Fascioloides Magna Research Articles

Endoparasites of Red Deer (Cervus elaphus L.) and Roe Deer (Capreolus capreolus L.) in Serbian Hunting Grounds.

In this study, parasitological examinations were conducted from 2019 to 2023. Fecal samples were collected from 289 wild ruminants (158 red deer and 131 roe deer) from hunting grounds in Vojvodina, which belong to the public company Vojvodinašume. Using qualitative and quantitative coprological diagnostic methods, the presence of protozoa (coccidia and Buxtonella sulcata), nematodes (gastrointestinal strongyles, Trichuris spp., Capillaria spp., Dictyocaulus spp., and Muellerius spp.), cestodes (Moniezia spp.), and trematodes (Fasciola hepatica, Fascioloides magna, Paramphistomum spp., and Dicrocoelium dendriticum) in the form of single and mixed infections were confirmed. Coproculture was used to identify the infective larvae of gastrointestinal strongyles. The total prevalence of endoparasitic infections in hunting ground 1 was 89.77% in red deer and 92.85% in roe deer, while in hunting ground 2, it was 72.97% in red deer and 85.96% in roe deer. Knowledge of the prevalence and assessment of the intensity of parasitic infections in wild ruminants is necessary for designing health protection programs in hunting grounds and planning control strategies, which are significant for this branch of hunting and public health.

A Comprehensive Multi-Omics Study of Serum Alterations in Red Deer Infected by the Liver Fluke Fascioloides magna

Liver fluke infections are acknowledged as diseases with global prevalence and significant implications for both veterinary and public health. The large American liver fluke, Fascioloides magna, is a significant non-native parasite introduced to Europe, threatening the survival of local wildlife populations. The aim of this study was to analyze differences in the serum proteome and metabolome between F. magna-infected and control red deer. Serum samples from red deer were collected immediately following regular hunting operations, including 10 samples with confirmed F. magna infection and 10 samples from healthy red deer. A proteomics analysis of the serum samples was performed using a tandem mass tag (TMT)-based quantitative approach, and a metabolomics analysis of the serum was performed using an untargeted mass spectrometry-based metabolomics approach. A knowledge-driven approach was applied to integrate omics data. Our findings demonstrated that infection with liver fluke was associated with changes in amino acid metabolism, energy metabolism, lipid metabolism, inflammatory host response, and related biochemical pathways. This study offers a comprehensive overview of the serum proteome and metabolome in response to F. magna infection in red deer, unveiling new potential targets for future research. The identification of proteins, metabolites, and related biological pathways enhances our understanding of host–parasite interactions and may improve current tools for more effective liver fluke control.

Bacillary hemoglobinuria in beef cattle infected with Fascioloides magna in Missouri.

Bacillary hemoglobinuria (BH) is an infectious disease, mostly affecting cattle, caused by Clostridium haemolyticum (C. novyi type D), with acute hepatic necrosis and intravascular hemolysis. Cattle are typically predisposed to BH by liver injury caused by Fasciola hepatica, although cases have been reported in cattle without evidence of this parasite. Here we describe a cluster of 14 BH cases from 7 counties in north-central to central Missouri submitted to a veterinary diagnostic laboratory between December 2020 and April 2023. Postmortem examination in all cases revealed hemoglobinuria and acute hepatic necrosis with large numbers of gram-positive bacilli with terminal-to-subterminal spores. Flukes, fluke ova, and/or fluke pigment consistent with Fascioloides magna were identified in 12 of 14 cases. Sequences of the nuclear ribosomal internal transcribed spacer 1 (ITS1) from one fluke had 100% identity to F. magna. C. novyi was detected by fluorescent antibody testing of liver impression smears (11 of 12 cases) and by immunohistochemistry of liver sections (7 of 7 cases). PCR on formalin-fixed, paraffin-embedded tissues amplified the C. haemolyticum beta toxin gene in each of the 7 cases tested. To our knowledge, a confirmed cluster of BH associated with F. magna has not been reported previously in cattle.

Identification and Molecular Characterization of Giant Liver Fluke (Fascioloides magna) Infection in European Fallow Deer (Dama dama) in Romania-First Report.

