A systematic review of the epidemiology of echinococcosis in domestic and wild animals

Prevalence and Molecular Characterization of Echinococcus granulosus Sensu Stricto in Northern Xinjiang, China

Echinococcus granulosus is an important zoonotic parasite globally causing cystic echinococcosis (CE) in humans and animals. In this study, prevalence of CE and variation of cox1 gene sequence were analyzed with isolates E. granulosus collected from different areas in northern Xinjiang, China. The survey showed that 3.5% of sheep and 4.1% of cattle were infected with CE. Fragment of cox1 was amplified from all the positive sheep and cattle samples by PCR. In addition, 26 positive samples across the 4 areas were included. The isolates were all E. granulosus sensu stricto (s.s.) containing 15 haplotypes (Hap1-15), and clustered into 2 genotypes, G1 (90.1%, 91/101) and G3 (9.9%, 10/101). Hap1 was the most common haplotype (48.5%, 49/101). Hap9 were found in humans samples, indicating that sheep and cattle reservoir human CE. It is indicate that E. granulosus may impact on control of CE in livestock and humans in the region.

Epidemiological survey of echinococcosis in Tibet Autonomous Region of China

BACKGROUND

The echinococcosis is prevalent in 10 provinces /autonomous region in western and northern China. Epidemiological survey of echinococcosis in China in 2012 showed the average prevalence of four counties in Tibet Autonomous Region (TAR) is 4.23%, much higher than the average prevalence in China (0.24%). It is important to understand the transmission risks and the prevalence of echinococcosis in human and animals in TAR.

METHODS

A stratified and proportionate sampling method was used to select samples in TAR. The selected residents were examined by B-ultrasonography diagnostic, and the faeces of dogs were tested for the canine coproantigen against Echinococcus spp. using enzyme-linked immunosorbent assay. The internal organs of slaughtered domestic animals were examined by visual examination and palpation. The awareness of the prevention and control of echinococcosis among of residents and students was investigated using questionnaire. All data were inputted using double entry in the Epi Info database, with error correction by double-entry comparison, the statistical analysis of all data was processed using SPSS 21.0, and the map was mapped using ArcGIS 10.1, the data was tested by Chi-square test and Cochran-Armitage trend test.

RESULTS

A total of 80 384 people, 7564 faeces of dogs, and 2103 internal organs of slaughtered domestic animals were examined. The prevalence of echinococcosis in humans in TAR was 1.66%, the positive rate in females (1.92%) was significantly higher than that in males (1.41%), (χ² = 30.31, P < 0.01), the positive rate of echinococcosis was positively associated with age (χ²_trend = 423.95, P < 0.01), and the occupational populations with high positive rates of echinococcosis were herdsmen (3.66%) and monks (3.48%). The average positive rate of Echinococcus coproantigen in TAR was 7.30%. The positive rate of echinococcosis in livestock for the whole region was 11.84%. The average awareness rate of echinococcosis across the region was 33.39%.

CONCLUSIONS

A high prevalence of echinococcosis is found across the TAR, representing a very serious concern to human health. Efforts should be made to develop an action plan for echinococcosis prevention and control as soon as possible, so as to control the endemic of echinococcosis and reduce the medical burden on the population.

Genetic characterization of Echinococcus species in eastern Ethiopia

Cystic echinococcosis (CE) is a neglected zoonotic disease with considerable economic and public health burden worldwide, particularly affecting developing countries like Ethiopia. To initiate effective prevention and control of CE, comprehensive data on the local lifecycles of the various species/genotypes of Echinococcus are needed. In the present study, conducted in eastern Ethiopia, a total of 1106 livestock animals were examined at three slaughterhouses, which resulted in combined prevalence of morphologically and molecularly confirmed CE of 8.4% (75/891) in cattle, 1.1% (1/95) in sheep, 0.0% (0/95) in goats and 12.0% (3/25) in camels. All cystic lesions recovered during post mortem examination were assessed for cyst condition and underwent molecular characterization by PCR and sequencing of a 1081 bp fragment of the mitochondrial cox1 gene. A total of 175 cysts belonged to E. granulosus s.s. (n = 165), E. ortleppi (n = 6) and E. canadensis G6/7 (n = 4). Of all examined cysts, only 14 were fertile and contained protoscoleces, all from the lungs of cattle: 5 were E. granulosus s.s., 6 E. ortleppi and 3 E. canadensis G6/7. In sheep, only one sterile liver cyst of E. granulosus s.s. was found, while in camels seven sterile or caseated/calcified cysts of E. granulosus s.s. and E. canadensis G6/7 were found in liver and lungs. In conclusion, the prevalence of CE was rather low compared to other regions of Ethiopia, and, based on the number of fertile cysts, three Echinococcus spp. contributed almost equally to transmission. Cattle seem to be, epidemiologically, the most important livestock species. Our data provide a substantial basis for more detailed investigations of the transmission dynamics of CE in the study area.

Prevalence estimation of Italian ovine cystic echinococcosis in slaughterhouses: A retrospective Bayesian data analysis, 2010-2015

Cystic echinococcosis (CE) is a complex zoonosis with domestic and sylvatic life-cycles, involving different intermediate and definitive host species. Many previous studies have highlighted the lack of a surveillance system for CE, its persistence in Italy, and endemicity in several Italian regions. Because of the absence of a uniform surveillance program for both humans and animals, disease occurrence is widely underestimated. This study aimed to estimate the prevalence of ovine CE in Italy. Survey data on the prevalence of Echinococcus granulosus complex infections in Italian sheep farms from 2010 to 2015 were obtained in collaboration with Regional Veterinary Epidemiology Observatories (OEVRs). Bayesian analysis was performed to estimate the true CE farm prevalence. The prior true CE prevalence was estimated using data from Sardinia. Second, Bayesian modelling of the observed prevalence in different regions and the true prevalence estimation from the first step were used to ultimately estimate the prevalence of ovine CE in Italy. We obtained survey data from 10 OEVRs, covering 14 Italian regions. We observed that the risk of CE infection decreased over the years, and it was strictly correlated with the density of susceptible species. Using Sardinia as prior distribution, where the disease farm prevalence was approximately 19% (95% CI, 18.82-20.02), we estimated that the highest endemic CE farm prevalence was in Basilicata with a value of 12% (95% BCI: 7.49-18.9%) and in Piemonte 7.64%(95% BCI: 4.12-13.04%). Our results provide spatially relevant data crucial for guiding CE control in Italy. Precise information on disease occurrence location would aid in the identification of priority areas for disease control implementation by the authorities. The current underestimation of CE occurrence should urge the Italian and European governments to become aware of the public health importance of CE and implement targeted interventions for high-risk areas.

Clinical review of liver hydatid disease and its unusual presentations in developing countries

Human hydatid cyst disease is an international public health issue that particularly affects the developing countries. In this article, we discuss the epidemiology of hydatid disease in third world countries, the life cycle of echinococcus granulosus and how to make the clinical diagnosis of the disease, including laboratory tests and imaging modalities as well as uncommon presentation of this entity that we have encountered at the American University of Beirut Medical Center (AUBMC). We emphasize on the new World Health Organization classification of hepatic echinococcosis with examples from our clinical practice at AUBMC, and finally we describe the treatment, including medical and interventional therapies.

