Fascioliasis and other plant-borne trematode zoonoses

Meta-analysis and systematic review of the prevalence and risk factors of animal fascioliasis in Eastern and Southern Africa between 2000 and 2023

Fascioliasis is a zoonotic disease of public health and economic importance. It is caused by trematodes species Fasciola hepatica, and Fasciola gigantica. The parasites infest the liver particularly the bile ducts, and cause harm to the host. The economic loss to both dairy and meat industry is attributed to emaciation, reduction in milk production, death, infertility, and losses to liver condemnation. However, fascioliasis remains poorly studied and limited data is available to guide appropriate interventions especially in low- and middle-income countries. This paper aimed to review the prevalence and risk factors of animal fascioliasis in Eastern and Southern Africa between 2000 and 2023. Globally recognized databases including Science Direct, PubMed and Google scholar were used to search the related studies on fascioliasis conducted between 2000 and 2023 in accordance with PRISMA guidelines. A review of papers was done for risk factors of fascioliasis, and data was extracted. A total of 106 articles met the inclusion criteria, data was extracted, analyzed using meta package in R software (version 4.21), and presented both quantitatively and qualitatively. Forest plots at a 95 % confidence interval were generated to show the prevalence estimate of different subgroups and Cochran's Q statistic was used to measure the level of heterogeneity between studies. The prevalence estimates for different animal species in Eastern and Southern Africa were 47.5 % (95 % CI: 38.0-57.2 %) in mules, 23.3 % (95 % CI: 17.0-31.1 %) in sheep, 23.4 % (95 % CI: 19.2-28.2 %) in cattle, 23.2 % (95 % CI: 19.3-27.6 %) in donkeys, 12.2 % (95 % CI: 9.9-14.8 %) in horses, and 7.9 % (95 % CI: 5.4-11.5 %) in goats. These findings clearly demonstrate the high prevalence of fascioliasis in animals in Eastern and Southern Africa. We therefore recommend enhanced awareness and promotion of effective prevention measures for the Fasciola infection control to maximize benefits from livestock production.

Infection rates of Fasciola spp. in cattle slaughtered at 13 abattoirs in six of nine provinces of South Africa

Fasciolosis or liver fluke infection is a snail-borne disease that affects the productivity of domestic ruminants including liver condemnation especially in cattle. However, there is paucity of information on the burden of infection due to lack of accurate data on liver condemnation related to correct geographical origin of infected animals. This distorts perception of the geographical occurrence of fasciolosis, particularly in South Africa among other countries. We aimed to determine the infection rates of Fasciola spp. in cattle slaughtered at selected abattoirs in South Africa. A total of 13 abattoirs consisting of 10 high throughput and three low throughput abattoirs across six provinces, were visited to screen for liver fluke infection in slaughtered cattle including tracing of the animals' geographical origin. A total of 57 livers from 673 slaughtered cattle (8.5 %) from 10 abattoirs were infected with Fasciola spp.. The highest infection rate from the study sites was 37 % and the lowest 4.5 %. Tracing of infected cattle showed that some abattoirs slaughtered cattle originating from other provinces. Forty-nine percent (29/57) of infected cattle had moderate body condition score (BCS) and recorded the highest intensity of fluke infection (>100 flukes per liver). Furthermore, young animals had high infection rates (51 %; 29/57) compared to adults (49 %; 28/57) and females (54 %; 31/57) compared to males (46 %; 26/57). The overall results highlighted the presence of Fasciola spp. in five provinces of South Africa, represented by more than four agro-ecological zones. Fasciola hepatica occurred in all six provinces while both Fasciola spp. co-occurred in one province. Furthermore, F. hepatica constituted the highest percentage (74 %; 710/960) of Fasciola spp. specimens collected. Fasciola gigantica were collected from abattoirs in one province and constituted 26 % (250/960) of the total collected flukes. Results from the study provide information on the burden of fasciolosis in cattle. This is based on abattoir surveys in South Africa, considering the traced geographical origin of animals slaughtered. Using data from surveys of this nature might support efforts to map the geographical distribution of fasciolosis in South Africa. Thus, contribute towards the development of effective control and treatment programs of fasciolosis to mitigate the burden of the disease in cattle.

Proteome-wide identification and comprehensive profiling of intrinsic disorder in Fasciola gigantica

Despite the wealth of proteome sequences from multicellular parasitic helminths, studies on intrinsically disordered proteins (IDPs) in these organisms remain limited, particularly compared to viruses, bacteria, and unicellular parasites. We provide a comprehensive analysis of intrinsic disorder within the proteome of Fasciola gigantica, a parasitic liver fluke, using multiple predictive tools. Out of 12,537 proteins analyzed, a significant portion exhibited a distinct amino acid composition, characterized by an enrichment of polar and charged residues and a relative depletion of hydrophobic and aromatic residues, which are hallmarks of IDPs. These compositional features likely confer structural flexibility and functional adaptability, facilitating the survival of the parasite in diverse and hostile environments within its host. The presence of IDPs was further supported by compositional profiling of experimentally validated proteins in the DisProt database. Approximately 34.15 % of the F. gigantica proteome comprises highly disordered proteins, while 59.27 % is moderately disordered, as calculated from six well-established predictors integrated under the RIDAO platform. The consistent findings across various predictors, including PONDR® and IUPred, underscore the reliability of these results. Additionally, a detailed analysis of the distribution of charged residues in the proteome was performed. The high prevalence of IDPs in F. gigantica suggests their critical role in host-pathogen interactions, potentially providing functional advantages such as binding promiscuity and adaptability, which are essential for the survival of the parasite within the host. This study highlights the importance of IDPs in the biology of F. gigantica and provides insights into their potential roles in the parasite's pathogenesis and interactions with the host immune system.

Comprehensive mitochondrial genomics of Fasciola gigantica from Sudan: insights into genetic diversity, evolutionary dynamics, and host adaptation

Introduction

This study presents a comprehensive analysis of the complete mitochondrial genomes of Fasciola gigantica isolated from cattle, sheep, and goats in Sudan, aiming to provide new insights into genetic diversity, evolutionary dynamics, and host adaptation.

Methods

Mitochondrial genomes were sequenced using high-throughput Illumina MiSeq technology, yielding sequences of 14,483 bp, slightly longer than the reference genome (14,478 bp). A sliding window analysis was conducted to assess nucleotide diversity, and phylogenetic analyses were performed using complete mitochondrial sequences, including and excluding non-coding regions.

Results

Key genetic variations were observed, including a non-canonical start codon (GTG) in the ND5 gene and an alternative stop codon (TAA) in ND4. Length polymorphisms in ND4L and cox1 suggested potential mitochondrial efficiency adaptations. Non-coding regions showed minor length differences, with the long non-coding region extending by 20 bp and the short by 4 bp. Sliding window analysis identified ND4 and ND5 as the most variable genes, while cox1, nd1, and cox2 were the most conserved. Phylogenetic analysis showed distinct clustering of Sudanese F. gigantica isolates with strong bootstrap support. Excluding the D-loop preserved phylogenetic structure, while D-loop-specific analysis revealed high variability, particularly in the sheep isolate.

