Intestinal infection with Echinococcus multilocularis in a dog

OBJECTIVE

To raise veterinary awareness of a newly recognized parasitic threat to canine and human health, highlight the increasing availability of molecular parasitological diagnostics and the need to implement best practices of cestocidal use in high-risk dogs.

ANIMAL

A young Boxer dog with vomiting and bloody diarrhea, suspected diagnosis of inflammatory bowel disease.

CLINICAL PRESENTATION, PROGRESSION, AND PROCEDURES

Bloodwork revealed inflammation, dehydration, and protein loss, addressed with supportive therapy. Fecal culture revealed only Escherichia coli. On centrifugal flotation, tapeworm eggs (which could be Taenia or Echinococcus spp) and, unusually, adult cestodes of Echinococcus were observed. The referring veterinarian was contacted to initiate immediate treatment with a cestocide due to zoonotic potential. Diagnosis was confirmed with a coproPCR which has higher sensitivity for Echinococcus spp than fecal flotation alone. DNA was identical to an introduced European strain of E multilocularis currently emerging in dogs, people, and wildlife. Since dogs can also self-infect and develop hepatic alveolar echinococcosis (severe and often fatal), this was ruled out using serology and abdominal ultrasound.

TREATMENT AND OUTCOME

Following cestocidal treatment, fecal flotation and coproPCR were negative for eggs and DNA of E multilocularis; however, coccidia were detected and diarrhea resolved following treatment with sulfa-based antibiotics.

CLINICAL RELEVANCE

This dog was serendipitously diagnosed with E multilocularis, acquired through ingestion of a rodent intermediate host likely infected from foxes and coyotes. Therefore, as a dog at high risk of reexposure from eating rodents, regular (ideally monthly) treatment with a labeled cestocide is indicated going forward.

Sensitivity comparison between Mini-FLOTAC and conventional techniques for the detection of Echinococcus multilocularis eggs

Canines serve as the definitive host of Echinococcus multilocularis. This study evaluated the sensitivity of the Mini-FLOTAC technique (MF) for the detection of E. multilocularis eggs in definitive hosts. First, we investigated the effects of heat inactivation and preservative conditions on the detection rate of eggs obtained from experimentally infected dogs. The sensitivity of MF was compared with that of eight other techniques: the centrifugal flotation with sucrose or zinc sulfate, MGL, AMS III, and a combination of MF and flotation/sedimentation techniques. Finally, we compared the sensitivity of MF and the centrifugal flotation with sucrose for the feces of E. multilocularis-infected foxes. The detection rate reached a plateau level with a specific gravity (s.g.) 1.22 for fresh eggs, but the highest rates were obtained with s.g. greater than 1.32 for heat-inactivated eggs. There was no significant difference in the detection rate among the preservative conditions. MF showed significantly higher EPG than the other techniques. Moreover, it showed higher diagnostic sensitivity for the fox feces than the centrifugal flotation technique. These results suggest that heat inactivation may alter s.g. of E. multilocularis eggs and that MF with zinc sulfate (s.g. = 1.32) would be effective for detecting heat-inactivated E. multilocularis eggs.

High Expression of Tim-3 in Alveolar Echinococcosis Mediates Depletion of CD8+ T Cell Function

OBJECTIVE

CD8⁺ T cells can participate in immune action by secreting various cytokines, which have a killing effect on certain viruses, tumor cells, and other antigenic substances. However, in studies such as chronic viral infections and some parasitic infections, CD8⁺ T lymphocyte showed functional depletion, and its immune dysfunction was an important reason for the persistence of infection. Tim-3 has been shown to be a negative regulator of CD8⁺ T cell function, causing depletion of CD8⁺ T cells in cancer and chronic infection. However, the relationship between Tim-3 and CD8⁺ T cells in Echinococcus multilocularis infection is not clear.

METHODS

In this study, we analyzed peripheral blood CD8⁺ T cells from 62 alveolar echinococcosis (AE) patients and 30 healthy controls.

RESULTS

Compared with the healthy control group, the proportion of CD8⁺ T cells in the peripheral blood of AE patients increased significantly, while the levels of perforin, granzyme B and IFN-γ in peripheral blood CD8⁺ T cell related factors of metabolically active alveolar echinococcosis (MAAE) patients decreased significantly. Later detection revealed that the expression of Tim-3 on CD8⁺ T cells in the peripheral blood of MAAE patients was significantly higher than that of metabolically inactive alveolar echinococcosis (MIAE) patients and healthy controls. The expression levels of function-related factors perforin, granzyme B and IFN-γ in CD8⁺ Tim-3⁺ T cell were significantly lower in the CD8⁺Tim-3^- T cells of AE patients. In vitro, the secretion of CD8⁺ T cell-associated factors was significantly restored by inhibiting Tim-3 expression.

CONCLUSION

Therefore, the depletion of CD8⁺ T lymphocyte in patients with alveolar echinococcosis disease is considered to be related to the high expression of Tim-3 on the surface.

The situation of echinococcosis in stray dogs in Turkey: the first finding of Echinococcus multilocularis and Echinococcus ortleppi

Echinococcosis, caused by larval stage of the genus Echinococcus, is one of the most important zoonotic diseases worldwide. The purpose of this study was to determine the presence and prevalence of Echinococcus species in stray dogs of Erzurum, a highly endemic region for cystic echinococcosis (CE) and alveolar echinococcosis (AE) in Turkey. The study samples consisted of 446 stray dog faecal specimens collected from an animal shelter in Erzurum, Turkey, between October 2015 and February 2016. The faecal samples were collected from individual dogs for the isolation of taeniid eggs using the sequential sieving and flotation method (SSFM). Molecular analyses and sequencing revealed the prevalence of Echinococcus spp. as 14.13% (63/446) in faecal samples. The stray dogs harboured five different Echinococcus spp.: E. granulosus s.s. (G1/G3) (n = 41), E. equinus (G4) (n = 3), E. ortleppi (G5) (n = 1), E. canadensis (G6/G7) (n = 3) and E. multilocularis (n = 16). E. granulosus s.s. was the most abundant species. Surprisingly, the occurrence of E. multilocularis in dogs was revealed for the first time in Turkey. E. ortleppi was also reported for the first time in Turkey. These findings highlight a significant public health risk for human AE and CE, presenting useful baseline data on Echinococcus spp. infection in dogs for designing control strategies.

Establishing and evaluation of a polymerase chain reaction for the detection of Echinococcus multilocularis in human tissue

BACKGROUND

Alveolar echinococcosis (AE) is caused by metacestode larva of the tapeworm Echinococcus multilocularis. AE diagnostics currently rely on imaging techniques supported by serology, but unequivocal detection of AE is difficult. Although polymerase chain reaction (PCR)-based methods to detect tapeworm DNA in biopsies have been suggested for several species, no validated protocol adhering to accepted guidelines has so far been presented for AE diagnostics. We herein established a PCR protocol for metacestode biopsies and technically evaluated the method using isolated parasite DNA and cells, biopsies of clinically relevant material, and formalin fixed paraffin-embedded (FFPE) human tissue blocks. We compared the results with an immunochemical (IHC) approach using the monoclonal antibody Em2G11 specific for the antigen Em2 of E. mulitlocularis.

METHODOLOGY/PRINCIPAL FINDINGS

Based on tapeworm 12S rDNA sequences we established and validated a PCR protocol for robust detection of as little as 50 parasite cells per specimen and report 127 cases of positive identification of Echinococcus species in samples from humans and animals. For further validation, we analyzed 45 liver, heart, brain, and soft tissue samples as well as cytological probes of aspirates of FFPE-material from 18 patients with clinically confirmed AE. Of each patient we analyzed (i) fully viable lesions with laminated layer; (ii) tissue with mAbEm2G11-positive small particles of E. multilocularis (spems); (iii) mAbEm2G11-negative tissue adjacent to the main lesion; and (iv) lymph node tissue with mAbEm2G11-positive spems. To identify the areas for the PCR-based approach, we performed IHC-staining with the monoclonal antibody Em2G11. Micro-dissected tissue of these areas was then used for PCR-analysis. 9 of 15 analyzed samples with viable E. multilocularis lesions with laminated layer were positive by PCR. Of this group, all samples preserved for less than 6 years (6/6) were tested positive. 11 of 15 samples of spems and 7 of 9 samples of the control group mAbEm2G11-negative tissue were negative by PCR. We further show that all probes from lymph nodes with spems are PCR negative.