Frozen hydatid cysts can replace incineration and sterilize cysts

In many countries of Mediterranean area, abattoirs are not equipped with incinerators. This led us to find an alternative that may be the freezing of organs before they are thrown into landfills. In this sense, the aim of this study was to evaluate the scolicidal effect of refrigeration at 4°C and freezing at -18°C. Different refrigeration times (24 and 48 h) and freezing times (3, 6, and 9 h) have been used in triplicate. Refrigeration at 4°C was not sufficient to completely kill protoscolex. For 24 h, the mortality rate did not exceed 44.44%. After 48 h, mortality rates varied from 20.13% to 65.49%. The freezing at -18 °C for 3 h remained insufficient to kill all protoscoleces although the mortality rate increased to 87.28%. However, freezing at -18 °C for 6 and 9 h has been found to be very effective in killing all protoscoleces present in the hydatid liquids. The present study demonstrates that freezing organs seized for hydatidosis at -18°C for at least 6 h may be an alternative to incineration and will sterilize hydatid cysts before they are dumped.

Knowledge Domain and Emerging Trends on Echinococcosis Research: A Scientometric Analysis

The echinococcosis of humans and animals is a chronic helminthic disease caused by the larva of genus Echinococcus tapeworms. It is a globally distributed disease which is an important socioeconomic and public health problem in many low and middle-income countries. This research aimed to firstly quantitatively analyze the publications with bibliometrics software and evaluated the hot topics and emerging trends of echinococcosis research from 1980 to 2017. A total of 7688 references on echinococcosis research were retrieved from the Web of Science Core Collection database. Then the reference was analyzed with CiteSpace software to make the knowledge network maps. The largest cluster (#0) with 83 members was cystic echinococcosis, and cystic echinococcosis, mebendazole, antibody and transmission were the four keywords with the strongest citation bursts in the echinococcosis research field. Furthermore, cystic echinococcosis, chemotherapy and immunodiagnosis, management of definitive and intermediate host are the top four research hot topics and emerging trends in the echinococcosis field. This research presents an insight into the echinococcosis field and valuable visualizing information for echinococcosis researchers to detect new viewpoints on cooperative countries/institutions, potential co-workers and research frontiers.

Cystic echinococcosis in slaughtered cattle at Addis Ababa Abattoir enterprise, Ethiopia

Cystic echinococcosis, caused by larval stages of the tapeworm Echinococcus granulosus, is responsible for hydatid cysts in the lungs, liver and other organs of intermediate hosts. A cross-sectional Abattoir study was conducted from October 2015 to May 2016 at Addis Ababa Abattoir enterprise, Ethiopia. For this purpose a total of 1209 cattle were examined using the classical meat inspection procedure for the presence of hydatid cysts. An overall prevalence of 21% (254/1209) of hydatid cyst was recorded in cattle slaughtered at Addis Ababa Abattoir enterprise. The prevalence of hydatid cyst was statistically significantly higher (P<0.05) in cattle with the age group of >6 years than those cattle with all other age categories. The study showed that lungs and livers were the most affected organs of cattle. Significantly (P < 0.05) higher overall number of hydatid cysts were observed in the lungs (63.9%; 1324/2071) than in the livers (35.4%; 734/2071). The study revealed the presence of an overall of 84.1% (333/396) sterile, 12.2% (48/396) calcified and 4.3% (17/396) fertile cysts. Of the total of 17 fertile hydatid cysts tested for viability, 17.6% (3/17) viable and 82.3% (14/17) nonviable cysts were observed. Overall, findings of the present study showed the widespread occurrence of hydatid cysts in internal organs of cattle that possibly incur significant economic losses through condemnation of edible organs rendering unfit for human consumption. Molecular studies on the role of intermediate host species, genotypes of E. granulosus, zoonotic impact and economic significance of echinococcosis are needed in different parts of Ethiopia.

Hepatitis in slaughterhouse workers

Slaughterhouse workers (SHW) are at increased risk of hepatitis which can occur due to different organisms and should be investigated for viral, bacterial, and parasitic organisms. Slaughter house personnel including butchers are at a higher risk of infections from cuts and blood-letting, with the possible risk of the transmission of blood-borne pathogens to their colleagues. The objective of this review is to evaluate the common etiologies of hepatitis in SHW which will assist in the assessment of these patients presenting with transaminitis. Types of Microorganisms causing hepatitis with their reservoirs, routes of transmission, laboratory diagnosis, clinical features, treatment options and preventive strategies are included in this review. Proper investigation and awareness is of utmost importance as it causes significant financial constraints derived from workers health cost and from livestock production losses when the disease is confirmed. The work up is essential because infected workers might be a source of infections to other colleagues, family and the consumers.

Neglected zoonotic diseases in Nigeria: role of the public health veterinarian

Zoonotic diseases accounts for about 75% of emerging infectious disease and can be devastating to both human and animal health globally. A subset of zoonotic diseases is referred to as "neglected zoonotic diseases - NZDs" as they mainly affect poor populations who live in close proximity to domestic or wild animals often in areas where access to health and adequate sanitary facilities are not available. Furthermore, underestimation of the burden of NZD has continually led to its further neglect in least developed countries such as Nigeria. Controlling zoonotic infections including NZDs in animals is crucial in reducing human infections. Veterinarians provides an understanding of the epidemiology of infectious diseases in animal population and are therefore integral for the overall reduction in global burden of NZDs worldwide. Due to the current lack of and in some cases weak involvement of Veterinarians in policy issues related to zoonotic diseases, there is need to elucidate their importance in NZDs control in Nigeria. This review therefore summarises the neglected zoonotic diseases so far documented in Nigeria and also highlight the important role of the Veterinarian in their prevention and control within both human and animal population. Important recommendations to strengthen the role of the public health Veterinarian for sustainable control of NZDs were made.

Seroprevalence of Hydatidosis in People Referring to Reference Laboratory of Gorgan, Golestan Province, Northern Iran 2017

BACKGROUND

Hydatidosis is a neglected global zoonotic disease, caused by larval stage of the cestode Echinococcus granulosus in human and animal. Because of high economic and medical importance of the disease, this study was performed to find the seroprevalence of human hydatidosis in Gorgan City, Golestan Province, northern Iran.

METHODS

In this cross-sectional study, blood samples were collected from people referring to Reference laboratory of Golestan University of Medical sciences in 2017. A relevant questionnaire was completed for demographic data for each person. Echinococcus IgG antibody was investigated by ELISA using native antigen B. The data were analyzed using SPSS software applying logistic regression.

RESULTS

Overall, 612 blood samples were collected. Cut-off was considered 0.29. Sixteen cases (2.6%) were seropositive for hydatidosis. The seroprevalence of hydatidosis was 2.3% and 4.7% among males and females, respectively. There was no statistically significant correlation between the hydatidosis and investigated variables such as sex, age, tribes, residence, education, etc.

