Echinococcosis: Control and Prevention

miRNAs and lncRNAs in Echinococcus and Echinococcosis

Echinococcosis are considered to be potentially lethal zoonotic diseases that cause serious damage to hosts. The metacestode of Echinococcus multilocularis and E. granulosus can result in causing the alveolar and cystic echinococcoses, respectively. Recent studies have shown that non-coding RNAs are widely expressed in Echinococcus spp. and hosts. In this review, the two main types of non-coding RNAs—long non-coding RNAs (lncRNAs) and microRNAs (miRNAs)—and the wide-scale involvement of these molecules in these parasites and their hosts were discussed. The expression pattern of miRNAs in Echinococcus spp. is species- and developmental stage-specific. Furthermore, common miRNAs were detected in three Echinococcus spp. and their intermediate hosts. Here, we primarily focus on recent insights from transcriptome studies, the expression patterns of miRNAs and lncRNAs, and miRNA-related databases and techniques that are used to investigate miRNAs in Echinococcus and echinococcosis. This review provides new avenues for screening therapeutic and diagnostic markers.

A hyperendemic focus of porcine cystic echinococcosis in the Banke District of Nepal

Detailed post mortem analyses of 68 free-ranging, slaughter-age pigs from two sites in the Banke District of Nepal identified 36% as being infected with Echinococcus granulosus. The cysts ranged from infertile, immature cysts a few millimetres in diameter to fertile cysts >10 cm in diameter. PCR RFLP and DNA sequencing identified the cysts as being E. granulosus sensu stricto. The Banke district has recently been identified as having a high prevalence of porcine cysticercosis. These data suggest that cestode zoonoses in this, and possibly other parts of Nepal may be a serious concern for human health. An assessment of the level of human cystic echinococcosis and neurocysticercosis, in the region is warranted and the introduction of control measures are required to limit the parasites' transmission.

Development and Validation of a Copro-Enzyme-Linked Immunosorbent Assay Sandwich for Detection of Echinococcus granulosus-Soluble Membrane Antigens in Dogs

Cystic echinococcosis (CE) is a parasitic zoonosis caused by the larval stage of the tapeworm Echinococcus granulosus. Detection of the adult stage in the canine definitive host is essential for estimating infection rates, surveillance and monitoring of CE control programs. This study sought to develop and validate a coproantigen sandwich enzyme-linked immunosorbent assay (copro-ELISA), based on antibodies against E. granulosus-soluble membrane antigens (EGMA), that is capable of distinguishing infected and noninfected dogs. Anti-E. granulosus polyclonal immunoglobulin G antibodies were obtained from rabbit antiserum against EGMA. Optimization of the test was performed with 51 positive and 56 negative stool samples of canine echinococcosis. Specificity, sensitivity, cross-reactivity, intra- and inter-assay precision, and over time detection were evaluated. According to the receiver operating characteristic analysis, the diagnostic sensitivity and specificity were 96.1% (CI: 85.9-99.6) and 98.2% (CI: 89.5-100), respectively. Negative and positive predictive values were 96.5% (CI: 91.7-100) and 98% (CI: 94.1-100), respectively. No cross-reactivity with Taenia hydatigena, Dipylidium caninum, or Toxocara canis was observed. Intra- and inter-assay repeatability showed values of less than 15% of the variation coefficient. The over time detection was from 20 to 27 days postinfection with E. granulosus. The copro-ELISA based on EGMA detection offers a simplified in-house development of diagnostic testing. This assay showed high specificity and sensitivity and had no cross-reactivity with other parasites. Further studies and development of this test in a kit format may be useful for the detection of active infection in dogs living in CE endemic regions.

First inter-laboratory comparison of Echinococcus granulosus sensu lato diagnosis in Latin America

OBJECTIVE

To compare the performance of polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA) tests for diagnosing Echinococcus granulosus in dog feces among national reference laboratories in Argentina, Chile, Peru, and Uruguay.

METHODS

National laboratories affiliated with the Ministry of Health/Agriculture of each country exchanged panels of 10 positive/negative samples obtained from their regular national surveillance programs in November 2015 - November 2016. All laboratories applied PCR; two also applied ELISA techniques. Sensitivity and specificity were determined for each laboratory and concordance of results among the laboratories was evaluated by Cohen Kappa coefficient.

RESULTS

Poor concordance (3 of 10 paired comparisons had values of Kappa > 0.4), low sensitivity and specificity across all laboratories, and poor performance of both techniques in detecting E. granulosus in canine feces was demonstrated in this study. An ex-post comparison of the laboratories' test protocols showed substantial heterogeneity that could partially explain poor concordance of results.

CONCLUSION

The results underscore the heterogeneity of canine echinococcosis diagnosis across the region and indicate possible sources of variability. Efforts to standardize canine echinococcosis testing must be included in the plan of action for the Regional Initiative for the Control of Cystic Echinococcosis. Future comparisons with fecal samples of known parasite load are needed.

Achievements of the HERACLES Project on Cystic Echinococcosis

The FP7 project 'Human Cystic Echinococcosis ReseArch in CentraL and Eastern Societies' (HERACLES), developed between 2013 and 2018 by nine partners in five countries, is one of the largest projects on cystic echinococcosis. Here we present the core HERACLES achievements, which should help to foster the translation of scientific investigations on health policies.

Control of cystic echinococcosis: Background and prospects

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

Long-term retrospective assessment of a transmission hotspot for human alveolar echinococcosis in mid-west China

Background

Human alveolar echinococcosis caused by infection with Echinococcus multilocularis is one of the most potentially pathogenic helminthic zoonoses. Transmission occurs involving wildlife cycles typically between fox and small mammal intermediate hosts. In the late 1980s/early 1990s a large focus of human AE was identified in poor upland agricultural communities in south Gansu Province, China. More detailed investigations in 1994–97 expanded community screening and identified key risk factors of dog ownership and landscape type around villages that could support susceptible rodent populations. A crash of the dog population (susceptible domestic definitive host) in the early 1990s appeared to stop transmission.

Methodology/Findings

We subsequently undertook follow-up eco-epidemiological studies based on human population screening and dog survey, in 2005/6 and in 2014/15. Our observations show a decrease in human AE prevalence, especially marked in the 11–30 year old age category. In 2015, although the dog population had recovered and in addition, forest protection and the reforestation of some areas may have favoured red fox (wild definitive host) population growth, there was no evidence of infection in owned dogs.

Conclusions/Significance

Those observations suggest that over decades socio-ecological changes resulted in a cascade of factors that exacerbated and then interrupted parasite emergence, with probable elimination of peri-domestic transmission of E. multilocularis in this area, despite the relative proximity of large active transmission foci on the eastern Tibetan Plateau. This study case exemplifies how anthropogenic land use and behavioural changes can modify emergence events and the transmission of endemic zoonotic parasite infections, and subsequently the importance of considering processes over the long-term in a systems approach in order to understand pathogen and disease distribution.

