multilocularis in free-roaming dogs and highlights the potential crucial role of dogs in the transmission of AE, which is a significant public health concern for humans in the region. These findings emphasize the necessity to design control strategies for AE in the region that cover both rural and urban areas and focus specifically on free-roaming dogs.

High parasite prevalence driven by the human-animal-environment interface: a One Health study in an urban area in southern of Chile

Parasitic infections remain a global health concern, affecting human populations worldwide. However, comprehensive studies evaluating human, animal, and environmental interactions driven transmission of parasites are limited. We conducted a One Health study in an urban area of Valdivia, Chile. Human participants provided fecal and blood samples for parasitological and serological analysis. Environmental soil samples were collected from public parks, and fecal samples from owned and stray dogs were analyzed. Detection of intestinal parasites employed microscopy and molecular techniques, including next-generation sequencing (NGS), while anti-Toxocara canis antibodies in humans were assessed using ELISA. Socioeconomic surveys explored risk factors associated with parasitism. Parasite prevalence was 28% in humans, 26% in owned dogs, and 44% in environmental dog feces. Anti-T. canis IgG antibodies were present in 33% of humans. Soil contamination was identified in up to 30.5% of park samples, harboring zoonotic parasites such as Toxocara sp. and Trichuris vulpis, the same species identified in environmental dog feces. Zoonotic subtypes of Giardia duodenalis and Blastocystis sp. were detected in humans. Our findings highlight significant zoonotic and environmental transmission contributing to human parasitic infections in urban settings, underscoring the need for integrated public health interventions. This study demonstrates the importance of adopting an OneHealth approach in the study of parasitology. The complex ecology of parasites requires an integrated perspective to fully understand their transmission pathways and develop effective control strategies. By emphasizing the interconnectedness of human, animal, and environmental health, we aim to contribute to the management and mitigation of this persistent public health issue.

Knowledge, attitudes, and perception of dog owners on the transmission, control and prevention of cystic echinococcosis and other gastrointestinal parasites in dogs of Southern provinces of Mozambique

In rural communities of Mozambique, dogs are utilized not only as companion animals, but also for shepherding livestock, guarding, and hunting purposes, increasing exposure of humans to zoonotic parasites. Thus, we conducted a study to assess knowledge, attitudes, and perceptions of rural dog owners living in the districts of Gaza and Inhambane provinces, south of Mozambique, on cystic echinococcosis (CE) followed by a survey on the prevalence of gastrointestinal parasites with emphasis on Taeniidae infection in dogs from the same districts. A structured questionnaire was administered to 335 dog owners to assess their knowledge, attitudes and perceptions related to the risk factors for transmission, control, and prevention of CE. Responses were analyzed with SPSS software using the Chi-square test. To determine the prevalence of endoparasites, 723 dog fecal samples were collected and processed using a flotation technique to detect helminths/protozoa eggs/cysts/oocysts and modified Ziehl Neelsen staining to detect Cryptosporidium oocysts. Samples positive for taeniids were further processed to identify them to species level using molecular techniques. 3% (10/335) of respondents of the questionnaire were aware of CE which was higher in males (2.7%; 9/335) compared to females, in respondents aged 26-45 years old (2.1%; 7/335), and in agro-pastoralists (1.8%; 6/335). An overall prevalence of 93.7% (678/723) for at least one parasite species was found. Prevalence was 7.6% (55/723) for Spirocerca spp., 50.9% (368/723) for Ancylostoma spp., 4% (29/723) for Toxocara spp., 5.4% (39/723) for Trichuris spp., 8.7% (63/723) for Sarcocystis spp., 8.4% (61/723) for Dipylidium caninum, 8.7% (63/723) for Isospora spp., 2.2% (16/723) for Giardia spp. and 1.7% (12/723) for Cryptosporidium spp. Prevalence of taeniids was 2.4% (17/723) with six isolates identified as Taenia hydatigena and two as Taenia multiceps. Results of questionnaire survey showed that the Knowledge of cystic echinococcosis in districts of southern Mozambique was limited, and we recommend the development of targeted public health campaigns to raise awareness of local communities about transmission cycles and prevention CE. Future epidemiological studies should be conducted to investigate the potential source of CE infections in cattle by screening both wild and domestic canids.

Human Alveolar Echinococcosis-A Neglected Zoonotic Disease Requiring Urgent Attention

Alveolar echinococcosis (AE) in humans is caused by the larval (metacestode) stage of Echinococcus multilocularis, commonly known as the 'fox tapeworm'. This disease predominantly targets the liver and has an invasive growth pattern, allowing it to spread to adjacent and distant tissues. Due to its gradual progression and tumour-like characteristics, early diagnosis and prompt intervention are crucial, particularly as there are currently no highly effective vaccines or chemotherapeutics against AE. Current estimates suggest that ~10,500 new infections occur annually worldwide; however, more research is required to refine the prevalence and incidence data for both human and animal hosts in endemic areas of the world. This article discusses the biology of E. multilocularis, outlines aspects of the pathogenesis, diagnosis, treatment, and management of AE, reviews its global distribution, annual incidence, and prevalence, highlights the role of molecular parasitology in advancing therapeutic strategies, and presents recommendations for improving the prevention and control of AE in human populations.

Human alveolar echinococcosis-global, regional, and national annual incidence and prevalence rates

BACKGROUND

Alveolar echinococcosis (AE) of humans is a disease caused by the larval (metacestode) stage of the 'fox tapeworm' Echinococcus multilocularis. AE primarily affects the liver and, like cancer, can spread to surrounding or distant organs. Its slow progression and resemblance to malignant tumours emphasise the critical importance of early detection and intervention, as there is no highly effective vaccine against AE. Although recognised as a neglected disease, there has been no recent, comprehensive review of the distribution, incidence and prevalence of AE in humans around the world.

OBJECTIVES

To estimate the global, regional, and national annual incidence rates and prevalences of human AE in endemic countries.

SOURCES

Incidence and prevalence data were obtained from published articles from 1980 to 2024, accessible via public databases.

CONTENT

This article provides a brief background on E. multilocularis, its biology and impact; reviews the geographic distribution and incidence of AE; and gives a perspective on the prevention and control of this neglected disease in humans.

IMPLICATIONS

The AE burden in humans is substantial and emphasises the need for enhanced public awareness, surveillance, prevention, and control, particularly in under-resourced communities to mitigate the health, economic, and psychological impact of AE.

Past, present and future epidemiology of echinococcosis in China based on nationwide surveillance data 2004-2022

OBJECTIVES

We evaluated the epidemiological characteristics of echinococcosis, a global public health threat, in China to inform global control efforts.

METHODS

Descriptive, statistical, cluster, spatial, and trend analyses were used to evaluate the epidemiology at national, provincial, and county levels based on 2004-2022 nationwide surveillance data from China.

RESULTS

Between 2004 and 2022, China recorded 72,676 cystic echinococcosis (CE) cases, 11,465 alveolar echinococcosis (AE) cases, and 5703 others, with an average annual cases per million (ANpM) of 3.45. Females had a higher incidence (ANpM = 3.87) than males (3.05), with most cases (41.15%) in the 30-49 age group, mainly among herders (38.76%) and farmers (37.82%). Seven provinces (Xizang, Qinghai, Xinjiang, Ningxia, Gansu, Sichuan, and Inner Mongolia) accounted for 98.12% of cases, with the Tibetan Plateau showing the highest rates (ANpMs = 155.51 for CE, 46.95 for AE). Surgery and case fatality rates were 39.45% and 5.23% in key surveillance regions (KSRs). Prevalence among residents (0.20%), livestock (1.33%), rodents (1.30%), and dogs (1.26%) declined with increased control funding in KSRs. Between 2023 and 2030, there will be an estimated 20,096 new cases and 45,323 cases requiring treatment.

CONCLUSION

The prevalence of echinococcosis has been alleviated in China, but significant control challenges remain, requiring sustained and targeted control measures.

Reemergence of Echinococcus granulosus Infections after 2004 Termination of Control Program in Magallanes Region, Chile

After termination of a control program in 2004, Echinococcus granulosus infections have reemerged in Magallanes Region, Chile. Prevalence in sheep >2 years of age in 2023 resembled levels observed at the start of the program. Resurgence underscores the need for continued surveillance, particularly in younger sheep, to monitor recent transmission trends.

A Review on the Epidemiology and Clinical Management of Neglected Tropical Diseases

Infectious disorders known as Neglected Tropical Diseases (NTDs) initially affect the world's underprivileged citizens. They have been disregarded for many years, first as a result of a general indifference to such a developing world and, more recently, as an outcome of the intense attention on AIDS, TB, and malaria. Tropical diseases mostly affect the region where health and hygiene are sacrificed, and most of the population lacks access to sufficient food and living resources. WHO has drafted and released the directions for regulation, prevention, and successful eradication of NTDs as per the revised roadmap of 2021-2030. This shifts from vertical disease programs to integrated cross-cutting methods. In the current work, we have provided comprehensive information on various aspects of neglected tropical diseases, including the clinical management of NTDs. This encompasses the causative agent of the diseases, their symptoms, pathogenesis, diagnosis, treatment, prognosis, and epidemiological perspective of major NTDs. This review will shed light on several perspectives of NTDs having influential roles in proposing strategies to control and treat them around the world.