CONCLUSION

The prevalence of human hydatidosis shows approximately the same range as other regions of Iran. Although due to the neighboring the Mazandaran Province reported as the highest seroprevalence of hydatidosis, we expected more rate of seropositivity.

Hepatic echinococcosis: A review

Cystic echinococcosis (CE) is a widely endemic helminthic disease caused by infection with metacestodes (larval stage) of the Echinococcus granulosus tapeworm and transmitted by dogs. E. granulosus are common parasites in certain parts of the world, and are present on every continent with the exception of Antarctica. As a result, a large number of people are affected by CE. In humans, the disease is characterized by slowly growing cyst commonly occurring in liver and lungs. Clinical features are mainly right upper quadrant pain, feeling of lump and enlarged tender liver. The cyst may be complicated by infection or rupture and may lead to anaphylactic reaction. The diagnosis depends on clinical suspicion. They appear in two ways as general (systemic) symptoms, and local symptoms based on the site and organ on which the larva settles. While cysts sometimes recover spontaneously, more severe clinical presentations are observed in immunosuppressed individuals. Ultrasonography supported by serology is the main diagnostic modality. The treatment varies from surgical intervention to minimally invasive treatments (percutaneous drainage) or medical therapies. Surgery is still the best treatment modality. Percutaneous drainage of the cyst is a good option in selected cases. New sensitive and specific diagnostic methods and effective therapeutic approaches against echinococcosis have been developed in the last 10 years.

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Echinococcal cysts, although fairly uncommon, should be considered in the differential diagnosis of hepatic cysts.

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Serum antibody assays generally have low sensitivities, but antigen assays may be of value.

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Imaging is crucial in determining cyst stage, size, location and complications.

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Uncomplicated active cysts can be managed with chemotherapy alone or in combination with a PAIR approach. Inactive cysts can be managed with the “watch-and-wait” strategy.

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Surgery is the first choice when there is cystobiliary fistula and significant extra-hepatic extension with high risk of perforation.

Current status and future prospective of vaccine development against Echinococcus granulosus

Cystic echinococcosis (CE) is one of the most important zoonotic parasite diseases in human, livestock, and wildlife worldwide. Development of effective vaccines against CE appears to be the most promising strategy to control this infectious disease. Use of potential livestock and canine vaccines against the larval and adult stage of E. granulosus life cycle may be the key to the production of powerful vaccines. Some progress has been accomplished in the development of vaccines against hydatidosis using empirical approaches, while such immunotherapies often fail to induce adequate immune responses. Therefore, it is of great interest to identify antigens (Ags) with high immunogenicity and develop effective vaccines and adjuvant constructs against CE. To this end, various tools can be applied, including immune-based genomics and proteomics, immunoinformatics, systems vaccinology and mathematical/computational modeling. In this review, we aimed to provide comprehensive insights upon the current status of vaccination trials against E. granulosus, and also articulate some perspectives on the production of novel anti-CE vaccines. Use of novel prospective technologies is also discussed to highlight the importance of development and advancement of the next generation vaccines against E. granulosus.

Epidemiological study of Echinococcus granulosus in sheep in the Gharb plain (North-West of Morocco)

Hydatidosis is considered endemic in Morocco and caused serious health problems in ruminants. The aim of this research is to present an epidemiological study on echinococcosis in sheep. The study was carried out between April 2016 and May 2017. A total number of 1600 sheeps was examined via autopsy for Echinococcus granulosus in various slaughterhouses in the Gharb plain of Morocco. The Results of the study showed that the prevalence of cystic echinococcosis was 7.63%. The infection was not significant among sheep which age is < 1 year (2.67%), while it increases among those which age is from 1 to 3 years old (8.63%). It also grows significantly among sheep which age is over 3 years old (11.71%). Parasitized at 62%, the liver is the most affected organ followed by the lungs (38%). Protoscoleces are only found in liquid cysts and contribute to their fertility which is estimated at 66.66% in the liver and 57.74% in the lungs. In addition, the prevalence of calcified cysts is 12.24% in the liver and 21.11% in the lungs. Examination of the fertile cysts revealed a high level of Protoscoleces viability, whether it's in the liver (65.93%) or in the lungs (59.30%). This study also shows how the evolution of echinococcosis is closely linked to sex and age.

Ecosystem change and zoonoses in the Anthropocene

Changes in land use, animal populations and climate, primarily due to increasing human populations, drive the emergence of zoonoses. Force of infection (FOI), which for these diseases is a measure of the ease with which a pathogen reaches the human population, can change with specific zoonoses and context. Here, we outline three ecosystem categories-domestic, peridomestic and sylvatic, where disease ecology alters the FOI of specific zoonoses. Human intervention is an overriding effect in the emergence of zoonoses; therefore, we need to understand the disease ecology and other influencing factors of pathogens and parasites that are likely to interact differently within ecological and cultural contexts. Planning for One Health and community ecology, such as an ecological impact assessment, is required to prepare and manage the emergence and impact of zoonoses in the Anthropocene.

Orbital alveolar echinococcosis: A case report

Purpose

To report a rare case of orbital alveolar echinococcosis in Iran.

Methods

A 23-year-old woman with multi-lobular mass lesion in the right orbit underwent excisional biopsy via a deep lateral orbitotomy approach. The pathologic investigation of the lesion was a multilobulated cystic lesion shown where the cyst wall structure was compatible with alveolar Hydatid cyst in histopathology. Clinical course, surgical, and medical management of the disease is noted briefly in the case of orbital involvement of the alveolar echinococcosis.

Results

Patient was treated with anti-fungal medication, and the cysts were successfully removed by a surgical excision.

Conclusion

Although orbital alveolar echinococcosis is extremely rare, it is noteworthy to study its clinical manifestations and radiological examinations to be able to make a true diagnosis.

Impact of disposing stray dogs on risk assessment and control of Echinococcosis in Inner Mongolia

Echinococcosis has been recognized as one of the most important helminth zoonosis in China. Available models always consider dogs as the mainly definitive hosts. However, such models ignore the distinctions between domestic dogs and stray dogs. In this study, we propose a 10-dimensional dynamic model distinguishing stray dogs from domestic dogs to explore the special role of stray dogs and potential effects of disposing stray dogs on the transmission of Echinococcosis. The basic reproduction number R₀, which measures the impact of both domestic dogs and stray dogs on the transmission, is determined to characterize the transmission dynamics. Global dynamic analysis of the model reveals that, without disposing the stray dogs, the Echinococcosis becomes endemic even the domestic dogs are controlled. Moreover, due to the difficulties in estimating the parameters involved in R₀ with real data and the limitation of R₀ in real-world applications, a new risk assessment tool called relative risk index I_risk is defined for the control of zoonotic diseases, and the studies of the risk assessment for Echinococcosis infection show that it is essential to distinguish stray dogs from domestic dogs in applications.