Fascioloidosis is a parasitic disease of primary wild and domestic ruminants, caused by giant liver fluke, Fascioloides magna. The definitive host of the liver fluke in its area of origin (North America) is the white-tailed deer (Odocoileus virginianus). In Europe, the red deer (Cervus elaphus) and European fallow deer (Dama dama) are definitive hosts and the most sensitive hosts to F. magna infection, on which the parasite exerts serious pathogenic effects. In this study, we analyzed fecal samples and livers of 72 D. dama from 11 hunting grounds in Arad County, Romania. Of the 72 fecal samples and livers from D. dama, trematodes of the genus Fascioloides were identified in four (5.56%). Sequencing revealed that the trematodes identified in the samples were similar to the sequence of F. magna (GenBank no. EF534992.1, DQ683545.1, KU232369.1). The sequence obtained from the molecular analysis has been deposited in GenBank® under accession number OQ689976.1. This study describes the first report of giant liver fluke (F. magna) infection in D. dama in Romania.

Development of a qPCR Duplex Assay for simultaneous detection of Fascioloides magna and Galba truncatula in eDNA samples: Monitoring beyond boundaries

Parasites constitute a significant economic burden and highly impact environmental, public, and animal health. The emergence of many parasitic diseases is environmentally mediated and they share the same biogeography with humans and both domestic and wild animals. American liver fluke, Fascioloides magna – a trematode parasite of domestic and wild ungulates – is an example of the anthropogenic introduction of an “invasive alien species” in Italy and Europe. Multiple introductions to Europe have led to the biogeographical expansion of the parasite across the Danube region mainly provided by the presence of suitable habitats for all hosts involved in the parasite's life cycle, human-assisted transport, and drastic environmental events such as flooding. In Italy, it was introduced and established in La Mandria Regional Park (LMRP) near Turin in 1865 along with imported wapitis (Cervus elaphus canadensis) from North America (Bassi, 1875), but with no reported expansion to the surrounding areas. LMRP isolated F. magna focus, poses an important threat of possible expansion since the enclosed area is vulnerable to occasional bidirectional passage of roe deer. Additionally, tributary rivers to the Po river system, traversing the enclosed area, could further bolster the possibility of such spread. In this study, we developed a duplex qPCR assay for F. magna and its principal intermediate host Galba truncatula optimized for testing eDNA samples to meet the needs for surveillance of the parasite. Moreover, we validated the developed assay in natura by testing samples derived from filtered water and sediments collected inside and outside LMRP's fenced-off area. Our findings for the first time demonstrate the presence of F. magna's eDNA outside the park's internal fenced-off area.

The Large American Liver Fluke (Fascioloides magna): A Survivor’s Journey through a Constantly Changing World

The large American liver fluke (Fascioloides magna) is considered an invasive trematode parasite in Europe. Its origin dates back before the Cretaceous-Paleogene Mass Extinction, after which it survived at least three population bottlenecks and successful host switches before it arrived in Europe. The authors review the evolutionary history of F. magna, the distribution by its ancient proboscidean hosts, and the probable drivers of the switch to the white-tailed deer (Odocoileus virginianus). The review collects knowledge on the biology of intermediate hosts, which helps understand the factors that influence the epidemiology of F. magna in aquatic ecosystems. The authors demonstrate the adaptation potential of the parasite using data from both North American and European endemics. Finally, the study calls attention to the epidemiological risk of human-induced global change, with a special interest in the invasive snail species Pseudosuccinea columella.

A proposed ectochory of Galba truncatula snails between wallow sites enhances transmission of Fascioloides magna at gemenc, in Hungary.