Designing multi-epitope vaccines against Echinococcus granulosus: an in-silico study using immuno-informatics

Cystic echinococcosis (CE) is a worldwide zoonotic public health issue. The reasons for this include a lack of specific therapy options, increasing antiparasitic drug resistance, a lack of control strategies, and the absence of an approved vaccine. The aim of the current study is to develop a multiepitope vaccine against CE by in-silico identification and using different Antigen B subunits. The five Echinococcus granulosus antigen B (EgAgB) subunits were examined for eminent antigenic epitopes, and then the best B-cell and Major Histocompatibility Complex MHC-binding epitopes were predicted. Most significant epitopes were combined to create an effective multi-epitope vaccine, which was then validated by testing its secondary and tertiary structures, physicochemical properties, and molecular dynamics (MD) modelling. A multi-epitope vaccine construct of 483 amino acid sequences was designed. It contains B-cell, Helper T Lymphocyte (HTL), and Cytotoxic T Lymphocyte (CTL) epitopes as well as the appropriate adjuvant and linker molecules. The resultant vaccinal construct had a GDT-HA value of 0.9725, RMSD of 0.299, MolProbity of 1.891, Clash score of 13.1, Poor rotamers of 0.9, and qualifying features with Rama favoured of 89.9. It was also highly immunogenic and less allergic. The majority of the amino acids were positioned in the Ramachandran plot's favourable area, and during the molecular dynamic simulation at 100 ns, no notable structural abnormalities were noticed. The resultant construct was significantly expressed and received good endorsement in the pIB2-SEC13-mEGFP expressional vector. In conclusion, the current in-silico multi-epitope vaccine may be evaluated in-vitro, in-vivo, and in clinical trials as an immunogenic vaccine model. It can also play a vital role in preventing this zoonotic parasite infection.

Echinococcus granulosus sensu lato control measures: a specific focus on vaccines for both definitive and intermediate hosts

Echinococcosis, a neglected zoonotic disease caused by Echinococcus tapeworms, presents significant public health challenges worldwide. Cystic and alveolar echinococcosis has substantial health and economic impacts, necessitating effective prevention and control strategies. The present review provides a framework to expand our knowledge regarding key components of echinococcosis prevention and control, including phases, options, targets and available tools as well as current gaps and challenges in the field. Furthermore, we discuss the progress made in developing vaccines for the intermediate and definitive hosts and review the limitations and obstacles in vaccine development for definitive hosts. Abundant information is available on various aspects of the Echinococcus vaccine in sheep. Livestock vaccination effectively reduces Echinococcus transmission to sheep, offering a feasible control measure in intermediate hosts. However, vaccine development for the definitive host, i.e. dogs, exhibits significant challenges. Information gaps regarding the immune-mediated protective responses in dogs, repeatability of results, factors influencing the immune response, reinfection resistance, potential age-related decreases in worm burden and factors associated with the antifecundity effect are key challenges that should be addressed in canine vaccine development, and research collaboration, innovative technologies, and a deeper understanding of transmission dynamics are crucial. Multisectoral coordination under the One Health framework, with long-term political commitment and national and international cooperation, is critical for effective control in endemic areas.

Challenges and pitfalls in managing lumbosacral hydatid disease: Lessons learned from clinical practice

OBJECTIVE

Lumbosacral hydatid disease (LHD), a rare skeletal parasitic disease that involves the lumbosacral region. In this study, we summarized the diagnostic and therapeutic procedures for patients with LHD to provide insights into managing this rare disease.

METHODS

Between 2000 and 2023, 16 patients diagnosed with LHD were retrospectively analyzed. Each patient's medical records and follow-up details, were carefully assessed. The average follow-up period was 11.25 ± 6.41 years, providing valuable insights into treatment durability and effectiveness.

RESULTS

The diagnosis was confirmed via imaging, serological tests, and pathological examination. The clinical symptoms included lumbago with lower limb numbness (25 %) and urinary and fecal incontinence (25 %). All patients underwent surgery, with an average of 2.6 surgeries per patient. Thirteen (81.25 %) patients experienced recurrence postoperatively.

CONCLUSION

LHD is a severe and complex skeletal parasitic disease with significant diagnostic and therapeutic challenges. Effective management requires a comprehensive strategy involving surgery and additional therapies.

Ecoepidemic modeling and dynamics of alveolar echinococcosis transmission

Alveolar echinococcosis, transmitted between definitive hosts and intermediate hosts via predation, threatens the health of humans and causes great economic losses in western China. In order to explore the transmission mechanism of this disease, an eco-epidemiological lifecycle model is formulated to illustrate interactions between two hosts. The basic and demographic reproduction numbers are developed to characterize the stability of the disease-free and endemic equilibria as well as bifurcation dynamics. The existence of forward bifurcation and Hopf bifurcation are confirmed and are used to explain the threshold transmission dynamics. Numerical simulations and bifurcation diagrams are also presented to depict rich dynamics of the model. Numerical analysis suggests that improving the control rate of voles will reduce the risk of transmission, while the high predation rate of foxes may also lead to a lower transmission risk, which is different from the predictions of previous studies. The evaluation of three control measures on voles implies that, when the fox's predation rate is low (high), the chemical (integrated) control will be more effective.

Environmental contamination with feces of free-roaming dogs and the risk of transmission of Echinococcus and Taenia species in urban regions of southeastern Iran

BACKGROUND

Dogs are the most important definitive hosts of zoonotic taeniid helminths worldwide. Different Echinococcus and Taenia species of domestic and wild carnivores pose a potential risk to human population. High populations of free-roaming dogs (FRDs) in urban areas of Iran and widespread contamination of the environment with dog feces is a potential source of infecting people living in the urban regions with cystic echinococcosis (CE). Our knowledge on the risk of CE transmission in the urban settings in the endemic regions is limited. The present study surveyed the species and genotypes of E. granulosus sensu lato and other taeniids by examining feces of free-roaming dogs in the urban areas in the city of Kerman, southeastern Iran.

METHODS

The city was divided into 100 consecutive blocks of which 25 blocks were randomly selected. Fecal samples of FRDs were counted, mapped and fresh samples were collected. Then Zinc chloride flotation, and sequential sieving was performed, and the samples were examined under an inverted microscope. Single individual taeniid eggs were isolated, partial nad1 gene was amplified and sequenced to identify species and genotypes.

RESULTS

In total 5607 fecal samples of dogs were mapped and 83 fresh samples were collected. Taeniid eggs were detected in nine fecal samples (10.8%) from seven out of the 25 city blocks (28.0%). Echinococcus eggs were found in four samples (4.8%) from three city blocks, two samples containing E. granulosus sensu stricto (2.4%), two samples containing E. canadensis G6/7 (2.4%). In addition, three samples contained eggs of Taenia hydatigena (3.6%), and one sample of Taenia serialis (1.2%).

CONCLUSIONS

This study documented the potential risk of CE transmission to humans resulting from the feces of dogs roaming freely in urban areas.

Receptor Tyrosine Kinase Signaling Involves Echinococcus-Host Intercommunication: A Potential Therapeutic Target in Hepatic Echinococcosis

Echinococcosis, one of the most serious and life-threatening parasitic forms of zoonosis worldwide, is caused by the larvae of Echinococcus granulosus (E. granulosus) and Echinococcus multilocularis (E. multilocularis). Various drugs are being applied clinically to treat zoonosis; however, their therapeutic efficacy remains a great challenge, especially with albendazole as the preferred drug of choice. Receptor tyrosine kinase (RTK) signaling controls normal cellular proliferation, differentiation, and metabolism in humans and mammals, which are intermediate hosts of E. granulosus and E. multilocularis. Disruption of RTK signaling can cause various forms of carcinogenesis and exacerbate the progression of certain forms of parasitic disease. As a result, a significant number of studies on tyrosine kinase inhibitors (TKIs) have been conducted for the treatment of cancer and parasitic infection, with some TKIs already approved for clinical use for cancer. Notably, RTK signaling has been identified in the parasites E. granulosus and E. multilocularis; however, the mechanisms of RTK signaling response in Echinococcus-host intercommunication are not fully understood. Thus, understanding the RTK signaling response in Echinococcus-host intercommunication and the potential effect of RTK signaling is crucial for identifying new drug targets for echinococcosis. The present review illustrates that RTK signaling in the host is over-activated following infection by E. granulosus or E. multilocularis and can further facilitate the development of metacestodes in vitro. In addition, some TKIs exert strong parasitostatic effects on E. granulosus or E. multilocularis, both in vitro and/or in vivo, through downregulation of RTK signaling molecules. The summarized findings suggest that RTK signaling may be a promising drug target and that TKIs could be potential anti-Echinococcus drugs warranting further research.

A case report of human primary renal cystic echinococcosis

In humans, solitary renal involvement or primary renal echinococcosis is rare, accounting for about 2-4 % of cases. Usually, patients shpw no obvious symptoms, but they can manifest as renal pain, renal mass, gross hematuria, and hydatiduria in rare cases. We report a case of primary renal cystic echinococcosis, which was originally misdiagnosed as a tuberculous renal abscess.