Knowledge, Awareness and Practices Regarding Cystic Echinococcosis among Livestock Farmers in Basrah Province, Iraq

Cystic echinococcosis (CE) is an endemic neglected parasitic zoonosis in many of the countries of the Middle East. The disease poses a remarkable economic burden for both animals and humans. In this study, we conducted a questionnaire survey among livestock farmers in Basrah province, southern Iraq, in order to evaluate their knowledge and awareness about CE, and to understand some of the risky practices that could contribute to spread and persistence of such disease. Of the interviewed participants (N = 314), 27.4% owned dogs on their farms. Among farmers owning dogs, 76.7% (66/86) never tied up their dogs, and 43% (37/86) indicated feeding uncooked animal viscera to their dogs. The majority (96.5%) of the farmers indicated that they did not de-worm their dogs at all. Only 9.8% (31/314) of the respondents indicated eating raw leafy vegetables without washing. Added to that, 32% of the interviewees indicated that they source water for domestic use from a river; meanwhile 94.3% (296/314) of them do not boil water before using it for domestic purposes. Half of the interviewed livestock farmers in Basrah were not aware about how humans get infected with CE disease, and 41.4% (130/314) did not even realize that CE is a dangerous disease to human health. Almost one in three of the respondents who owned dogs on their farms viewed de-worming of their dogs as a low priority practice. This study highlights the gap in knowledge and awareness about CE among the study population. Risky practices associated with dog keeping management and food and water handling practices were identified. The insight from this research could be used to improve the delivery of a health education message relevant to cystic echinococcosis control at the human-animal interface in Iraq.

Modelling the regional vulnerability to Echinococcosis based on environmental factors using fuzzy inference system: A case study of Lorestan Province, west of Iran

Background and aim

Echinococcosis as a zoonosis disease is one of the most important parasitic helminth that is affected by many risk factors such as the environmental factors. Thus, we predicted the regional vulnerability to Echinococcosis based on environmental factors using a fuzzy inference system (FIS) in Lorestan Province.

Methods

Our study was cross-sectional study on 200 patients from Lorestan Province (west of Iran) who underwent surgery for hydatidosis between October 2005 and November 2014. In order to model the vulnerability to Echinococcosis, first we determined the effective environmental variables. In the next step, the FIS was designed and implemented using MATLAB v.2012 software. Thus, definition and determination of linguistic variables, linguistic values, and their range were performed based on expert knowledge. Then, the membership functions of inputs (environmental variables) and output (vulnerability to Echinococcosis) were defined. A fuzzy rules base was formed. Also, the defuzzification of output was done using a centroid defuzzification function. To test the accuracy of the predictive model, we calculated the AUC (to this purpose, we used four different thresholds, 5%, 10%, 15%, and 20%) using IDRISI Selva v.17.0 software.

Results

Based on the results of this study, Aligoudarz and Koohdasht counties were identified as a highest and lowest risk area in Lorestan, respectively. The results showed that a predictive model was more efficient than a random model (AUC>0.5). Also, potential vulnerable areas cover 78.29% at threshold of 5%, 60.72% at threshold of 10%, 43.54% at threshold of 15%, and 39.82% at threshold of 20% of the study area.

Conclusion

According to the success of this research, we emphasized the necessity of attention to fuzzy approach to model vulnerability to hydatidosis. This approach can provide a practical economic basis for making informed preventive services decisions and the allocation of health resources.

Latent class models for Echinococcus multilocularis diagnosis in foxes in Switzerland in the absence of a gold standard

Background

In Europe the principal definitive host for Echinococcus multilocularis, causing alveolar echinococcosis in humans, is the red fox (Vulpes vulpes). Obtaining reliable estimates of the prevalence of E. multilocularis and relevant risk factors for infection in foxes can be difficult if diagnostic tests with unknown test accuracies are used. Latent-class analysis can be used to obtain estimates of diagnostic test sensitivities and specificities in the absence of a perfect gold standard. Samples from 300 foxes in Switzerland were assessed by four different diagnostic tests including necropsy followed by sedimentation and counting technique (SCT), an egg-PCR, a monoclonal and a polyclonal copro-antigen ELISA. Information on sex, age and presence of other cestode species was assessed as potential covariates in the Bayesian latent class models. Different Bayesian latent-class models were run, considering dichotomized test results and, additionally, continuous readings resulting in empirical ROC curves.

Results

The model without covariates estimated a true parasite prevalence of 59.5% (95% CI: 43.1–66.4%). SCT, assuming a specificity of 100%, performed best among the four tests with a sensitivity of 88.5% (95% CI: 82.7–93.4%). The egg-PCR showed a specificity of 93.4% (95% CI: 87.3–99.1%), although its sensitivity of 54.8% was found moderately low (95% CI: 48.5–61.0%). Relatively higher sensitivity (63.2%, 95% CI: 55.3–70.8%) and specificity (70.0%, 95% CI: 60.1–79.4%) were estimated for the monoclonal ELISA compared to the polyclonal ELISA with a sensitivity and specificity of 56.0% (95% CI: 48.0–63.9%) and 65.9% (95% CI: 55.8–75.6%), respectively. In the Bayesian models, adult foxes were found to be less likely infected than juveniles. Foxes with a concomitant cestode infection had double the odds of an E. multilocularis infection. ROC curves following a Bayesian approach enabled the empirical determination of the best cut-off point. While varying the cut-offs of both ELISAs, sensitivity and specificity of the egg-PCR and SCT remained constant in the Bayesian latent class models.

Conclusions

Adoption of a Bayesian latent class approach helps to overcome the absence of a perfectly accurate diagnostic test and gives a more reliable indication of the test performance and the impact of covariates on the prevalence adjusted for diagnostic uncertainty.

Electronic supplementary material

The online version of this article (10.1186/s13071-017-2562-1) contains supplementary material, which is available to authorized users.

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

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

Zataria multiflora would attenuate the hepatotoxicity of long-term albendazole treatment in mice with cystic echinococcosis

Hepatic injury is the major limitation of long-term albendazole administration in patients with cystic echinococcosis (CE), which could give rise to cessation of treatment. The objective of the present study was to evaluate the protective effects of Zataria multiflora aromatic water (AW) against the hepatic injury induced by long-term albendazole treatment in mice with CE. Fifty healthy BALB/c female mice were infected intraperitoneally by injection of 1500 protoscoleces per animal. Five months after infection, the infected animals were divided into five treatment groups including Z. multiflora (40ml/l in drinking water for 90days), albendazole (200mg/kg/day for 90days), Z. multiflora+albendazole 200 (40ml/l Z. multiflora and 200mg/kg/day albendazole for 90days), Z. multiflora+albendazole100 (40ml/l Z. multiflora and 100mg/kg/day albendazole for 90days), and untreated (control) group. At the end of the treatment period, anesthesia was performed and blood samples were collected directly from the heart prior to euthanasia. Liver variables and oxidative stress markers were measured in the blood serum samples. A decrease in serum liver enzyme activity in the both Z. multiflora+albendazole groups was observed when compared to control, Z. multiflora and albendazole groups; however, the results for Z. multiflora+albendazole 100 were significant (p<0.007) and superior compared to those for Z. multiflora+albendazole 200. No significant differences for oxidative stress markers were observed between the different groups. The results of the present study revealed that a combined therapy with Z. multiflora AW and albendazole is effective against hepatic injury induced by CE and/or long term albendazole administration in mice with cystic echinococcosis.