CONCLUSIONS/SIGNIFICANCE

We present a sensitive PCR method for the detection of E. multilocularis in human tissue, particularly in fresh biopsy material and tissue blocks stored for less than 5 years. While the diagnostic sensitivity of material containing only spems was higher using IHC, PCR detection was possible in IHC negative liver tissue and in patients with negative serology. Our results support the view that spems do not contain parasitic DNA or viable cells of the parasite. spems thus most probably do not directly contribute to metastasis formation during AE.

High endemicity of alveolar echinococcosis in Yili Prefecture, Xinjiang Autonomous Region, the People's Republic of China: Infection status in different ethnic communities and in small mammals

Alveolar echinococcosis (AE) is a life-threatening disease in humans caused by the larval stage of Echinococcus multilocularis. The tapeworm is transmitted between small mammals and dogs/foxes in the Northern Hemisphere. In this study 286 AE cases were reported from eight counties and one city in Yili Prefecture, Xinjiang Autonomous Region, the People's Republic of China from 1989 to 2015 with an annual incidence (AI) of 0.41/100,000. Among the patients, 73.08% were diagnosed in the last 11 years. Four counties in the high mountainous areas showed higher AI (0.51-1.22 cases/100,000 residents) than the four counties in low level areas (0.19-0.29/100,000 residents). The AI of AE in Mongolian (2.06/100,000 residents) and Kazak (0.93/100,000 residents) ethnic groups was higher than the incidence in other ethnic groups indicating sheep-farming is a risk for infection given this activity is mainly practiced by these two groups in the prefecture. A total of 1411 small mammals were captured with 9.14% infected with E. multilocularis metacestodes. Microtus obscurus was the dominant species in the mountain pasture areas with 15.01% of the voles infected, whereas Mus musculus and Apodemus sylvaticus were the dominant small mammals in the low altitude areas. Only 0.40% of A. sylvaticus were infected with E. multilocularis. PCR amplification and sequencing analysis of the mitochondrial cox1 gene showed that E. multilocularis DNA sequences from the small mammals were identical to isolates of local human AE cases. The overall results show that Yili Prefecture is a highly endemic area for AE and that the high-altitude pasture areas favorable for M. obscurus may play an important role in its transmission in this region.

Human Alveolar Echinococcosis, Croatia

Alveolar echinococcosis is a parasitic disease caused by the tapeworm larval stage of Echinococcus multilocularis. This zoonotic disease has not been known to occur in Croatia. We report a confirmed case of human alveolar echinococcosis in a patient in Croatia who had never visited a known E. multilocularis–endemic area.

The occurrence of Echinococcus spp. in golden jackal (Canis aureus) in southwestern Hungary: Should we need to rethink its expansion?

Alveolar echinococcosis and cystic echinococcosis are severe zoonotic diseases caused by Echinococcus multilocularis and Echinococcus granulosus s.l. in Europe. To present knowledge, in the European continent, the most important definitive hosts of these parasites belong to the Canidae family. The golden jackal as an opportunistic mesopredator frequently preys on rodents including arvicolids and other easily available food resources, such as viscera and other carrion. By these reasons, the golden jackal can promote the maintenance of both Echinococcus multilocularis and Echinococcus granulosus s.l. Our investigation was conducted in the southwestern part of Hungary where one of the densest golden jackal populations exists. We examined altogether 173 golden jackal small intestines to determine the presence of Echinococcus multilocularis and Echinococcus granulosus s.l. After the molecular diagnostic procedure, we found 27 Echinococcus multilocularis-positive (prevalence: 15.6%; mean intensity: 664 worms) and three Echinococcus granulosus s.l. infected hosts (prevalence: 1.7%; mean intensity: 554.3 worms). We suggest the invasion of the golden jackal in Europe can enhance the spread of both Echinococcus multilocularis and Echinococcus granulosus s.l. This novel epidemiological situation can influence the geographical distribution of these helminths and the characteristics of their endemic in different host species, as well as in humans.

Alveolar echinococcosis in a dog in the eastern United States

An 8-y-old Labrador Retriever was presented to a small animal practice in northern Virginia with a history of recent lethargy. Physical examination findings were unremarkable. Ultrasound revealed several large hepatic masses and multiple smaller masses involving the pancreas. Cytologic findings on fine-needle aspirates of the hepatic masses included inflammation and necrosis with eosinophilic, membranous oval structures consistent with cestode infection. Histopathologic findings for biopsies of these masses included extensive necrosis, inflammation, and PAS-positive hyaline-like membranous material interpreted as metacestode cyst wall. A PCR product was generated from aspirate material using primers specific for Echinococcus multilocularis. Subsequent sequence data were 100% homologous to E. multilocularis NADH dehydrogenase subunit I gene sequences. The dog received daily oral albendazole (10 mg/kg) treatment, but its condition deteriorated, and the dog was euthanized. The dog, born in Mississippi, was brought as a puppy to Virginia with no other travel history. To our knowledge, alveolar echinococcosis has not been reported previously in a dog in the United States; E. multilocularis infection was apparently acquired in the mid-Atlantic region of the United States.

Molecular characterization of human Echinococcus isolates and the first report of E. canadensis (G6/G7) and E. multilocularis from the Punjab Province of Pakistan using sequence analysis

BACKGROUND

Echinococcosis is a zoonotic parasitic disease causing serious health problems in both humans and animals in different endemic regions across the world. There are two different forms of human echinococcosis: Cystic Echinococcosis (CE) and Alveolar Echinococcosis (AE). CE is caused by the larval stage of Echinococcus granulosus sensu lato and AE by the larval stage of Echinococcus multilocularis. Geographically, CE is universally distributed, while AE is prevalent in the northern hemisphere. Although the disease is endemic in neighboring countries (China, Iran and India) of Pakistan, there are limited reports from that country. Besides, there are no comprehensive data on the genotyping of Echinococcus species in humans based on sequence analysis. This study aimed to detect the presence of human CE and to identify Echinococcus spp. in human isolates through genetic characterization of hydatid cysts in the Punjab Province of Pakistan.

METHODS

Genetic analysis was performed on 38 human hydatid cyst samples collected from patients with echinococcosis using mitochondrial cytochrome c oxidase subunit 1 (cox1), cytochrome b (cytb) and NADH subunit 1 (nad1). Patient data including age, epidemiological history, sex, and location were obtained from hospital records.

RESULTS

According to the sequence analysis we detected E. granulosus sensu stricto (n = 35), E. canadensis (G6/G7) (n = 2), and E. multilocularis (n = 1). Thus, the majority of the patients (92.1%, 35/38) were infected with E. granulosus s.s. This is the first molecular confirmation of E. canadensis (G6/G7) and E. multilocularis in human subjects from Pakistan.

CONCLUSIONS

These findings suggested that E. granulosus s.s. is the dominant species in humans in Pakistan. In addition, E. canadensis (G6/G7) and E. multilocularis are circulating in the country. Further studies are required to explore the genetic diversity in both humans and livestock.

Epidemiological characteristics of hepatic echinococcosis, concurrent cerebral echinococcosis, and pulmonary echinococcosis in Ganzi County, Sichuan Province, China

Human echinococcosis has become a major public health problem in most parts of the world. The objective of this article was to study the demographics of patients with hepatic echinococcosis in Ganzi County to elucidate the main risk factors, as well as to report the concurrent prevalence of cerebral echinococcosis and pulmonary echinococcosis.We recruited 195 patients with hepatic echinococcosis from the Datongma area of Ganzi County from January 2018 to November 2018. The patients' demographics, living environments, supported medical resources, knowledge of echinococcosis prevention and control, and hygienic practices were investigated and analyzed. The prevalence of cerebral echinococcosis and pulmonary echinococcosis were also investigated.The data were analyzed to identify risk factors for human echinococcosis. Our analysis showed that the herding Tibetan population within the 20 to 60 age group, and females, in particular, were at the highest risk of human echinococcosis infection. Having stray dogs around habitations and intimate activities with dogs and livestock were also behavioral risk factors. People with poor health literacy and low educational qualifications had possible risks of infection. In terms of hygiene, not using tap water as the drinking water source and lack of medical staff were significantly correlated with echinococcosis prevalence. Four patients were diagnosed with cerebral echinococcosis. Among them, 1 patient had both cerebral echinococcosis and pulmonary echinococcosis.Possible high-risk factors for echinococcosis were being female, herding population, in the 20 to 60 age group, having stray dogs around habitations, having activities with dogs and livestock, having poor health literacy, having low educational qualifications, and not using tap water as a drinking water source. The detection rate for brain echinococcosis in patients with hepatic echinococcosis was high (2.05%). Effective preventive strategies should be implemented in epidemic areas. Head CT scans should be applied for early detection of cerebral echinococcosis to carry out the treatment.