Each year temporary puddles are formed on compacted earth roads as a consequence of heavy rains and subsequent flooding in the large floodplain forests of the Danube River, Hungary, Central Europe, Hungary. After the receding of floodwaters, the muddy puddles persist from spring to mid-fall, where they are densely populated by Galba truncatula snails on an annual basis. These snails are the sole intermediate host of Fascioloides magna liver fluke of deer in the forest. According to field observations, G. truncatula is a very rare species on banks of river branches and lakes within the forest but always appears in large aggregations in these semi-natural potholes. Red deer (Cervus elaphus) leave their droppings in puddles while they wallow in the mud, therefore the snails encounter the miracidia of F. magna frequently. Snails are not able to dig themselves into the tamp soil of roads therefore they are destroyed by the wheels of vehicles which drive down the roads from autumn to the end of winter. Therefore, snails colonize these puddles regularly every spring. Since there is no connection between the distant puddles, it is supposed that deer and wild boars repeatedly introduce the snails into the puddles each year carrying snails with the help of mud, which is stuck on their fur while they wallow. This method of transport is supported by the fact that shell remnants of snails can be found on the bark of rubbing trunks situated nearby wallows. It seems that the sequential creation of wallow sites and the repeated introduction of G. truncatula enhance the likelihood for the trematode to infect both hosts.

Hatchability of Fascioloides magna Eggs in Cervids.

The giant liver fluke (Fascioloides magna) is an invasive parasite found permanently in three foci in Europe. The fluke has an indirect life cycle involving a final and an intermediate host. The currently accepted terminology determines three types of final hosts: definitive, dead-end, and aberrant hosts. Recently, roe deer (Capreolus capreolus) has been classified as an aberrant host, which cannot contribute to the reproduction of F. magna. This study investigated the hatchability of F. magna eggs of red deer (Cervus elaphus) and roe deer origin to compare the suitability of the two host species for the maintenance of the parasite. The study was carried out on a newly invaded area, two years after the first reported observation of F. magna. The prevalence of the parasite proved to be 68.4% (CI95% 44.6-85.3%) in red deer and 36.7% (CI95% 24.8-50.0%) in roe deer. The difference between the two species was confirmed to be significant (p = 0.02). The mean intensity proved to be 10.0 (CI95% 4.9-22.6) and 7.59 (CI95% 2.7-24.2) in the red deer and the roe deer, respectively. The difference of the mean intensities did not prove to be significant (p = 0.72). Of the 70 observed pseudocysts, 67 originated from red deer and 3 from roe deer. Most of the pseudocysts contained two flukes, while a few pseudocysts contained one or three parasites. Egg production was observed in all three types of pseudocysts. We did not find more than three flukes in any pseudocyst. The apparent proportion of self-fertilisation in flukes without mating partners was 23.5% and 100% in red deer and roe deer, respectively. The survival of single-parent eggs was not confirmed to be worse than that of gregarious parents. The viability of offspring originating from roe and red deer differed significantly. Our findings suggest that F. magna adapted to the new populations of susceptible hosts rather than vice versa.

Epidemiological tools to assess the spread of Fascioloides magna

The giant liver fluke (Fascioloides magna) has four continuously expanding focus endemics in Europe. The parasite is considered an invasive species in our continent and could affect the local host populations or, after host switching, it can infect other potential host species. Therefore it is important to track this alien species' presence. The authors compared the gold standard test with the effectiveness of two potential screening tests, the conventional sedimentation method and an illustrated guideline-based approach, which could be applicable in the field. The gold standard test was based on the necropsy detection of adult flukes in the liver tissue of hunted animals (N=319). Besides applying the linear regression, the sensitivity and specificity were determined in both approaches. The analysis showed that the shed egg number was moderately associated with the fluke burden (R2=0.5679; p<0.0001) and the flukes' dry mass (R2=0.6016; p<0.0001). The final results of sensitivity (100%; CI95%: 97.2 – 100) and specificity (96.3%; CI95%: 92.5 – 98.5) confirmed that the illustrated guideline-based approach is a capable method for monitoring the F. magna expansion in endemic areas.

Comparison of mitochondrial cox1 gene in Fascioloides magna from different host species

Large American liver fluke (Fascioloides magna) was introduced to Europe at least twice, via invaded North American deer species. These imports resulted in formation of three permanent foci of fascioloidosis - Italian, Czech and Danube floodplain forests. Molecular analysis revealed that flukes in Italian foci represent separate genetic group, and that flukes from Czech and Danube foci are genetically identical. Since previous studies of genetic structure of F. magna from Croatia were based on samples collected from red deer in one limited area (Baranja), the aim of this study was to analyse genetic diversity of 111 fluke samples collected from various hosts (red, roe and fallow deer, wild boar) and geographic locations in Croatia. On 355 base pair long cytochrome oxidase subunit 1 sequence, three haplotypes were identified - previously published CO1-Ha3 and CO1-Ha4, and one new haplotype named CO1-Ha36. Results obtained in our study confirmed as expected, that F. magna in Croatia has a Danube origin and that haplotypes are shared among different final host species.