Human alveolar echinococcosis caused by infection with Echinococcus multilocularis is one of the most potentially pathogenic helminthic zoonoses. Transmission occurs involving wildlife cycles typically between fox and small mammal intermediate hosts. A large focus of human alveolar echinococcosis was identified in the late 1980s in poor upland agricultural communities in south Gansu Province, China, and has been monitored until 2015. Observations suggest that over decades landscape and socio-ecological changes resulted in a cascade of factors that exacerbated and then interrupted parasite emergence, with probable elimination of peri-domestic transmission of E. multilocularis in this area, despite the relative proximity of large active transmission foci on the eastern Tibetan Plateau. This study case exemplifies how anthropogenic land use and behavioural changes can modify emergence events and the long-term transmission of endemic parasitic infections, and subsequently the importance of considering disease ecology transmission socio-ecosystems in order to understand parasite and disease distribution.

Epidemiological factors associated with human cystic echinococcosis: a semi-structured questionnaire from a large population-based ultrasound cross-sectional study in eastern Europe and Turkey

BACKGROUND

Cystic echinococcosis (CE) is a neglected parasitic zoonosis prioritized by the WHO for control. Several studies have investigated potential risk factors for CE through questionnaires, mostly carried out on small samples, providing contrasting results. We present the analysis of risk factor questionnaires administered to participants to a large CE prevalence study conducted in Bulgaria, Romania and Turkey.

METHODS

A semi-structured questionnaire was administered to 24,687 people from rural Bulgaria, Romania and Turkey. CE cases were defined as individuals with abdominal CE cysts detected by ultrasound. Variables associated with CE at P < 0.20 in bivariate analysis were included into a multivariable logistic model, with a random effect to account for clustering at village level. Adjusted odds ratios (AOR) with 95% CI were used to describe the strength of associations. Data were weighted to reflect the relative distribution of the rural population in the study area by country, age group and sex.

RESULTS

Valid records from 22,027 people were analyzed. According to the main occupation in the past 20 years, "housewife" (AOR: 3.11; 95% CI: 1.51-6.41) and "retired" (AOR: 2.88; 95% CI: 1.09-7.65) showed significantly higher odds of being infected compared to non-agricultural workers. "Having relatives with CE" (AOR: 4.18; 95% CI: 1.77-9.88) was also associated with higher odds of infection. Interestingly, dog-related and food/water-related factors were not associated with infection.

CONCLUSIONS

Our results point toward infection being acquired in a "domestic" rural environment and support the view that CE should be considered more a "soil-transmitted" than a "food-borne" infection. This result helps delineating the dynamics of infection transmission and has practical implications in the design of specific studies to shed light on actual sources of infection and inform control campaigns.

Evidence for camels (Camelus bactrianus) as the main intermediate host of Echinococcus granulosus sensu lato G6/G7 in Mongolia

Cystic echinococcosis (CE), the parasitic disease caused by the larval stage of Echinococcus granulosus sensu lato (s.l.), is a global public health problem. In Mongolia, despite wide distribution of human CE, not enough information is available on the prevalence and molecular characterization of CE in livestock and its zoonotic linkage with human cases. We investigated the distribution of human CE cases and livestock population using statistical models to get insight into the zoonotic linkage. The incidence of human CE cases increased by a factor of 1.71 for one interquartile range increment in the density of the camel population. No significant association was observed with other livestock species. The samples collected from 96 camels and 15 goats in an endemic region showed a CE prevalence of 19.7% and 6.7%, respectively. All livestock CE were E. granulosus s.l. G6/G7 species of the E. granulosus s.l. complex. The genetic diversity was investigated using the haplotype network based on full cox1 gene analysis of the samples collected from livestock CE and nucleotide sequences previously reported from human CE and wild canids infection in Mongolia. Four haplotypes were identified within the livestock samples, two of which had not been previously reported. A common haplotype was identified among humans, camels, goats, and a wolf, all of which were within the same geographical area. A mixed infection of E. granulosus s.l. G6/G7 with different haplotypes in the intermediate host was identified. To the best of our knowledge, this is the most comprehensive description of the current epidemiological situation of CE in Mongolia with substantial evidence that camels might be the main intermediate host of E. granulosus s.l. G6/G7 in Mongolia. Moreover, our result presents the first report in the country to provide insight into the prevalence of E. granulosus s.l. G6/G7 in livestock.

Elevated incidence of alveolar echinococcosis in immunocompromised patients

Introduction

Recent experimental data has revealed that the course of alveolar echinococcosis (AE) depends on adaptive immunity. For this study, we aimed to analyze the incidence and outcome of AE in immunocompromised humans.

Material and methods

Retrospective analysis of 131 patients with a median age of 54 years treated for AE between 1971 and 2017 at a Swiss tertiary referral Centre. Fifty-two percent were females and 65 patients (50%) were diagnosed incidentally. Fourteen patients (16%) were operated on laparoscopically. Overall, median follow-up was 48 months.

Results

New diagnoses have increased fourfold in immunocompetent and tenfold in immunocompromised patients in the past decade (p ≤ 0.005). Forty-one patients (31.3%) had co-existing or previous immunosuppressive conditions including 16 malignancies (36%), 11 auto-immune diseases or immunosuppressive therapies (31%), 5 infectious diseases (11%), 4 chronic asthma conditions (9%), 2 previous transplantations (4%) and 4 other immunocompromising conditions (9%). Serum levels of anti-Em18, −Em2 and -EgHF antibodies were neither associated with immunocompetence at diagnosis nor during follow-up, but significantly decreased after treatment with benzimidazole (n = 43) or surgery (n = 88) in all patients. Adjuvant therapy for ≥1 year (p = 0.007) with benzimidazole and resection status (R0) (p = 0.002) were both correlated with recurrence-free survival. Survival at 5 and 10 years after surgery was 97% and 94%, respectively, and after conservative treatment 91% and 73%, respectively. Curative surgery (p = 0.014) and immunocompetence (p = 0.048) correlated significantly with overall survival.

Conclusion

The incidence of human AE has increased over the last 2 decades with surgical interventions resulting in excellent outcomes. We have observed an association of immunosuppressive conditions with both incidence and survival of AE eventually justifying the implementation of a screening program for patients at risk in endemic regions.

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Alveolar echinococcosis incidence increased significantly in Switzerland.

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Immunosuppression may lead to an increased susceptibility for the disease.

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Coexisting immunosuppressive conditions lead to worse survival of AE.

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Adjuvant treatment with benzimidazole increases recurrence-free survival.

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Resections with sufficient safety margin improve recurrence-free survival.

A serological survey of echinococcosis, toxocariasis and trichinellosis among rural inhabitants of Central Yakutia

In 2018, a seroepidemiological survey was carried out in 3 ulus, or districts (Churapchinsky, Megino-Kangalassky and Ust-Aldansky) in Central Yakutia (Sakha Republic, Russian Federation) about 3 helminth zoonoses, namely, echinococcosis (alveolar or cystic), toxocariasis and trichinellosis. Ninety rural volunteers agreed to answer a questionnaire that inquired about demographic and environmental parameters along with food habits. Then they were asked to provide a venous blood sample. Serological investigations were carried out by enzyme-linked immunosorbent assay. Four subjects tested positive for echinococcosis, 1 for toxocariasis and 2 for trichinellosis. No demographic or environmental or dietary possible risk factor was found to be associated with these positive results. In conclusion, only echinococcosis and trichinellosis appeared to be in Yakutia as health threats among the 3 investigated zoonoses.