Discussion

These findings highlight significant genetic variation and evolutionary divergence among F. gigantica isolates in Sudan. The observed diversity, particularly within non-coding and variable coding regions, underscores the influence of regional evolutionary pressures and host-associated adaptations. This work enhances understanding of F. gigantica's genetic landscape and supports the development of more targeted molecular surveillance and control strategies for fascioliasis in endemic regions.

Prevalence and associated risk factors of bovine Schistosoma and Fasciola infections among cattle in South Achefer District, North West Ethiopia

Bovine schistosomiasis and fasciolosis, caused by flatworms from different species of Schistosoma and Fasciola, continue to be significant animal health concerns in cattle farming in developing countries like Ethiopia. However, not enough epidemiological information is available in most parts of Ethiopia in this respect. Therefore, the present study aimed to determine the magnitude of these two important zoonotic diseases and the associated risk factors in south Achefer district, northwest Ethiopia. A cross-sectional study was carried out in June and August of 2020. The research cattle, which belonged to farmers in three selected localities, were chosen by a simple random sampling method. Freshly collected faecal samples were subjected to a parasitological test using the sedimentation technique to identify eggs of Schistosoma and Fasciola. We used Pearson's chi-square (χ2) test to ascertain the degree of variation between the proportions of disease occurrence. Logistic regression analyses were performed for the risk factor analysis. The overall prevalence of Schistosoma bovis and Fasciola hepatica was 9.6 % (37/384) and 54.2 % (208/384), respectively. Cross-bred cattle had around twice the odds of contracting Fasciola hepatica than local cattle (adjusted odds ratio, AOR: 1.87, 95 % CI: 1.02-3.43). The prevalence of Fasciola hepatica was more than seven times higher in younger cattle than in older cattle (AOR: 7.31, 95 % CI: 3.54-15.08). Comparatively to cattle in good physical health, those in poor physical condition were shown to contract Fasciola hepatica more than four times (AOR: 4.85, 95 % CI: 1.94-12.14). This study indicated that bovine Schistosoma and Fasciola infections remain among the major cattle health problems in the study area. Therefore, appropriate intervention methods should be implemented for effective zoonotic disease control in the study area.

Neglected Tropical Diseases and Female Infertility: Possible Pathophysiological Mechanisms

Battling female infertility has posed a global challenge, where neglected tropical diseases (NTDs) are nonetheless a notable contributing factor. NTDs affect a variety of diseases, often of a chronic nature, which are often cited as some of the most lethal diseases operating against the most economically disadvantaged populations across the globe. The various causative agents for NTDs have been documented and could originate from a myriad of sources-from bacteria, fungi and viruses to ecto- and endoparasitic species-including but not limited to helminths and protozoa. This paper will seek to describe how NTDs influence female reproductive health, together with likely mediators. While these diseases have curable forms, their effects have gone well beyond female infertility, to major pain, disability and even mortality, particularly in poorer countries, thus causing economic hardship, reduced productivity and a pool of social stigma. NTDs adversely affect female reproductive functions through multiple mechanisms, including ROS-sensitive signalling, depression of steroidogenic markers and promotion of apoptosis. The effects also may reflect their influence on ovarian histomorphology, consequently resulting in female infertility. Current-directed studies, however, suggest a potential benefit in combining drugs for the most common NTDs as a deterrent to possible female infertility endowed by NTD infection. Nonetheless, further clinical investigations will be instrumental in elucidating the probable preventive value of combination drugs as adjuvant therapy to NTDs infections. This will provide comprehensive insight into the pathophysiological and molecular basis for the impairment of female fertility brought about by NTDs, leading to the development of preventive models to curb the adverse effects of NTDs on female reproductive health. Therefore, attention should be given to providing the right, timely and effective mode of treatment for NTDs-related female infertility.

Factors contributing to the abundance and spatial distribution of the invasive intermediate host snail (Pseudosuccinea columella) in uMgungundlovu district, KwaZulu-Natal, South Africa

Fascioliasis is a parasitic disease commonly affecting cattle, goats, and sheep globally. Lymnaeidae snail species are important in the epidemiology and dispersal of fascioliasis since they are intermediate hosts of the Fasciola spp. Our study mapped at micro-geographical scale, the distribution and abundance of Pseudosuccinea columella in uMgungundlovu district, which is in the northern part of the KwaZulu-Natal province, and measured physicochemical parameters at potential transmission sites. The study examined the impact of physicochemical parameters and presence of other snail species on P.columella abundance and distribution in KwaZulu-Natal's uMgungundlovu district. Data were analyzed using R studio, a negative binomial mixed model, and various statistical tests, including the variance inflation factor and the Wilcoxon rank sum test. Overall, 1406 freshwater snails, distributed in 45 sampling sites. Pseudosuccinea columella (569) had a widespread coverage in 34 sites (75.6%) of them but not found at 11 sites. Water pH ranged between 6.60 ± 0.38 and 7.46 ± 0.15, while dissolved oxygen (DO) values varied across the sites. GLM analysis suggested that water pH had an influence on the abundance of P.columella. The intermediate host snail of Fasciola, P. columella is abundant and widely distributed across all the 7 municipalities in the uMgungundlovu district suggesting the need for increased snail monitoring to reduce its invasiveness and livestock productivity losses due to Fasciola infections.

Susceptibility of lymnaeid snails to Fasciola hepatica and Fasciola gigantica (Digenea: Fasciolidae): a systematic review and meta-analysis

Background

Fasciolosis is a food-borne disease that causes major economic losses, globally. This zoonotic disease is caused by Fasciola hepatica and Fasciola gigantica species which employ freshwater snails from the family Lymnaeidae as their intermediate hosts. Thus, a key aspect of understanding the epidemiology of the disease lies in understanding the transmission ecology of the parasite. Therefore, this systematic review and meta-analysis were conducted to assess the experimental susceptibility and prevalence of natural infections of F. hepatica and F. gigantica in lymnaeid snails.

Methods

Relevant peer-reviewed articles published in the past 20 years (2004-2023) were searched and appraised. Prevalence and infection rate estimates were based on 41 studies that met the inclusion criteria.

Results

Five thousand five hundred and seventy-five (5,575) lymnaeid snails were subjected to experimental infections and 44,002 were screened for natural infections. The overall pooled infection rate was higher in experimental infections 50% (95% CI [42-58%]) compared to natural infections of field-collected snails 6% (95% CI [0-22%]). The highest pooled infection rate was recorded in South America at 64% (95% CI [48-78%]) for experimental infections while the lowest was recorded for natural infections at 2% (95% CI [0-6%]) in Europe and 2% (95% CI [0-17%]) in Asia. In experimental studies, F. gigantica recorded the highest pooled prevalence at 73% (95% CI [61-84%] compared to F. hepatica which recorded 47% (95% CI [38-56%]). For natural infections, however, F. hepatica had the highest prevalence (12% (95% CI [0-30%]) while the lowest was noted for naturally infected F. gigantica at 2% (95% CI [0-18%]). Based on the snail species, the highest pooled prevalence was recorded for Pseudosuccinea columella infected with F. hepatica and F. gigantica at 47% (95% CI [33-61%]) while the lowest was recorded for F. hepatica naturally infected Galba truncatula at 4% (95% CI [0-10%]). Natural Fasciola spp. infections in intermediate snail hosts decreased in prevalence while experimental infections have increased in prevalence over the past 20 years.