Trends and correlates of cystic echinococcosis in Chile: 2001-2012

Echinococcosis is a neglected zoonotic disease affecting over 1 million people worldwide at any given time. It is the leading cause of hospital admissions for parasitic diseases in Chile. We conducted a retrospective investigation of hospitalized cases to describe the epidemiological trends of echinococcosis in Chile. We also examined the potential environmental risk factors for echinococcosis hospitalization rates. Through nation-wide hospital discharge data, a total of 11,516 hospitalized patients with cystic echinococcosis were identified between January 2001 and December 2012. The mean age of hospitalization was 40 years, with notable gender difference in pediatric patients. The hospitalization rate was found to be overall steadily decreasing from 2001 (7.02 per 100,000) to 2012 (4.53 per 100,000) with a 5% decrease per year (rate ratio = 0.95 [95% CI: 0.94, 0.96]). The hospitalization rate was higher in the south of Chile compared to the north. Goat density and intermediate precipitation were found to be significantly positively associated with the hospitalization rate while annual average temperature was found to be significantly negatively associated with the hospitalization rate. Findings of this study indicate that echinococcosis is still an important public health burden in Chile related to interaction with livestock and climate. Efforts should be placed on targeted prevention measures for farmers and raising awareness of echinococcosis among health care workers.

Humans are infected by many types of parasites that originate from animals. Cystic echinococcosis (CE) is a tapeworm infection that affects over 1 million people over the world at any given time, with symptoms such as abdominal pain, chest pain, vomiting, and allergic reactions. The lifecycle of this parasite is maintained between dogs and livestock, and humans are ‘accidentally’ infected through ingesting parasite eggs. This makes the control of CE difficult for public health practitioners. Attempts have been made to better understand which animals or environmental factors increase or decrease the number of human CE infections, but mainly with data from only one point in time. In this study, we studied the trends of this disease in Chile, a country with many cases of CE, over a 12-year period. Then, using a statistical model, we examined the risk factors related to animals and the environment that contribute to a higher rate of CE hospitalizations. We found that higher goat density, intermediate precipitation level and low temperatures are important factors associated with an increase in hospitalization rates related to CE in Chile. This new knowledge contributes to a better overall understanding of the trends and risk factors of CE, which will help to implement targeted prevention and control strategies in regions where the disease is common.

The impact of socio-cultural factors on transmission of Taenia spp. and Echinococcus granulosus in Kosovo

Echinococcus granulosus sensu latu (s.l.) and Taenia hydatigena are common parasites of ruminant intermediate hosts in the Balkans. Transmission is linked mainly to home slaughtering and the feeding of infected organs to dogs. In Kosovo, many old sheep are slaughtered particularly during Eid al-Adha (Feast of Sacrifice). To determine whether this tradition could affect parasite transmission, we compared the probability of 504 dogs to contract taenid infections after deworming during one period before Eid al-Adha and a similar period beginning with this event. Initially, taeniid eggs were detected in 6·2% (CI 4·2–8·6) of the dogs. The prevalence before Eid al-Adha was significantly lower (1·2%, CI 0·4–2·6) as compared with the prevalence after the event (4·3%, CI 2·6–6·3). A comparable trend was apparent at species level for T. hydatigena and E. granulosus. These results indicate that the pronounced increase of taeniid infections, including E. granulosus s.l., after Eid al-Adha is linked to traditional home slaughtering that occurs during this celebration. This particular epidemiological situation provides an opportunity for implementing focussed control activities.

Seroprevalence of IgG Antibodies against Echinococcus granulosus by ELISA Method Using Recombinant Agb in Lorestan Province, Western Iran

BACKGROUND

Cystic echinococcosis (CE) is a zoonotic disease with global prevalence, which causes considerable health problems and economic losses throughout the world. The aim of this study was to assess the seroepidemiology of CE in Doroud City, Lorestan Province, Iran, considered a neglected endemic location.

METHODS

An ELISA was performed using recombinant AgB from Apr to Jul 2015 in Lorestan Province, Western Iran. The commercial Hydatidosis IgG ELISA kit (Vircell SL, Granada, Spain) was used to confirm the obtained results.

RESULTS

In the present study, out of 927 collected sera, 25 samples (2.6%) were found as seropositive for E. granulosus IgG antibodies. The prevalence of IgG antibodies against E. granulosus was significantly higher in rural areas (3.24%) than in urban area (1.20%) (P<0.001). Moreover, there was no significant relationship between age, occupation, sex, and literacy with seropositivity (P>0.05). Moreover, there was no statistically significant difference between the prevalence of CE in males (13/349, 3.72%) and females (12/553, 2.12%). With regard to occupation, farmers and ranchmen had the highest rate of infection (5.5%). There was a significant association between eating unwashed vegetables and seropositivity (P<0.001). Seropositive cases in rural areas were more than in urban areas.

CONCLUSION

Since all the seropositive cases used unwashed local vegetables, the contamination may occur through the consumption of such vegetables.

Why more research needs to be done on echinococcosis in Pakistan

Background

Echinococcosis has a worldwide geographical distribution with endemic foci on every inhabited continent. Due to the frequent outbreaks in different parts of Pakistan in the recent past, echinococcosis is being described as a neglected tropical disease and is considered one of the most neglected parasitic diseases in the country. In endemic regions, predominantly settings with limited resources, there are high numbers of echinococcosis patients, as these communities do not have access to appropriate treatment. In Pakistan, there are limited reports on echinococcosis. The disease is prevalent in human and livestock, but this has not been sufficiently explored yet. Pakistan is an agricultural country and due to the disease’s zoonotic mode of transmission, there is a dire need of future research on it. The present paper is an effort to highlight the importance of echinococcosis in Pakistan.

Discussion

There is a dire need for future research on echinococcosis in Pakistan as very few investigations had been carried out on this topic thus far. The prevalence of the disease in neighbouring countries highlights that Pakistan might be at severe risk of this zoonotic infection and further supports the need for more research. In Pakistan, the majority of the population lives in rural areas with limited acess to proper hygienic/sanitary facilities. These conditions favour the outbreak of diseases such as echinococcosis. The limited available data could result in higher outbreaks in the future, and thus cause the already weak healthcare system to overburden.

The country has a meagre annual budget for health, which is being spent on known infections such as polio, dengue fever and hepatic viral infections. A proper surveillance system for echinococcosis is required across the country as treatment is usually expensive, complicated and may require extensive surgery and/or prolonged drug therapy. Development of new/novel drugs and other treatment modalities receives very little, if any, attention. Prognostic awareness programmes against this infection involve deworming of the infected animals, improved food inspection and slaughterhouse hygiene, and public education campaigns.

Conclusion

Future research on echinococcosis is anticipated to demonstrate whether the epidemiology, diagnosis and recombinant vaccines/antibodies relating to echinococcosis can meet the quality standards (purity, potency, safety and efficacy) defined by the World Health Organization. Research work should be carried out on the epidemiology and serodiagnosis of echinocossis in the different areas of Pakistan, which will be useful for the proper eradication of echinococcosis in this region. The health department should implement awareness-raising campaigns for the general public in order to reduce the burden of disease.