Echinococcus multilocularis: Diagnostic problem in a liver core biopsy

Echinococcus multilocularis causes an aggressive form of hydatidosis whose histomorphological picture is generally not well recognized. We report a case of 39-year-old women presenting with poorly circumscribed nodules in the right hepatic lobe. Owing to the clinical suspicion of focal nodular hyperplasia and hepatocellular adenoma, a core biopsy was performed. The histological findings of necrotic fibrous tissue infiltrated by narrow epithelial cords and small cysts containing cytokeratin positive material were in concordance with the diagnosis of cholangiocarcinoma. Subsequent examination of the surgically resected necrotic nodules with a vital tissue at the periphery corresponded to a reparative fibrosis accompanied by a striking ductular proliferation. Serological and molecular genetic work-up led to the diagnosis of Echinococcus multilocularis. The aim of this report is to point out the unusual histological features of the solid foci of alveolar hydatidosis, which consisted of necrotic fibrous tissue with ductular reaction. Such findings in a core biopsy may simulate regressively altered carcinoma.

Echinococcus multilocuraris -first recorded case of Norway rat (Rattus norvegicus) in Poland

INTRODUCTION

Echinococcus multilocularis is a very dangerous zoonotic parasite threatening human health. The red fox is the main definitive host, and cats and dogs less commonly. Rats can be intermediate hosts.

OBJECTIVE

The aim of the study was to determine the parasitofauna of Norway rats and some cats and dogs living on a farm near a forest.

MATERIAL AND METHODS

A parasitological section on 15 Norway rats was conducted. The internal organs were examined by means of macroscopic and microscopic methods. For molecular examination, a QIAmp DNA Mini Kit (Qiagen) was used.

RESULTS

Based on necropsy, parasitological and molecular examinations, of the 15 examined rats, 1 was found to have larvae of E. multilocularis, while 3 others had eggs of Hymenolepis diminuta, H. nana and Syphacia obvelata. The faeces of the pets did not contain any developmental forms of parasites.

CONCLUSIONS

This is the first case of Echinococcus multilocularis infestation in a rat in Poland.

A novel protocol to isolate, detect and differentiate taeniid eggs in leafy greens and berries using real-time PCR with melting curve analysis

BACKGROUND

Zoonotic taeniid cestodes are amongst the most important food-borne parasites affecting human health worldwide. Contamination of fresh produce with the eggs of Echinococcus granulosus (s.l.), Echinococcus multilocularis, and some Taenia species pose a potential food safety risk. However, very few studies have attempted to investigate the potential contamination of fresh produce with taeniid eggs and the available methods are not standardized for this purpose. Established protocols do exist for testing leafy greens and berries for contamination with protozoan parasites and are used in national surveillance programmes. This methodology could be suitable for the detection of taeniids. The objective of this project was to develop and standardize a sensitive and reliable method to detect contamination of leafy greens and berries with eggs of zoonotic taeniids and to differentiate between E. multilocularis, E. granulosus (s.l.) and Taenia spp.

METHODS

We compared the efficacy of different wash solutions to remove Taenia spp. eggs from spiked produce, assessed two DNA extraction kits for their performance on Taenia spp. eggs, and adapted a published conventional multiplex PCR into a real-time PCR with fluorescence melting curve analysis (MCA) that was optimized for use on produce washes. Analytical specificity of this protocol was assessed using non-spiked produce washes as well as a variety of other potentially contaminating parasites.

RESULTS

The protocol as established in this study had an analytical sensitivity of detecting five eggs per spiked sample for both romaine lettuce and strawberries. Unequivocal identification of E. multilocularis, E. granulosus (s.l.) and Taenia spp. was possible through MCA. Amplicon sequencing allowed identification of Taenia to the species level. The real-time PCR also amplified DNA from Dicrocoelium sp., but with a clearly discernable melting curve profile.

CONCLUSION

The new protocol for screening produce for taeniid contamination was highly sensitive. Melting curve analysis and the possibility of amplicon sequencing made this assay very specific. Once further validated, this method could be employed for surveillance of produce for contamination with taeniid parasites to assess potential risks for consumers.

A novel multiplex real-time PCR for the detection of Echinococcus multilocularis, Toxoplasma gondii, and Cyclospora cayetanensis on berries

Foodborne parasites (FBP) are of major public health importance and warrant appropriate detection and control strategies. Most of the FBP considered for risk-ranking by a panel of experts are potentially transmitted via consumption of contaminated fresh produce, including berries. In this study we focused on the potential of three FBP, namely Echinococcus multilocularis, Toxoplamsa gondii, and Cyclospora cayetanensis, as contaminants of berries. Surveys to assess these parasites as contaminants of fresh produce in general, and berries in particular, are scanty or non-existent mainly due to the lack of optimized laboratory methods for detection. The aim of the present study was to develop and evaluate a novel multiplex qPCR for the simultaneous detection of E. multilocularis, T. gondii, and C. cayetanensis from berry fruits. The efficiency and linearity of each channel in the multiplex qPCR were within the acceptable limits for the range of concentrations tested. Furthermore, the method was shown to have good repeatability (standard deviation ≤0.2 C_q) and intermediate precision (pooled standard deviation of 0.3-0.6 C_q). The limit of detection was estimated to 10 oocysts for Toxoplasma and Cyclospora, and 5 eggs for Echinococcus per 30 g of raspberries or blueberries. In conclusion, evaluation of the present method showed that the newly developed multiplex qPCR is highly specific, precise, and robust method that has potential for application in food-testing laboratories.

A multiplex PCR for differential detection of Echinococcus granulosus sensu stricto, Echinococcus multilocularis and Echinococcus canadensis in China

BACKGROUND

Echinococcosis caused by Echinococcus is one of the most major infectious diseases in north-west highland of China. E. granulosus sensu strict, E. multilocularis, and E. canadensis are known to be the only three species related to human health transmitting in the areas. To achieve targeted treatment and control of echinococcosis, the accurate identification and discrimination of the species are important. However, currently the available diagnostic approaches do not present ideal results either in accuracy or efficiency.

METHODS

In the study, a set of primers were designed to aim at the three human-pathogenic Echinococcus species in China. The one-step multiplex PCR assay was developed and evaluated for the specificity and sensitivity. A total of 73 parasitic lesions and 41 fecal materials obtained from human and various animals collected in the clinic and the field were tested to assess the applicability of this method.

RESULTS

The multiplex PCR effectively detected the individual DNA from the targeted species and their random mixtures generating with distinguishable expected size of products. The detection limit of the assay for each of the three species was 5 pg/μl when they were tested separately. When DNA mixtures of the targeted species containing the same concentration were used as templates, the lowest amount of DNA which can be detected was 50 pg/μl, 10 pg/μl and 5 pg/μl for E. granulosus s. s., E. multilocularis, and E. canadensis respectively. No cross-reactivity was observed when DNA from eight genetically close species was used as control templates. The multiplex PCR identifications of all samples were in line with the original sequencing results except for those infected with E. shiquicus, which showed negative signals in the developed assay. Of all the tested stool materials, 16 were previously found positive for Echinococcus by visual and microscopic examination. Among these 16 samples, 13 were confirmed by the multiplex PCR, and the other three tested negative. Additionally, the multiplex PCR identified another 14 positive feces from the remained 25 stool samples which absence of worms.

CONCLUSIONS

The developed multiplex PCR shows advantages in fast diagnosis and large-scale epidemiological investigation, which proven to be a promising tool utilized in clinic and surveillance system.

First report of Echinococcus multilocularis in cats in Poland: a monitoring study in cats and dogs from a rural area and animal shelter in a highly endemic region

BACKGROUND

Alveolar echinococcosis is a dangerous zoonotic disease caused by larval forms of Echinococcus multilocularis. In its life-cycle, the principal definitive host is the red fox; however, domesticated carnivorous animals (dogs and cats) can also act as definitive hosts. Until now, there were no data concerning this infection in cats in Poland. The aim of this study was to estimate the prevalence of E. multilocularis in cats and dogs originating from rural areas and animal shelters in a region characterised by a high prevalence of E. multilocularis in red foxes.

