Echinococcus multilocularis in the red fox (Vulpes vulpes) in Slovenia

Exposure assessment of anticoagulant rodenticides in the liver of red foxes (Vulpes vulpes) in Slovenia

The study deals with the environmental residues of anticoagulant rodenticides (ARs) in Slovenia to evaluate the toxicological risk of secondary poisoning of red foxes (Vulpes vulpes) as representatives of non-target wildlife, and in relation to the investigated use patterns of ARs and specific local parameters in Slovenia. From 2019 to 2022, 148 liver tissue samples of adult red foxes were collected from almost all state geographical regions. The samples were extracted with methanol/water (2:1, v/v), cleaned-up using a solid supported liquid-liquid extraction, and measured by liquid chromatography-electrospray tandem mass spectrometry (LC-ESI-MS/MS) with reporting limits of 0.5 to 5.0 ng/g. Residues of at least one rodenticide were detected in 77.7 % of the samples. The second generation ARs of bromadiolone, brodifacoum and difenacoum were the most frequently found, appearing in 75.0, 51.4, and 18.9 % of the samples, respectively. Concentrations of pooled ARs ranged from 1.5 to 2866.5 ng/g with mean and median values of 601.4 and 350.2 ng/g, respectively. We determined bromadiolone and brodifacoum at concentrations of ≥800 ng/g in 10.8 and 10.1 % of the samples, and 1.4 and 0.7 % of the samples contained residues >2000 ng/g, respectively. These concentrations are much higher than those found in comparable studies in Europe and elsewhere in the world. Residues of ARs were detected in all monitored statistical regions of Slovenia, with higher concentrations in the eastern parts of the country. First generation ARs were found in only 9.5 % of samples, and residues were below 10 ng/g with one exception (coumatetralyl with 55 ng/g). The results of the study indicate a serious toxicological risk for red foxes in Slovenia as part of the Western Balkans, and will contribute to the growing body of knowledge about the protection of European ecosystems, as wildlife is not limited by national borders.

Emergence of Echinococcus multilocularis in Central Continental Croatia: A Human Case Series and Update on Prevalence in Foxes

Human alveolar echinococcosis (HAE), caused by the metacestode stage of Echinococcus multilocularis, has emerged in many European countries over the last two decades. Here, we report the first data on the new HAE focus with increasing incidence in central Croatia, describe its clinical presentation and outcomes in diagnosed patients, and provide an update on the prevalence and geographic distribution of Echinococcus multilocuaris in red foxes. After the initial case in 2017 from the eastern state border, from 2019 to 2022, five new autochthonous HAE cases were diagnosed, all concentrated in the Bjelovar-Bilogora County (the county incidence in 2019 and 2021: 0.98/10⁵, in 2022: 2.94/10⁵/year; prevalence for 2019-2022: 4.91/10⁵). The age range among four female and two male patients was 37-67 years. The patients' liver lesions varied in size from 3.1 to 15.5 cm (classification range: P2N0M0-P4N1M0), and one patient had dissemination to the lungs. While there were no fatalities, postoperative complications in one patient resulted in liver transplantation. In 2018, the overall prevalence of red foxes was 11.24% (28/249). A new focus on HAE has emerged in central continental Croatia, with the highest regional incidence in Europe. Screening projects among residents and the implementation of veterinary preventive measures following the One Health approach are warranted.

Wild Carnivore Survey of Echinococcus Species in Slovenia

Wild carnivores are definitive hosts and potential reservoirs for the tapeworm Echinococcus sp. which can cause cystic and alveolar echinococcosis. Both are considered neglected and important food-borne pandemics. This study is the first to molecularly test Slovenian wild carnivores for Echinococcus species that can cause disease in humans. Fecal samples from 210 red foxes (Vulpes vulpes), 42 wolves (Canis lupus), 39 golden jackals (Canis aureus), 18 martens (Marten sp.), 2 Eurasian lynx (Lynx lynx), 2 European badger (Meles meles), and 1 Eurasian otter (Lutra lutra) were examined for Echinococcus granulosus sensu lato (EGsl: E. granulosus sensu stricto, E. canadensis) and E. multilocularis (EM) using real-time PCR. Red foxes (29.1%) and golden jackals (18%) were positive for EM. All animals examined were negative for EGsl. Univariate analysis showed no significant differences in EM prevalence with respect to animal species (red fox vs., golden jackal) (p = 0.22), age (p = 0.12), and sex (p = 0.18). Prevalence of EM was associated with the region (p < 0.001), with regions in central and southern Slovenia having higher EM prevalence and risk of infection. Due to the increase in population and expansion of habitat, the golden jackal may soon become as important definitive host for EM as the red fox.