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.

Echinococcosis transmission on the Tibetan Plateau

Since the mid-1990s detailed studies and field investigations on the Tibetan Plateau have revealed human echinococcosis to be an under-reported major public health problem, particularly in the dominant pastoral communities in the eastern and central regions. Human prevalence surveys showed that cystic echinococcosis (CE, caused by Echinococcus granulosus) and alveolar echinococcosis (AE, caused by Echinococcus multilocularis) are co-endemic with higher burdens of each disease than other endemic world regions. Epidemiological investigations identified some major risk factors for human CE and AE including dog ownership, husbandry practices and landscape features. Dogs appear to be the major zoonotic reservoir for both E. granulosus and E. multilocularis, but the latter is also transmitted in complex wildlife cycles. Small mammal assemblages especially of vole and pika species thrive on the Plateau and contribute to patterns of E. multilocularis transmission which are influenced by landscape characteristics and anthropogenic factors. Tibetan foxes are a principal definitive host for both E. multilocularis and E. shiquicus. In 2006 a national echinococcosis control programme was initiated in Tibetan communities in northwest Sichuan Province and rolled out to all of western China by 2010, and included improved surveillance (and treatment access) of human disease and regular deworming of dogs with annual copro-testing. Control of echinococcosis in Tibetan pastoral communities poses a difficult challenge for delivery and sustainability.

Effective long-term control of Echinococcus multilocularis in a mixed rural-urban area in southern Germany

Effective preventive strategies are available to control Echinococcus multilocularis in foxes in order to reduce the human infection risk. Reduction of E. multilocularis prevalence in foxes was achieved in various studies by distributing praziquantel-containing bait by hand or by aircraft in either rural or settlement areas. Here, an integrated approach is described from southern Germany (district of Starnberg). Baseline data were obtained in winter 2002/03, when the prevalence rate in the project area was 51%. Between December 2005 and December 2011, air distribution of bait in agricultural and recreational areas was combined with distribution by hand in towns and villages, in order to cover the entire fox population, with a bait density of 50 pieces / km² (baiting area: 213 km²). In addition, a control area without anthelmintic treatment was selected. Prevalence was reduced in the baiting area to 1% by March 2007. Subsequently, from 2007 to the end of 2011, prevalence rates remained at a low level with 2.4% (2007), 2.4% (2008), 2.6% (2009), 1.2% (2010) and 0.0% (2011). In the un-baited control area the prevalence rates remained high, ranging from 19.6% to 35.1% with an average of 27.3%. During the 6 years of anthelmintic treatment, differences between baiting and control areas were highly significant (P<0.001). In the suburban and urban parts of the study area prevalence could be reduced to less than 1%, i.e. to a level below the limit of detection, which was maintained even after the measures had been discontinued. The applicability and effectiveness of anthelmintic baiting was therefore confirmed even for a heavily settled and fragmented landscape, which posed challenges for practical application of the control measures. The cost of the project ranged between € 1.70 and € 2.00 per inhabitant of the baiting area per year.

Echinococcosis: Advances in the 21st Century

Echinococcosis is a zoonosis caused by cestodes of the genus Echinococcus (family Taeniidae). This serious and near-cosmopolitan disease continues to be a significant public health issue, with western China being the area of highest endemicity for both the cystic (CE) and alveolar (AE) forms of echinococcosis. Considerable advances have been made in the 21st century on the genetics, genomics, and molecular epidemiology of the causative parasites, on diagnostic tools, and on treatment techniques and control strategies, including the development and deployment of vaccines. In terms of surgery, new procedures have superseded traditional techniques, and total cystectomy in CE, ex vivo resection with autotransplantation in AE, and percutaneous and perendoscopic procedures in both diseases have improved treatment efficacy and the quality of life of patients. In this review, we summarize recent progress on the biology, epidemiology, diagnosis, management, control, and prevention of CE and AE. Currently there is no alternative drug to albendazole to treat echinococcosis, and new compounds are required urgently. Recently acquired genomic and proteomic information can provide a platform for improving diagnosis and for finding new drug and vaccine targets, with direct impact in the future on the control of echinococcosis, which continues to be a global challenge.

Praziquantel treatment of dogs for four consecutive years decreased the transmission of Echinococcus intermedius G7 to pigs in villages in Lithuania

Echinococcus granulosus sensu lato comprises a number of recognized species which cause cystic echinococcosis (CE) in humans and intermediate hosts. These species have particular geographic distributions, with E. granulosus sensu stricto (genotypes G1/2/3 and micro variants) being most widely spread. In Lithuania, E. intermedius (G7) is known to be the only species circulating between pigs and dogs but is also infecting cattle and humans. In fact, recent reports showed a rise of the incidence to 1.13 human cases/100,000 inhabitants/year. Most of the pigs reared on the backyard farms in Lithuania are slaughtered on site during the cold season (October–April) and are used for own consumption. Therefore, in this study, we examined the impact on taeniid transmission of treating dogs with baits containing an oral formulation of praziquantel every two months during the pig slaughtering season in endemic villages in Lithuania. This study started in November 2006 and ended in January 2011; the first dog treatment was administered in February 2007. The results show that the prevalence of E. intermedius, E. multilocularis and Taenia spp. decreased significantly in treated dogs from the second year of the study when compared to untreated dogs. The treatment of dogs also had an impact on reducing the incidence of CE in fattener pigs from 17.6% (2006-2007) to 3.8% (2008; P < 0.05) and in sows from 26.9% (2006-2007) to 3.6% (2008), and eventually to zero in 2010 (P < 0.05) in fatteners and sows as compared to animals from “control” areas (30.7% and 63.7%, respectively). The results document a significant decrease in the transmission of E. intermedius (G7) after treatment of dogs with praziquantel in a relatively short time on farm level in Lithuania. Taeniid prevalence in dogs remained low in 2017 in the areas where anthelmintic intervention was performed until 2010 and, surprisingly, it was also strongly reduced in control areas. Reduction of taeniid transmission is likely associated with a decrease in the number of dogs in the villages as well as an overall decline in backyard pig farming after 2014 due to the outbreaks of African swine fever in Lithuania.

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The prevalence of E. intermedius, E. multilocularis and Taenia spp. decreased significantly in dogs treated strategically during the home slaughter season for pigs.

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Dog treatment also reduced the incidence and intensity of CE in fattener pigs and sows.

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Treatment should target all dogs, not just free-roaming dogs.

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.

Prevalence and risk factors associated with human cystic echinococcosis in Iran

Cystic echinococcosis (CE), as a zoonotic helminthic infection, imposes a large socioeconomic burden to societies throughout the world. This study aimed to analyze the demographic, clinical, diagnostic and therapeutic data of CE patients across all provinces in Iran. In this cross-sectional study, the mentioned data were routinely collected by provincial medical universities during the time from March 2016 to March 2017. The provincial population census was used to calculate the prevalence of CE per 1,000,000 populations for all provinces. T test and Chi squared test were used to compare variables between genders. Statistical analysis was done at 95% significant level using STATA 14 software. The overall prevalence of CE was 6.8 cases per 1,000,000 populations in Iran. The highest and lowest prevalence was reported for Northeast (15.2) and southeast (0.7) of Iran, respectively. There was a significant difference in the prevalence between male and female (5.8 vs. 7.9, p < 0.001). An increasing trend of the prevalence was found by age in both males and females. Abdominal pain was reported as the highest proportion of symptom (39.0%) and the liver was a commonly infected organ (62.7%). CT scan (39.0%) and MRI (1.9%) had the highest and lowest proportion among types of CE diagnosis, respectively. About 67% of the patients washed the vegetable by water without any disinfectant. Due to global efforts on the control and prevention of CE, it still remains endemic in many countries throughout the world. Incidence trend of CE in Iran showed being endemic for CE and more investigations are needed on all aspects of the disease.