Liver Proteome Alterations in Red Deer (Cervus elaphus) Infected by the Giant Liver Fluke Fascioloides magna.

Liver fluke infections are recognised as diseases with worldwide distribution and considerable veterinary and public health importance. The giant liver fluke, Fascioloides magna, is an important non-native parasite which has been introduced to Europe, posing a threat to the survival of local wildlife populations such as red deer (Cervus elaphus). The aim of the study was to analyse differences in liver proteomes between F. magna-infected and control red deer groups using a label-based high-throughput quantitative proteomics approach. The proteomics analysis identified 234 proteins with differential abundance between the control and infected groups. Our findings showed that F. magna infection in this definitive host is associated with changes in the metabolism of proteins and fatty acids, oxidative stress, fibrosis, and signaling pathways. The identified proteins and associated biological pathways represent a valuable contribution to the understanding of host-parasite interactions and the pathogenesis of liver fluke infection.

Molecular Cloning and Characterization of a Fasciola gigantica Nuclear Receptor Subfamily 1 (FgNR1).

Fasciola gigantica, a giant liver fluke, causes tremendous loss to the livestock economy in several regions throughout the world. The situation of drug resistance has been emerging increasingly; therefore, novel drugs and drug targets need to be discovered. The adult F. gigantica inhabits the major bile ducts where bile salts accumulate-these are steroid-like molecules that mediate several physiological processes in organisms through interacting with their specific nuclear receptors. However, the molecular mechanism of the interaction in the parasitic organisms have not been clearly understood. In this study, putative nuclear receptor subfamily 1 of F. gigantica (FgNR1) was identified. Nucleotide and amino acid sequences of the FgNR1 homolog were obtained from the transcriptome of F. gigantica and predicted for properties and functions using bioinformatics. The full-length cDNA was cloned and expressed in the bacterial expression system and then used for immunization. Western analysis and immunolocalization suggested that FgNR1 could be detected in the crude worm antigens and was highly expressed in the caeca and testes of the adult parasite. Moreover, the bile could significantly activate the expression of FgNR1 in cultured parasites. Our results indicated that FgNR1 has high potential for the development of a novel anthelminthic drug in the future.

Wild Boar (Sus scrofa)—Fascioloides magna Interaction from the Perspective of the MHC Genes

Fascioloidosis is a parasitic disease caused by a trematode Fascioloides magna. Since major histocompatibility complex (MHC) genes play an important role in the immune response, the aim of this study was to compare the potential differences in MHC class II SLA-DRB1 exon 2 genes between wild boar populations from infected (cases) and non-infected areas (controls). During the winter of 2021, a total of 136 wild boar tissue samples were collected, 39 cases and 97 controls. DNA was extracted and sequenced using the Illumina platform. Differences in distributions of allele combinations were calculated using the Chi-Square test for homogeneity and between proportions using the large-sample test and Fisher-Irwin test. Analysis revealed 19 previously described swine leucocyte antigen (SLA) alleles. The number of polymorphic sites was 79 (29.6%), with 99 mutations in total. Nucleotide diversity π was estimated at 0.11. Proportions of the alleles SLA-DRB1*12:05 (p = 0.0008379) and SLA-DRB1*0101 (p = 0.0002825) were statistically significantly higher in controls, and proportions of the SLA-DRB1*0602 (p = 0.006059) and SLA-DRB1*0901 (p = 0.0006601) in cases. Alleles SLA-DRB1*04:09, SLA-DRB1*0501, SLA-DRB1*11:09, and SLA-DRB1*1301 were detected only in cases, while SLA-DRB1*0404, SLA-DRB1*0701, SLA-DRB1*02:10, and SLA-DRB1*04:08 were present only in controls. We did not confirm the existence of specific alleles that could be linked to F. magna infection. Detected high variability of the MHC class II SLA-DRB1 exon 2 genes indicate high resistance potential against various pathogens.