Epidemiological update of cystic echinococcosis in livestock and assessment of practices related to its control in the Mediterranean area

Cystic echinococcosis (CE), caused by the tapeworm Echinococcus granulosus, is a zoonotic parasitic disease that still represents a serious threat to human and animal health worldwide. The Mediterranean basin is recognized as one of the major hotspots of CE due to several factors, including the presence of diverse intermediate host species as well as socio-economic and cultural conditions of local communities. This study aims to take a closer look at epidemiological data on CE in the Mediterranean area and assess the knowledge attitudes and practices of shepherds towards this disease in four countries (Algeria, Greece, Italy and Tunisia), highly endemic for CE, with the final goal of identifying highly endemic risk areas and practices in use which might potentially allow the persistence of E. granulosus infection in these areas. To update the epidemiological scenario of CE in Mediterranean areas, a comprehensive review of peer-reviewed literature on CE prevalence data published during the 2017-2023 period was carried out and, through a geographical information system (GIS), a map displaying the current CE distribution in the Mediterranean area was generated. In addition, a questionnaire survey was conducted through in-depth interviews of the farmers to collect information on their management system as well as knowledge attitudes and practices towards CE. From the farmer-participatory survey some risky practices emerged including the non-regular deworming of dogs or the use of ineffective drugs or dosing, as well as the provision of uncooked animal viscera to dogs. Finally, lower levels of knowledge and awareness of the disease was observed among farmers from North Africa compared with those of European countries. In conclusion, the results obtained highlight that CE is still a very serious problem in Mediterranean areas and increased efforts are needed to promote awareness among farmers and to turn research results into policy in order to reduce the spread of this disease, according to the One Health perspective.

Cystic echinococcosis (Echinococcus granulosus sensu lato infection) in Tunisia, a One Health perspective for a future control programme

The emergence of pandemics with dramatic consequences for human health has obscured endemic diseases that continue to pose a problem for human and animal health in several regions of the world. Among these diseases, cystic echinococcosis, a zoonotic parasitic infection caused by a group of cestodes, Echinococcus granulosus sensu lato, remains a real human and animal health problem in several regions of the world, including the Mediterranean Basin. Despite the implementation of a number of governmental control programmes using several tools (dog treatment, meat inspection, etc.), this infection is still highly prevalent in North Africa. Here we present a review of the epidemiology of cystic echinococcosis in Tunisia, an analysis of the constraints limiting the effectiveness of the control programmes implemented, and finally argue for the use of the One Health framework to improve the effectiveness of future programmes.

Unveiling the anti-echinococcal efficacy of amide-based compounds: An in-silico and in-vitro study

Cystic echinococcosis (CE) is a significant global public health concern, particularly in regions where livestock rearing is prevalent. Despite its impact on morbidity and mortality, CE has received insufficient attention compared to other neglected tropical diseases. The complexities in CE management arise from challenges in early detection, effective treatment, and parasite eradication. The present study addresses this gap by exploring innovative therapeutic approaches using amide-based compounds. In recent years, computational approaches and in-vitro studies have become prominent in neglected tropical disease drug discovery. Leveraging insights from previous studies on amide-based compounds with anti-parasitic potential, this study systematically designed, synthesized, and characterized a library of 30 amide compounds. The research integrated in-silico screening, molecular docking, and in-vitro experimentation to assess the anti-echinococcal potential of these compounds. The study identified five promising amide compounds, namely 3,5-dinitro-N-p-tolylbenzamide, N-p-tolyl-1-naphthamide, N-p-tolyl-4-(trifluoromethoxy)benzamide, 4-pentyl-N-p-tolylbenzamide, and 2,3,4,5,6-pentafluoro-N-p-tolylbenzamide, based on their docking scores. These compounds were synthesized and characterized through various spectroscopic techniques, confirming their structural integrity. The in-vitro cytotoxicity assay on HepG2 cell lines revealed varying degrees of cytotoxicity for the synthesized compounds. Notably, 4-pentyl-N-p-tolylbenzamide demonstrated the least cytotoxicity. Subsequent scolicidal activity assessments on E. granulosus protoscoleces demonstrated the potent protoscolicidal activity of N-p-tolyl-1-naphthamide, indicating its potential as an effective anti-echinococcal agent. Overall, this study presents a comprehensive exploration of amide-based compounds as potential therapeutic agents against CE. The findings contribute to the development of innovative strategies for CE treatment, addressing the urgent need for effective and safe drugs in managing this neglected tropical disease.

In vitro and ex vivo protoscolicidal effect of poly(amidoamine) nanoemulsion against Echinococcus granulosus

Hydatidosis causes a serious health hazard to humans and animals leading to significant economic and veterinary and public health concern worldwide. The present study aimed to evaluate the in vitro and ex vivo protoscolicidal effects of synthesized poly(amidoamine), PAMAM, nanoemulsion. In this study, PAMAM was characterized through dynamic light scattering technique to investigate the particle size and zeta potential of nanoemulsified polymer. For the in vitro and ex vivo assays, we used eosin dye exclusion test and scanning electron microscope (SEM) to evaluate the effects of the prepared and characterized PAMAM nanoemulsion against protoscoleces from Echinococcus granulosus sensu lato G6 (GenBank: OQ443068.1) isolated from livers of naturally infected camels. Various concentrations (0.5, 1, 1.5 and 2 mg/mL) of PAMAM nanoemulsion at different exposure times (5, 10, 20 and 30 min) were tested against protoscolices. Our findings showed that PAMAM nanoemulsion had considerable concentration- and time-dependent protoscolicidal effect at both in vitro and ex vivo experiments. Regarding in vitro assay, PAMAM nanoemulsion had a potent protoscolicidal effect when compared with the control group with a highest protoscolicidal activity observed at the concentration of 2 mg/mL at all exposure times, such that 100% of protoscolices were killed after 20 min of exposure. Also, the mortality of protoscolices was 100% after 30 min of exposure to 1 and 1.5 mg/mL of PAMAM nanoemulsion, in vitro. Concerning ex vivo assay PAMAM nanoemulsion recorded the highest mortality rates at the concentration of 2 mg/mL (55, 99.4 and 100% at 10, 20, 30 min, respectively). Ultrastructure examination of examined protoscolices after 20 min of exposure to PAMAM nanoemulsion showed a complete loss of rostellar hooks, disruption of suckers with disorganization of hooks with partial or complete loss of them, and damage of protoscolices tegument with loss of their integrity in the form of holes and contraction of the soma region were observed in 1.5 and 2 mg/mL of PAMAM, in vitro and ex vivo, showing more damage in the in vitro conditions. It can be concluded that PAMAM nanoemulsion is a promising protoscolicidal agent offering a high protoscolicidal effect at a short exposure time. Further in vivo studies and preclinical animal trials are required to evaluate its efficacy and clinical applications against hydatid cysts.

Ultrasonography screening of hepatic cystic echinococcosis in sheep flocks used for evaluating control progress in a remote mountain area of Hejing County, Xinjiang

BACKGROUND

Although ultrasonography (US) has been widely used in the diagnosis of human diseases to monitor the progress of cystic echinococcosis (CE) control, the screening method for hepatic CE in sheep flocks requires adjustment. In this study, we used a US scanner to screen sheep flocks and evaluated the efficacy of dosing dogs once a year with praziquantel for 7 years from 2014 to 2021.

METHODS

All sheep in the three flocks were screened using an ultrasound scanner in 2014 and compared with the prevalence of infection in 2021 in Bayinbuluke, Xinjiang, China. Sheep age was determined using incisor teeth. Cyst activity and calcification were determined using US images. The dogs were dewormed with praziquantel once a year to control echinococcosis in the community.

RESULTS

Three flocks had 968 sheep in 2014, with 13.22%, 22.62%, 18.7%, 27.27%, 11.88%, and 6.3% of sheep aged 1, 2, 3, 4, 5, and ≥ 6 years old, respectively. US scanning revealed that the overall CE prevalence was 38.43% (372/968), with active cysts and calcified cysts present in 9.40% (91/968) and 29.02% (281/968) of the sheep, respectively. For the young sheep aged 1 and 2 years, the prevalence of active and calcified cysts was: 1.56% and 0.91%, and 10.94% and 18.72%, respectively. Approximately 15.15% and 16.52% of the 4- and 5-year-old sheep, respectively, harbored active cysts. There was no significant difference in the infection rates of sheep between 2014 and 2021 (P > 0.05).

CONCLUSIONS

US is a practical tool for the field screening of CE in sheep flocks. One-third of the sheep population in the flocks was 1-2 years old, and these sheep played a very limited role in CE transmission, as most of the cysts were calcified. Old sheep, especially culled aged sheep, play a key role in the transmission of CE. Dosing dogs once a year did not affect echinococcosis control.

A regressive analysis of the main environmental risk factors of human echinococcosis in 370 counties in China

BACKGROUND

Echinococcosis is a natural focal, highly prevalent disease in China. Factors influencing the spread of echinococcosis are not only related to personal exposure but also closely related to the environment itself. The purpose of this study was to explore the influence of environmental factors on the prevalence of human echinococcosis and to provide a reference for prevention and control of echinococcosis in the future.

METHODS

Data were collected from 370 endemic counties in China in 2018. By downloading Modis, DEM and other remote-sensing images in 2018. Data on environmental factors, i.e., elevation, land surface temperature (LST) and normalized difference vegetation index (NDVI) were collected. Rank correlation analysis was conducted between each environmental factor and the prevalence of echinococcosis at the county level. Negative binomial regression was used to analyze the impact of environmental factors on the prevalence of human echinococcosis at the county level.