Conclusions

While there seems to be a strong intermediate host specificity between the two Fasciola spp., experimental infection results showed that G. truncatula and R. natalensis are susceptible to F. hepatica and F. gigantica, respectively.

A comprehensive analysis of fasciolosis prevalence and risk factors in humans and animals: First report in Algeria

This systematic review and meta-analysis examined 27 studies published between 2003 and 2024 to assess the prevalence of Fasciola hepatica infestation in various animal species in Algeria. Diagnostic methods included liver inspection (16 studies), ELISA (7 studies), coproscopy (4 studies), bile microscopy (1 study), and abattoir data analysis (1 study). For humans, coproscopy and immunoelectrophoresis (IEP) were used in one study in Algiers. Among the 1,006,751 animals examined, 15,868 tested positive, resulting in an overall prevalence of 1.57% (CI 1.55-1.59). Prevalence was higher in the northeastern regions of Algeria (El Tarf, Annaba, and Jijel) at 15.95%, compared to other regions (0.9%-2.95%) (p<0.0001). Cattle showed the highest prevalence (3.91%; CI 3.84-3.98) (p<0.001), followed by sheep (0.42%; CI 0.40-0.44) and goats (0.12%; CI 0.10-0.14). Camels had a prevalence rate of 4%. Trend analysis over 20 years indicated a progressive decrease in prevalence, from 13.29% (2004-2009) to 1.79% (2010-2019) and 1.12% (2020-2024) (p<0.0001). The ELISA method was found to be the most sensitive, revealing a prevalence of 16.40% (CI 15.23-17.57) (true adjusted prevalence is 12.38%) (p<0.0001), significantly higher than liver inspection (1.83%), coproscopy (1.04%), and abattoir data analysis (1.10%). Prevalence increased with animal age across all species. This study clearly shows that fasciolosis in Algeria is most prevalent in the northeast region and that cattle are the high-risk group of animals. As a result, control strategies are urgently needed, targeting cattle in particular in northeast Algeria, to prevent and control this disease and thus reduce Fasciola infection.

A Systematic Review and Meta-analysis on the Prevalence of Bovine Fascioliasis in Nigeria

OBJECTIVE

Bovine fascioliasis, a parasitic disease caused by Fasciola species, severely affects cattle health and agricultural productivity in tropical regions like Nigeria. It leads to economic losses through liver condemnations, decreased meat and milk production, and increased veterinary expenses. Despite its public health and economic significance, existing data on its prevalence and epidemiological patterns in Nigeria is limited.

METHODS

This systematic review and meta-analysis compiled findings from 40 studies conducted between 1980 and 2024 to evaluate the prevalence and distribution of bovine fascioliasis in Nigeria.

RESULTS

The analysis included 5,174,019 cattle and identified 120,678 infections, with a pooled prevalence of 29% (95% CI: 0.21, 0.38) using a random-effects model. A high level of heterogeneity was noted (I² = 100%, tau² = 0.0893). Subgroup analyses showed a higher prevalence in cross-sectional studies (33%, 95% CI: 0.25-0.42) compared to retrospective studies (18%, 95% CI: 0.04, 0.40). Diagnostic methods notably impacted prevalence estimates, with serological tests reporting 72%, versus 33% for microscopy and 22% for post-mortem examinations. Regional disparities were also evident, with the South-South zone exhibiting the highest prevalence in the country, underscoring the influence of environmental factors.

CONCLUSION

This study reveals the significant burden of bovine fascioliasis in Nigeria and highlights the need for region-specific, evidence-based control strategies. The findings also point to critical gaps in diagnostic standardization and surveillance, underscoring the necessity for improved diagnostic tools and integrated management practices to alleviate the effects of this parasitic disease.

In silico design of an epitope-based vaccine ensemble for fasliolopsiasis

Introduction

Fasciolopsiasis, a food-borne intestinal disease is most common in Asia and the Indian subcontinent. Pigs are the reservoir host, and fasciolopsiasis is most widespread in locations where pigs are reared and aquatic plants are widely consumed. Human infection has been most commonly documented in China, Bangladesh, Southeast Asia, and parts of India. It predominates in school-age children, and significant worm burdens are not uncommon. The causal organism is Fasciolopsis buski, a giant intestinal fluke that infects humans and causes diarrhoea, fever, ascites, and intestinal blockage. The increasing prevalence of medication resistance and the necessity for an effective vaccination make controlling these diseases challenging.

Methods

Over the last decade, we have achieved major advances in our understanding of intestinal fluke biology by in-depth interrogation and analysis of evolving F. buski omics datasets. The creation of large omics datasets for F. buski by our group has accelerated the discovery of key molecules involved in intestinal fluke biology, toxicity, and virulence that can be targeted for vaccine development. Finding successful vaccination antigen combinations from these huge number of genes/proteins in the available omics datasets is the key in combating these neglected tropical diseases. In the present study, we developed an in silico workflow to select antigens for composing a chimeric vaccine, which could be a significant technique for developing a fasciolopsiasis vaccine that prevents the parasite from causing serious harm.

Results and discussion

This chimeric vaccine can now be tested experimentally and compared to other vaccine candidates to determine its potential influence on human health. Although the results are encouraging, additional validation is needed both in vivo and in vitro. Considering the extensive genetic data available for intestinal flukes that has expanded with technological advancements, we may need to reassess our methods and suggest a more sophisticated technique in the future for identifying vaccine molecules.

Inverted Patterns of Schistosomiasis and Fascioliasis and Risk Factors Among Humans and Livestock in Northern Tanzania

Fascioliasis and schistosomiasis are parasitic trematodiases of public health and economic concern in humans and livestock. However, data on the distribution and risk factors for fascioliasis remain limited, while epidemiological gaps hinder schistosomiasis control in Tanzania. This One Health, cross-sectional study examined the prevalence and risk factors of schistomiasis and fascioliasis in northern Tanzania, involving 310 livestock and 317 human participants from Arusha, Kilimanjaro, and Manyara regions. Using standard parasitological methods, livestock fascioliasis prevalence was 21.3%, while schistosomiasis prevalence was 1.0%. Human fascioliasis prevalence was 1.9%, while schistosomiasis prevalence was 12.6%. Female animals, particularly cattle in Kilimanjaro and Manyara, had higher odds of fascioliasis. Human-animal contact through husbandry increased schistosomiasis risk (aOR = 4.21; 95% CI: 1.81-9.80), while the use of borehole-water was protective (aOR = 0.33; 95% CI: 0.11-0.97). Fascioliasis risk was higher among individuals aged 36-55 years (aOR = 7.66; 95% CI: 1.36-43.23), with cabbage consumption offering protection (aOR = 0.08; 95% CI: 0.01-0.89). The study revealed inverted prevalence patterns of fascioliasis and schistosomiasis in humans and livestock, driven by vector-dependent transmission dynamics. These findings emphasize the need for an integrated One Health approach to manage shared human and animal health risks in Tanzania.