Evaluation of direct costs associated with alveolar and cystic echinococcosis in Austria

Background

Cystic echinococcosis (CE) is a globally occurring zoonosis, whereas alveolar echinococcosis (AE) is endemic only in certain parts of the Northern Hemisphere. The socioeconomic impact of human echinococcosis has been shown to be considerable in highly endemic regions. However, detailed data on direct healthcare-related costs associated with CE and AE are scarce for high income countries. The aim of this study was to evaluate direct costs of human disease caused by CE and AE in Austria.

Methods

Clinical data from a registry maintained at a national reference center for echinococcosis at the Medical University of Vienna were obtained for the years 2012–2014. These data were used in conjunction with epidemiological data from Austria’s national disease reporting system and diagnostic reference laboratory for echinococcosis to assess nationwide costs attributable to CE and AE.

Results

In Austria, total modelled direct costs were 486,598€ (95%CI 341,825€ – 631,372€) per year for CE, and 683,824€ (95%CI 469,161€ - 898,486€) for AE. Median costs per patient with AE from diagnosis until the end of a 10-year follow-up period were 30,832€ (25^th– 75^th percentile: 23,197€ - 31,220€) and 62,777€ (25^th– 75^th percentile: 60,806€ - 67,867€) for inoperable and operable patients, respectively. Median costs per patients with CE from diagnosis until end of follow-up after 10 years were 16,253€ (25^th– 75^th percentile: 8,555€ - 24,832€) and 1,786€ (25^th– 75^th percentile: 736€ - 2,146€) for patients with active and inactive cyst stages, respectively. The first year after inclusion was the most cost-intense year in the observed period, with hospitalizations and albendazole therapy the main contributors to direct costs.

Conclusions

This study provides detailed information on direct healthcare-related costs associated with CE and AE in Austria, which may reflect trends for other high-income countries. Surgery and albendazole therapy, due to surprisingly high drug prices, were identified as important cost-drivers. These data will be important for cost-effectiveness analyses of possible prevention programs.

Cystic and alveolar echinococcosis, caused by E. granulosus and E. multilocularis, both occur in humans in Austria. Lesions may develop at any site, with the liver being most frequently affected. Morbidity–especially for alveolar echinococcosis–can be significant and treatment may include major surgery or long-term suppressive medical therapy. The present study was performed to investigate direct healthcare-related costs of cystic and alveolar echinococcosis in Austria based on the data from a clinical registry maintained at the reference center for echinococcosis, the reference laboratory for echinococcosis and data from the national disease reporting system. Annual incidences of AE and CE were estimated at λ = 12 and λ = 40 newly diagnosed cases per year, respectively. Estimated costs due to cystic echinococcosis were 486,598€ (95%CI 341,825€ – 631,372€) per year, and 683,824€ (95%CI 469,161€ - 898,486€) for AE. Major cost drivers were surgical interventions with hospitalizations and drug costs. These data will provide a basis for cost-effectiveness analyses of prevention programs, and highlight possible targets for cost reduction strategies.

Community perception and knowledge of cystic echinococcosis in the High Atlas Mountains, Morocco

Background

Cystic echinococcosis (CE), a neglected zoonosis caused by the larval stage of the tapeworm Echinococcus granulosus, remains a public health issue in many developing countries that practice extensive sheep breeding. Control of CE is difficult and requires a community-based integrated approach. We assessed the communities’ knowledge and perception of CE, its animal hosts, and its control in a CE endemic area of the High Atlas Mountains, Morocco.

Methods

We conducted twenty focus group discussions (FGDs) stratified by gender with villagers, butchers and students in ten Berber villages that were purposefully selected for their CE prevalence.

Results

This community considers CE to be a severe and relatively common disease in humans and animals but has a poor understanding of the parasite’s life cycle. Risk behaviour and disabling factors for disease control are mainly related to cultural practices in sheep breeding and home slaughtering, dog keeping, and offal disposal at home, as well as in slaughterhouses. Participants in our focus group discussions were supportive of control measures as management of canine populations, waste disposal, and monitoring of slaughterhouses.

Conclusions

The uncontrolled stray dog population and dogs having access to offal (both at village dumps and slaughterhouses) suggest that authorities should be more closely involved in CE control. This study also highlights the need for improved knowledge about the transmission cycle of the parasite among communities and health professionals. Inter-sectoral collaboration between health staff, veterinarians, and social scientists appears to be crucial for sustainable control of this parasitic zoonosis.

Electronic supplementary material

The online version of this article (10.1186/s12889-018-6372-y) contains supplementary material, which is available to authorized users.

Protoscolicidal Effects of the Garlic Chloroformic Extract on the Protoscolices of Hydatid Cyst at a Short Exposure Time, up to Five Minutes

BACKGROUND

The treatment of choice for hydatidosis as an important zoonotic disease is surgery. Different agents are injected into the cyst to prevent secondary hydatidosis. To avoid the side effects of such protoscolicidal agents, considering the high protoscolicidal effects of the garlic extract, we conducted the present study on protoscolices in limited applicable times and compared the extract with some chemical agents.

METHODS

Sheep's liver and lung cysts were collected. Ninety tubes were selected and divided into 3 sets (for different exposure times), each one comprising 5 groups of 6 tubes. Each tube contained 3000-4000 protoscolices. The groups were 0.5% cetrimide (as positive control), 20% hypertonic sodium chloride, 0.5% silver nitrate, 0.9% normal saline (as negative control), and the garlic chloroformic extract (200 mg/mL). The viability of the protoscolices was assessed using 0.1% eosin. The ANOVA and LSD were used to compare the mean viability of the protoscolices after exposure to the different agents at different times and concentrations. The data were analyzed using SPSS software, version 17. A P<0.05 was considered significant.

RESULTS

Our findings showed that the protoscolicidal effects of the garlic extract at 1 (P<0.001) and 2 (P<0.001 and P=0.003) minutes of exposure were higher than those of sodium chloride and silver nitrate. At 5 minutes of exposure, there was no difference between the garlic extract and sodium chloride (P=0.36); however, the difference between these agents and silver nitrate was significant.

CONCLUSION

The garlic chloroformic extract in a short exposure time had high protoscolicidal effects and could substitute other agents.

