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 giant liver fluke, Fascioloides magna, common in North America and introduced into Europe in the 19th century, is an underappreciated model system for epidemiological studies on biological invasions, interactions with other native parasites and for health impact assessments within both definitive and intermediate snail host populations. Owing to its first contemporary appearance in Europe and then its subsequent spread, fascioloidosis has become a fluke-livestock/wildlife-snail combination of increasing interest for veterinarians, parasitologists and population geneticists. Here, we present a description of its recent epidemiology, biogeography and biology, inclusive of host species lists. Special emphasis is placed upon known definitive hosts of F. magna within Europe and considerations upon this fluke\'s local intermediate snail hosts. This helps us envisage plausible future epidemiological scenarios for further expansion across Europe, potentially even invasion into the UK. In line with others who draw attention upon needs for better systematic monitoring of putative risk-areas of fluke transmission, we close by highlighting why better surveillance of F. magna across continental Europe, and neighbouring territories, is justified.

Human induced translocation and introduction of species have reshaped parasite fauna on a global scale. The introduction of the large American liver fluke Fascioloides magna from North America to Europe is an example of an invasive alien parasite causing significant ecological and economic damage. Recent genetic studies have shown that F. magna was introduced to Europe on multiple occasions forming three permanent foci of infection. This study primarily focuses on the poorly researched genetic structuring of F. magna flukes originating from Croatia and Serbia. Additional samples from USA and Italy are also included, thereby providing novel insights into F. magna\'s biogeography. Partial cox1 and nad1 genes were amplified from 216 F. magna flukes extracted from red deer, roe deer, fallow deer, white-tailed deer and wild boar. Seven cox1 and nine nad1 haplotypes were identified, of which two cox1 and four nad1 haplotypes have not been not previously found. Our analysis has expanded the knowledge about possible sources of F. magna introduction to Europe, by identifying a cox1 haplotype shared by flukes from the north-eastern parts of the USA and Italy and another cox1 haplotype shared by flukes also from north eastern parts of the USA and the Danube floodplains.

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.

The foodborne intestinal trematode Fasciolopsis buski causes the neglected zoonotic disease fasciolopsiasis. We detected F. buski infection in 14 pediatric patients in Sitamarhi, Bihar, and in pigs in Sivasagar, Assam, India. Proper diagnostic methods and surveillance are urgently needed to accurately estimate the true burden of this disease in India.

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.

A 4-yr-old male intact lesser spot-nosed guenon (Cercopithecus petaurista), housed at a North American zoological facility, presented with acute lethargy, inappetence, and mild neurologic signs. Physical examination revealed hemorrhagic pleural effusion in the right hemithorax. This guenon\'s condition improved over several days but then deteriorated, and the guenon presented with lethargy and weakness. A hemorrhagic pleural effusion was identified within the left hemithorax. The guenon developed respiratory and cardiac arrest while anesthetized. Gross examination revealed tract formation in the liver, adhesions of the liver to the diaphragm, hemorrhagic thoracic and abdominal effusion, and a single trematode within the right hemithorax. Morphologic features and species identification by PCR confirmed that the parasite was Fascioloides magna. Histologic examination revealed tract formation in the liver associated with biliary hyperplasia, fibrosis and hepatic necrosis, severe bile peritonitis, and pleuritis. This is the first report of an infection by F. magna in a primate.

Pseudosuccinea columella is considered invasive and has become an important intermediate host of both Fasciola species in many regions of the world. This systematic review assessed the geographical distribution of P. columella, and its implications in the transmission of Fasciola hepatica and Fasciola gigantica, globally. A literature search was conducted on Google Scholar, JSTOR and PubMed databases using Boolean operators in combination with predetermined search terms for thematic analysis. Results show that P. columella has been documented in 22 countries from Europe (3), Africa (8), Oceania (2), North America (3) and South America (6). Furthermore, this snail species has shown to adapt to and inhabit a vast array of freshwater bodies including thermal lakes and ditches with acidic soils. Studies showed that P. columella transmits F. hepatica, with natural and experimental infections documented in sub-Saharan Africa, Europe, South America and North America. Experimental infection studies in Cuba showed the presence of P. columella populations resistant to F. hepatica infection. Furthermore, some populations of this invasive snail collected from F. hepatica endemic locations in Brazil, Venezuela, Australia, South Africa, Colombia and Argentina were found without Fasciola infection. As a result, the role played by this snail in the transmission of Fasciola spp. in these endemic areas is still uncertain. Therefore, further studies to detect natural infections are needed in regions/countries where the snail is deemed invasive to better understand the veterinary and public health importance of this snail species in Fasciola-endemic areas and determine the global dispersion of resistant populations of P. columella.