RESULTS

According to rank correlation analysis, the prevalence of human echinococcosis in each county was positively correlated with elevation, negatively correlated with LST, and negatively correlated with NDVI in May, June and July. Negative binomial regression showed that the prevalence of human echinococcosis was negatively correlated with annual LST and summer NDVI, and positively correlated with average elevation and dog infection rate. The prevalence of human cystic echinococcosis was inversely correlated with the annual average LST, and positively correlated with both the average elevation and the prevalence rate of domestic animals. The prevalence of human alveolar echinococcosis was positively correlated with both NDVI in autumn and average elevation, and negatively correlated with NDVI in winter.

CONCLUSION

The prevalence of echinococcosis in the population is affected by environmental factors. Environmental risk assessment and prediction can be conducted in order to rationally allocate health resources and improve both prevention and control efficiency of echinococcosis.

Investigation of patients with new infection of echinococcal cyst in Sardinia, Italy

Cystic Echinococcosis (CE) is a zoonotic disease caused by the larval stage of a tapeworm of Taeniidae family, genus Echinococcus and species Echinococcus granulosus sensu lato (s.l.). CE is a worldwide public health problem and is highly incident in all Mediterranean areas. Following clinical, image techniques and serological investigations all 83 subjects involved in the study were diagnosed for CE. General and clinical data were entered into a database and evaluated. The 43.37% were female and 56.63% male, mean age was 50.71 while the range most represented (22.7%) was between 61->70 years. The purposes of our survey were to investigate these 83 patients enrolled in the study and to deeply examine 20 (24.10%) patients that developed a new echinococcal cyst. Moreover, the causes at the basis of the onset of a new cyst were analysed, together with a possible correlation with different treatments related to primary infection corresponding to surgery (n=7), albendazole (n=6), PAIR (n=3) and watch and wait (n=4). A possible link with medical treatments of the primary infection was observed in the subjects who underwent surgery or PAIR and a likely correlation attributable to high environmental contamination in subjects managed with drugs or watch and wait was detected. Moreover, our analysis evidenced that patients with a new infection presented a more severe diagnosis along with a major mortality rate. Finally, these data may have an important contribution for an epidemiological point of view concerning the percentage of CE in a specific geographical endemic area, such as Sardinia.

Global, Regional and National Burden of Human Cystic Echinococcosis from 1990 to 2019: A Systematic Analysis for the Global Burden of Disease Study 2019

BACKGROUND

Cystic echinococcosis (CE) is a neglected tropical parasitic disease that poses huge disease, social and economic burdens worldwide; however, there has been little knowledge on the global morbidity, mortality and disability-adjusted life years (DALYs) of CE until now. This study aimed to collect the most up-to-date data about the global, regional and national disease burden due to CE from 1990 to 2019 and to project trends in the next 10 years.

METHODS

We measured the global, regional and national morbidity, mortality and DALYs of CE from 1990 to 2019 based on the Global Burden of Disease Study 2019 (GBD 2019) data, and we examined the correlation between socioeconomic development levels and the disease burden of CE. In addition, the disease burden due to CE was projected from 2020 to 2030.

RESULTS

The age-standardized incidence rate (ASIR) of CE reduced from 2.65/105 [95% UI: (1.87/105 to 3.7/105)] in 1990 to 2.6/105 [95% UI: (1.72/105 to 3.79/105)] in 2019 (EAPC = -0.18%). The number of deaths, DALYs, age-standardized mortality rate (ASMR) and age-standardized DALY rate due to CE all showed a tendency to decline from 1990 to 2019. A higher disease burden of CE was measured in women than in men in 2019. There was a significant difference in the ASMR of CE by region according to the socio-demographic index (SDI), and lower burdens of CE were estimated in high-SDI regions. The global ASIR of CE is projected to decline from 2020 to 2030; however, the ASMR and age-standardized DALY rate are projected to rise.

CONCLUSIONS

The global burden of CE remains high, and it is recommended that more health resources are allocated to low-SDI regions, women and the elderly aged 55 to 65 years to reduce the disease burden of CE.

Echinococcus species in wildlife

Transmission of Echinococcus spp. in life cycles that involve mainly wildlife is well recognized for those species with small mammals as intermediate hosts (e. g. E. multilocularis), as well as for E. felidis and the 'northern' genotypes of E. canadensis (G8 and G10). In contrast, the remaining taxa of E. granulosus sensu lato are best known for their domestic life cycles, and the numerous wild mammal species (mainly ungulates) that have been recorded with cystic echinococcosis in the past were mainly considered a result of spill-over from the dog-livestock transmission system. This view was challenged with the advent of molecular characterization, allowing discrimination of the metacestodes, although the contribution of wild mammals to various Echinococcus life cycles has remained uncertain for scarcity of wildlife studies. Numerous records of cysts in wild ungulates date back to the 20th century, but cannot with certainty be allocated to the Echinococcus species and genotypes that are recognized today. This means that our current knowledge is largely restricted to studies of the past two decades that kept adding gradually to our concepts of transmission in various geographic regions. In particular, new insights were gathered in the past years on E. granulosus s.l. in wildlife of sub-Saharan Africa, but also on transmission patterns of E. multilocularis in previously neglected regions, e. g. North America. Here, an update is provided on the current state of knowledge on wild mammals as hosts for all Echinococcus species, listing >150 species of wild hosts with references, as well as estimates on their epidemiological impact and our current gaps of knowledge.

Baiting not-owned dogs against Echinococcus granulosus: innovative tools for integrated control

Cystic echinococcosis (CE), caused by the larval stage of the cestode Echinococcus granulosus, is one of the most widespread zoonoses in Mediterranean countries. Baiting not-owned dogs with praziquantel (PZQ), due to their key role in the maintaining the transmission of CE, currently appears to be the most effective way to limit the transmission of CE, as well as an important aspect to introduce for the control of this parasitic disease. Therefore, this study aims to test 3 types of PZQ-based baits by evaluating different parameters (integrity over time, attractiveness and palatability for dogs, and mechanical resistance after release to different altitudes) and the bait acceptance in field by target animals, i.e. not-owned dogs, by using camera traps. The double PZQ-laced baits (with a double layer of highly palatable chews) showed the greatest resistance in the environment while also preserving the attractiveness and palatability up to 10 days, also withstood heights of 25 m, thus resulting as the most suitable also for drone delivery. The results on the field showed that most of the baits were consumed by not-owned dogs (82.2%), while the remaining were consumed by wild boars (8.9%), foxes (6.7%), badgers (1.1%) and hedgehogs (1.1%), confirming the specific and high attractiveness of the double PZQ-laced baits for the target population and highlights how an anthelmintic baiting programme may be a viable tool for the management of E. granulosus among free-ranging dog populations in endemic rural areas.

Reinfection of farm dogs following praziquantel treatment in an endemic region of cystic echinococcosis in southeastern Iran

Cystic Echinococcosis (CE) as a prevalent tapeworm infection of human and herbivorous animals worldwide, is caused by accidental ingestion of Echinococcus granulosus eggs excreted from infected dogs. CE is endemic in the Middle East and North Africa, and is considered as an important parasitic zoonosis in Iran. It is transmitted between dogs as the primary definitive host and different livestock species as the intermediate hosts. One of the most important measures for CE control is dog deworming with praziquantel. Due to the frequent reinfection of dogs, intensive deworming campaigns are critical for breaking CE transmission. Dog reinfection rate could be used as an indicator of the intensity of local CE transmission in endemic areas. However, our knowledge on the extent of reinfection in the endemic regions is poor. The purpose of the present study was to determine E. granulosus reinfection rate after praziquantel administration in a population of owned dogs in Kerman, Iran. A cohort of 150 owned dogs was recruited, with stool samples collected before praziquantel administration as a single oral dose of 5 mg/kg. The re-samplings of the owned dogs were performed at 2, 5 and 12 months following initial praziquantel administration. Stool samples were examined microscopically using Willis flotation method. Genomic DNA was extracted, and E. granulosus sensu lato-specific primers were used to PCR-amplify a 133-bp fragment of a repeat unit of the parasite genome. Survival analysis was performed using Kaplan-Meier method to calculate cumulative survival rates, which is used here to capture reinfection dynamics, and monthly incidence of infection, capturing also the spatial distribution of disease risk. Results of survival analysis showed 8, 12 and 17% total reinfection rates in 2, 5 and 12 months following initial praziquantel administration, respectively, indicating that 92, 88 and 83% of the dogs had no detectable infection in that same time periods. The monthly incidence of reinfection in total owned dog population was estimated at 1.5% (95% CI 1.0-2.1). The results showed that the prevalence of echinococcosis in owned dogs, using copro-PCR assay was 42.6%. However, using conventional microscopy, 8% of fecal samples were positive for taeniid eggs. Our results suggest that regular treatment of the dog population with praziquantel every 60 days is ideal, however the frequency of dog dosing faces major logistics and cost challenges, threatening the sustainability of control programs. Understanding the nature and extent of dog reinfection in the endemic areas is essential for successful implementation of control programs and understanding patterns of CE transmission.

Diagnosis and treatment of unusual multiorgan Echinococcus hydatid cysts

Background

Echinococcosis is a zoonotic disease caused by Echinococcus granulosus. Usually, the liver is the most affected organ, accounting for approximately 70% to 85% of cases. The lungs represent 20% of the cases. Fewer than 10% are found in other sites, including the bone, brain, spleen, and kidneys.