Alveolar echinococcosis in nutria (Myocastor coypus), invasive species in Slovenia

The present report describes a case of Echinococcus multilocularis infection in nutria (Myocastor coypus) culled in the central area of Slovenia. Post-mortem exam showed multiple cystic lesions in the liver. Gross examination, as well as parasitological and histopathological examinations, revealed numerous cysts of various sizes, filled with yellow clear fluid and displacing most of the liver parenchyma. The cyst lumina contained numerous protoscolices approximately 100 μm in diameter and calcareous corpuscles. The protoscolices had two visible suckers and a rostellum with birefringent hooks. The lesions were consistent with an E. multilocularis cyst. Molecular analysis confirmed that the nutria was infected with E. multilocularis. To our knowledge, this is the first report of echinococcosis in nutria in Slovenia that presents gross, parasitological, and histological lesions and the result of molecular analysis. Nutrias in Slovenia are dangerous invaders but can also be a relevant bioindicator of the presence of the parasite in the environment.

Morphological and molecular analyses of Taenia and Mesocestoides species from red foxes (Vulpes vulpes) in northwestern China

In this study, 263 tapeworms were collected from eight road-killed red foxes in Xinjiang Uygur Autonomous Region (XUAR, northwestern China). The tapeworms were analyzed based on morphological characters and mitochondrial cytochrome c oxidase subunit 1 (cox1) gene sequences. Eighty-three Taenia and 180 Mesocestoides tapeworms were identified according to the presence or absence of rostellum, and the number, the length and the shape of the large rostellar hooks. The morphological and molecular analyses revealed that i) 180 Mesocestoides tapeworms, here named as Mesocestoides sp. (Vulpes vulpes), showed 99.21% (378/381 bp) identity to Mesocestoides sp. reported from red fox in Mongolia; and ii) 83 Taenia tapeworms belonged to three species. The first Taenia species [n = 16, named as Taenia sp. (Vulpes vulpes)], based on the length of large rostellar hooks (337–342 μm) and its cox1 sequence, was identified as a potentially novel species, which is phylogenetically close to Taenia laticollis. The second species [n = 54, named as Taenia sp. (Vulpes vulpes & Rhombomys opimus)], was morphologically similar to Taenia endothoracicus according to the number (n = 52), the length (319–332 μm) and the shape of the large rostellar hooks. This species, infecting three red foxes, shared 100% cox1 sequence identity with Taenia sp. (Rhombomys opimus) genotype C found previously in great gerbils (Rhombomys opimus) in the same region. The third species (n = 13, named as Taenia polyacantha-like), had shorter large rostellar hooks (178–180 μm) and showed 96.27% (361/375 bp) sequence identity to Taenia polyacantha reported from red fox in Italy. The “great gerbil-red fox” life cycle of Taenia sp. (Vulpes vulpes & Rhombomys opimus), belonging to the mitochondrial lineage of T. endothoracicus, is confirmed. The T. polyacantha-like species was firstly found in red fox in China. Taenia sp. (Vulpes vulpes) is a potentially novel species, which is close to T. laticollis based on its phylogenetic properties.

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The life cycle of Taenia sp. (Vulpes vulpes & Rhombomys opimus) is confirmed.

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The Taenia polyacantha-like species was firstly found in China.

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Taenia sp. (Vulpes vulpes) is a potentially novel species in China.