METHODS

Samples of faeces were collected from 67 cats and 268 dogs from a rural area (villages and animal shelters) of a highly endemic region in southeastern Poland. Samples were examined using nested PCR (E. multilocularis), multiplex PCR (E. multilocularis, Taenia spp.) and PCR [E. granulosus (s.l.)]. Additionally, faeces were examined microscopically (flotation). Moreover, intestines from 110 red foxes shot in the investigated area were examined (sedimentation and counting technique).

RESULTS

Positive PCR results for E. multilocularis were obtained in 4 cats (6.0%) and 4 dogs (1.5%). There were no significant differences between groups of animals (from a shelter and with an owner) concerning the prevalence of E. multilocularis in both cats and dogs. Taenia spp. were found in 10 cats (14.9%) (Taenia taeniaeformis and T. hydatigena) and 26 dogs (9.7%) (T. hydatigena, T. serialis, T. taeniaeformis, T. crassiceps, T. pisiformis and T. ovis) and Mesocestoides litteratus was found in 4 cats (6.0%) and 3 dogs (1.1%). All samples were negative for E. granulosus by PCR. Taking into consideration PCR and flotation results, 29 cats (43.3%) and 73 dogs (27.2%) were infected with helminths (26.9 and 11.9%, respectively, were infected with tapeworms). The highly endemic status of the investigated area was confirmed by examination of red foxes: 48.2% of examined red foxes were infected with E. multilocularis.

CONCLUSIONS

To the best of our knowledge, this study reports the presence of E. multilocularis in cats for the first time in Poland and confirms the role of dogs in this infection in highly endemic areas.

Survey of German pet owners quantifying endoparasitic infection risk and implications for deworming recommendations

BACKGROUND

Dogs and cats can transmit zoonotic helminths to humans, e.g. Toxocara spp. and Echinococcus multilocularis. Strategic deworming may help minimize this risk. Studies in several European countries have shown that pets are dewormed less frequently against roundworms and tapeworms than recommended by the European Scientific Counsel Companion Animal Parasites (ESCCAP). The objective of this study was to identify percentages of dogs and cats falling into the different risk categories defined by the German ESCCAP guidelines and to evaluate whether deworming frequency and parasite monitoring in Germany follows these guidelines.

RESULTS

According to questionnaire results from 500 dog and 500 cat owners, deworming of dogs in Germany averages 2.07 times/year while for cats this average is 1.72 times/year. In contrast, evaluation of risk factors placed only 2% (10/500) of dogs in ESCCAP category A with a recommended deworming/examination frequency of 1-2 times per year, while 4.8% (24/500) were placed in category B (4 treatments/examinations per year recommended), 30.8% (154/500) in category C (12 treatments/examinations per year against tapeworms and 4 treatments/examinations per year against roundworms recommended) and 62.4% (312/500) in category D (12 treatments/examinations per year recommended). All cats were placed either in risk group A [52.8% (264/500)] or D [47.2% (236/500)]. Generalized linear models indicated that risk group D cats were treated significantly more often against helminths than risk group A cats. There were no significant differences in deworming frequency between risk groups in dogs. The most important factor influencing deworming frequency was the frequency of veterinary visits. Dogs and cats were treated significantly more often if owners visited their veterinarian more than once yearly.

CONCLUSIONS

The percentage distribution of risk groups considerably varied between dogs and cats. Nevertheless, 62% of dogs and 47% of cats were assigned to category D for which monthly treatments/examinations are recommended by the ESCCAP guidelines. Veterinarians play a key role in instructing pet owners with regard to helminthoses and their prevention, and should take the time for adequate risk assessments. The reported low deworming frequencies despite the high potential parasite infection risk suggests that pet owner advice through veterinarians needs to be improved.

Alveolar echinococcosis in a dog; analysis of clinical and histological findings and molecular identification of Echinococcus multilocularis

Echinococcus multilocularis is a zoonotic tapeworm of medical and veterinary importance that occasionally infects accidental intermediate hosts causing severe disease or even death. In dogs, alveolar echinococcosis has been reported mainly in central Europe and Canada. The paper presents clinical, biochemical and histological signs of alveolar echinococcosis in a dog from Slovakia and the results of mitochondrial nad1 gene analysis. In 2016, 11-years old Siberian husky female suffering from inappetence was presented to the Veterinary Clinic in Žilina. Biochemical blood examination and blood count showed only minor changes, but abdominal ultrasonography showed the hepatomegaly and the presence of nonhomogeneous hypodense lobulated formation in the left liver lobe. Histological and molecular examinations of excided tissue confirmed the diagnosis of alveolar echinococcosis of the liver. BLAST analysis of E. multilocularis nad1 gene revealed that the nucleotide sequence did not exactly match the previously identified M1 (AJ237639) and/or M2 genotype (AJ237640). In total, two single nucleotide polymorphisms (SNPs) occurred within overlapping region of nad1 gene. In the discussion, clinical and laboratory findings of the infection in other dog patients are compared and the possibilities of diagnosis and therapy of the disease are discussed.

First identification of Echinococcus multilocularis in golden jackals in Croatia

Alveolar echinococcosis, caused by the tapeworm Echinococcus multilocularis, is one of the world's most dangerous zoonosis and an emerging disease with growing incidence in humans. The disease has been reported in new areas and host species in the last two decades, and the primary hosts of the parasite - red fox, golden jackal and grey wolf - are expanding their distribution in Europe. Here we report the morphological and molecular identification of Echinococcus multilocularis tapeworms in one of 29 carcasses of adult golden jackals in Croatia, where the only previous report of the parasite was in red foxes in 2016. These results suggest that alveolar echinococcosis should be treated as an emerging disease in Croatia.

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.

Detection of Echinococcus Multilocularis Infection in a Colony of Cynomolgus Monkeys (Macaca Fascicularis) using Serology and Ultrasonography

Five animals in a colony of cynomolgus monkeys ( Macaca fascicularis) died or were euthanatized because of alveolar echinococcosis, during a period of 5 years. The remainder of the colony was screened for possible infection with Echinococcus multilocularis, using serology and ultrasonography. A total of 46 animals out of a group of 55 were examined. The presence of anti-Em2 antibodies analyzed with enzyme-linked immunosorbent assay was demonstrated in 3 monkeys. In 2 of these 3 monkeys, multilocular structures compatible with metacestodal cysts in the liver were identified, using ultrasonography. The presence of alveolar echinococcosis was subsequently confirmed at postmortem examination in 1 animal. The other animals are still alive. Two other monkeys were negative in the serological examination but had cystic structures in the liver, which were identified as bile duct cysts at postmortem examination in 1 animal. The other monkey is still alive. These findings suggest that serology for antibodies against the Em2 antigen may represent a useful method in identifying animals that might be infected with E. multilocularis and are therefore at risk of developing fatal alveolar echinococcosis.

Surveillance and management of Echinococcus multilocularis in a wildlife park

The fox tapeworm Echinococcus multilocularis is the causative agent of alveolar echinococcosis, a severe zoonotic disease that may be fatal if untreated. A broad spectrum of mammalian species may be accidentally infected even in captivity. In April 2011, liver lesions due to E. multilocularis were observed during the necropsy of a captive-born nutria (Myocastor coypus) in a French wildlife park, leading to initiation of a study to survey the parasite's presence in the park. A comparable environmental contamination with fox's feces infected by E. multilocularis was reported inside (17.8%) and outside (20.6%) the park. E. multilocularis worms were found in the intestines of three of the five roaming foxes shot in the park. Coprological analyses of potential definitive hosts in captivity (fox, lynx, wildcat, genet, wolf, bear and raccoon) revealed infection in one Eurasian wolf. Voles trapped inside the park also had a high prevalence of 5.3%. After diagnosis of alveolar echinococcosis in a Lemur catta during necropsy, four other cases in L. catta were detected by a combination of ultrasound and serology. These animals were treated twice daily with albendazole. The systematic massive metacestode development and numerous protoscoleces in L. catta confirmed their particular sensitivity to E. multilocularis infection. The autochthonous origin of the infection in all the captive animals infected was genetically confirmed by EmsB microsatellite analysis. Preventive measures were implemented to avoid the presence of roaming foxes, contact with potential definitive hosts and contaminated food sources for potential intermediate hosts.