Public health risks associated with food-borne parasites

Parasites are important food‐borne pathogens. Their complex lifecycles, varied transmission routes, and prolonged periods between infection and symptoms mean that the public health burden and relative importance of different transmission routes are often difficult to assess. Furthermore, there are challenges in detection and diagnostics, and variations in reporting. A Europe‐focused ranking exercise, using multicriteria decision analysis, identified potentially food‐borne parasites of importance, and that are currently not routinely controlled in food. These are Cryptosporidium spp., Toxoplasma gondii and Echinococcus spp. Infection with these parasites in humans and animals, or their occurrence in food, is not notifiable in all Member States. This Opinion reviews current methods for detection, identification and tracing of these parasites in relevant foods, reviews literature on food‐borne pathways, examines information on their occurrence and persistence in foods, and investigates possible control measures along the food chain. The differences between these three parasites are substantial, but for all there is a paucity of well‐established, standardised, validated methods that can be applied across the range of relevant foods. Furthermore, the prolonged period between infection and clinical symptoms (from several days for Cryptosporidium to years for Echinococcus spp.) means that source attribution studies are very difficult. Nevertheless, our knowledge of the domestic animal lifecycle (involving dogs and livestock) for Echinoccocus granulosus means that this parasite is controllable. For Echinococcus multilocularis, for which the lifecycle involves wildlife (foxes and rodents), control would be expensive and complicated, but could be achieved in targeted areas with sufficient commitment and resources. Quantitative risk assessments have been described for Toxoplasma in meat. However, for T. gondii and Cryptosporidium as faecal contaminants, development of validated detection methods, including survival/infectivity assays and consensus molecular typing protocols, are required for the development of quantitative risk assessments and efficient control measures.

Echinococcus granulosus hydatid cyst location is modified by Fasciola hepatica infection in cattle

BACKGROUND

Natural parasite infection occurs in wild and domestics animals with more than one parasite species at the same time, generating an infection called polyparasitism. Cystic echinococcosis reports are usually based only on infection with Echinoccocus granulosus leaving aside other internal parasitoses that could modulate both the immune response and pathogenesis of the natural infection. Fasciola hepatica is another cosmopolitan parasite in ruminants with a similar distribution to E. granulosus in different parts of the world, but no information of the effect of co-infection with E. granulosus has been described. The aims of this report were to establish E. granulosus prevalence and explore the association of F. hepatica co-infection and natural E. granulosus infections in cattle.

RESULTS

From 1725 animals, the prevalence of E. granulosus and F. hepatica was 21.16 and 51.3%, respectively. Considering both infections, older cattle (> 4 years) presented higher prevalence compared to younger animals. In E. granulosus-infected cattle, 5.21% had fertile cysts, 71.78% infertile cysts, and in 23.01% cysts were smaller than 1 cm in diameter. Considering cyst location, 39.72% had lungs cysts, 24.72% had liver cysts and 36.94% had cysts in both organs. Cyst location significantly differed between age groups: 44.68% of younger animals had cysts only in the lungs, while older animals presented hydatid cyst in the lungs and liver simultaneously (44.15%). With E. granulosus infection alone, 30.26% of cysts were found in the lungs, 31.79% in the liver and 37.95% in both organs. Regarding the co-infection of E. granulosus with F. hepatica, the proportion was significantly different (P < 0.05) with most animals having cysts only in the lungs (49.41%) and a lower level of liver infection (15.88%). Analyzing organ cyst distribution and F. hepatica absence/presence ratio within each cyst type, small cysts showed the highest difference in ratio.

CONCLUSIONS

To the best of our knowledge, this is the first report indicating that F. hepatica co-infection in cattle could be affecting the instate of hydatid cysts in the liver, displacing toward lung localization, suggesting an antagonistic relationship.

Innovative tools for the diagnosis of Echinococcus granulosus in definitive hosts

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

Molecular phylogeny based on six nuclear genes suggests that Echinococcus granulosus sensu lato genotypes G6/G7 and G8/G10 can be regarded as two distinct species

Tapeworms of the species complex of Echinococcus granulosus sensu lato (s. l.) are the cause of a severe zoonotic disease - cystic echinococcosis, which is listed among the most severe parasitic diseases in humans and is prioritized by the World Health Organization. A stable taxonomy of E. granulosus s. l. is essential to the medical and veterinary communities for accurate and effective communication of the role of different species in this complex on human and animal health. E. granulosus s. l. displays high genetic diversity and has been divided into different species and genotypes. Despite several decades of research, the taxonomy of E. granulosus s. l. has remained controversial, especially the species status of genotypes G6-G10. Here the Bayesian phylogeny based on six nuclear loci (7387 bp in total) demonstrated, with very high support, the clustering of G6/G7 and G8/G10 into two separate clades. According to the evolutionary species concept, G6/G7 and G8/G10 can be regarded as two distinct species. Species differentiation can be attributed to the association with distinct host species, largely separate geographical distribution and low level of cross-fertilization. These factors have limited the gene flow between genotypic groups G6/G7 and G8/G10, resulting in the formation of distinct species. We discuss ecological and epidemiological differences that support the validity of these species.

Prevalence of abdominal cystic echinococcosis in rural Bulgaria, Romania, and Turkey: a cross-sectional, ultrasound-based, population study from the HERACLES project

BACKGROUND

Cystic echinococcosis is a neglected zoonotic infection that is distributed worldwide and prioritised by WHO for control efforts. The burden of human cystic echinococcosis is poorly understood in most endemic regions, including eastern Europe. We aimed to estimate the prevalence of abdominal cystic echinococcosis in rural areas of Bulgaria, Romania, and Turkey.

METHODS

We did a cross-sectional ultrasound-based survey that recruited volunteers from 50 villages in rural areas of Bulgaria, Romania, and Turkey. These villages were in provinces with annual hospital incidence of cystic echinococcosis within the mid-range for the respective countries. All people who attended a session were allowed to participate if they agreed to be screened. Abdominal ultrasound screening sessions were hosted in public community structures such as community halls, primary health-care centres, schools, and mosques. Lesions were classified using an adapted WHO classification. We reported the prevalence of abdominal cystic echinococcosis adjusted by sex and age through direct standardisation, using the country's rural population as a reference.

FINDINGS

From July 1, 2014, to Aug 3, 2015, 24 693 individuals presented to screening sessions and 24 687 underwent ultrasound screening. We excluded a further six indivduals due to missing data, leaving 24 681 people in our analysis. Abdominal cystic echinococcosis was detected in 31 of 8602 people screened in Bulgaria, 35 of 7461 screened in Romania, and 53 of 8618 screened in Turkey. The age and sex adjusted prevalence of abdominal cystic echinococcosis was 0·41% (95% CI 0·29-0·58) in Bulgaria, 0·41% (0·26-0·65) in Romania, and 0·59% (0·19-1·85) in Turkey. Active cysts were found in people of all ages, including children, and in all investigated provinces.

INTERPRETATION

Our results provide population-based estimates of the prevalence of abdominal cystic echinococcosis. These findings should be useful to support the planning of cost-effective interventions, supporting the WHO roadmap for cystic echinococcosis control.

FUNDING

European Union Seventh Framework Programme.