Case presentation

A young man was referred to a local hospital for dull pain in the right flank, fever, and mild cough. Computed tomography showed 2 large cysts: the first involved the left lung and measured 130 × 90.5 × 120 mm, whereas the second cyst was located in the right kidney and measured 130 × 100 × 120 mm. Surgery was performed to remove both lesions in 2 separate surgical sessions.

Conclusions

Echinococcosis is a compulsorily notifiable disease. Collaboration between medical doctors from different specializations is necessary. A multidisciplinary approach is important for the correct therapeutic management of the disease. Furthermore, the high possibility of recurrence makes the long-term follow-up mandatory.

An innovative strategy for deworming dogs in Mediterranean areas highly endemic for cystic echinococcosis

BACKGROUND

Cystic echinococcosis (CE), caused by the larval stage of Echinococcus granulosus sensu lato, is a zoonotic parasitic disease of economic and public health importance worldwide, especially in the Mediterranean area. Canids are the main definitive hosts of the adult cestode contaminating the environment with parasite eggs released with feces. In rural and peri-urban areas, the risk of transmission to livestock as well as humans is high because of the free-roaming behavior of owned/not owned dogs. Collecting data on animal movements and behavior using GPS dataloggers could be a milestone to contain the spread of this parasitosis. Thus, this study aims to develop a comprehensive control strategy, focused on deworming a dog population in a pilot area of southern Italy (Campania region) highly endemic for CE.

METHODS

Accordingly, five sheep farms, tested to be positive for CE, were selected. In each sheep farm, all shepherd dogs present were treated every 2 months with praziquantel. Furthermore, 15 GPS dataloggers were applied to sheep and dogs, and their movements were tracked for 1 month; the distances that they traveled and their respective home ranges were determined using minimum convex polygon (MCP) analysis with a convex hull geometry as output.

RESULTS

The results showed that the mean daily walking distances traveled by sheep and dogs did not significantly differ. Over 90% of the point locations collected by GPS fell within 1500 mt of the farm, and the longest distances were traveled between 10:00 and 17:00. In all the sheep farms monitored, the area traversed by the animals during their daily activities showed an extension of < 250 hectares. Based on the home range of the animals, the area with the highest risk of access from canids (minimum safe convex polygon) was estimated around the centroid of each farm, and a potential scheme for the delivery of praziquantel-laced baits for the treatment of not owned dogs gravitating around the grazing area was designed.

CONCLUSIONS

This study documents the usefulness of geospatial technology in supporting parasite control strategies to reduce disease transmission.

Serological Comparison of Native Antigen ELISAs with Rapid ICT Test Kits for the Diagnosis of Human Alveolar and Cystic Echinococcosis in China

BACKGROUND

The aim of this study was to compare the diagnostic performance of native antigen ELISAs and ADAMU-AE/CE commercial ICT test kits in subjects either exposed to Echinococcus infection or with clinically diagnosed alveolar (AE) or cystic (CE) echinococcosis.

METHODS

A total of 370 subjects with a previous clinical confirmation of CE or AE from northwestern China were recruited. Serum samples were also obtained from 3923 children/teenagers during a community survey. All sera were tested using native antigen ELISAs. The ADAMU-AE/CE test kits were subsequently used for the serology of the 370 clinically confirmed individuals and of 251 children/teenagers that were ELISA antibody-positive for both Echinococcus species but ultrasound-negative during baseline survey. An analysis of the association between the serological tests and ultrasound classification was carried out amongst 89 AE and 164 CE cases. A Kappa consistency analysis was undertaken to compare the diagnostic performance of the native antigen ELISAs and the ADAMU kits and the ultrasound imaging results. The χ² test was also used for a comparison of the different seropositivity rates between the groups.

FINDINGS

There was poor consistency (Kappa = 0.26 and 0.28 for AE and CE respectively) between the native antigen ELISAs and the ADAMU kits for the diagnosis of AE and CE among the cases and the surveyed children/teenagers, but a relatively good consistency (Kappa = 0.63) between the ADAMU-AE kit and ultrasound observations for the AE cases. Additionally, of the 251 teenagers co-positive for both AE and CE antibodies by the native antigen ELISAs, only one was found positive by the ADAMU-AE kit, verified as a new AE case on subsequent ultrasound follow-up. The remainder (N = 250) were negative by serology using the ADAMU-AE/CE kits and by ultrasound examination. The two native antigen ELISAs did not discriminate well between cases of clinically diagnosed AE and CE. In contrast, ADAMU-AE and ADAMU-CE commercial ICT test kits readily differentiated cases of AE from CE with specificities of 99% for AE and 100% for CE.

CONCLUSIONS

The ADAMU-AE/CE kits proved reliable, accurate, and amenable diagnostic tools in the clinical setting for confirmation of suspected AE/CE cases. The native antigen ELISAs tests can provide useful information on the level of human exposure to Echinococcus infection.

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

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

Magnetic resonance imaging and next-generation sequencing for the diagnosis of cystic echinococcosis in the intradural spine: a case report

BACKGROUND

Cystic echinococcosis (CE) is a parasitic zoonotic disease caused by the larval stage of Echinococcus granulosus. The liver and lungs are the most common sites for infection. Infection of the intradural spine is rare.

CASE PRESENTATION

A 45-year-old woman of Han ethnicity presented with a chronic history of recurrent lumbar pain. Magnetic resonance imaging of the lumbar spine revealed the classical characteristic of multiple cystic lesions of variable sizes, manifesting a "bunch of grapes" appearance, localized within the spinal canal at the L4-L5 vertebral level. In the meanwhile, metagenomic next-generation sequencing identified Echinococcosis granulosa. The patient underwent surgery to remove the cyst entirely and subsequently took albendazole 400 mg orally twice daily for 6 months.

CONCLUSION

Spinal CE should be suspected in patients with multiple spinal cystic lesions and zoonotic exposure. metagenomic next-generation sequencing serves as a robust diagnostic tool for atypical pathogens, particularly when conventional tests are inconclusive. Prompt and aggressive treatment for spinal cystic echinococcosis is imperative, and further research is warranted for improved diagnostic and therapeutic strategies.

Protective efficacy of six recombinant proteins as vaccine candidates against Echinococcus granulosus in dogs

BACKGROUND

Cystic echinococcosis (CE) is caused by the infection of Echinococcus granulosus sensu lato (E. granulosus s.l.), one of the most harmful zoonotic helminths worldwide. Infected dogs are the major source of CE transmission. While praziquantel-based deworming is a main measure employed to control dog infections, its efficacy is at times compromised by the persistent high rate of dog re-infection and the copious discharge of E. granulosus eggs into the environment. Therefore, the dog vaccine is a welcome development, as it offers a substantial reduction in the biomass of E. granulosus. This study aimed to use previous insights into E. granulosus functional genes to further assess the protective efficacy of six recombinant proteins in dogs using a two-time injection vaccination strategy.

METHODS

We expressed and combined recombinant E. granulosus triosephosphate isomerase (rEgTIM) with annexin B3 (rEgANXB3), adenylate kinase 1 (rEgADK1) with Echinococcus protoscolex calcium binding protein 1 (rEgEPC1), and fatty acid-binding protein (rEgFABP) with paramyosin (rEgA31). Beagle dogs received two subcutaneous vaccinations mixed with Quil-A adjuvant, and subsequently orally challenged with protoscoleces two weeks after booster vaccination. All dogs were sacrificed for counting and measuring E. granulosus tapeworms at 28 days post-infection, and the level of serum IgG was detected by ELISA.

RESULTS

Dogs vaccinated with rEgTIM&rEgANXB3, rEgADK1&rEgEPC1, and rEgFABP-EgA31 protein groups exhibited significant protectiveness, with a worm reduction rate of 71%, 57%, and 67%, respectively, compared to the control group (P < 0.05). Additionally, the vaccinated groups exhibited an inhibition of worm growth, as evidenced by a reduction in body length and width (P < 0.05). Furthermore, the level of IgG in the vaccinated dogs was significantly higher than that of the control dogs (P < 0.05).

CONCLUSION

These verified candidates may be promising vaccines for the prevention of E. granulosus infection in dogs following two injections. The rEgTIM&rEgANXB3 co-administrated vaccine underscored the potential for the highest protective efficacy and superior protection stability for controlling E. granulosus infections in dogs.

Presence of Echinococcus granulosussensulato in the endoparasitic fauna of feral dogs in Tierra del Fuego, Argentina

The feral dog population from Tierra del Fuego (Argentina) has affected provincial sheep production, and is responsible for the decrease of 43% of the sheep stock. In addition, feral dogs preys on the native fauna, especially the guanaco (Lama guanicoe), a species protected by law. Except for some data on the aforementioned impact, very little is known about feral dogs features in this region, such as distribution, abundance, diet, reproduction, health status, among others. Therefore, a descriptive observational study was carried out in the period 2018-2021 in Tierra del Fuego, with the aim to recognize the endoparasitic fauna of these dogs, with emphasis on Echinococcus granulosus sensu lato (s.l.). Feces samples were collected from 83 feral dogs captured in 15 farms, which were evaluated using flotation and sedimentation coproparasitological techniques, and optical microscope observation. These qualitative methods showed that 66.3% of the samples were positive. Nine parasitic forms were found, including eggs of taenids, Toxocara canis and Toxascaris leonina, and Sarcocystis spp. oocysts and Giardia spp. cysts. Samples with more than one parasitic form were also observed, among which the Taenia/Sarcocystis spp. association was the most frequent. For the diagnosis of canine echinococcosis, the detection of Echinococcus spp. antigens by Copro-ELISA and the molecular confirmation by Copro-PCR were performed. The Copro-ELISA test was positive in 10/80 (12.5%) of the samples processed, while 11 samples (13.8%) were positive by Copro-PCR. Their distribution showed that 9 (81.8%) corresponded to farms with sheep farming, and 2 (18.2%) with cattle farming. The presence of E. granulosus s.l. in feral dogs from Tierra del Fuego is the most relevant finding in this study. These results confirm that feral dogs have access to viscera infected with hydatid cysts. However, the intermediate hosts involved (sheep, cattle or guanacos) should be investigated. Its impact on the transmission of cystic echinococcosis in this region should be evaluated, as well as the adequacy of the disease prevention and control actions implemented in Tierra del Fuego should be considered. Finally, the existence of a wild cycle of the disease should be evaluated, in which feral dogs would act as a source of infection for other animals and humans.