Alveolar echinococcosis in Europe and Poland. Threats to humans

The increasing number of detected cases of alveolar echinococcosis (AE) in recent years in Central-Eastern Europe strongly support the need of accurate diagnosis of the disease in patients and its differentiation from cystic echinococcosis. Accordingly to the EU notification requirements both parasitoses are reported jointly as echinococcosis, which makes it impossible to assess epidemiological situation of each disease. AE threat to humans is due to the environmental contamination with eggs of the tapeworm Echinococcus multilocularis excreted by infected foxes. Also contribution of dogs to the parasite transmission should be taken into account in endemic areas. The article presents current data on human cases of AE registered in humans in Europe and Poland, threats of this parasitosis to humans and results of studies on E. multilocularis infection in animals, the definitive hosts.

[Case report: Diagnosis under the microscope - disseminated echninococcosis, the multilocular form with protoscoleces]

Echinococcosis (hydatidosis) is a rare severe tissue parasitosis. In the Czech Republic it is caused by two species of tapeworm: Echinococcus granulosus or Echinococcus multilocularis. The species differ in both their usual hosts during their life cycle as well as in the typical form of lesions in infested tissues. In both cases the liver is the most common primary infested organ.We describe an autopsy case of a massive hepatic parasitic lesion in an 81 year-old man. There were metastatic parasitic cysts in both lungs and the hepatic mass spread per continuitatem in the right adrenal gland. The lesion was microscopically represented by small cystic forms with PAS positive laminar membranes and frequent occurrence of protoscoleces in the peripheral parts of the liver and the adrenal gland.The diagnosis of echinococcosis was settled after microscopic exploration of necroptic material. The overall appearance and pattern of spreading corresponded to alveolar echinococcosis, however the massive presence of protoscoleces in the liver is very rare for E. multilocularis. Protoscoleces are usually found in infections caused by E. granulosus. Cystic echinococcosis typically presents with one larger cyst or a small number of bigger cysts with prominent fibrous rim. Because of the unavailability of molecular diagnostic methods (PCR, immunohistochemistry), that are able to distinguish individual species of parasite, the case was closed according to the typical histological findings as disseminated alveolar echinococcosis with the rare appearance of protoscoleces with possible association with immunosuppressive therapy.We have found about ten other cases of alveolar echinococcosis published in last ten years in the Czech Republic. All these cases were diagnosed in living patients. It is assumed that most of these patients were infected in the vicinity of their homes.

Proposal of an ultrasonographic classification for hepatic alveolar echinococcosis: Echinococcosis multilocularis Ulm classification-ultrasound

AIM: To establish an ultrasonographic classification based on a large sample of patients with confirmed hepatic alveolar echinococcosis (AE).

METHODS: Clinical data and ultrasonography (US) findings of 185 patients (100 males; 85 females; mean age at diagnosis: 51.4 ± 17.6 years; mean age at time of US examination: 58.7 ± 18.2 years) were retrospectively reviewed with respect to the US morphology of hepatic AE lesions. The sonomorphological findings were grouped according to a five-part classification scheme.

RESULTS: Application of the new classification resulted in the following distribution of sonomorphological patterns among the patients examined: hailstorm (54.1%); pseudocystic (13.5%); ossification (13.0%); hemangioma-like (8.1%); and metastasis-like (6.5%). Only 4.9% of lesions could not be assigned to a sonomorphological pattern.

CONCLUSION: The sonomorphological classification proposed in the present study facilitates the diagnosis, interpretation and comparison of hepatic alveolar echinococcosis in routine practice and in the context of scientific studies.

A Newly Discovered Epidemic Area of Echinococcus multilocularis in West Gansu Province in China

Alveolar echinococcosis (AE) is a lethal parasitic disease. In Gansu Province of China, all AE cases reported in literature were from Zhang and Min Counties, the southern part of the province. Here, we report the discovery of nine AE cases and one cystic echinococcosis (CE) case from Nanfeng Town of Minle County, in the middle of Hexi Corridor in west Gansu Province. The diagnosis of these cases were confirmed by serology, histopathology, computed tomography, B-ultrasound, immunohistochemistry method, DNA polymerase chain reaction and sequencing analysis. Because eight of nine AE cases came from First Zhanglianzhuang (FZLZ) village, we conducted preliminary epidemiological analyses of 730 persons on domestic water, community and ecology such as 356 dogs’ faeces of FZLZ, in comparison with those of other five villages surrounding FZLZ. Our studies indicate that Nanfeng Town of Minle County is a newly discovered focus of AE in China as a CE and AE co-epidemic area. Further research of Echinococcus multilocularis transmission pattern in the area should be carried for prevention of this parasitic disease.

Occurrence and prevalence of selected zoonotic agents: Echinococcus multilocularis, Trichinella spiralis and hepatitis E virus (HEV) in the population of Polish hunters--results of the study conducted in 2010-2012

In Poland the development of the knowledge concerning zoonotic pathogens, of which free-living animals are the reservoir of is gaining in importance both in epidemiological aspect as well as in the context of prevention for improving public health. Dietary habits such as the consumption of forest undergrowth products and wild game meat, and the way of those products being prepared (in the process of barbequing) pose a risk factors of infection with the foodborne pathogens such as Echinococcus multilocularis, Trichinella spp., and HEV.

AIM

The aim of this study is to estimate the prevalence of infections caused by Trichinella spp., Echinococcus multilocularis, and HEV in the population of Polish hunters, describing their geographical distribution in Poland, and to try to define basic factors, which may contribute to their occurrence.

MATERIAL AND METHODS

In 2010-2012 a cross-sectional study was carried out among Polish hunters. A blood samples were collected as well as a survey of 1027 participants recruited in the 16 provinces was also carried out. Serological tests were performed for the presence of specific antibodies against Echinococcus multilocularis, Trichinella spp. and HEV using commercial or "in home" ELISA tests. In case of positive result for Echinococcus, an Em2plus ELISA or/and western blot test were carried out, and for positive results for IgM for HEV a recomLine HEV IgM test was carried out.

RESULTS

In the studied population a total number of 2 cases of Echinococcus multilocularis infection were found. Moreover in 47 (4,6%) participants presence of antibodies against Trichinella spp. were found, including 17 positive and 30 borderline results. In 206 persons (25%) IgG anti-HEV antibodies were found (by ELISA test). Geographical diversity in prevalence of both, the Trichinella spp. and HEV cases was observed.

SUMMARY AND CONCLUSIONS

The study confirmed presence of zoonotic infections such as Echinococcus multilocularis, Trichinella spp., and hepatitis E (HEV) among Polish hunters. In the case of Echinococcus multilocularis, and Trichinella spp., it appears that these infections are more common in the studied sample than in the general population. Additionally results on the prevalence of HEV infections indicate a need for further research on the occurrence of the virus in the country.

Molecular discrimination of Echinococcus granulosus and Echinococcus multilocularis by sequencing and a new PCR-RFLP method with the potential use for other Echinococcus species

BACKGROUND/AIM

To develop a novel polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) protocol using a new genomic marker sequence and a novel set of restriction enzymes in order to detect and discriminate 2 Echinococcus species, E. granulosus and E. multilocularis, found in formalin-fixed paraffin-embedded (FFPE) human tissues.

MATERIALS AND METHODS

DNA was isolated from 11 FFPE human tissue samples positive for cystic echinococcosis or alveolar echinococcosis. A mitochondrial genomic marker region was amplified and sequenced using a novel primer pair and a new PCR-RFLP protocol was developed for the detection and discrimination of E. granulosus and E. multilocularis using a set of restriction enzymes including AccI, MboI, MboII, and TsoI.

RESULTS

The selected marker region was amplified using DNA isolated from FFPE human tissue samples positive for cystic echinococcosis or alveolar echinococcosis and the discrimination of E. granulosus and E. multilocularis was accomplished by use of the novel PCR-RFLP method.

CONCLUSION

In this PCR-RFLP protocol, use of any single restriction enzyme is enough for the discrimination of E. granulosus and E. multilocularis. The PCR-RFLP protocol can be potentially used for the discrimination of 5 other Echinococcus species: E. oligarthus, E. shiquicus, E. ortleppi, E. canadensis, and E. vogeli.

[Liposarcoma in the lung misinterpreted as an infection of Echinococcus multicularis]

Primary liposarcoma of the lung is an extremely rare disease. Only 14 cases have been reported in the literature in English. Liposarcoma is not sensitive to chemotherapy or radiotherapy. Surgical resection is considered the only therapeutic option. We present a case of a giant liposarcoma occupying two thirds of the right thoracic cavity.