Parasites in Food: From a Neglected Position to an Emerging Issue

Foodborne parasites have long been a neglected group of pathogens, as they often have insidious, chronic effects, rather than being acute diseases, and they are often associated with impoverished or marginalized populations. In addition, due to the long incubation period for most foodborne parasites, source attribution is often difficult, if not impossible. However, global trends have enabled foodborne parasites to emerge in different populations in new locations, transmitted through different food types, and sometimes with unexpected symptoms. This emergence of foodborne parasites has brought them into focus. In this chapter, six foodborne parasites are used as examples on emergence: Echinococcus multilocularis is spreading to new locations; Cryptosporidium spp. are beginning to be associated not only with water, but also with salads; Trypanosoma cruzi is being manifest with acute disease due to foodborne transmission, particularly transmitted with juices; Trichinella spp. have become less of a burden regarding transmission via pork in many countries, but now game animals are becoming a concern; anisakiasis is becoming a global problem as the world develops a taste for sushi, and similarly for opisthorchiasis, which is increasingly being associated with cholangiocarcinoma. However, the emergence of these foodborne parasites provides an incentive for increased efforts being made toward control. In this chapter, having described how the parasites are emerging from their neglected position, the focus turns toward control. In addition to considering control measures that may be applied to the specific parasites, an overview is provided of some of the organized collaborations, projects, and consortia, as well as some of their outputs, that have in focus the control of these emerging and important pathogens.

Identification of emu-TegP11, an EF-hand domain-containing tegumental protein of Echinococcus multilocularis

Tegumental proteins (TegPs) are a group of proteins that coat on the surface of worms, mainly being involved in ion uptake and immune evasion. Echinococcus species have many TegPs, but none of them have been characterized and their role remains unclear. The genome-wide analysis revealed that there were at least 14 tegp genes (tegp1 - 14) in Echinococcus species, the majority of which were found to contain an EF-hand domain or a dynein light chain-like domain or both. Despite low identity, all TegP11 proteins from 25 flatworms were conserved in structure. Echinococcus multilocularis TegP11 (emu-TegP11) was verified to be secreted by extracellular vesicles and to be localized in different spatiotemporal patterns in protoscoleces. Moreover, emu-TegP11 was also shown to have weak or no Ca²⁺-binding capacity. In treated macrophages, emu-TegP11 interfered with the small RNA-induced silencing pathway via inducing ectopic expression of some key component genes. Additionally, emu-TegP11 remarkably promoted NO secretion possibly by upregulation of inos gene expression (p < 0.05). It was further shown that emu-TegP11 acted as a suppressor of inflammation, with il-12B and il-1β being significantly down-regulated (p < 0.01), and il-10 and il-4 being significantly upregulated (p < 0.05). The study demonstrates a regulatory role of emu-TegP11, likely acting as a immunomodulator to be involved in regulation of host immune system during Echinococcus infection.

Metazoan Parasite Vaccines: Present Status and Future Prospects

Eukaryotic parasites and pathogens continue to cause some of the most detrimental and difficult to treat diseases (or disease states) in both humans and animals, while also continuously expanding into non-endemic countries. Combined with the ever growing number of reports on drug-resistance and the lack of effective treatment programs for many metazoan diseases, the impact that these organisms will have on quality of life remain a global challenge. Vaccination as an effective prophylactic treatment has been demonstrated for well over 200 years for bacterial and viral diseases. From the earliest variolation procedures to the cutting edge technologies employed today, many protective preparations have been successfully developed for use in both medical and veterinary applications. In spite of the successes of these applications in the discovery of subunit vaccines against prokaryotic pathogens, not many targets have been successfully developed into vaccines directed against metazoan parasites. With the current increase in -omics technologies and metadata for eukaryotic parasites, target discovery for vaccine development can be expedited. However, a good understanding of the host/vector/pathogen interface is needed to understand the underlying biological, biochemical and immunological components that will confer a protective response in the host animal. Therefore, systems biology is rapidly coming of age in the pursuit of effective parasite vaccines. Despite the difficulties, a number of approaches have been developed and applied to parasitic helminths and arthropods. This review will focus on key aspects of vaccine development that require attention in the battle against these metazoan parasites, as well as successes in the field of vaccine development for helminthiases and ectoparasites. Lastly, we propose future direction of applying successes in pursuit of next generation vaccines.

Environmental risk factors and changing spatial patterns of human seropositivity for Echinococcus spp. in Xiji County, Ningxia Hui Autonomous Region, China

Background

Human echinococcoses are parasitic helminth infections that constitute a serious public health concern in several regions across the world. Cystic (CE) and alveolar echinococcosis (AE) in China represent a high proportion of the total global burden of these infections. This study was conducted to predict the spatial distribution of human seropositivity for Echinococcus species in Xiji County, Ningxia Hui Autonomous Region (NHAR), with the aim of identifying communities where targeted prevention and control efforts are required.

Methods

Bayesian geostatistical models with environmental and demographic covariates were developed to predict spatial variation in the risk of human seropositivity for Echinococcus granulosus (the cause of CE) and E. multilocularis (the cause of AE). Data were collected from three cross-sectional surveys of school children conducted in Xiji County in 2002–2003, 2006–2007 and 2012–2013. Environmental data were derived from high-resolution satellite images and meteorological data.

Results

The overall seroprevalence of E. granulosus and E. multilocularis was 33.4 and 12.2%, respectively, across the three surveys. Seropositivity for E. granulosus was significantly associated with summer and winter precipitation, landscape fragmentation variables and the extent of areas covered by forest, shrubland, water and bareland/artificial surfaces. Seropositivity for E. multilocularis was significantly associated with summer and winter precipitations, landscape fragmentation variables and the extent of shrubland and water bodies. Spatial correlation occurred over greater distances for E. granulosus than for E. multilocularis. The predictive maps showed that the risk of seropositivity for E. granulosus expanded across Xiji during the three surveys, while the risk of seropositivity for E. multilocularis became more confined in communities located in the south.

Conclusions

The identification of high-risk areas for seropositivity for these parasites, and a better understanding of the role of the environment in determining the transmission dynamics of Echinococcus spp. may help to guide and monitor improvements in human echinococcosis control strategies by allowing targeted allocation of resources.

Spatiotemporal patterns and environmental drivers of human echinococcoses over a twenty-year period in Ningxia Hui Autonomous Region, China

BACKGROUND

Human cystic (CE) and alveolar (AE) echinococcoses are zoonotic parasitic diseases that can be influenced by environmental variability and change through effects on the parasites, animal intermediate and definitive hosts, and human populations. We aimed to assess and quantify the spatiotemporal patterns of human echinococcoses in Ningxia Hui Autonomous Region (NHAR), China between January 1994 and December 2013, and examine associations between these infections and indicators of environmental variability and change, including large-scale landscape regeneration undertaken by the Chinese authorities.

METHODS

Data on the number of human echinococcosis cases were obtained from a hospital-based retrospective survey conducted in NHAR for the period 1 January 1994 through 31 December 2013. High-resolution imagery from Landsat 4/5-TM and 8-OLI was used to create single date land cover maps. Meteorological data were also collected for the period January 1980 to December 2013 to derive time series of bioclimatic variables. A Bayesian spatio-temporal conditional autoregressive model was used to quantify the relationship between annual cases of CE and AE and environmental variables.