Infection of sheep by Echinococcus multilocularis in Gansu, China: evidence from mitochondrial and nuclear DNA analysis

BACKGROUND

In the normal life cycle of the parasite (Echinococcus multilocularis) that causes alveolar echinococcosis, domestic and wild carnivores act as definitive hosts, and rodents act as intermediate hosts. The presented study contributes to the research on the distribution and transmission pattern of E. multilocularis in China having identified sheep as an unusual intermediate host taking part in the domestic transmission of alveolar echinococcosis in Gansu Province, China.

METHODS

From 2020 to 2021, nine whitish different cyst-like were collected from the liver of sheep in Gansu Province for examination. A near complete mitochondrial (mt) genome and selected nuclear genes were amplified from the cyst-like lesion for identification. To confirm the status of the specimen, comparative analysis with reference sequences, phylogenetic analysis, and network analysis were performed.

RESULTS

The isolates displayed ≥ 98.87% similarity to E. multilocularis NADH dehydrogenase sub-unit 1 (nad1) (894 bp) reference sequences deposited in GenBank. Furthermore, amplification of the nad4 and nad2 genes also confirmed all nine samples as E. multilocularis with > 99.30% similarity. Additionally, three nuclear genes, pepck (1545 bp), elp-exons VII and VIII (566 bp), and elp-exon IX (256 bp), were successfully amplified and sequenced for one of the isolates with 98.42% similarity, confirming the isolates were correctly identified as E. multilocularis. Network analysis also correctly placed the isolates with other E. multilocularis.

CONCLUSIONS

As a result of the discovery of E. multilocularis in an unusual intermediate host, which is considered to have the highest zoonotic potential, the result clearly demonstrated the necessity for expanded surveillance in the area.

A Novel Designed Sandwich ELISA for the Detection of Echinococcus granulosus Antigen in Camels for Diagnosis of Cystic Echinococcosis

Echinococcus spp. are important cosmopolitan zoonotic parasitic tapeworms that cause a disease called hydatidosis or cystic echinococcosis (CE), which has remarkable economic losses. The objective of our study was to develop a specific IgG polyclonal antigen-based ELISA (Sandwich ELISA; capture ELISA) method for the detection of circulating Echinococcus granulosus (E. granulosus) antigens in camels infected with hydatid cysts before slaughtering and its application in serodiagnosis of CE in animals to assess the positive rate of hydatidosis in camels slaughtered in Giza governorate abattoirs in Egypt. In this study, molecular identification of Echinococcus sp. isolate was performed based on the NADH dehydrogenase subunit 1 (NAD1) gene, revealing the isolate (GenBank: OQ443068.1), which is identical to the G6 E. granulosus sensu lato genotype. The positive rate of hydatid cysts was determined in slaughtered camels' organs (n = 587). The results revealed that hydatid cysts were found in 46.5% (273/587) of the examined camels. Pulmonary echinococcosis was significantly more prevalent in the slaughtered camels (60%, 164/273) than hepatic echinococcosis (39.9%, 109/273), (p = 0.001, Chi Square = 11.081). Cyst fertility rates were higher in hepatic (90.8%, 99/109) than in pulmonary cysts (83.5%, 137/164) and the most viable protoscoleces were recorded from fertile the hepatic cysts (67.85 ± 12.78). In this study, hydatid cyst germinal layer antigen (GlAg) was isolated and used for the immunization of rabbits to raise IgG polyclonal antibodies (anti-Echinococcus GlAb IgG). These IgG polyclonal antibodies were purified by affinity chromatography using a protein A column, then labeled with horseradish peroxidase. Electrophoretic analysis of IgG polyclonal antibodies and crude GlAg was performed in 10% polyacrylamide gels. The SDS-PAGE revealed four bands at molecular weights of 77 kDa, 65 kDa, 55 kDa, and 25 kDa. The Sandwich ELISA was performed to evaluate the sensitivity and specificity and cross-reactivity of the prepared IgG polyclonal antibodies. The circulating hydatid antigen was found in 270 out of the 273 samples with hydatidosis, with a sensitivity of 98.9% (270/273), a specificity of 94.9% (296/312) and a diagnostic efficacy of 96.8%. Regarding the cross reactivity, anti-Echinococcus GlAb IgG showed a low cross-reactivity with Fasciola gigantica infected camel sera (3/8), and Myiasis (Cephalopina titillator larvae; 3/20). No cross-reactivity was recorded with uninfected camel sera (negative sera for E. granulosus), and no cross-reactivity was found with antigens of Eimeria spp., Toxoplasma gondii, Cryptosporidium sp., and Hyalomma dromedarii (ticks' infestation). Then, Sandwich ELISA was conducted again to detect E. granulosus antigen in all the collected camel sera, which resulted in a 48.7% (286/587) positive rate of CE compared to 46.5% (273/587) using a postmortem inspection (PM diagnosis) (p = 0.5, Chi Square = 0.302). In conclusion, the Sandwich ELISA technique introduced in this study appears to be a sufficiently sensitive diagnostic assay for the detection of camels' echinococcosis using anti-Echinococcus GlAb IgG. In addition, it might offer a significant medical and veterinary importance in helping the early detection of hydatidosis, as well as its early treatment.

When wildlife comes to town: interaction of sylvatic and domestic host animals in transmission of Echinococcus spp. in Namibia

The present study was conducted in the isolated desert town of Oranjemund in the far south of Namibia. It is an extremely arid region where no livestock husbandry is practiced and only animals adapted to the desert can be found. However, in and around the city, artificial irrigation maintains lush green patches of grass that attract wild animals, in particular oryx antelopes (Oryx gazella). In 2015 four oryx antelopes were euthanised due to poor conditions and a post-mortem examination was conducted. Two were found positive for cystic echinococcosis and 16 cysts were collected for molecular analyses. In addition, faecal samples from black-backed jackals (n=5) and domestic dogs (n=9), which were regularly observed to feed on oryx carcasses, were collected and taeniid eggs isolated. Parasite species identification of the cysts and eggs was done by amplifying and sequencing the mitochondrial nad1 gene. Both oryx antelopes were found infected with E. ortleppi and one co-infected with E. canadensis G6/7. Both Echinococcus species were able to develop fertile cysts in oryx, making oryx antelopes competent hosts for these parasites. Therefore, the analysis of faecal samples was of high interest and although the numbers were quite small, taeniid eggs were found in three out of five faecal samples of jackals and in all nine dog samples. However, species determination was only successful with two jackal and one dog sample. All three were positive for E. canadensis G6/7. The absence of E. ortleppi may be due to the low number of faecal samples examined. In our small study, we discovered a rather unique lifecycle of Echinococcus spp. between jackals and domestic dogs as definitive hosts and oryx antelopes as intermediate hosts. Here, the presence of E. canadensis G6/7 is of particular concern, as it is the second most important causative agent of CE in humans.

Cystic echinococcosis in Iceland: a brief history and genetic analysis of a 46-year-old Echinococcus isolate collected prior to the eradication of this zoonotic disease

Cystic echinococcosis (CE) is considered the most severe parasitic disease that ever affected the human population in Iceland. Before the start of eradication campaign in the 1860s, Iceland was a country with very high prevalence of human CE, with approximately every fifth person infected. Eradication of CE from Iceland by 1979 was a huge success story and served as a leading example for other countries on how to combat such a severe One Health problem. However, there is no genetic information on Echinococcus parasites before eradication. Here, we reveal the genetic identity for one of the last Echinococcus isolates in Iceland, obtained from a sheep 46 years ago (1977). We sequenced a large portion of the mitochondrial genome (8141 bp) and identified the isolate as Echinococcus granulosus sensu stricto genotype G1. As G1 is known to be highly infective genotype to humans, it may partly explain why such a large proportion of human population in Iceland was infected at a time . The study demonstrates that decades-old samples hold significant potential to uncover genetic identities of parasites in the past.

Current status of cystic echinococcosis control in the Falkland Islands: has elimination been achieved?