Alveolar echinococcosis in a highly endemic area of Northern Slovakia between 2000 and 2013

Long-term surveillance of Echinococcus multilocularis occurrence in red foxes in Slovakia revealed the existence of highly endemic areas, with an overall prevalence rate of 41.6 % in the northern part of the country. Between 2000 and 2013, 26 human cases of alveolar echinococcosis were detected and only three of them were not in endemic localities in northern Slovakia. Remarkable is the occurrence of the disease in eight people younger than 35 years, including three patients aged eight, 14 and 19 years. Occurrence of E. multilocularis in red foxes throughout the country and high incidence of alveolar echinococcosis in young people indicate high infectious pressure in the environment of northern Slovakia. It can be assumed that the real incidence of alveolar echinococcosis is significantly higher than recorded by official data due to the lack of existing registration and reporting system. For effective management of prevention and control strategies for this disease improvement of the national surveillance system and engagement of specialists outside the medical community are necessary. Our study presents a comprehensive picture of the epidemiological situation of E. multilocularis in northern Slovakia. In addition, we report the first list of confirmed human cases of this serious parasitosis in Slovakia.

An invasive vector of zoonotic disease sustained by anthropogenic resources: the raccoon dog in northern Europe

The raccoon dog (Nyctereutes procyonoides) is an introduced species in Europe with a continually expanding range. Since the species is capable of affecting local ecosystems and is a vector for a number of severe zoonotic diseases, it is important to understand its food habits. Raccoon dog diet was studied in Estonia by examining the contents of 223 stomach samples collected during the coldest period of the year, August to March, in 2010-2012. The most frequently consumed food categories were anthropogenic plants (e.g. cereals, fruits; FO = 56.1%) and carrion (e.g. carcasses of artiodactyls and carnivores; FO = 48.4%). Carrion was also the only food category that was consumed significantly more frequently by raccoon dogs exhibiting symptoms of sarcoptic mange than by uninfected animals. Small mammals, which represent intermediate hosts for the zoonotic tapeworm Echinococcus multilocularis, were more commonly recorded in samples also containing anthropogenic plants than expected by chance. Comparison of raccoon dog and red fox (Vulpes vulpes) diet in Estonia revealed higher overlap than found elsewhere in Europe, with 'carrion' and 'anthropogenic plants' making up the bulk of both species' diet; however, raccoon dogs were more omnivorous than red foxes. Our results suggest that while the use of most food categories reflects the phenology of natural food sources, 'anthropogenic plants' and 'carrion' provide an essential resource for raccoon dogs during the coldest period of the year, with the latter resource especially important for individuals infected with sarcoptic mange. Since both of these food categories and small mammals are often found at supplementary feeding sites for wild boar (Sus scrofa), this game management practice may facilitate high densities of mesocarnivores and promote the spread of some severe zoonotic diseases, including alveolar echinococcosis, trichinellosis, rabies and sarcoptic mange.

Dynamics of the force of infection: insights from Echinococcus multilocularis infection in foxes

Characterizing the force of infection (FOI) is an essential part of planning cost effective control strategies for zoonotic diseases. Echinococcus multilocularis is the causative agent of alveolar echinococcosis in humans, a serious disease with a high fatality rate and an increasing global spread. Red foxes are high prevalence hosts of E. multilocularis. Through a mathematical modelling approach, using field data collected from in and around the city of Zurich, Switzerland, we find compelling evidence that the FOI is periodic with highly variable amplitude, and, while this amplitude is similar across habitat types, the mean FOI differs markedly between urban and periurban habitats suggesting a considerable risk differential. The FOI, during an annual cycle, ranges from (0.1,0.8) insults (95% CI) in urban habitat in the summer to (9.4, 9.7) (95% CI) in periurban (rural) habitat in winter. Such large temporal and spatial variations in FOI suggest that control strategies are optimal when tailored to local FOI dynamics.

Human alveolar echinococcosis (AE) is caused by the fox tapeworm E. multilocularis and has a high fatality rate if untreated. The frequency of the tapeworm in foxes can be reduced through the regular distribution of anthelmintic baits and thus decrease the risk of zoonotic transmission. Here, we estimate the force of infection to foxes using a mathematical model and data from necropsied foxes. The results suggest that the frequency of anthelmintic baiting of foxes can be optimised to local variations in transmission that depend upon season and type of fox habitat.

[Lethal alveolar echinococcosis in a dog: clinical symptoms and pathology]

Epidemiological data indicate a progressing spread of the fox tapeworm in Germany. Here we report on a case of lethal alveolar echinococcosis in a dog from Brandenburg. The patient was clinically presented with abdominal distension. Ultrasonic examination revealed severe structural alterations of the liver and in a fine needle aspiration cytology larval tape worm fragments were suspected. Explorative laparotomy suggested inoperable lesions and the animal was euthanized with unfavorable prognosis. Pathology confirmed the diagnosis of hepatic echinococcosis. PCR analysis of the liver identified Echinococcus multilocularis, the so called "small fox tapeworm". The infection, reportable in Germany, is an important zoonotic disease that is transmitted by accidentally ingested tapeworm eggs shed by foxes or dogs. The prevalence between 7.6% and 16.7% in the fox population of Brandenburg is significantly lower than in the endemic regions of South and Southwest Germany, however, it is suspected to increase. This underlines the importance of a regional monitoring in domestic animals living in close contact to humans. In this regard, especially dogs should be taken into consideration as a potential definitive host and source of infection for people.

Alveolar echinococcosis in a Belgian urban dweller

Human alveolar echinococcosis is a rare parasitic disease caused by larvae of the tapeworm E. multilocularis that colonizes the intestines of foxes. The disease predominantly affects the liver and mimics slow growing liver cancer. With a mere 13 reports coming mostly from southern rural regions Belgium has so far been spared from the disease. However alveolar echinococcosis appears to be slowly spreading to non-endemic European countries like Belgium and to urban centres. We report the first autochthonous case involving a patient having lived exclusively in downtown Brussels. Heightened awareness by the medical community is necessary to detect this lethal disease at an early curable stage. In patients with an undetermined focal liver lesion--especially if calcified--and no firm evidence of malignancy, serological screening should be performed to exclude alveolar echinococcosis.

Alveolar echinococcosis-spreading disease challenging clinicians: A case report and literature review

Human alveolar echinococcosis (AE) is a potentially deadly disease; recent studies have shown that the endemic area of Echinococcus multilocularis, its causative agent, is larger than previously known. This disease has low prevalence and remains underreported in Europe. Emerging clinical data show that diagnostic difficulties are still common. We report on a 76-year old patient suffering from AE lesions restricted to the left lobe of the liver who underwent a curative extended left hemihepatectomy. Prior to the resection a liver biopsy under the suspicion of an atypical malignancy was performed. After the intervention he developed a pseudoaneurysm of the hepatic artery that was successfully coiled. Surprisingly, during surgery, the macroscopic appearance of the tumour revealed a growth pattern that was rather typical for cystic echinococcosis (CE), i.e., a gross tumour composed of multiple large vesicles with several centimeters in diameter. In addition, there were neither extensive adhesions nor infiltrations of the neighboring pancreas and diaphragm as was expected from previous imaging results. The unexpected diagnosis of AE was confirmed by definite histopathology, specific polymerase chain reaction and serology results. This is a rare case of unusual macroscopic presentation of AE that posed immense diagnostic challenges and had an eventful course. To our knowledge this is the first case of an autochthonous infection in this particular geographic area of Germany, the federal state of Saxony. This report may provide new hints for an expanding area of risk for AE and emphasizes the risk of complications in the scope of diagnostic procedures and the limitations of modern radiological imaging.

Molecular identification of Echinococcus multilocularis infection in small mammals from Northeast, Iran

BACKGROUND

Alveolar echinococcosis is a zoonotic disease caused by the metacestode of Echinococcus multilocularis. Many species of small mammals, including arvicolid rodents or Ochotona spp., are natural intermediate hosts of the cestode. The main aim of this study was to identify natural intermediate hosts of E. multilocularis in Chenaran County, Razavi Khorasan Province, northeastern Iran, where the prevalence of infected wild and domestic carnivores is high.

METHODOLOGY/PRINCIPAL FINDINGS

A program of trapping was carried out in five villages in which this cestode was reported in carnivores. The livers of 85 small mammals were investigated for the presence of E. multilocularis infection using multiplex PCR of mitochondrial genes. Infections were identified in 30 specimens: 23 Microtus transcaspicus, three Ochotona rufescens, two Mus musculus, one Crocidura gmelini, and one Apodemus witherbyi.