RESULTS

Annual CE incidence demonstrated a negative temporal trend and was positively associated with winter mean temperature at a 10-year lag. There was also a significant, nonlinear effect of annual mean temperature at 13-year lag. The findings also revealed a negative association between AE incidence with temporal moving averages of bareland/artificial surface coverage and annual mean temperature calculated for the period 11-15 years before diagnosis and winter mean temperature for the period 0-4 years. Unlike CE risk, the selected environmental covariates accounted for some of the spatial variation in the risk of AE.

CONCLUSIONS

The present study contributes towards efforts to understand the role of environmental factors in determining the spatial heterogeneity of human echinococcoses. The identification of areas with high incidence of CE and AE may assist in the development and refinement of interventions for these diseases, and enhanced environmental change risk assessment.

Oral Application of Recombinant Bacillus subtilis Spores to Dogs Results in a Humoral Response against Specific Echinococcus granulosus Paramyosin and Tropomyosin Antigens

Bacillus subtilis is known as an endospore- and biofilm-forming bacterium with probiotic properties. We have recently developed a method for displaying heterologous proteins on the surface of B. subtilis biofilms by introducing the coding sequences of the protein of interest into the bacterial genome to generate a fusion protein linked to the C terminus of the biofilm matrix protein TasA. Although B. subtilis is a regular component of the gut microflora, we constructed a series of recombinant B. subtilis strains that were tested for their ability to be used to immunize dogs following oral application of the spores. Specifically, we tested recombinant spores of B. subtilis carrying either the fluorescent protein mCherry or else selected antigenic peptides (tropomyosin and paramyosin) from Echinococcus granulosus, a zoonotic intestinal tapeworm of dogs and other carnivores. The application of the recombinant B. subtilis spores led to the colonization of the gut with recombinant B. subtilis but did not cause any adverse effect on the health of the animals. As measured by enzyme-linked immunosorbent assay and immunoblotting, the dogs were able to develop a humoral immune response against mCherry as well as against E. granulosus antigenic peptides. Interestingly, the sera of dogs obtained after immunization with recombinant spores of E. granulosus peptides were able to recognize E. granulosus protoscoleces, which represent the infective form of the head of the tapeworms. These results represent an essential step toward the establishment of B. subtilis as an enteric vaccine agent.

The choose of different surgical therapies of hepatic alveolar echinococcosis: A single-center retrospective case-control study

The aim of this study was to evaluate different surgical therapies for hepatic alveolar echinococcosis in different clinical stages.We analyze the clinical data of 115 patients who received surgical treatment in West China Hospital from January 2004 to June 2016. Among these patients, 77 cases underwent radical hepatic resection (group A, n = 77); 17 cases underwent palliative resection (group B, n = 17), and 21 cases underwent liver transplantation (group C, n = 21) with 12 cases of orthotopic liver transplantation and 9 cases of liver autotransplantation.The postoperative complication rate of radical hepatic resection group was 13.0% (10/77), which is statistically significant (P < .05) than the rate of palliative resection group 29.4% (5/17) or liver transplantation group 23.8% (5/21). The follow-up period ranged from 1 to 72 months. The overall median survival rate of radical resection was 72/77, higher than the rate of palliative group (12/17) or transplantation group (17/21), which was also statistically significant (P < .01).In our study, we believe in that all stages of hepatic alveolar echinococcosis should take active surgical interventions, and radical hepatic resection should be considered as the first-choice treatment for early stage of alveolar echinococcosis, while palliative surgery is still helpful to relieve symptoms and improve the life quality for advanced patients. Liver transplantation might also be an alternative option for the late-stage hepatic alveolar echinococcosis.

Immunology of cystic echinococcosis (hydatid disease)

BACKGROUND

The neglected disease cystic echinococcosis is caused by larval Echinococcus granulosus flatworms, which form bladder-like hydatid cysts in liver, lungs, and other organs.

SOURCES OF DATA

Published literature.

AREAS OF AGREEMENT

Establishing larvae are susceptible to antibody-dependent killing, as attested by successful animal vaccination, whereas once established they are partially protected by the so-called laminated layer. Host responses are Th2 dominated, with a Th1 component. Diagnostic antigens from cyst fluid are known, but responses appear absent in one-fifth of patients.

AREAS OF CONTROVERSY

Is evasion mainly based on induction of Th2 or regulatory responses by the parasite?

GROWING POINTS

The parasite induces regulatory responses. The laminated layer has immune-regulatory properties.

AREAS TIMELY FOR DEVELOPING RESEARCH

Develop tools for functional genomics; characterize immunologically interesting proteins suggested by genomic information; analyse infection in broader context of granulomatous responses; identify molecules secreted/excreted by intact larvae/cysts towards their outside, including diffusible immune-regulators.

The echinococcoses in Asia: The present situation

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

Combating echinococcosis in China: strengthening the research and development

Echinococcosis is a neglected zoonotic disease, causing great morbidity and mortality due to the wide distribution of its endemic areas. China holds a high percentage in the global burden of both cystic and alveolar echinococcosis. A national survey conducted between 2012 and 2016 showed that an estimated 50 million people are at risk of contracting the disease in western China, of whom about 0.17 million are cases with echinococcosis.

Despite this, research and development on echinococcosis in China is greatly inadequate compared to that in other countries. In this paper, we argue that there is a need for more research and work to be conducted in China on echinococcosis, including researching techniques in regards to diagnosis, treatment, and vaccination, and developing products through technical transformation and piloting strategies to control and even elimination.

However, great opportunities exist for China to strengthen the research and development on this disease through initiatives such as Health China 2030, the Belt and Road Initiative, the China-Africa cooperation, as well as through further cooperation between China and the World Health Organization. All of these can bring us closer to controlling echinococcosis in China as well as in other countries. One element of crucial importance will be the training and development of professionals, which can be strengthened through international cooperation.

Management of osseous cystic echinococcosis

INTRODUCTION

Osseous cystic echinococcosis (CE) is one of the most complicated and devastating conditions caused by Echinococcus granulosus. Its management is difficult and there is scant literature about it. Areas covered: A literature review was performed to provide an update on its diagnosis, treatment and follow-up. Expert commentary: In most cases diagnosis of osseous CE can only be confirmed by surgery. Osseous CE should be managed by experienced physicians and addressed as a chronic disease with therapies must be aimed at controlling the disease and its sequels or complications, rather than with a curative intent.

Alveolar echinococcosis in Germany, 1992-2016. An update based on the newly established national AE database

PURPOSE

Alveolar echinococcosis is a rare disease caused by the parasite Echinococcus multilocularis. The newly established national database should enable us to determine high-risk areas and evaluate the endemic levels.

METHODS

The national database was implemented using SQL Workbench. We used EpiInfo™ software to display the prevalence of disease. Moran's I geodata analysis according to cluster and high risk areas was performed with GeoDa™. SAS Version 9.2 was used for the statistical analysis of the cases (n = 523).

RESULTS

The analysis showed a concentration of cases in Baden-Württemberg and Bavaria. Moran's I showed a heterogeneous case distribution throughout Germany (I = 0.208815, Z = 32.6175, p < 0.001). In the period from 1992 to 2016, the prevalence was 0.64/100,000 inhabitants in the whole of Germany, 2.18/100,000 inhabitants in Baden-Württemberg and 1.48/100,000 inhabitants in Bavaria. The analysis also revealed a difference between men and women, with a prevalence of 0.58/100,000 and 0.69/100,000, respectively. The analysis of spatial autocorrelation and possible risk areas showed that the southeast regions of Baden-Württemberg (I = 0.188514, Z = 11.3197, p < 0.001) and the southwest part of Bavaria (I = 0.176953, Z = 13.5144, p < 0.001) constitute the high risk areas.