First detection of Echinococcus multilocularis in Croatia

Echinococcus multilocularis has been spreading through Europe but has not yet been reported in Croatia. We report the results of a surveillance programme to detect E. multilocularis in red foxes (Vulpes vulpes) in different parts of Croatia. PCR-based screening of faecal samples from 238 red foxes in 2015 and 150 in 2016 indicate prevalences of 7.5% in 2015 and 6.6% in 2016 (overall 7.2%, CI 4.9 to 10.3). Positive samples were confirmed by sequencing parts of the nad1 gene and the gene encoding mitochondrial 12S rRNA. Geographic locations of all examined and positive cases were mapped to provide data on the distribution of E. multilocularis. Our results provide the first detection of E. multilocularis in Croatia and extend the southern boundary of this parasite's endemic area.

Global Distribution of Alveolar and Cystic Echinococcosis

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

The geographical distribution and prevalence of Echinococcus multilocularis in animals in the European Union and adjacent countries: a systematic review and meta-analysis

BACKGROUND

This study aimed to provide a systematic review on the geographical distribution of Echinococcus multilocularis in definitive and intermediate hosts in the European Union (EU) and adjacent countries (AC). The relative importance of the different host species in the life-cycle of this parasite was highlighted and gaps in our knowledge regarding these hosts were identified.

METHODS

Six databases were searched for primary research studies published from 1900 to 2015. From a total of 2,805 identified scientific papers, 244 publications were used for meta-analyses.

RESULTS

Studies in 21 countries reported the presence of E. multilocularis in red foxes, with the following pooled prevalence (PP): low (≤ 1 %; Denmark, Slovenia and Sweden); medium (> 1 % to < 10 %; Austria, Belgium, Croatia, Hungary, Italy, the Netherlands, Romania and the Ukraine); and high (> 10 %; Czech Republic, Estonia, France, Germany, Latvia, Lithuania, Poland, Slovakia, Liechtenstein and Switzerland). Studies from Finland, Ireland, the United Kingdom and Norway reported the absence of E. multilocularis in red foxes. However, E. multilocularis was detected in Arctic foxes from the Arctic Archipelago of Svalbard in Norway.

CONCLUSIONS

Raccoon dogs (PP 2.2 %), golden jackals (PP 4.7 %) and wolves (PP 1.4 %) showed a higher E. multilocularis PP than dogs (PP 0.3 %) and cats (PP 0.5 %). High E. multilocularis PP in raccoon dogs and golden jackals correlated with high PP in foxes. For intermediate hosts (IHs), muskrats (PP 4.2 %) and arvicolids (PP 6.0 %) showed similar E. multilocularis PP as sylvatic definitive hosts (DHs), excluding foxes. Nutrias (PP 1.0 %) and murids (PP 1.1 %) could play a role in the life-cycle of E. multilocularis in areas with medium to high PP in red foxes. In areas with low PP in foxes, no other DH was found infected with E. multilocularis. When fox E. multilocularis PP was >3 %, raccoon dogs and golden jackals could play a similar role as foxes. In areas with high E. multilocularis fox PP, the wolf emerged as a potentially important DH. Dogs and cats could be irrelevant in the life-cycle of the parasite in Europe, although dogs could be important for parasite introduction into non-endemic areas. Muskrats and arvicolids are important IHs. Swine, insectivores, murids and nutrias seem to play a minor or no role in the life-cycle of the parasite within the EU and ACs.

Stability of the southern European border of Echinococcus multilocularis in the Alps: evidence that Microtus arvalis is a limiting factor

The known range of the zoonotic fox tapeworm Echinococcus multilocularis has expanded since the 1990s, and today this parasite is recorded in higher abundances throughout large parts of Europe. This phenomenon is mostly attributed to the increasing European fox populations and their invasion of urban habitats. However, these factors alone are insufficient to explain the heterogeneous distribution of the parasite in Europe. Here, we analysed the spatial interrelationship of E. multilocularis with the known distribution of seven vole species in Ticino, southern Switzerland. Among 404 necropsied foxes (1990-2006) and 79 fox faecal samples (2010-2012), E. multilocularis was consistently found in the north of the investigated area. No expansion of this endemic focus was recorded during the 22 years of the study period. This stable endemic focus is coincident with the known distribution of the vole species Microtus arvalis but not, or only partly, with the distribution of the other autochthonous vole species. Our results give evidence that this vole species plays a crucial role in the maintenance of the parasite's life cycle and that its absence could be a limiting factor for the spread of E. multilocularis in this region.