Electronic supplementary material

The online version of this article (doi:10.1186/s40249-017-0309-z) contains supplementary material, which is available to authorized users.

Comparative proteomics of hydatid fluids from two Echinococcus multilocularis isolates

The hydatid fluid (HF) that fills Echinococcus multilocularis metacestode vesicles is a complex mixture of proteins from both parasite and host origin. Here, a LC-MS/MS approach was used to compare the HF composition of E. multilocularis H95 and G8065 isolates (EmH95 and EmG8065, respectively), which present differences in terms of growth and fertility. Overall, 446 unique proteins were identified, 392 of which (88%) were from parasite origin and 54 from culture medium. At least 256 of parasite proteins were sample exclusive, and 82 of the 136 shared proteins presented differential abundance between E. multilocularis isolates. The parasite's protein repertoires in EmH95 and EmG8065 HF samples presented qualitative and quantitative differences involving antigens, signaling proteins, proteolytic enzymes, protease inhibitors and chaperones, highlighting intraspecific singularities that could be correlated to biological features of each isolate. The repertoire of medium proteins found in the HF was also differential between isolates, and the relevance of the HF exogenous protein content for the parasite's biology is discussed. The repertoires of identified proteins also provided potential molecular markers for important biological features, such as parasite growth rate and fertility, as well potential protein targets for the development of novel diagnostic and treatment strategies for alveolar echinococcosis.

BIOLOGICAL SIGNIFICANCE

E. multilocularis metacestode infection of mammal hosts involve complex interactions mediated by excretory/secretory (ES) products. The hydatid fluid (HF) that fills the E. multilocularis metacestode vesicles contains complex repertoires of parasite ES products and host proteins that mediate important molecular interactions determinant for parasite survival and development, and, consequently, to the infection outcome. HF has been also extensively reported as the main source of proteins for the immunodiagnosis of echinococcosis. The performed proteomic analysis provided a comprehensive profiling of the HF protein composition of two E. multilocularis isolates. This allowed us to identify proteins of both parasite and exogenous (medium) origin, many of which present significant differential abundances between parasite isolates and may correlate to their differential biological features, including fertility and growth rate.

Global Distribution of Alveolar and Cystic Echinococcosis

Alveolar echinococcosis (AE) and cystic echinococcosis (CE) are severe helminthic zoonoses. Echinococcus multilocularis (causative agent of AE) is widely distributed in the northern hemisphere where it is typically maintained in a wild animal cycle including canids as definitive hosts and rodents as intermediate hosts. The species Echinococcus granulosus, Echinococcus ortleppi, Echinococcus canadensis and Echinococcus intermedius are the causative agents of CE with a worldwide distribution and a highly variable human disease burden in the different endemic areas depending upon human behavioural risk factors, the diversity and ecology of animal host assemblages and the genetic diversity within Echinococcus species which differ in their zoonotic potential and pathogenicity. Both AE and CE are regarded as neglected zoonoses, with a higher overall burden of disease for CE due to its global distribution and high regional prevalence, but a higher pathogenicity and case fatality rate for AE, especially in Asia. Over the past two decades, numerous studies have addressed the epidemiology and distribution of these Echinococcus species worldwide, resulting in better-defined boundaries of the endemic areas. This chapter presents the global distribution of Echinococcus species and human AE and CE in maps and summarizes the global data on host assemblages, transmission, prevalence in animal definitive hosts, incidence in people and molecular epidemiology.

First molecular identification of Echinococcus vogeli and Echinococcus granulosus (sensu stricto) G1 revealed in feces of domestic dogs (Canis familiaris) from Acre, Brazil

Background

Echinococcus granulosus (sensu lato) (s.l.) and Echinococcus vogeli are causative agents of chronic zoonotic diseases such as cystic and polycystic echinococcosis, respectively. In Brazil, polycystic echinococcosis has a restricted geographical distribution in the North Region, while cystic echinococcosis is observed in the South Region. Domestic dogs (Canis familiaris) fed with raw viscera represent a risk factor for E. granulosus (s.l.) infection in the South Region. Although this practice is frequent, it remains unclear whether domestic dogs are infected with E. vogeli in the state of Acre, located in the Amazon basin in the North Region of Brazil. The aim of this study was to investigate this gap in the polycystic echinococcosis epidemiology.

Methods

Sixty-five fecal samples were collected from the ground in five municipalities (Sena Madureira, n = 14; Rio Branco, n = 06; Bujari, n = 06; Xapuri, n = 30; and Epitaciolândia, n = 09) located in the state of Acre, northern Brazil. The samples were screened for parasites by copro-PCR using the cox1 gene associated with automated sequencing.

Results

Echinococcus vogeli was molecularly confirmed in a sample from Sena Madureira and E. granulosus (sensu stricto) (s.s.) (G1) in a sample from Rio Branco.

Conclusions

These findings indicate that molecular assays are useful in typing Echinococcus taxa from fecal samples of dogs in northern Brazil. The present study is the first molecular record of E. vogeli in domestic dogs found in the state of Acre, reinforcing their role as a source of infection for humans. Because E. granulosus (s.s.) (G1) was detected for the first time in the North Region, from the epidemiological standpoint this finding is highly relevant, because it expands the known geographical distribution, which was previously restricted to the South Region of Brazil.

Mathematical modelling of Echinococcus multilocularis abundance in foxes in Zurich, Switzerland

Background

In Europe, the red fox (Vulpes vulpes) is the main definitive host of Echinococcus multilocularis, the aetiological agent of a severe disease in humans called alveolar echinococcosis. The distribution of this zoonotic parasite among the fox population is remarkably aggregated with few heavily infected animals harbouring much of the parasite burdens and being responsible for most of the environmental parasitic egg contamination. Important research questions explored were: (i) spatial differences in parasite infection pressure related to the level of urbanization; (ii) temporal differences in parasite infection pressure in relation to time of the year; (iii) is herd immunity or an age-dependent infection pressure responsible for the observed parasite abundance; (iv) assuming E. multilocularis infection is a clumped process, how many parasites results from a regular infection insult.

Methods

By developing and comparing different transmission models we characterised the spatio-temporal variation of the infection pressure, in terms of numbers of parasites that foxes acquired after exposure per unit time, in foxes in Zurich (Switzerland). These included the variations in infection pressure with age of fox and season and the possible regulating effect of herd immunity on parasite abundance.

Results

The model fitting best to the observed data supported the existence of spatial and seasonal differences in infection pressure and the absence of parasite-induced host immunity. The periodic infection pressure had different amplitudes across urbanization zones with higher peaks during autumn and winter. In addition, the model indicated the existence of variations in infection pressure among age groups in foxes from the periurban zone.

Conclusions

These heterogeneities in infection exposure have strong implications for the implementation of targeted control interventions to lower the intensity of environmental contamination with parasite eggs and, ultimately, the infection risk to humans.

Electronic supplementary material

The online version of this article (doi:10.1186/s13071-016-1951-1) contains supplementary material, which is available to authorized users.