Liver fluke, Fascioloides magna, is an important non-native parasite introduced to Europe, posing a threat to survival of local wildlife populations. The aim of this study was to assess the serum and liver protein profile of control and F. magna infected wild boars, by means of shotgun tandem mass tag - based quantitative high resolution proteomics approach. In serum, 4 differentially abundant proteins were found out of total 1073 identified, while in liver from 3520 identified proteins, 116 were differentially abundant between healthy and F. magna infected wild boars. Pathway analysis revealed that most of the proteins differing in abundance are involved in metabolism, biological oxidations, cellular responses to stimuli, fatty acid metabolism, and others. Validation of proteomic results was performed for paraoxonase-1, ceruloplasmin, glutathione S-transferase and liver enzymes by ELISA and automated assays. Complementary analysis of liver and serum in F. magna infection enabled insight into changes of proteome profile of the host at local and sistemic level. Our findings showed that chronic infection with F. magna is associated with immune response in host, oxidative stress and metabolomic changes in liver. SIGNIFICANCE: Liver fluke infections are recognised as worldwide neglected diseases with considerable veterinary and public health importance. Pathological changes, clinical signs and outcome of F. magna infection are strongly related to the type of final hosts and their different tolerance to infection. In order to gain insight into host-parasite interactions in wild boars, dead-end host for F. magna, we assessed proteomics profile of serum and liver of control animals and those infected with F. magna. Proteomics analysis of serum and liver in parallel showed as advantageous and beneficial, demonstrating protein alterations mainly at local level. Bioinformatics analysis enabled elucidation of molecular pathways associated with F. magna infection. Identification and validation of proteins associated with infection may have added value to current tools for efficient liver fluke control.

Associated with the spreading in (north)western direction of Fascioloides magna from its historic endemic area in Bohemia with its cervid hosts, unusual noticeable hepatic lesions (black-colored tissue, hemorrhage) were observed in deer harvested in hunting grounds and one deer farm located in the Upper Palatinate Forest close to the border to the Czech Republic, initially in the years of 2007 and 2009, respectively. Confirmation of the suspected diagnosis of F. magna infection in October 2011 prompted investigations on the occurrence of \"fascioloidosis\" among wild ungulates in that locality. From October 2011 to January 2014, livers from 89 cervids and two wild boars were examined for flukes. Thirty-seven livers (40.6%) harbored F. magna: 17 of 21 red deer, nine of 24 sika deer, six of eight fallow deer, four of 36 roe deer, one of two wild boars. Fluke burdens ranged from 2 up to 151 in red deer, from 2 up to 37 in fallow deer, and from 1 up to 7 in sika deer and in roe deer; one fluke was recovered from the liver of one wild boar. No other parasites were recovered from the livers. The rate of recovery of F. magna differed significantly (p < 0.001) among the species of deer (red deer, 81.0%; sika deer, 37.5%; fallow deer, 75.0%; roe deer, 11.1%) and between the age groups (< 1 year: 22.2%, 1 to 2 years: 26.0%, and > 2 years: 70.0%, respectively). There was no association (p > 0.1) between the rate of recovery of F. magna and the sex of the combined 80 deer of ≥ 1 year of age (male: 41.8% and female: 31.4%). The occurrence of F. magna in the wild ungulates in the Upper Palatinate Forest area in northeastern Bavaria is of epidemiological importance for the further spreading of the parasite into Germany with migrating deer.