Detailed characterisation of the Co-Smad protein in liver fluke Fasciola gigantica

Fasciolosis, caused by the liver flukes Fasciola hepatica and Fasciola gigantica, is a zoonotic parasitic disease associated with substantial economic losses in livestock. The transforming growth factor-beta signalling pathway is implicated in developmental processes and biological functions throughout the animal kingdom, including the Fasciola spp. It may also mediate host-helminth interactions during infection. In this work, we present an exploration of FgSmad4, the sole member of the Co-Smad protein family in F. gigantica. The isolated FgSmad4 cDNA was 4,014 bp in length encoding for a protein comprising 771 amino acids. FgSmad4 exhibited typical Co-Smad protein features, including Mad Homology 1 (MH1) and Mad Homology 2 (MH2) domains, a Nuclear Localisation Signal, a DNA-Binding Motif, and a Nuclear Export Signal. Sequence and phylogenetic analyses of FgSmad4 revealed that its MH1 and MH2 sequences are most similar to those of other trematode species. The MH1 domain, in particular, closely resembles the Co-Smad protein in mammalian hosts more than those in cestodes and nematodes. The expression patterns of FgSmad4 during the liver fluke's developmental stages showed significant variation. Transcript levels were highest at the newly excysted juvenile stage, followed by unembryonated egg, redia, and metacercaria, with the lowest expression in the adult fluke, embryonated egg, and cercaria stages. Our results underscore the conservation and suggest the potential role of FgSmad4, a key transforming growth factor-beta signalling molecule within the liver fluke F. gigantica. As Co-Smad is typically involved in several biological pathways, the precise functions and mechanisms of this identified FgSmad4 necessitate further exploration.

Modeling the effects of water temperature on the population dynamics of Galba viatrix and infection by Fasciola hepatica: a two-year survey in Andean Patagonia, Argentina

Background

The trematode parasite Fasciola hepatica (liver fluke) can infect livestock, wild mammals, and humans, generating serious economic losses worldwide. Aquatic or amphibious snails of the Lymnaeidae family are the intermediate host of this parasite. Both snail population dynamics and parasite development are closely associated with temperature, although most field studies have recorded air temperature rather than water temperature. Our aim was to statistically model the population dynamics of lymnaeid snails and their infection by F. hepatica under natural environmental conditions in Northwest Andean Patagonia.

Methods

For two years, we sampled snails monthly in four bodies of water, while registering water and air temperature hourly, and assessing F. hepatica infection in snails. Hierarchical Bayesian modeling allowed us to estimate the functional relationship between water temperature and population growth, the probability of detecting snails, and infection by F. hepatica.

Results

A total of 1,411 Galba viatrix snails were collected, identified, and analyzed for F. hepatica infection. All sites showed seasonal variation in the number of snails collected and in water temperature as well as sharp variations in snail counts between surveys adjacent in time. The hierarchical model revealed that water temperature acts, at least, at two different time scales: water temperature at the time of sampling determines snail detection probability, whereas the average water temperature between sampling dates affects lymnaeid population growth. We found maximum F. hepatica prevalences in snails of 40% (2/5 and 4/10), followed by 33% (65/197). These are the highest prevalences recorded in G. viatrix populations in Argentina to date. Our modeling evidenced that the positive effects of water temperature on infection probability increases with snail size and prevalence on the previous survey, while previous prevalence strongly enhances the effects of snail size.

Conclusions

Our results underscore the high temporal and spatial variability in the population of snails and the prevalence of F. hepatica, as well as the major impact temperature has on detecting snails. Our models provide quantifications of the effects of water temperature on the population growth of G. viatrix, its detection, and infection under natural field conditions. These are crucial steps towards generating mechanistic models of F. hepatica transmission that would facilitate the design and simulation of potential interventions based on treatments and on environmental and livestock management, taking into account the specific characteristics of each region.

Retrospective comparative analysis of human fascioliasis versus bacterial liver abscess

This study aimed to compare the clinical characteristics of human fascioliasis and bacterial liver abscesses to provide a reference for the early and effective differentiation of these 2 diseases to avoid misdiagnosis. We retrospectively compared the epidemiological and clinical characteristics of 95 patients with human fascioliasis and 95 with bacterial liver abscess admitted to the First Affiliated Hospital of Dali University between January 2013 and March 30, 2023. The human fascioliasis group exhibited a higher proportion of female patients and a greater frequency of abdominal pain and lesions affecting both lobes of the liver. Additionally, eosinophil count, percentage of eosinophils, red blood cells, hemoglobin, total protein, albumin, carbohydrate antigen-125 (CA-125), CA-199, and CA-724 levels were elevated compared to the bacterial liver abscess group. Conversely, the proportion of patients with diabetes, duration of hospital stay, and the incidence of lesions affecting the right lobe of the liver, cavity formation, ascites, pleural effusion, white blood cells, total bilirubin, alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, and gamma-glutamyl transferase levels were lower in the fascioliasis group compared to the bacterial liver abscess group. Furthermore, higher thrombin time and fibrinogen levels were observed in the fascioliasis group than in the bacterial liver abscess group (P < .05). Human fascioliasis predominantly occurs from August to November, while bacterial liver abscess exhibits a consistent incidence throughout the year. Human fascioliasis predominantly affects young women and demonstrates a seasonal pattern. It is associated with severe abdominal symptoms, widespread lesions, significantly elevated eosinophil levels, and seasonal incidence. Bacterial liver abscess predominantly affects elderly men with diabetes, and it is associated with localized lesions and severe inflammatory manifestations and occurs throughout the year.

Molecular Characterization and Phylogenetic Analysis of Fasciola gigantica Based on ITS-1 Genetic Marker and copro-epidemiological Survey from Ruminants of Pakistan

PURPOSE

Fascioliasis is a zoonotic parasitic disease spread by genus Fasciola that causes considerable health and economic losses to both humans and livestock. Pakistan is an endemic region for fascioliasis and only a few molecular studies have been conducted to describe the etiology of disease in the country.

METHODS

Current study involved the molecular characterization of adult fluke specimens (n = 31) through ITS-1 region of rDNA collected from four host species (sheep, goats, cattle and buffaloes) of district Sargodha. Moreover, coprology based epidemiology (n = 28620) and association of different risk factors with disease prevalence was also determined. Additionally, an overview of prevalence of fascioliasis in Pakistan, including molecular studies in the four provinces and livestock species, was also carried out.