Ecology and Life Cycle Patterns of Echinococcus Species

The genus Echinococcus is composed of eight generally recognized species and one genotypic cluster (Echinococcus canadensis cluster) that may in future be resolved into one to three species. For each species, we review existing information on transmission routes and life cycles in different geographical contexts and - where available - include basic biological information of parasites and hosts (e.g., susceptibility of host species). While some Echinococcus spp. are transmitted in life cycles that involve predominantly domestic animals (e.g., dog - livestock cycles), others are wildlife parasites that do or do not interact with domestic transmission. In many cases, life cycle patterns of the same parasite species differ according to geography. Simple life cycles contrast with transmission patterns that are highly complex, involving multihost systems that may include both domestic and wild mammals. Wildlife transmission may be primary or secondary, i.e., resulting from spillovers from domestic animals. For most of the species and regions, existing information does not yet permit a conclusive description of transmission systems. Such data, however, would be highly relevant, e.g., for anticipation of geographical changes of the presence and frequency of these parasites in a warming world, or for initiating evidence-based control strategies.

Molecular and Morphological Characterizations of Echinococcus granulosus from Human and Animal Isolates in Kashan, Markazi Province, Iran

BACKGROUND

One of the most important zoonotic helminths in the world is known as Echinococcus granulosus. Different strains of the E. granulosus have been described based on morphological and molecular characterizations, however, there is limited information regarding the characteristics of the phenotypes and genotypes of E. granulosus in Iran.

METHODS

The present study was prepared to evaluate the phenotypic and genotypic diversity of E. granulosus isolates collected from human, goat, sheep, and cattle based on 19 standard morphometric parameters and mitochondrial and nuclear genes (CO1, ND1, and ITS1) in Kashan, Markazi Province, Iran during 2013-2014.

RESULTS

The biometric analysis for the 19 characters revealed that the 19 morphometric values of cattle isolates were exceptionally higher than human, goat, and sheep isolates (P<0.05). Molecular analysis confirms the morphological findings. Phylogenic analysis of the CO1, NAD1 and ITS1 genes for all isolates, independent of the host, revealed that the common sheep strain (G1) is traveling among livestock in Kashan and the strains are highly adapted to goats, cattle, sheep, and humans.

CONCLUSION

Both morphological and molecular results of this study indicated that the only genotype G1 of E. granulosus travels between humans and other intermediate hosts of this parasite in the area study.

Echinococcosis: Control and Prevention

Human cystic echinococcosis (CE) has been eliminated or significantly reduced as a public health problem in several previously highly endemic regions. This has been achieved by the long-term application of prevention and control measures primarily targeted to deworming dogs, health education, meat inspection, and effective surveillance in livestock and human populations. Human CE, however, remains a serious neglected zoonotic disease in many resource-poor pastoral regions. The incidence of human alveolar echinococcosis (AE) has increased in continental Europe and is a major public health problem in parts of Eurasia. Better understanding of wildlife ecology for fox and small mammal hosts has enabled targeted anthelmintic baiting of fox populations and development of spatially explicit models to predict population dynamics for key intermediate host species and human AE risk in endemic landscapes. Challenges that remain for echinococcosis control include effective intervention in resource-poor communities, better availability of surveillance tools, optimal application of livestock vaccination, and management and ecology of dog and wildlife host populations.

Reprint of "Echinococcus granulosus sensu stricto (s.s.) from the critically endangered antelope Addax nasomaculatus in Tunisia"

Echinococcus granulosus sensu lato (s.l.) is a zoonotic disease highly endemic in Tunisia. Canids including stray and semi-stray dogs, jackals and foxes are known as definitive hosts and a wide range of ungulates have been shown to harbour the metacestode hydatid stage and may serve as intermediate hosts. Fertile hydatid cysts of Echinococcus equinus and E. granulosus sensu stricto (s.s.) were recently molecularly identified for the first time from Tunisian donkeys. E. granulosus (s.s.) was also identified from wild boars in Tunisia. Here we report the confirmation of hydatid cysts caused by E. granulosus (s.s.) in the critically endangered antelope, Addax nasomaculatus in Tunisia. DNA-based molecular analysis revealed that A. nasomaculatus was infected with E. granulosus (s.s.) which had a 100% identity with the main globally distributed E. granulosus (s.s.) (EgTu01) haplotype. Cysts of Taenia hydatigena (n=33) were also observed on the liver and in the body cavity. Due to their endangered status and their relatively small numbers, it is unlikely that hydatid infection of A. nasomaculatus will form a major contribution to the epidemiology and transmission of E. granulosus in Tunisia, but infection may result in pathology, morbidity and early mortality, and may still play a role in the perpetuation of the parasite in wildlife cycles.

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.

Echinococcus multilocularis in foxes and raccoon dogs: an increasing concern for Baltic countries

BACKGROUND

In Europe, the life-cycle of Echinococcus multilocularis is predominantly sylvatic, involving red foxes (Vulpes vulpes) as the main definitive hosts and rodents such as muskrats and arvicolids as intermediate hosts. The parasite is the etiological agent of human alveolar echinococcosis, a malignant zoonotic disease caused by the accidental ingestion of eggs shed by definitive hosts in their faeces. The aims of this study were to investigate the prevalence of E. multilocularis in red foxes and raccoon dogs (Nyctereutes procyonoides) and to study the environmental factors favouring the perpetuation of the parasite in Latvia.

METHODS

A total of 538 red foxes and 407 raccoon dogs were collected across Latvia from 2010 to 2015. The sedimentation and counting technique was used for collecting E. multilocularis adult worms from fox and raccoon dog intestines. The morphological identification of the parasite was confirmed by molecular analysis.

RESULTS

The prevalence of E. multilocularis was significantly higher in foxes (17.1%; intensity of infection 1-7,050 worms) (P < 0.001) than in raccoon dogs (8.1%; intensity of infection 5-815 worms). In foxes, a significant positive correlation (r (10) = 0.7952, P = 0.001) was found between parasite prevalence and the intensity of infection. A positive relationship (R s = 0.900, n = 5, P = 0.037) between parasite prevalence and precipitation was also observed. In raccoon dogs, a significant negative relationship (F (1,8) = 9.412, P = 0.015) between animal density and parasite prevalence, and a significant positive relationship (F (1,8) = 7.869, P = 0.023) between parasite prevalence and agricultural land cover, were detected.

CONCLUSIONS

The results of this study confirm the red fox as the most important definitive host of E. multilocularis and, consequently, as the main target for control programmes in the Baltic countries. Raccoon dogs seem to play a secondary role in the life-cycle of E. multilocularis within the investigated European region.

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.

Excretory/secretory products in the Echinococcus granulosus metacestode: is the intermediate host complacent with infection caused by the larval form of the parasite?