Echinococcosis in wild carnivorous species: epidemiology, genotypic diversity, and implications for veterinary public health

Echinococcosis is a zoonosis caused by helminths of the genus Echinococcus. The infection, one of the 17 neglected tropical diseases listed by the World Health Organization, has a cosmopolitan distribution and can be transmitted through a variety of domestic, synanthropic, and sylvatic cycles. Wildlife has been increasingly regarded as a relevant source of infection to humans, as demonstrated by the fact that a significant proportion of human emerging infectious diseases have a wildlife origin. Based on available epidemiological and molecular evidence, of the nine Echinococcus species currently recognized as valid taxa, E. canadensis G8-G10, E. felidis, E. multilocularis, E. oligarthrus, E. shiquicus, and E. vogeli are primarily transmitted in the wild. E. canadensis G6-G7, E. equinus, E. granulosus s.s., and E. ortleppi are considered to be transmitted mainly through domestic cycles. We summarize here current knowledge on the global epidemiology, geographical distribution and genotype frequency of Echinococcus spp. in wild carnivorous species. Topics addressed include the significance of the wildlife/livestock/human interface, the sympatric occurrence of different Echinococcus species in a given epidemiological scenario, and the role of wildlife as natural reservoir of disease to human and domestic animal populations. We have also discussed the impact that human activity and intervention may cause in the transmission dynamics of echinococcosis, including the human population expansion an encroachment on shrinking natural habitats, the increasing urbanization of wildlife carnivorous species and the related establishment of synanthropic cycles of Echinococcus spp., the land use (e.g. deforestation and agricultural practices), and the unsupervised international trade and translocation of wildlife animals. Following the 'One Health' approach, we have also emphasized that successful veterinary public health interventions in the field of echinococcosis requires an holistic approach to integrate current knowledge on human medicine, veterinary medicine and environmental sciences.

Intestinal parasites of the red fox (Vulpes vulpes) in Slovenia

In the present study, 428 foxes were collected and examined for intestinal helminths using the washing-out method. Parasites were found in 93.2% of the examined animals. The most frequently identified nematodes were Uncinaria stenocephala (58.9%), Toxocara canis (38.3%) and Molineus patens (30.6%). Other nematodes found were Pterygodermatites affinis (4.2%), Capillaria sp. (2.8%), Crenosoma vulpis (2.8%), Toxascaris leonina (2.5%), Trichuris vulpis (0.7%) and Physaloptera sp. (0.2%). Mesocestoides sp. (27.6%) and Taenia crassiceps (22.2%) were the most prevalent cestodes, followed by T. polyacantha (6.5%), Hymenolepis nana (2.1%), T. pisiformis (2.1%) and Dipylidium caninum (1.4%). The study also revealed four trematode species: Rossicotrema donicum (1.6%), Heterophyes heterophyes (1.1%), Metagonimus yokogawai (1.1%), Prohemistomum appendiculatum (0.4%) and two protozoan species: oocysts of Sarcocystis (2.8%) and Isospora (0.4%). This is the first extensive study on the intestinal parasites of the red fox (Vulpes vulpes) in Slovenia. The 2.6% prevalence of Echinococcus multilocularis in the same sample population as investigated herein has been reported previously (Vergles Rataj et al., 2010).

The impact of globalisation on the distribution of Echinococcus multilocularis

In the past three decades, Echinococcus multilocularis, the cause of human alveolar echinococcosis, has been reported in several new countries both in definitive hosts (canids) as well as in people. Unless treated, infection with this cestode in people is fatal. In previously endemic countries throughout the Northern Hemisphere, geographic ranges and human and animal prevalence levels seem to be increasing. Anthropogenic influences, including increased globalisation of animals and animal products, and altered human/animal interfaces are thought to play a vital role in the global emergence of this pathogenic cestode. Molecular epidemiological techniques are a useful tool for detecting and tracing introductions, and differentiating these from range expansions.