Attempts to control cystic echinococcosis (CE) caused by Echinococcus granulosus in the Falkland Islands have been ongoing for over 50 years. No human cases have been recorded since the 1980s but there is a need to establish if the parasite has been completely eliminated from domestic animals. A study was carried out in 2018/2019 to identify dogs infected with E. granulosus using copro-antigen and copro-polymerase chain reaction (PCR) analysis. In addition, annual slaughter data were analysed to establish infection levels of E. granulosus and 2 other taeniid parasites. Results showed that 4 out of 589 dogs (0.7%) tested positive by copro-antigen analysis. Results from similar surveys carried out in 2010, 2012 and 2014 showed 17 (3%), 0 and 6 (1%) copro-antigen-positive dogs, respectively, with 8 dogs being confirmed by PCR in 2010. Annual abattoir data showed that from 2006 to 2020, 36 sheep were identified with E. granulosus (mean 0.0055%), 14 186 sheep with Taenia hydatigena (mean 2.2%) and 465 with Taenia ovis (mean 0.072%). Prevalences of T. hydatigena and T. ovis showed spontaneous rises in certain years where the infections could also be detected in lambs indicating that viable taeniid eggs were present. Observations of farm management procedures indicated that there were occasions when dogs could get access to infective taeniid material. In conclusion, E. granulosus is still present in sheep and dogs but at low prevalences. The increasing presence of T. hydatigena however, indicates that control measures are defective in some areas and there is potential for a re-emergence of CE.

Update on the genetic diversity and population structure of Echinococcus granulosus in Gansu Province, Tibet Autonomous Region, and Xinjiang Uygur Autonomous Region, Western China, inferred from mitochondrial cox1, nad1, and nad5 sequences

The identification of additional Echinococcus granulosus sensu lato (s.l.) complex species/genotypes in recent years raises the possibility that there might be more variation among this species in China than is currently understood. The aim of this study was to explore intra- and inter-species variation and population structure of Echinococcus species isolated from sheep in three areas of Western China. Of the isolates, 317, 322, and 326 were successfully amplified and sequenced for cox1, nad1, and nad5 genes, respectively. BLAST analysis revealed that the majority of the isolates were E. granulosus s.s., and using the cox1, nad1, and nad5 genes, respectively, 17, 14, and 11 isolates corresponded to Elodea canadensis (genotype G6/G7). In the three study areas, G1 genotypes were the most prevalent. There were 233 mutation sites along with 129 parsimony informative sites. A transition/transversion ratio of 7.5, 8, and 3.25, respectively, for cox1, nad1, and nad5 genes was obtained. Every mitochondrial gene had intraspecific variations, which were represented in a star-like network with a major haplotype with observable mutations from other distant and minor haplotypes. The Tajima's D value was significantly negative in all populations, indicating a substantial divergence from neutrality and supporting the demographic expansion of E. granulosus s.s. in the study areas. The phylogeny inferred by the maximum likelihood (ML) method using nucleotide sequences of cox1-nad1-nad5 further confirmed their identity. The nodes assigned to the G1, G3, and G6 clades as well as the reference sequences utilized had maximal posterior probability values (1.00). In conclusion, our study confirms the existence of a significant major haplotype of E. granulosus s.s. where G1 is the predominant genotype causing of CE in both livestock and humans in China.

MicroRNA-Transcription factor regulatory networks in the early strobilar development of Echinococcus granulosus protoscoleces

BACKGROUND

Echinococcus granulosus sensu lato has a complex developmental biology with a variety of factors relating to both intermediate and final hosts. To achieve maximum parasite adaptability, the development of the cestode is dependent on essential changes in transcript regulation. Transcription factors (TFs) and miRNAs are known as master regulators that affect the expression of downstream genes through a wide range of metabolic and signaling pathways. In this study, we aimed to develop a regulatory miRNA-Transcription factor (miRNA-TF) network across early developmental stages of E. granulosus protoscoleces by performing in silico analysis, and to experimentally validate TFs expression in protoscoleces obtained from in vitro culture, and from in vivo experiments.

RESULTS

We obtained list of 394 unique E. granulosus TFs and matched them with 818 differentially expressed genes which identified 41 predicted TFs with differential expression. These TFs were used to predict the potential targets of 31 differentially expressed miRNAs. As a result, eight miRNAs and eight TFs were found, and the predicted network was constructed using Cytoscape. At least four miRNAs (egr-miR-124a, egr-miR-124b-3p, egr-miR-745-3p, and egr-miR-87-3p) and their corresponding differentially expressed TFs (Zinc finger protein 45, Early growth response protein 3, Ecdysone induced protein 78c and ETS transcription factor elf 2) were highlighted in this investigation. The expression of predicted differentially expressed TFs obtained from in vitro and in vivo experiments, were experimentally validated by quantitative polymerase chain reaction. This confirmed findings of RNA-seq data.

CONCLUSION

miRNA-TF networks presented in this study control some of the most important metabolic and signaling pathways in the development and life cycle of E. granulosus, providing a potential approach for disrupting the early hours of dog infection and preventing the development of the helminth in the final host.

Unveiling the incidences and trends of the neglected zoonosis cystic echinococcosis in Europe: a systematic review from the MEmE project

The neglected zoonosis cystic echinococcosis affects mainly pastoral and rural communities in both low-income and upper-middle-income countries. In Europe, it should be regarded as an orphan and rare disease. Although human cystic echinococcosis is a notifiable parasitic infectious disease in most European countries, in practice it is largely under-reported by national health systems. To fill this gap, we extracted data on the number, incidence, and trend of human cases in Europe through a systematic review approach, using both the scientific and grey literature and accounting for the period of publication from 1997 to 2021. The highest number of possible human cases at the national level was calculated from various data sources to generate a descriptive model of human cystic echinococcosis in Europe. We identified 64 745 human cystic echinococcosis cases from 40 European countries. The mean annual incidence from 1997 to 2020 throughout Europe was 0·64 cases per 100 000 people and in EU member states was 0·50 cases per 100 000 people. Based on incidence rates and trends detected in this study, the current epicentre of cystic echinococcosis in Europe is in the southeastern European countries, whereas historical endemic European Mediterranean countries have recorded a decrease in the number of cases over the time.

Comparison of multiplex copro PCR with coproscopy followed by PCR on recovered eggs for the detection of Echinococcus granulosus and Taenia spp. infection in dogs

Echinococcosis and taeniasis are important helminth diseases that carry considerable impact on human and animal health. Domestic dogs and other canids are definitive hosts for several parasites of this group, including Echinococcus granulosus, Taenia multiceps, T. ovis, T. hydatigena and E. multilocularis. Detection of infection in dog populations is imperative for estimating the risk to susceptible humans and animals, and for its mitigation through prevention measures in dogs, other animals and humans. To date, identification of taeniid eggs, antigens or DNA in fecal samples are the most practical diagnostic modalities available for canine definitive hosts. Although widely used for this purpose, there is limited information comparing copro PCR and combined coproscopy-PCR protocols for the detection of taeniids. In the current study, a widely used multiplex PCR was performed on a large number of dog fecal samples using DNA extracted directly from feces. The samples were also tested by fecal flotation and coproscopy, eggs were isolated from microscopically-positive samples and extracted DNA was tested using the same multiplex PCR. The total number of taeniid positive samples detected using both methods was 46/317 (14.5%), including 10/317 (3.2%) E. granulosus positive samples. Both copro PCR and coproscopy have identified an equal number of samples as taeniid positive (n = 32). However, for the purpose of identification to species level, the copro PCR was significantly more sensitive than coproscopy followed by PCR on isolated eggs (sensitivity 0.7 vs. 0.41, p = 0.012), with 32/317 (10.1%) and 19/317 (6%) positive samples identified, respectively. The difference in identification of E. granulosus was highly apparent, as the majority of the E. granulosus positive samples (8/10) were detected by the copro PCR only. Coproscopy and egg PCR have identified 5/317 (1.6%) positive samples not detected by the copro PCR, including only a single sample (0.3%) positive for E. granulosus. Adding these positive samples to those identified by the copro PCR did not significantly improve the overall sensitivity (p = 0.074). Therefore, using both copro PCR and coproscopy in parallel may not be advantageous for taeniid detection and identification, at least until the egg PCR is further optimized and performs better. These results should be weighed against the different advantages that coproscopy based approach may offer.

Liver cystic echinococcosis: a parasitic review

Liver cystic echinococcosis (CE), known as hydatid disease, is caused by the tapeworm Echinococcus granulosus sensu lato. Humans are accidental hosts in this zoonotic disease process, and hepatic infection accounts for over two-thirds of all cases. Since signs and symptoms are mainly non-specific, especially in early disease, clinicians should have a low threshold to include CE as a differential diagnosis in patients with positive serology and suggestive radiological findings, especially in endemic regions. The standard management for liver CE depends on the patient's symptoms, the radiological stage, the size and location of the cyst, the presence of complications and the treating clinicians' expertise. In this review, we discuss the lifecycle of Echinococcus granulosus sensu lato and its epidemiology and then focus on discussing the clinical features, diagnosis and treatment options of CE of the liver.

Outcomes of inferior vena cava reconstruction using artificial or autologous materials in ex vivo liver resection and autotransplantation

BACKGROUND

The use of artificial or autologous materials for inferior vena cava (IVC) reconstruction is controversial. This study retrospectively explored the effects of different materials on perioperative outcomes.

METHODS

This study included 91 patients who underwent IVC reconstruction during liver autotransplantation between 2014 and 2020. A univariate analysis was performed to select variables affecting postoperative morbidity. The effect of IVC reconstruction materials on perioperative outcomes was tested with a multivariable generalized linear model. The effects on postoperative morbidity and operation time were further tested with the multivariate regression analysis based on the generalized estimating equation. Adjusted models were used in all analyses.