The genus Echinococcus consists of parasites that have a life cycle with two mammalian hosts. Their larval stage, called the hydatid cyst, develops predominantly in the liver and lungs of intermediate hosts. The hydatid cyst is the causative agent of cystic hydatid disease and the species Echinococcus granulosus, G1 haplotype, is responsible for the vast majority of cases in humans, cattle and sheep. Protein characterization in hydatid cysts is essential for better understanding of the host-parasite relationship and the fertility process of Echinococcus. The aims of this work were the identification and quantitative comparison of proteins found in hydatid fluid from fertile and infertile cysts from E. granulosus, in order to highlight possible mechanisms involved in cyst fertility or infertility. Hydatid fluid samples containing proteins from both E. granulosus and Bos taurus were analysed by LC-MS/MS. Our proteomic analysis of fertile and infertile cysts allowed identification of a total of 498 proteins, of which 153 proteins were exclusively identified in the fertile cyst, 271 in the infertile cyst, and 74 in both. Functional in silico analysis allowed us to highlight some important aspects: (i) clues about the possible existence of an "arms race" involving parasite and host responses in fertile and infertile cysts; (ii) a number of proteins in hydatid fluid without functional annotation or with possible alternative functions; (iii) the presence of extracellular vesicles such as exosomes, which was confirmed by transmission electron microscopy.

[Targeting abattoirs to control cystic echinococcosis in Algeria]

Cystic echinococcosis (CE) is an important anthropozoonotic parasitic common in Algeria. The predominant life cycle of E. granulosus is a synanthropic cycle with domestic dogs as definitive hosts and livestock animals as intermediate hosts. Slaughter activity represents a potential source for dogs to access infected offal. The aim of the present study was to determine if the contact between dogs and potentially infected offal was possible in licensed abattoirs. Eighty-one private and public abattoirs located in eastern Algeria were assessed with respect to their level of protection against the intrusion of dogs.We have demonstrated that in 42 % of these abattoirs, dogs could easily come in contact with potentially parasitized offal. The most common incorrect practices were the dumping of offal freely into the environment, the feeding of dogs with offal, and the leaving of unattended offal in an unsealed chamber. Overall, some hazardous practices remained common customs of workers, and enough abattoirs remain non-compliant that the cattledog domestic cycle of CE is unlikely to be broken. Hence, some recommended measures to interrupt parasite transmission include the following: recognition of the importance of abattoirs in the maintenance of canine echinococcosis, the controlled and proper disposal of offal, the abolishment of the custom of feeding dogs with infected offal and improvements in the level of health education of abattoir staff.

Risk factors for Echinococcus coproantigen positivity in dogs from the Alay valley, Kyrgyzstan

Echinococcosis, caused by the zoonotic cestodes Echinococcus granulosus (sensu lato) and Echinococcus multilocularis, is highly endemic in the Central Asian Republic of Kyrgyzstan, and is being identified increasingly as a public health problem, especially amongst pastoral communities. As domestic dogs are considered to be the main source of human infection, the identification of potential transmission pathways is of relevance when considering implementing an echinococcosis control scheme. The current report describes the results of an analytical study of canine Echinococcus coproantigen enzyme-linked immunosorbent assay (ELISA) prevalence in the Alay valley of southern Kyrgyzstan prior to the commencement of regular praziquantel dosing of dogs. A logistic regression model using a form of Bayes modal estimation was used to identify possible risk factors for coproantigen positivity, and the output was interpreted in a Bayesian context (posterior distributions of the coefficients of interest). The study found that sheepdogs had lower odds of coproantigen positivity, as did dogs in households with donkeys, where owners had knowledge of echinococcosis, and households which engaged in home slaughtering. Surprisingly, there was no evidence of an association between free roaming or previous praziquantel dosing and coproantigen positivity, as has been found in previous studies. Possible reasons for these findings are discussed in the context of the epidemiology of echinococcosis and potential intervention approaches.

Hepatic Echinococcal Cysts: A Review

Cystic echinococcosis (CE) is a widely endemic helminthic disease caused by infection with metacestodes (larval stage) of the Echinococcus granulosus tapeworm. E. granulosus are common parasites in certain parts of the world, and are present on every continent with the exception of Antarctica. As a result, a large number of people are affected by CE. The increased emigration of populations from endemic areas where prevalence rates are as high as 5-10% and the relatively quiescent clinical course of CE pose challenges for accurate and timely diagnoses. Upon infection with CE, cyst formation mainly occurs in the liver (70%). Diagnosis involves serum serologic testing for antibodies against hydatid antigens, but preferably with imaging by ultrasound or CT/MRI. Treatment methods include chemotherapy with benzimidazole carbamates and/or surgical approaches, including percutaneous aspiration injection and reaspiration. The success of these methods is influenced by the stage and location of hepatic cysts. However, CE can be clinically silent, and has a high risk for recurrence. It is important to consider the echinococcal parasite in the differential diagnosis of liver cystic lesions, especially in patients of foreign origin, and to perform appropriate long-term follow-ups. The aim of this review is to highlight the epidemiology, natural history, diagnostic methods, and treatment of liver disease caused by E. granulosus.

The landscape epidemiology of echinococcoses

Echinococcoses are parasitic diseases of major public health importance globally. Human infection results in chronic disease with poor prognosis and serious medical, social and economic consequences for vulnerable populations. According to recent estimates, the geographical distribution of Echinococcus spp. infections is expanding and becoming an emerging and re-emerging problem in several regions of the world. Echinococcosis endemicity is geographically heterogeneous and over time it may be affected by global environmental change. Therefore, landscape epidemiology offers a unique opportunity to quantify and predict the ecological risk of infection at multiple spatial and temporal scales. Here, we review the most relevant environmental sources of spatial variation in human echinococcosis risk, and describe the potential applications of landscape epidemiological studies to characterise the current patterns of parasite transmission across natural and human-altered landscapes. We advocate future work promoting the use of this approach as a support tool for decision-making that facilitates the design, implementation and monitoring of spatially targeted interventions to reduce the burden of human echinococcoses in disease-endemic areas.

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.

Echinococcus granulosus sensu stricto (s.s.) from the critically endangered antelope Addax nasomaculatus in Tunisia

Echinococcus granulosus sensu lato (s.l.) is a zoonotic disease highly endemic in Tunisia. Canids including stray and semi-stray dogs, jackals and foxes are known as definitive hosts and a wide range of ungulates have been shown to harbour the metacestode hydatid stage and may serve as intermediate hosts. Fertile hydatid cysts of Echinococcus equinus and E. granulosus sensu stricto (s.s.) were recently molecularly identified for the first time from Tunisian donkeys. E. granulosus (s.s.) was also identified from wild boars in Tunisia. Here we report the confirmation of hydatid cysts caused by E. granulosus (s.s.) in the critically endangered antelope, Addax nasomaculatus in Tunisia. DNA-based molecular analysis revealed that A.nasomaculatus was infected with E. granulosus (s.s.) which had a 100% identity with the main globally distributed E. granulosus (s.s.) (EgTu01) haplotype. Cysts of Taenia hydatigena (n=33) were also observed on the liver and in the body cavity. Due to their endangered status and their relatively small numbers, it is unlikely that hydatid infection of A. nasomaculatus will form a major contribution to the epidemiology and transmission of E. granulosus in Tunisia, but infection may result in pathology, morbidity and early mortality, and may still play a role in the perpetuation of the parasite in wildlife cycles.