RESULTS

The phylogenetic analysis revealed that Fasciola gigantica was the main etiological agent infecting the livestock species of this region. The coprological survey revealed an overall prevalence of 30.18% among the livestock species (sheep = 32.31%, goats = 30.67%, cattle = 31.01%, buffaloes = 25.23%). It was inferred that females were slightly more susceptible to infection (32.59%) and that the older age group had higher infection rate (34.01%) in all the host species.

CONCLUSION

The current study suggests that fascioliasis is a disease of primary concern indicating its status as one of the prevalent diseases affecting livestock in this region. It was also concluded that both Fasciola gigantica and Fasciola hepatica existed among the infected animals in addition to presence of hybrid/intermediate form in Pakistan with F. gigantica as dominant species in Punjab province.

Fasciola hepatica Soluble Antigen (FhAg)-Induced NETs Under Hypoxic Conditions Exert Cytotoxic Effects on Hepatic Cells In Vitro

Fasciola hepatica is a parasitic trematode that causes fasciolosis in sheep, provoking a decrease in their reproductive capacity, weight gain, meat and milk production, and wool quality. In the pathogenesis of F. hepatica, the penetration and migration of parasitic stages through the liver provoke intense inflammatory immune responses and tissue damage. The aim of this study was to investigate the cytotoxic effects of Fascila hepatica-induced ovine NETs in exposed hepatocytes in vitro, and to analyze whether F. hepatica antigens (FhAg) trigger the release of ovine NETs under hypoxic conditions as well as the roles of matrix metalloproteinase-9 (MMP-9) and CD11b in this cellular process in vitro. Here, isolated ovine PMNs were co-cultured with FhAg under hypoxia (5% O2) and NETs were visualized via immunofluorescence analyses, confirming their classical characteristics. The quantification of NETs in response to FhAg in hypoxic conditions significantly enhanced the formation of anchored and cell-free NETs (p < 0.01), and NADPH oxidase (NOX) inhibitor diphenylene iodonium (DPI) significantly reduced their production (p < 0.05). Furthermore, the cytotoxic effect of NETs on hepatic cells was determined by using a live/dead-staining with Sytox Orange, thereby demonstrating that FhAg-induced NETs are cytotoxic for hepatic cells (p = 0.001). We additionally analyzed PMN supernatants to determine the enzymatic activity of MMP-9, observing that FhAg exposure enhances MMP-9 release in ovine PMNs (p < 0.05) but not in bovine PMNs. Interestingly, by using flow cytometric analysis, we determined that the exposure of PMNs to FhAg does not increase the CD11b surface expression of ovine PMNs. This could be an effect of the activation of other surface receptors or transcription factors involved in F. hepatica-induced NETosis. Consequently, we hypothesize that F. hepatica-induced NETs play a role in the pathogenesis of fasciolosis, contributing to liver tissue damage if released in an uncontrolled manner.

Morphometric and Molecular Characterization of Fasciola spp. in Livestock From Northwestern Provinces of Iran

BACKGROUND

Liver flukes from the genus Fasciola are the causative agents for human and livestock fascioliasis. Accurate identification of Fasciola spp. is essential to understanding the epidemiology of fascioliasis. This study aimed to determine the morphometric and molecular characterization of Fasciola spp. in livestock from Northwestern provinces of Iran.

METHODS

Five hundred adult Fasciola flukes were obtained from different definitive hosts (cattle, sheep, goats, and buffaloes) in four local abattoirs in the northwestern provinces of Iran (West-Azerbaijan, East-Azerbaijan, Ardabil, and Zanjan) from September 2021 to August 2022. All samples were examined by morphometric criteria; then, 49 samples were identified using PCR-RFLP based on ITS1 region and 23 sequence of isolates analyzed by cox1 marker. PCR-RFLP methods compared morphometric results, and cox1 gene sequences were used to confirm PCR-RFLP results and phylogenetic analysis.

RESULTS

The differences between the body length, body width, cephalic cone length, cephalic cone width, body area, and distance between the ventral sucker and posterior end of the body in two species were significant (p < 0.05). Based on the morphometric criteria, 139 samples (27.8%) were identified as Fasciola gigantica and 361 (72.2%) as Fasciola hepatica. Similarly, PCR-RFLP analysis of ITS1 region confirmed morphometric results. No hybrid forms of Fasciola were detected. Partial sequences of cox1 showed 13 variable sites with eight haplotypes in F. hepatica and 12 variable sites with five haplotypes in F. gigantica.

CONCLUSION

Based on the results of this study, the PCR-RFLP method can be used to confirm the morphological method of Fasciola species, but it is insufficient to study their genetic diversity. Also, sequences of cox1 results of the present study showed that F. hepatica and F. gigantica species in the Northern provinces of Iran have different genetic structures and haplotypes.

Fasciolopsis buski isolated from human host, India has distinct clade based on nuclear ribosomal DNA sequences

Fasciolopsiasis caused by Fasciolopsis buski, is a significant cause of morbidity. In the present study F. buski detected during endoscopy of a 50-year-old male patient form Uttar Pradesh, India was used for phylogenetic analysis based on 28S rDNA and ITS2 regions. The parasite was genetically similar to an isolate of pig from Meghalaya. The intra-species genetic variation for 28S rDNA was 1-3% (India), 5% (Vietnam) and for ITS2, 1-2% (India) while 17 % from Vietnam. Thus, F. buski from humans or pigs from India were closely related than those from Vietnam and China which were grouped into separate clades.

First report and molecular characterisation of an adult liver fluke (Fasciola hepatica) in a brown bear (Ursus arctos) in Türkiye

Fascioliasis, caused by the parasite Fasciola hepatica, is a worldwide zoonotic disease that can have serious consequences for livestock, certain wild animals and humans. This study was conducted to morphologically and molecularly characterise a F. hepatica isolate from a brown bear. After examination of the internal organs, a Fasciola sp. isolate was obtained from the bile ducts of the liver. The adult parasite was morphologically analysed under a stereomicroscope and identified as F. hepatica. Measurements of body length, body width and ventral sucker area were then recorded. After isolation of the genomic DNA, a partial gene of the mitochondrial cytochrome oxidase subunit 1 (mt-CO1) was amplified by PCR. The amplified mt-CO1 PCR products were sequenced by one-way sequence analysis. According to the BLAST search results, the sequence of the isolate was identified as F. hepatica. In conclusion, this is the first report on the occurrence of F. hepatica in brown bears and the molecular characterisation of the isolate.

Prevalence of bovine fasciolosis and direct financial losses in cattle slaughtered in Bamenda and Bafoussam abattoirs, Western Highlands, Cameroon

BACKGROUND

Bovine fascioliasis is a parasitic disease that affects cattle. It leads to direct and indirect great economic loss due to animal mortalities, growth retardation and expenditure on anthelmintics, reduction livestock productivity and essentially condemnation of infected liver by inspection service. The study was carried out to determine the seasonal prevalence and estimated financial losses of fascioliasis in cattle in the Western Highlands of Cameroon.