RESULTS

A median operation time of 710 (633-790) min, a median blood loss of 2200 (1550-3000) mL, an incidence of 33% (30/91) for major morbidities and a median comprehensive complication index (CCI) of 0.0 (0.0-26.2) were observed, with no IVC reconstruction-related complications postoperatively or in the long term. The IVC reconstruction material had no significant effect on postoperative outcomes, while artificial materials significantly increased inpatient cost (191 ± 35 vs. 164 ± 36 k Yuan, p < 0.001). The multivariate regression revealed a significant shift in outcomes of operation time (p = 0.0368).

DISCUSSION

Artificial grafts are recommended for IVC reconstruction if cost is not a factor.

Genetic characterization of human echinococcosis in Southern Punjab, Pakistan

Introduction

Echinococcosis is a neglected tropical zoonotic infection that affects both the human and livestock populations. In Pakistan, the infection is long-standing, but data on its molecular epidemiology and genotypic characterization in the southern Punjab region are limited. The aim of the current study was the molecular characterization of human echinococcosis in southern Punjab, Pakistan.

Methods

Echinococcal cysts were obtained from a total of 28 surgically treated patients. Patients' demographic characteristics were also recorded. The cyst samples were subjected to further processing to isolate DNA in order to probe the Nad1 and Cyt-b genes, followed by DNA sequencing and phylogenetic analysis for genotypic identification.

Results

The majority of the echinococcal cysts were from male patients (60.7%). The liver was the most commonly infected organ (60.71%), followed by the lungs (25%), spleen (7.14%), and the mesentery (7.14%). Molecular and genotypic identification through sequencing and phylogenetic tree analysis showed that most of the cysts (24/28, 85.7%) were caused by the species Echinococcus granulosus sensu stricto (E. granulosus s.s.) (G1 and G3), followed by Echinococcus multilocularis (E. multilocularis) and Echinococcus canadensis (E. canadensis) (G6/G7) (3/28, 10.8%, and 1/28, 3.5%, respectively).

Conclusion

The current study concluded that the majority of human infections were caused by E. granulosus s.s., followed by the E. multilocularis and E. canadensis species (G6/G7). Genotypic characterization among both human and livestock populations is needed to explore the genetic diversity of echinococcosis.

Assessment of risk, landscape epidemiology and management strategies to combat alveolar echinococcosis in the rural communities of Hunza, Pakistan

Background

Human alveolar echinococcosis (AE) is a neglected zoonotic disease. Prevalence of AE in humans is reported in Pakistan as a result of poor economic and sanitary conditions, close proximity to wildlife and limited knowledge of AE. Studies on the prevalence and transmission of AE have been limited, especially for rural Pakistan. The study objectives were to identify knowledge, attitudes and practices relating to AE, to determine awareness of the disease, and to identify knowledge about possible risk factors of infections involving the landscape epidemiological attributes of rural villages in Hunza, one of the districts of Gilgit-Baltistan, a region of Pakistan that borders China.

Methods

A community-based cross-sectional study was conducted among the general population of Hunza to establish the level of awareness, knowledge, attitudes, practices, landscape epidemiology, and disease management and control relating to AE in rural areas of Hunza. Data were collected by questionnaire.

Results

A total of 387 questionnaires was received. Statistical analysis showed that the population's knowledge about the disease was poor. The attitudes and practices of the participants indicated that their risk of infection was low. Knowledge of landscape epidemiology of the disease was poor but knowledge about AE disease management was good. The attitudes of residents toward disease treatment and control strategies were positive, although the overall knowledge of participants about prevention of infection was poor.

Conclusion

Knowledge of AE is poor among the residents of Hunza, Pakistan. Our study demands continued and strengthened awareness of the changes to lifestyle and practices associated with AE, not only in the study locality but throughout other areas of Pakistan.

Societal drivers of human echinococcosis in China

BACKGROUND

Echinococcosis is a parasitic zoonotic disease that threatens human health and economic development. In China, 370 counties are endemic for echinococcosis. Qinghai-Tibet Plateau has the most patients and people at risk. Therefore, analyzing the societal factors related to susceptibility to the disease is critical for efficient prevention and control of echinococcosis.

METHODS

The demographic characteristics and lifestyle of echinococcosis cases were clustered using K-means cluster analysis to determine the main factors of risk of echinococcosis.

RESULTS

Middle-aged and young people as well as those with a low education level and herdsmen are at risk of contracting echinococcosis. Nomadism, domestic and feral dogs in the surrounding environment, and drinking heavily polluted natural surface water are the main behavioral risk factors. The cystic echinococcosis (CE) and alveolar echinococcosis (AE) cluster analysis focused on female, middle-aged, and young people, winter settlement and summer nomadism, and domestic and feral dogs in the surrounding environment. There were significant differences in lifestyle between Qinghai-Tibet Plateau cases and non-Qinghai-Tibet-Plateau cases.

CONCLUSION

According to the distribution of cases and CE and AE, this study identified the factors of risk of echinococcosis in the Qinghai-Tibet Plateau and non-Qinghai-Tibet Plateau. Adapted control techniques appropriate for the various epidemic areas should be established to serve as a reference for echinococcosis prevention.

Clinical characteristics and antibodies against Echinococcus granulosus recombinant antigen P29 in patients with cystic echinococcosis in China

Objectives

Cystic echinococcosis (CE) is a neglected parasitic zoonotic disease caused by the larval stage of the tapeworm Echinococcus granulosus (E. granulosus). This study aimed to understand the clinical characteristics of human CE in Ningxia Hui Autonomous Region (NHAR) located in northwest China and to investigate the antibody profiles against the recombinant E. granulosus antigen P29 (rEg.P29) in plasma of CE patients.

Methods

A total of 37 human CE patients, along with 37 healthy donors enrolled in this study and demographic and clinical data were analyzed, including age, gender, laboratory data, symptoms, and cysts description. Plasma levels of cytokines, total IgG, and total IgE were determined by sandwich ELISA kits. Specific antibodies against rEg.P29 and hydatid cyst fluid (HCF) were assessed by indirect ELISA.

Results

The results revealed that females have a higher percentage of CE patients than males. The incidence of CE reached a peak in the 41–50 years-old group. The liver was the most frequent location, accounting for 91.9%. Based on the CT images, cysts of 34 patients who had liver involvement, were classified as 1 (2.9%) CE1, 12 (35.3%) CE2, 5 (14.7%) CE3a, 1 (2.9%) CE3b, and 15 (44.2%) CE5. Twenty-nine (78.4%) patients had a single cyst and 8 (21.6%) had at least two cysts. The most frequently reported symptom was upper abdominal pain. The plasma level of IL-6 and total IgE were significantly increased in CE patients compared with healthy donors. Additionally, IgG response to rEg.P29 in CE patients was significantly higher than in healthy donors, and the dominant IgG subclass was IgG4. Further analysis of different patient groups revealed that rEg.P29-specific IgG and IgG4 were only elevated in CE patients with CE2 type cysts.

Conclusions

This study systematically investigated the clinical characteristics of patients with CE and may provide a reference basis for the diagnosis and treatment of CE in NHAR. Furthermore, tests of specific IgG and IgG4 against rEg.P29 can be used as an assisted method for imaging techniques to identify cystic activity and determine the best therapeutic approach for CE.

Modelling diagnostics for Echinococcus granulosus surveillance in sheep using Latent Class Analysis: Argentina as a case study

Echinococcus granulosus sensu lato is a globally prevalent zoonotic parasitic cestode leading to cystic echinococcosis (CE) in both humans and sheep with both medical and financial impacts, whose reduction requires the application of a One Health approach to its control. Regarding the animal health component of this approach, lack of accurate and practical diagnostics in livestock impedes the assessment of disease burden and the implementation and evaluation of control strategies. We use of a Bayesian Latent Class Analysis (LCA) model to estimate ovine CE prevalence in sheep samples from the Río Negro province of Argentina accounting for uncertainty in the diagnostics. We use model outputs to evaluate the performance of a novel recombinant B8/2 antigen B subunit (rEgAgB8/2) indirect enzyme-linked immunosorbent assay (ELISA) for detecting E. granulosus in sheep. Necropsy (as a partial gold standard), western blot (WB) and ELISA diagnostic data were collected from 79 sheep within two Río Negro slaughterhouses, and used to estimate individual infection status (assigned as a latent variable within the model). Using the model outputs, the performance of the novel ELISA at both individual and flock levels was evaluated, respectively, using a receiver operating characteristic (ROC) curve, and simulating a range of sample sizes and prevalence levels within hypothetical flocks. The estimated (mean) prevalence of ovine CE was 27.5% (95%Bayesian credible interval (95%BCI): 13.8%-58.9%) within the sample population. At the individual level, the ELISA had a mean sensitivity and specificity of 55% (95%BCI: 46%-68%) and 68% (95%BCI: 63%-92%), respectively, at an optimal optical density (OD) threshold of 0.378. At the flock level, the ELISA had an 80% probability of correctly classifying infection at an optimal cut-off threshold of 0.496. These results suggest that the novel ELISA could play a useful role as a flock-level diagnostic for CE surveillance in the region, supplementing surveillance activities in the human population and thus strengthening a One Health approach. Importantly, selection of ELISA cut-off threshold values must be tailored according to the epidemiological situation.