Fascioloides magna and other liver parasites in cloven-hoofed game from northeastern Bavaria, Germany: occurrence and pathological findings with special emphasis on red deer (Cervus elaphus)

The first detection of Fascioloides (F.) magna in northeastern Bavaria in 2011 was presumably correlated to natural migration movements of free ranging wild ruminants originating from the neighboring Czech Republic, where high infection rates have been reported frequently. To gain more data on the continuing spreading and current occurrence of the giant liver fluke in surrounding regions, 700 livers of cloven-hoofed game originating from eleven different northeastern Bavarian counties were investigated for the presence of F. magna and accompanying liver parasites in the hunting season 2019–2020. Macroscopically altered liver tissue was further investigated by pathohistological and parasitological examination. F. magna was detected in 5.9% (38/640) of livers from red deer (0.7% < 1 year, 9.8% > 1 year; p < 0.05) whereas none of the investigated livers of wild boar, roe, and fallow deer was infected (n=60). Mild pathological alterations of the liver tissue were documented in 15, moderate in 14, and major in 9 of all F. magna-positive cases. Histologically, the fluke-specific pigment haematin, large trematode eggs, and periportal fibrosis were detected in the liver tissue of infected animals. In 9% of all investigated livers, parasitic stages of other parasites, i.e., Dicrocoelium dendriticum (6.0%), Fasciola hepatica (0.3%), Taenia spp. (1.7%), and Echinococcus multilocularis (1.0%), were found. According to the results of this study, F. magna is not restricted to formerly known affected regions of Upper Franconia, but is also present in the military training ground Grafenwöhr, Upper Palatinate, and the Bavarian Forest National Park, Lower Bavaria, with estimated prevalences of 3.6 and 16.4%, respectively, and thus seems to spread in suitable habitats in northeastern Bavaria.

The Occurrence of Fascioloides Magna (Bassi, 1875) in the Wild Cervid Population in the Lower Silesian Wilderness - Epidemiological and Pathological Aspects.

Fascioloides magna is a parasite of high veterinary importance due to its pathogenicity for wild and domestic ruminants. The aim of our study was to describe the presence of trematode infection in the red deer population in the Lower Silesian Wilderness, one of the established fascioloidosis foci in Central Europe, and to assess the overall prevalence of F. magna in the studied area. In order to achieve this, a coprological study of different cervid species was performed. The livers of 99 red deer were collected over three years and examined for the presence of trematodes. Prevalence and infection intensity was estimated and a histopathological analysis was performed. In addition, 172 faecal samples from red deer, fallow deer and roe deer were examined. By year, Fascioloides magna was isolated from the livers of 2/30 (6.7%), 9/34 (26.5%) and 10/35 (28.6%) red deer. Severe hepatic lesions, including massive tissue damage, extensive fibrosis, and cirrhotic changes in the liver parenchyma were observed. Faecal examination revealed the presence of F. magna eggs, with a prevalence of approximately 40%, 50% and 53% in roe deer, fallow deer and red deer, respectively. The eggs of F. magna may be commonly excreted in the faeces of roe deer, as well as those of red deer and fallow deer. The presence of F. magna throughout the cervid population in the Lower Silesian Wilderness favours the risk of the trematode's transmission to livestock or farmed deer.

FASCIOLOIDES MAGNA IN FREE-RANGING ROCKY MOUNTAIN BIGHORN SHEEP (OVIS CANADENSIS).

From February to May 2021, four nonmigratory rams from the Radium-Stoddart bighorn sheep (BHS; Ovis canadensis) herd in the Rocky Mountains of southeastern British Columbia, Canada, died from infection with the giant liver fluke, Fascioloides magna. Affected animals were emaciated, weak, and lethargic or were found dead. Gross lesions, histopathology, and parasite burdens were consistent with those reported in experimentally infected BHS, domestic sheep, and other aberrant hosts. Although BHS range does not typically overlap with fluke-contaminated aquatic habitats, the change in migratory behavior recently observed in some Radium-Stoddart rams may have exposed the affected animals to F. magna. We describe clinical signs and gross and histopathologic findings of hepatobiliary trematodiasis associated with F. magna in free-ranging BHS. From experimental data and our findings, giant liver fluke is pathogenic and is a threat to the conservation of the Radium-Stoddart BHS herd and other BHS herds in endemic F. magna regions.