METHODOLOGY

A total of 2167 cattle were selected. Later, the cattle, have being the carcasses, were dissected, and the livers were dissected and carefully examined for adult liver flukes. Faeces were collected immediately after the cattle were killed and examined using the formol-ether concentration technique. Condemned livers were weighted to estimate the financial losses using the average price of a kilogram of liver.

RESULTS

A total 428 of cattle were found with infected livers or egg in the faeces giving a total prevalence of 19.75%. Among the infected carcass, 18.64% had both the Fasciola eggs in the faeces and flukes in the liver while 1.10% had only flukes in the liver. Results revealed that prevalence of Fasciola spp. was significantly higher during the rainy season (23.48%) than 16% in the dry season (p = 0.00). A significantly (p = 0.000) higher prevalence was also observed in females (33.9%) than in males (13.1%). Age range showed significant (p = 0.000) influence with the animals of 8-10 years old recorded the highest prevalence of 39.3%. Furthermore, 433.1 kg of liver was condemned giving a direct financial loss of 1221,550 FCFA (2049.64 USD) and an annual financial loss due to liver condemnation estimated to 1814,775 (3045.01 USD).

CONCLUSION

Findings of this study indicated that bovine fascioliasis is prevalent in cattle in the Western Highlands of Cameroon, and it leads to an important financial loss particularly in the rainy season.

Molecular characterization of Fasciola hepatica obtained from cattle and horse in Central Chile

Liver fluke infection, caused by the trematode Fasciola hepatica, is a parasitic zoonotic disease affecting various mammals, including humans, and has significant implications for public, animal, and ecosystem health. This study provides the first genetic characterization of F. hepatica in Chile, focusing on the complete mitochondrial gene cox1. Samples were collected from two different host species: cattle and horses. Our findings revealed that 70 % of detected haplotypes were found in either cattle or horses, which coincides with their geographical origin. Interestingly, the use of full-length sequences resulted in the identification of 80 % unique sequences, whereas this reduced to 45 % when analyzing the traditionally used short sequences. This underestimation of genetic diversity suggests that broader sequencing efforts might be essential for a more accurate understanding of F. hepatica genetic landscape. This research underscores the importance of understanding the genetic variability in parasites to improve strategies for disease control and treatment.

Global warming induced spread of the highest human fascioliasis hyperendemic area

BACKGROUND

Climate change is driving the occurrence of several infectious diseases. Within a One Health action to complement the ongoing preventive chemotherapy initiative against human fascioliasis in the Northern Bolivian Altiplano hyperendemic area, field surveys showed a geographical expansion of its lymnaeid snail vector. To assess whether climate change underlies this spread of the infection risk area, an in-depth analysis of the long-term evolution of climatic factors relevant for Fasciola hepatica development was imperative.

METHODS

We used monthly climatic data covering at least a 30-year period and applied two climatic risk indices, the water-budget-based system and the wet-day index, both of verified usefulness for forecasting fascioliasis transmission in this endemic area. To reveal the long-term trends of the climatic factors and forecast indices, we applied procedures of seasonal-trend decomposition based on locally weighed regression and trend analysis on the basis of linear models. To further demonstrate the changes detected, we depicted selected variables in the form of anomalies.

RESULTS

This study revealed a notorious climatic change affecting most of the hyperendemic area, with a strong impact on crucial aspects of the fascioliasis transmission. Trends in maximum and mean temperatures show significant increases throughout the endemic area, while trends in minimum temperatures are more variable. Precipitation annual trends are negative in most of the localities. Trends in climatic risk indices show negative trends at lower altitudes or when farther from the eastern Andean chain. However, monthly and yearly values of climatic risk indices indicate a permanent transmission feasibility in almost every location.

CONCLUSIONS

Warmer temperatures have enabled lymnaeids to colonize formerly unsuitable higher altitudes, outside the endemicity area verified in the 1990s. Further, drier conditions might lead to an overexploitation of permanent water collections where lymnaeids inhabit, favoring fascioliasis transmission. Therefore, the present preventive chemotherapy by annual mass treatments is in need to widen the area of implementation. This study emphasizes the convenience for continuous monitoring of nearby zones for quick reaction and appropriate action modification.

Climatic variations and Fasciola: a review of impacts across the parasite life cycle

Fasciolosis, caused by the liver fluke Fasciola spp., is a significant parasitic disease of livestock and humans worldwide. Fasciola transmission and life cycle are highly dependent on climatic conditions, especially temperature and humidity. This dependency has gained significance in the context of ongoing climate change. This literature review examined evidence on the effects of temperature variability on the developmental stages of Fasciola spp. and the snail intermediate hosts. We reviewed free larval stages of Fasciola spp. development, as well as snail intermediate hosts, while investigating the climate-related factors influencing each stage. We found that Fasciola spp. egg hatching and development were inhibited below 10 °C and optimal between 20 and 30 °C, miracidia hatching time decreased with higher temperatures and cercarial shedding by snail hosts accelerated around 27 °C. Further, metacercarial viability declined at higher temperatures but was prolonged by higher humidity. Snail intermediate host growth rates peaked at 25 °C, and their susceptibility to Fasciola infection depends on temperature, underscoring its importance in transmission dynamics. Overall, the Fasciola life cycle and snail host development exhibit stage-specific temperature thresholds, indicating a complex relationship between temperature fluctuations and parasite transmission potential. This research highlights the key role of temperature and humidity on Fasciola spp. and snail development, shedding light on the potential consequences of climate change on their survival, development, and disease transmission. Data limitations, primarily from the scarcity of high-resolution climate-related experiments, should drive future research to enhance predictive models and deepen our understanding of the impact of climate change on this parasitic disease.

Parasites of the liver: A global problem?

Parasitic liver diseases can be caused by trematodes, cestodes, nematodes, and protozoa. This pathology is significant because millions of people in different parts of the world have liver parasites, which can manifest themselves in the development of inflammation, liver cysts, cholecystitis, cholelithiasis, pancreatitis and liver cirrhosis that are often threatening their lives. The International Agency for Research on Cancer considers three species of trematodes, Schistosoma haematobium, Opisthorchis viverrini and Clonorchis sinensis, to be carcinogens. Complex modern examination methods, in some cases including extensive screening of large populations, are required for diagnosing liver parasites. Treatment of parasitic liver diseases is differentiated and can involve a combination of surgical and therapeutic measures. There is no doubt that the clinical and epidemiological scale allows one to regard parasitic liver diseases as a global healthcare problem.