CONCLUSIONS/SIGNIFICANCE

A range of small mammals therefore act as natural intermediate hosts for the transmission of E. multilocularis in Chenaran County, and the prevalence suggested that E. multilocularis infection is endemic in this region. The existence of the life cycle of this potentially lethal cestode in the vicinity of human habitats provides a significant risk of human infection.

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

BACKGROUND

Human echinococcosis is a neglected zoonosis caused by parasites of the genus Echinococcus. The most frequent clinical forms of echinococcosis, cystic echinococcosis (CE) and alveolar echinococcosis (AE), are responsible for a substantial health and economic burden, particularly to low-income societies. Quantitative epidemiology can provide important information to improve the understanding of parasite transmission and hence is an important part of efforts to control this disease. The purpose of this review is to give an insight on factors associated with echinococcosis in animal hosts by summarising significant results reported from epidemiological studies identified through a systematic search.

METHODOLOGY AND PRINCIPAL FINDINGS

The systematic search was conducted mainly in electronic databases but a few additional records were obtained from other sources. Retrieved entries were examined in order to identify available peer-reviewed epidemiological studies that found significant risk factors for infection using associative statistical methods. One hundred studies met the eligibility criteria and were suitable for data extraction. Epidemiological factors associated with increased risk of E. granulosus infection in dogs included feeding with raw viscera, possibility of scavenging dead animals, lack of anthelmintic treatment and owners' poor health education and indicators of poverty. Key factors associated with E. granulosus infection in intermediate hosts were related to the hosts' age and the intensity of environmental contamination with parasite eggs. E. multilocularis transmission dynamics in animal hosts depended on the interaction of several ecological factors, such as hosts' population densities, host-prey interactions, landscape characteristics, climate conditions and human-related activities.

CONCLUSIONS/SIGNIFICANCE

Results derived from epidemiological studies provide a better understanding of the behavioural, biological and ecological factors involved in the transmission of this parasite and hence can aid in the design of more effective control strategies.

Human alveolar echinococcosis in Poland: 1990-2011

Background

Alveolar echinococcosis (AE) caused by Echinococcus multilocularis infections is a dangerous old disease in the Northern Hemisphere. The aim of the paper was to collect and analyze data on human AE in Poland in the last two decades.

Methodology/Principal Findings

The sources of data were both the cases officially registered and detected by an active field and laboratory surveillance. The cases were verified by clinical, epidemiological, and laboratory criteria. Altogether 121 human cases of AE were detected. Among these 83 (68,6%) cases were classified as confirmed, 16 as probable and 22 as possible. During the two decades a continuous increase in detection rate was noticed. The cases were 6–82 years old at the time of diagnosis (mean - 47.7 years). Sex ratio M/F was 0.86/1.0. The AE was fatal in 23 (19%) patients (mean age at death - 54.1 years). Family agglomeration of AE was found in 4 foci, involving 9 patients. Seventy six of the cases were diagnosed in an advanced stage of disease. In all cases the liver was the primary location of AE. In 30 (24.8%) patients a spread to other organs was observed. Ninety four of the patients were treated with albendazole. In 73 (60%) patients a surgical operation was performed, including 15 liver transplantations.

Conclusions/Significance

The studies confirmed that AE is an emerging disease in Poland, which is the fourth country in Europe with over 120 cases detected. The results also indicate the need of a wider national programme for implementation of screening in the highest AE risk areas (north-eastern Poland) with an effort to increase the public awareness of the possibility of contracting E. multilocularis, and above all, training of the primary care physicians in the recognition of the risk of AE to allow for an early detection of this dangerous disease.

Human alveolar echinococcosis (AE) is a consequence of accidental ingestion of the eggs of the tapeworm Echinococcus multilocularis. AE constitutes a serious and increasing medical and epidemiological problem in many countries including Poland. The natural environments with a high AE prevalence are the areas where the definitive hosts (foxes, raccoons) and the intermediate hosts (rodents) live. The increasing population of infected foxes that penetrate nearby the village and urban buildings and infected dogs poses a certain risk to human health. This report is a joint clinical and epidemiological analysis of 121 AE cases recorded in the years 1990–2011 in Poland. The highest percentage of E. multilocularis infected foxes in the north-eastern regions of Poland (about 40% of the examined population infected) bears a clear-cut relation to the highest incidence of detected AE human cases in those areas. An epidemiological and clinical survey of the local population conducted for over a dozen years has contributed to the discovery of several new AE cases. Alveolar echinococcosis in humans caused by Echinococcus multilocularis infection belongs to the emerging diseases in Poland where a continuous increase in the detection rate was noticed during the last two decades.

Alveolar echinococcosis in the Zoological Garden Basle

Alveolar echinococcosis (AE) is a rare, but potentially severe zoonotic disease caused by Echinococcus (E.) multilocularis. Recent findings indicated an increasing importance of AE for non-human primates living in regions endemic for E. multilocularis. The death of five cynomolgus monkeys (Macaca fascicularis) and a lowland gorilla (Gorilla g. gorilla) due to AE raised concern about the incidence of this parasite in the Basle Zoo. Consequently, a project was initiated to investigate the prevalence amongst an affected group of cynomolgus monkeys, as well as in foxes and mice. Three out of 46 monkeys were seropositive for E. multilocularis antigen. In two of these monkeys and in another three animals, which were seronegative, structures compatible with metacestodal cysts were observed using ultrasonography. Seven out of 35 free roaming foxes caught at the zoo were positive for an intestinal E. multilocularis copro-antigen ELISA, four of them shed taeniid eggs simultaneously. No lesions compatible with AE were present in 50 necropsied mice from the zoo area. These results indicate that the fox population is a potential source to introduce E. multilocularis and may thus represent a risk for the zoo animals.

Ein Fall von alveolärer Echinococcose beim Hund: Haustiere als seltene Fehlzwischenwirte von Echinococcus multilocularis

A 2-years old male Labrador retriever dog was presented with intermittent therapy-resistant diarrhoea, accompanied by vomiting, inappetence, apathy, and mild fever. The blood analysis showed an anaemia, neutrophilia, eosinophilia, and increased liver enzymes. Abdominal palpation was slightly painful. X-rays and echography revealed a severely enlarged liver with multiple cavernous structures. Histopathologic examination of liver biopsies showed a severe chronic granulomatous hepatitis with numerous parasitic cysts. Morphology of the cysts was compatible with the metacestode stage of Echinococcus multilocularis. The dog was only 2-years old at the time of diagnosis. Although alveolar hydatid disease of the liver is rare in dogs, it should be envisaged as a possible differential diagnosis in cases of space-occupying processes in the liver, even in young animals, as the incubation period of this disease in the dog can be considerably shorter than in humans.

A pilot study on developing mucosal vaccine against alveolar echinococcosis (AE) using recombinant tetraspanin 3: Vaccine efficacy and immunology

Background

We have previously evaluated the vaccine efficacies of seven tetraspanins of Echinococcus multilocularis (Em-TSP1–7) against alveolar echinococcosis (AE) by subcutaneous (s.c.) administration with Freund's adjuvant. Over 85% of liver cyst lesion number reductions (CLNR) were achieved by recombinant Em-TSP1 (rEm-TSP1) and -TSP3 (rEm-TSP3). However, to develop an efficient and safe human vaccine, the efficacy of TSP mucosal vaccines must be thoroughly evaluated.

Methodology/Principal Findings

rEm-TSP1 and -TSP3 along with nontoxic CpG ODN (CpG oligodeoxynucleotides) adjuvant were intranasally (i.n.) immunized to BALB/c mice and their vaccine efficacies were evaluated by counting liver CLNR (experiment I). 37.1% (p<0.05) and 62.1% (p<0.001) of CLNR were achieved by these two proteins, respectively. To study the protection-associated immune responses induced by rEm-TSP3 via different immunization routes (i.n. administration with CpG or s.c. immunization with Freund's adjuvant), the systemic and mucosal antibody responses were detected by ELISA (experiment II). S.c. and i.n. administration of rEm-TSP3 achieved 81.9% (p<0.001) and 62.8% (p<0.01) CLNR in the liver, respectively. Both the immunization routes evoked strong serum IgG, IgG1 and IgG2α responses; i.n. immunization induced significantly higher IgA responses in nasal cavity and intestine compared with s.c. immunization (p<0.001). Both immunization routes induced extremely strong liver IgA antibody responses (p<0.001). The Th1 and Th2 cell responses were assessed by examining the IgG1/IgG2α ratio at two and three weeks post-immunization. S.c. immunization resulted in a reduction in the IgG1/IgG2α ratio (Th1 tendency), whereas i.n. immunization caused a shift from Th1 to Th2. Moreover, immunohistochemistry showed that Em-TSP1 and -TSP3 were extensively located on the surface of E. multilocularis cysts, protoscoleces and adult worms with additional expression of Em-TSP3 in the inner part of protoscoleces and oncospheres.