CONCLUSIONS

The prevalence of disease is noticeably high in the Swabian Jura, the Bavarian Alps and the Alpine foothills. Raising awareness and educating doctors in high risk areas may prevent new cases and assist in earlier diagnosis.

Analysis of Lethality in Echinococcal Disease

The information on mortality from echinococcosis is important not only for a better understanding of the severity of the disease, but also for evaluating the effectiveness of public health interventions. The aim of this research was to study the causes of mortality from echinococcosis. We have collected and analyzed the materials of 1,470 patients in 10 age - groups in the Republic of Armenia (from 2000 to 2016). To find out the causes of mortality from echinococcosis, we have analyzed the medical histories and protocols of postmortem examinations of 19 deaths from echinococcosis and 17 deaths due to other indirect causes not associated with the parasite. The average annual death rate from echinococcosis is 0.007 per 10,000 population, and the mortality is 1.29 (per 100 patients). The highest mortality occurs in people aged 70-79. Mortality from echinococcosis is also recorded among the unoperated children. The rupture of the parasitic cyst and hepatic insufficiency are major among the direct causes of mortality. Sometimes the hydatid cysts unrecognized during the life were first diagnosed at autopsy. Insufficient qualification of doctors in the field of helminthology, as well as the latent course of the disease or manifestation of minor symptoms in echinococcosis over a long period often led to medical errors. Further decline in mortality can be achieved by early diagnosis, timely hospitalization and treatment before the development of severe complications worsening the prognosis and outcomes of surgical intervention.

MicroRNA expression profile in RAW264·7 macrophage cells exposed to Echinococcus multilocularis metacestodes

MicroRNAs (miRNAs) are short noncoding RNAs, involved in the regulation of parasite diseases. However, a role of miRNAs in Echinococcus multilocularis infection remains largely unknown. In this study, we first found the expression levels of key genes involved in miRNA biogenesis and function, including Ago2, Xpo5, Tarbp2 and DgcR8, were obviously altered in the macrophage RAW264·7 cells exposed to E. multilocularis metacestodes. Compared with the control, 18 and 32 known miRNAs were found to be differentially expressed (P 2) in the macrophages exposed to E. multilocularis metacestodes for 6 and 12 h, respectively. Among these, several are known to be involved in regulating cytokine activities and immune responses. Quantitative real-time polymerase chain reaction results showed that the expression of nine selected miRNAs was consistent with the sequencing data at each treatment time points. Moreover, there were statistically significant correlations between the expression levels of miRNAs and their corresponding targeted genes. Our data give us some clues to pinpoint a role of miRNAs in the course of infection and immunity of E. multilocularis.

The disease burden of human cystic echinococcosis based on HDRs from 2001 to 2014 in Italy

Background

Cystic echinococcosis (CE) is an important neglected zoonotic parasitic infection belonging to the subgroup of seven Neglected Zoonotic Disease (NZDs) included in the World Health Organization’s official list of 18 Neglected Tropical Diseases (NTDs). CE causes serious global human health concerns and leads to significant economic losses arising from the costs of medical treatment, morbidity, life impairments and fatality rates in human cases. Moreover, CE is endemic in several Italian Regions. The aim of this study is to perform a detailed analysis of the economic burden of hospitalization and treatment costs and to estimate the Disability Adjusted Life Years (DALYs) of CE in Italy.

Methods and findings

In the period from 2001 to 2014, the direct costs of 21,050 Hospital Discharge Records (HDRs) belonging to 12,619 patients with at least one CE-related diagnosis codes were analyzed in order to quantify the economic burden of CE. CE cases average per annum are 901 (min—max = 480–1,583). Direct costs include expenses for hospitalizations, medical and surgical treatment incurred by public and private hospitals and were computed on an individual basis according to Italian Health Ministry legislation. Moreover, we estimated the DALYs for each patient. The Italian financial burden of CE is around € 53 million; the national average economic burden per annum is around € 4 million; the DALYs of the population from 2001 to 2014 are 223.35 annually and 5.26 DALYs per 10⁵ inhabitants.

Conclusion

In Italy, human CE is responsible for significant economic losses in the public health sector. In humans, costs associated with CE have been shown to have a great impact on affected individuals, their families and the community as a whole. This study could be used as a tool to prioritize and make decisions with regard to a surveillance system for this largely preventable yet neglected disease. It demonstrates the need of implementing a CE control program aimed at preventing the considerable economic and social losses it causes in high incidence areas.

CE is a neglected tropical disease that remains a considerable health problem in endemic regions and which leads to substantial economic losses for agriculture sectors and public health systems. The parasitic cycle requires a definitive host (canidae) and an intermediate host (livestock species), while humans are only occasionally hosts. CE is more prevalent in areas where extensive or semi-extensive farming of livestock (mostly sheep) is common. The study of prevalence and health expenditure at the national macro-regional and regional level is a prerequisite for creating awareness of the importance of this disease. The Italian Ministry of Health provides remuneration to its regions’ hospitals for treatment of illnesses. In this study 21,050 hospital discharge records with CE diagnosis from 2001 to 2014 related to 12,619 patients were analyzed. The median of CE hospitalizations per annum was 848. The direct costs of HDRs for echinococcosis were estimated to be € 53,175,934.34. The assessment of economic remuneration by Italian Regions grouped by Nomenclature of Territorial Units 1 (NUTS1) shows that Southern Italy and its major islands spent €13,523,999 and €15,171,739 respectively. The national annual average direct cost for 10⁵ inhabitants was € 6,398. The study of the National DALYs, a measure of social burden of disease, shows that 41% was correlated to Island patients DALYs per annum are 223.4. An analysis of direct costs and an estimate of DALYs are key factors for establishing how to prioritize control measures for CE, which is essentially a preventable disease.

Simulating control of a focal wildlife outbreak of Echinococcus multilocularis

The parasitic tapeworm Echinococcus multilocularis is the causative agent of alveolar echinococcosis, a serious zoonotic infection present in Europe that can be fatal. The United Kingdom currently has E. multilocularis free status but the possibility of introduction exists, most likely via an imported or returning dog or other deliberately introduced animal that has not had anthelmintic treatment. We have developed a model to predict the probability of successfully eliminating a focal outbreak of E. multilocularis using a programme of anthelmintic bait distribution. We investigated three different potential control programmes, each with 36 monthly campaigns commencing five, ten or 15 years after disease introduction over an area of 2827km². We assumed equilibrium disease prevalence of 30%, 40% and 55% based on the range of values reported across Europe. However, for all of these scenarios, equilibrium had not been reached at five to 15 years after introduction and simulated local prevalence values were between 0.5% and 28%. We found that it is possible to eliminate the disease with a 38%-86% success rate if control is started five years after introduction, dropping to 0% to 56% if control is delayed until 15 years after introduction, depending upon the prevalence equilibrium. We have also estimated the costs involved in these programmes to be from €7 to €12 million (2013 prices).