Anthelmintic activity of three selected ethnobotanical plant extracts against Strongyloides venezuelensis

The agropastoral farmers have employed Turraea vogelii(TVL),Senna podocarpa(SPL), and Jaundea pinnata (JPL) leaves for treating various diseases, including intestinal parasites in livestock and the human population in Nigeria. Gastrointestinal nematodes are highly significant to livestock production and people's health, and natural products are interesting as sources of new drugs. In this study, we evaluated the effectiveness of extracts derived from these plants in treating parasitic infections using third-stage infective larvae (L3) of Strongyloides venezuelensis. We obtained crude extracts using n-gexane (Hex), ethyl acetate (Ea), and methanol (Met). The extracts were analyzed for their phytochemical composition, and their ability to prevent hemolysis were tested. The mean concentrations of total phenols in SPL Hex, SPL Ea, and SPL Met were 92.3 ± 0.3, 103.0 ± 0.4, and 128.2 ± 0.5 mg/100 g, respectively. Total tannin concentrations for JPL Ea, SPL Ea, SPL Hex, and TVL Hex were 60.3 ± 0.1, 89.2 ± 0.2, 80.0 ± 0.1, and 66.6 ± 0.3 mg/100 g, respectively. The mean lethal concentration (LC50) at 72 h for JPL Ea 39 (26-61) μg/mL. SPL Ea was 39 (34-45) μg/mL, and TVL Hex 31 (26-36) μg/mL. The antiparasitic activities of the extracts against L3 were dose- and time-dependent. All the extracts were slightly hemolytic to the erythrocytes. In this study, the plant extract tested demonstrated significant anti-S. venezuelensis activity. These phytobotanical extracts could be used to create formulations for the potential treatment of helminthiasis in animals and humans.

Dairy farmworkers' knowledge of the causes, risk factors, and clinical signs of bovine lameness

Background and Aim

Observing lameness in dairy cows is the primary animal-based indicator of their overall welfare and health status. The study evaluated dairy farmworkers' understanding of bovine lameness's causes, risk factors, and clinical symptoms in Kwa-Zulu Natal Province, South Africa.

Materials and Methods

Eleven dairy farms provided the data through questionnaires. The questionnaire consisted of five sections: The first section (A) gathered demographic data (age, gender, experience, level of study), and the second section (B) dealt with farm specifics (size, grazing method). Sections C, D, and E cover farm workers' knowledge of lameness risk factors, clinical signs of lameness, and treatment and management of lameness, respectively.

Results

About 85.5% of horses experience lameness during summer, contrasted to 15% during autumn. The seasonal results were statistically significant (p < 0.05). 93% of respondents identified a decrease in appetite as the most common sign of lameness, while 94% reported reduced milk yield and 90% increased lying time; a significant correlation was found between awareness of clinical signs and localities (p < 0.05). Age, gender, and occupation level (p < 0.05) were identified as contributing factors to the movement problem in the dairy industry, necessitating training for farm workers to enhance their knowledge.

Conclusion

Although there is a satisfactory (81%) understanding of lameness by farm workers. There is still need for improvement, hence, farm worker training and retraining are essential for managing and reducing the instances of bovine lameness.

A Knowledge, attitude and practice (KAP) study on sheep owners regarding fasciolosis in northwest of Tunisia

Fasciolosis is a worldwide zoonotic snail-borne infection that affects ruminants, it causes high economic losses among livestock. A participatory epidemiological survey was conducted on 204 sheep owners of Sejnane region (District of Bizerte, Northwest Tunisia) to assess their knowledge, attitude and practice regarding fasciolosis. All interviewed sheep owners are aware of this parasitic infection (100%, 204/204), among them, 81% (165/204) reported history of clinical cases in their sheep flocks. According to 33.73% (113/335) of them, sheep get infected by fasciolosis mainly by grazing in wet areas, 79.9% (163/204) of these farmers think that wet climate is the most favourable for the infection. Weight loss (28.40%, 121/426) and submandibular oedema (20.42%, 87/426) are the main clinical signs of fasciolosis cited by interviewed sheep owners and the majority of them (98.53%; 201/204) confirmed that fasciolosis causes significant economic losses. Fasciolosis infection persists in Sejnane region despite the use of antiparasitic drugs, this is due mainly to the fact that animals graze in moist grass (39.88%, 132/331). Treat animals (51.47%, 193/375), prohibit grazing on moist grass (15.20%, 57/357), prohibit grazing on wet soils (14.33%, 53/357) and avoid pastures (10.93%, 41/357) are the main prevention measures cited by interviewed sheep owners. Only 18,14% (37/204) of responders knew that fascioliasis is a zoonotic disease. These results could be considered by animal health decision makers and field veterinarians when implementing control programmes in order to increase breeders' knowledge of fasciolosis.

Global distribution of zoonotic digenetic trematodes: a scoping review

BACKGROUND

Digenetic trematodes, including blood flukes, intestinal flukes, liver flukes, lung flukes, and pancreatic flukes, are highly diverse and distributed widely. They affect at least 200 million people worldwide, so better understanding of their global distribution and prevalence are crucial for controlling and preventing human trematodiosis. Hence, this scoping review aims to conduct a comprehensive investigation on the spatio-temporal distribution and epidemiology of some important zoonotic digenetic trematodes.

METHODS

We conducted a scoping review by searching PubMed, Web of Science, Google Scholar, China National Knowledge Infrastructure, and Wanfang databases for articles, reviews, and case reports of zoonotic digenetic trematodes, without any restrictions on the year of publication. We followed the inclusion and exclusion criteria to identify relevant studies. And relevant information of the identified studies were collected and summarized.

RESULTS

We identified a total of 470 articles that met the inclusion criteria and were included in the review finally. Our analysis revealed the prevalence and global distribution of species in Schistosoma, Echinostoma, Isthmiophora, Echinochasmus, Paragonimus, Opisthorchiidae, Fasciolidae, Heterophyidae, and Eurytrema. Although some flukes are distributed worldwide, developing countries in Asia and Africa are still the most prevalent areas. Furthermore, there were some overlaps between the distribution of zoonotic digenetic trematodes from the same genus, and the prevalence of some zoonotic digenetic trematodes was not entirely consistent with their global distribution. The temporal disparities in zoonotic digenetic trematodes may attribute to the environmental changes. The gaps in our knowledge of the epidemiology and control of zoonotic digenetic trematodes indicate the need for large cohort studies in most countries.

CONCLUSIONS

This review provides important insights into the prevalence and global distribution of some zoonotic digenetic trematodes, firstly reveals spatio-temporal disparities in these digenetic trematodes. Countries with higher prevalence rate could be potential sources of transmitting diseases to other areas and are threat for possible outbreaks in the future. Therefore, continued global efforts to control and prevent human trematodiosis, and more international collaborations are necessary in the future.