Conclusions

Our study indicated that i.n. administration of rEm-TSP3 with CpG is able to induce both systemic and local immune responses and thus provides significant protection against AE.

Humans and rodents become infected with E. multilocularis by oral ingesting of the eggs, which then develop into cysts in the liver and progress an endless proliferation. Untreated AE has a fatality rate of >90% in humans. Tetraspanins have been identified in Schistosoma and showed potential as the prospective vaccine candidates. In our recent study, we first identified seven tetraspanins in E. multilocularis and evaluated their protective efficacies as vaccines against AE when subcutaneously administered to BALB/c mice. Mucosal immunization of protective proteins is able to induce strong local and systemic immune responses, which might play a crucial role in protecting humans against E. multilocularis infection via the intestine, blood and liver. We focused on Em-TSP3, which achieved significant vaccine efficacy via both s.c. and i.n. routes. The adjuvanticity of nontoxic CpG OND as i.n. vaccine adjuvant was evaluated. The widespread expression of Em-TSP3 in all the developmental stages of E. multilocularis, and the strong local and systemic immune responses evoked by i.n. administration of rEm-TSP3 with CpG OND adjuvant suggest that this study might open the way for developing efficient, nontoxic human mucosal vaccines against AE.

Detection of Echinococcus multilocularis in carnivores in Razavi Khorasan province, Iran using mitochondrial DNA

Background

Echinococcus multilocularis is the source of alveolar echinococcosis, a potentially fatal zoonotic disease. This investigation assessed the presence of E. multilocularis infection in definitive hosts in the Chenaran region of Razavi Khorasan Province, northeastern Iran.

Methodology/Principal Findings

Fecal samples from 77 domestic and stray dogs and 14 wild carnivores were examined using the flotation/sieving method followed by multiplex PCR of mitochondrial genes. The intestinal scraping technique (IST) and the sedimentation and counting technique (SCT) revealed adult Echinococcus in the intestines of five of 10 jackals and of the single wolf examined. Three jackals were infected only with E. multilocularis but two, and the wolf, were infected with both E. multilocularis and E. granulosus. Multiplex PCR revealed E. multilocularis, E. granulosus, and Taenia spp. in 19, 24, and 28 fecal samples, respectively. Echinococcus multilocularis infection was detected in the feces of all wild carnivores sampled including nine jackals, three foxes, one wolf, one hyena, and five dogs (6.5%). Echinococcus granulosus was found in the fecal samples of 16.9% of dogs, 66.7% of jackals, and all of the foxes, the wolf, and the hyena. The feces of 16 (21.8%) dogs, 7 of 9 (77.8%) jackals, and all three foxes, one wolf and one hyena were infected with Taenia spp.

Conclusions/Significance

The prevalence of E. multilocularis in wild carnivores of rural areas of the Chenaran region is high, indicating that the life cycle is being maintained in northeastern Iran with the red fox, jackal, wolf, hyena, and dog as definitive hosts.

Echinococcus multilocularis causes alveolar echinococcosis, a serious zoonotic disease present in many areas of the world. The parasite is maintained in nature through a life cycle in which adult worms in the intestine of carnivores transmit infection to small mammals, predominantly rodents, via eggs in the feces. Humans may accidentally ingest eggs of E. multilocularis through contact with the definitive host or by direct ingestion of contaminated water or foods, causing development of a multivesicular cyst in the viscera, especially liver and lung. We found adult E. multilocularis in the intestine and/or eggs in feces of all wild carnivores examined and in some stray and domestic dogs in villages of Chenaran region, northeastern Iran. The life cycle of E. multilocularis is being maintained in this area by wild carnivores, and the local population and visitors are at risk of infection with alveolar echinococcosis. Intensive health initiatives for control of the parasite and diagnosis of this potentially fatal disease in humans, in this area of Iran, are needed.

[Hair coat contamination with zoonotic helminth eggs of farm and pet dogs and foxes]

Infections of dogs with Toxocara canis and Echinococcus multilocularis pose an infection-risk particularly for contact persons. We examined specimens of hair coat and faeces of 124 farm dogs, 118 household dogs, 49 kennel dogs, 15 puppies from two litters, and 46 red foxes. Microscopically identified eggs of Toxocara or taeniids were further investigated by species-specific PCRs. In farm dogs, eggs of E. multilocularis or T. canis were identified in each 2.4% of faecal samples, eggs of T. cati (gastrointestinal passage) in 7.3%, respectively. Household dogs excreted eggs of T. canis (0.8%) and of T. cati (2.5%). In kennel dogs, eggs of T. canis (4.1%), but not of T. cati were detectable. Coat samples contaminated with eggs of Toxocara spp. were found from farm dogs (5.6%), household dogs (1.7%) and kennel dogs (2.0%). Taeniid eggs were isolated from the coat samples from only two farm dogs (1.6%); a molecular species determination was not achieved. In six intrauterinely infected puppies, Toxocara-eggs were found in 17/38 samples taken within six weeks. No intact Toxocara eggs could be isolated from the coat of nine puppies from a second litter 13 days after deworming. Of the 46 red foxes investigated (dissection and faecal samples) 13 (28.3%) were infected with E. multilocularis and 20 (43.5%) with Toxocara. Eggs of taeniids and Toxocara were found in 13% (in three cases confirmed as E. multilocularis) and 21.7%, respectively, of the coat samples. None of the retrieved Toxocara eggs in the coat samples were embryonated. Thus, an infection of humans through the transmission of E. multilocularis eggs after direct contact with dogs or foxes is conceivable, whereas a corresponding infection risk by Toxocara eggs must be critically challenged.

[X-ray irradiation against Echinococcus multilocularis protoscoleces in vitro]

OBJECTIVE

To explore the effect of X-ray irradiation on Echinococcus multilocularis protoscoleces in vitro.

METHODS

Echinococcus multilocularis protoscoleces were collected from cysts of infected Meriones meridianus and then cultured in RPMI 1640 medium. Protoscoleces were subpackaged into culture flasks at a density of about 10(4) per flask after culture for 3 days. Each group has 10 culture flasks. There were seven groups named as blank control group, low dose group (15 Gy and 30 Gy), medium dose group (45 Gy and 60 Gy), high dose group (75 Gy and 90 Gy), albendazole group (2 500 ng/ml), 45 Gy X-ray + 2 500 ng/ml albendazole group, and 75 Gy X-ray + 2 500 ng/ml albendazole group. Protoscoleces received three radiations on every other day with a source-skin distance of 100 cm and at a dose rate of 200 cGy/min after 3 days in culture. At each day after irradiation, protoscoleces were counted by light microscope with 0.1% eosin staining, and calculated mortality rate (per 100 protoscoleces) until all the parasites in experimental groups died. At the same time, the morphological changes of protoscoleces were observed.

RESULTS

There were significant differences in protoscolex mortality between X-ray groups and blank control group (P < 0.05), between X-ray + albendazole groups and albendazole group (P < 0.05). Protoscolex mortality in albendazole group were higher than that of blank control group (P < 0.05). Significant difference were also found in protoscolex mortality between albendazole combined with radiation and radiation only (P < 0.05). Before radiation, protoscoleces was normal with complete structure. After radiation, the parasites were mostly valgus type protoscoleces with disordered rostellar hooks and deformed acetabulum, and finally died.

CONCLUSION

X-ray can kill Echinococcus multilocularis protoscoleces in vitro.

First detection of Echinococcus multilocularis in Sweden, February to March 2011

Surveillance for the fox tapeworm, Echinococcus multilocularis, has been carried out in Sweden since 2000, with about 300 red foxes analysed annually. We report the first finding of E. multilocularis in Sweden, in a fox shot in December 2010 in the south-west of the country. A second infected fox shot in the same location was detected in March 2011. This paper describes the national monitoring programme and the ongoing work to estimate the prevalence and spread of the infection.