Gross and histologic description of trematodosis in fetal and neonatal beef calves in North Dakota and Minnesota.

Hepatic trematodes, such as Fasciola hepatica and Fascioloides magna, have variable distribution throughout the United States. F. magna is endemic in the upper midwestern United States, and F. magna infections are diagnosed frequently in weaned calves and adult beef cattle at the North Dakota State University Veterinary Diagnostic Laboratory (NDSU-VDL). Rarely, liver fluke infestation has also been observed in much younger calves, including aborted fetuses. We describe here, in 2 fetal and 7 neonatal beef calves submitted to the NDSU-VDL between 2011 and 2020, parasitic migration tracts in livers, consisting of regionally extensive, random, linear tracts of fibrosis admixed with black porphyrin pigment, along with foci of necrosis and hemorrhage, and mixed inflammatory cells, which were caused presumptively by F. magna infection. Samples were not available from our 9 cases for PCR assay and sequencing, but we did confirm F. magna within liver samples collected from regional cattle in 2020 and 2021. Fetal and neonatal trematodosis was often concurrent with other common causes of fetal abortion and neonatal calf loss in our cases; however, based on the prepatent period of F. magna, fetal and neonatal beef calf trematode infestations occurred in utero.

Fascioloides magna

This datasheet on Fascioloides magna covers Identity, Distribution, Hosts/Species Affected, Further Information.

Sika Deer (Cervus nippon) are not "Dead-End Hosts" of the Giant Liver Fluke, Fascioloides magna (Bassi, 1875) Ward, 1917.

Fascioloides magna, although of North American origin, is well established in central Europe. Here it is expanding its geographic range and has been exposed to new potential final hosts including native and naturalized species. Based on their contribution to the propagation and transmission of F. magna, its final hosts have been grouped into three types including 'dead-end hosts' that comprise species in which flukes reach the liver but rarely mature and produce few eggs which are not excreted. Sika deer (Cervus nippon) were classified as dead-end hosts, this being quoted in the literature without robust substantiation. In an investigation on the occurrence of F. magna among sympatric wild ungulates in a recently established focus of the parasite in Germany, nine of 24 sika deer were found infected with up to seven F. magna in their livers, and six of the fluke-positive sika deer had Fascioloides eggs in their feces. Most flukes were recovered in pairs from fibrous capsules. Associated with the low fluke burden, gross pathology of the livers was generally mild. The presence of mature flukes in fibrous capsules, and passing of ova in the feces, demonstrates sika deer to be suitable definitive hosts of F. magna and to be of epidemiologic significance because of their implication in the transmission of the fluke.

Liver Fluke Infection Throughout Human Evolution.

The species of liver fluke that infect humans are zoonotic parasites that we share with other animals. The complex way in which humans have interacted with their environment, and the animals that live alongside them, has affected our ancestors' risk of infection by these helminths for millions of years. Here, we describe the range of flukes that can survive in the human liver and the health consequences that result from infection. Our focus is on Clonorchis sinensis (Chinese liver fluke), Fasciola hepatica (sheep liver fluke), F.gigantica (giant liver fluke), Opisthorchis viverrini (Southeast Asian liver fluke), O.felineus (cat liver fluke), and Dicrocoelium dendriticum (lancet liver fluke). We use our knowledge of where different kinds of liver flukes are endemic to estimate when and where human ancestors would have been exposed to infection over deep time. DNA evidence is used to investigate the evolutionary origins of the major species of liver flukes. The archaeological evidence for different species of fluke helps to show in which periods of human history they were most common. These flukes spread to humans from wild animals in early prehistory because of our ancestor's hunter-gatherer lifestyle and later from farm animals after the development of agriculture. We explore when and how some species have been able to spread across the world, whereas others are limited to particular geographic regions because of the endemic distribution of snail and vertebrate intermediate hosts. It is clear that human activity and migrations have played a key role in the expanding geographical range where we find liver flukes endemic today.