Laboratory Assessment of Molluscicidal Activities of Cannabis sativa, Acacia nilotica, and Tinospora cordifolia Against Snail Host of Fasciola spp

Background: The potential molluscicidal extracts, obtained from indigenous plants Cannabis sativa, Acacia nilotica, and Tinospora cordifolia, were tested for toxicity against freshwater pulmonate snail Lymnaea acuminata, an intermediate host of Fasciola hepatica. The organic extracts had a significant effect on young snails. Materials and Methods: All organic extracts and column-purified fractions gave median lethal concentrations (19-100.05 mg/L; 24 h) that fell well within the threshold level of 100 mg/L, set for a potential molluscicide by the World Health Organization. Results: The toxicity of T. cordifolia stem acetone extract (96 h LC50: 16.08 mg/L) was more pronounced compared with C. sativa leaf ethanol extract (96 h LC50: 16.32 mg/L) and A. nilotica leaf ethanol extract (96 h LC50: 24.78 mg/L). β-caryophyllene, gallic acid, and berberine were characterized and identified as active molluscicidal components. Co-migration of β-caryophyllene (retardation factor [Rf] 0.95), gallic acid (Rf 0.30), and berberine (Rf 0.23) with column-purified parts of Cannabis sativa, Acacia nilotica, and Tinospora cordifolia on thin-layer chromatography demonstrates same Rf value, that is, 0.95, 0.30, and 0.23, respectively. Conclusion: This study indicates that these extracts thus represent potential plant-derived molluscicides that are worthy of further investigations.

Bioclimatic analysis and spatial distribution of fascioliasis causative agents by assessment of Lymnaeidae snails in northwestern provinces of Iran

BACKGROUND

Snails of the Lymnaeidae family are the intermediate hosts of Fasciola species, the causative agents of fascioliasis. The purpose of this study was to determine the prevalence of Fasciola species in lymnaeid snails and to investigate the association of geoclimatic factors and Fasciola species distribution in northwestern provinces of Iran using geographical information system (GIS) data.

METHODS

A total of 2000 lymnaeid snails were collected from 33 permanent and seasonal habitats in northwestern Iran during the period from June to November 2021. After identification by standard morphological keys, they were subjected to shedding and crushing methods. Different stages of Fasciola obtained from these snails were subjected to the ITS1 polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method for species identification. The associations of weather temperature, rainfall, humidity, evaporation, air pressure, wind speed, elevation, and land cover with the distribution of Fasciola species were investigated. Geographical and statistical analysis was performed using ArcMap and SPSS software, respectively, to determine factors related to Fasciola species distribution.

RESULTS

Of the 2000 snails collected, 19 were infected with Fasciola hepatica (0.09%), six with F. gigantica (0.03%), and 13 with other trematodes. Among geoclimatic and environmental factors, mean humidity, maximum humidity, and wind speed were significantly higher in areas where F. hepatica was more common than F. gigantica. The altitude of F. hepatica-prevalent areas was generally lower than F. gigantica areas. No significant relationship was observed between other investigated geoclimatic factors and the distribution of infected snails.

CONCLUSIONS

The present study showed the relationship of humidity and wind speed with the distribution of snails infected with F. hepatica or F. gigantica in the northwestern regions of Iran. In contrast to F. gigantica, F. hepatica was more prevalent in low-altitude areas. Further research is recommended to elucidate the relationship between geoclimatic factors and the presence of intermediate hosts of the two Fasciola species.

Intra- and interspecies variation and population dynamics of Fasciola gigantica among ruminants in Sudan

Fasciola gigantica is a widespread parasite that causes neglected disease in livestock worldwide. Its high transmissibility and dispersion are attributed to its ability to infect intermediate snail hosts and adapt to various mammalian definitive hosts. This study investigated the variation and population dynamics of F. gigantica in cattle, sheep, and goats from three states in Sudan. Mitochondrial cytochrome c oxidase subunit I (COI) and NADH dehydrogenase subunit 1 (ND1) genes were sequenced successfully to examine intra and interspecific differences. ND1 exhibited higher diversity than COI, with 15 haplotypes and 10 haplotypes, respectively. Both genes had high haplotype diversity but low nucleotide diversity, with 21 and 11 polymorphic sites for ND1 and COI, respectively. Mismatch distribution analysis and neutrality tests revealed that F. gigantica from different host species was in a state of population expansion. Maximum likelihood phylogenetic trees and median networks revealed that F. gigantica in Sudan and other African countries had host-specific and country-specific lineages for both genes. The study also indicated that F. gigantica-infected small ruminants were evolutionarily distant, suggesting deep and historical interspecies adaptation.

Diagnosis of fasciolosis antibodies in Brazilian cattle through ELISA employing both native and recombinant antigens

Bovine fasciolosis is a parasitic disease with a global reach. Coprological based on egg detection in fecal samples and liver inspection to evaluate the presence of the parasite is currently the gold standard for diagnosing chronic fasciolosis in cattle. However, these techniques are labor-intensive and ineffective during the acute phase of the disease. Serodiagnosis using native and recombinant antigens has become an interesting alternative in efforts to identify cattle fasciolosis. We evaluated cattle from abattoir (n = 139) and farms (n = 500) through liver inspection and coprological examination, respectively. Our laboratory team optimized and validated enzyme-linked immunosorbent assay tests based on somatic antigen, excretory/secretory proteins, and the recombinant antigen cathepsin L-1 to detect serum antibodies against fasciolosis in cattle. For animals from abattoir, 10 were positive for fasciolosis according to liver inspection. Both FhES and FhrCL-1 presented an area under the receiver operating characteristic (AUROC) curve of 0.80, with a sensitivity of 0.80 (95% CI: 0.46-0.95) and 0.70 (95% CI: 0.38-0.90) and specificity of 0.81 (95% CI: 0.73-0.87) and 0.87 (95% CI: 0.80-0.92), respectively. For those cattle from farms, 28 were positive only for fasciolosis according to coprological examination. In this scenario, FhES gave the best performance, with an AUROC of 0.84, sensitivity of 0.79 (95% CI: 0.60-0.90), and specificity of 0.86 (95% CI: 0.82-0.89). In conclusion, our study highlights the potential of serodiagnosis for accurately screening cattle fasciolosis. The promising sensitivity and specificity values of FhES when compared to liver inspection or coprological examination enhance its importance for cattle fasciolosis diagnosis.

IMPORTANCE

The aim of this article was to identify antibodies against fasciolosis in cattle in Brazil. The methodology was reproduced in our laboratory and applied for the first time to the Brazilian cattle herd. The antigens tested can be used as a screening test and thus speed up the diagnosis of bovine fascioliasis.

Fosfatriclaben, a prodrug of triclabendazole: Preparation, stability, and fasciolicidal activity of three new intramuscular formulations

In this study, we present the preparation, stability, and in vivo fasciolicidal activity of three new intramuscular formulations in sheep of a prodrug based on triclabendazole, named fosfatriclaben. The new formulations were ready-to-use aqueous solutions with volumes recommended for intramuscular administration in sheep. The use of poloxamers (P-407 and P-188) and polysorbates (PS-20 and PS-80) in the new formulations improved the aqueous solubility of fosfatriclaben by 8-fold at pH 7.4. High-performance liquid chromatography with UV detection was used to evaluate the stability of fosfatriclaben in the three formulations. High recovery (> 90%) of fosfatriclaben was found for all formulations after exposure at 57 ± 2 °C for 50 h. The three intramuscular formulations showed high fasciolicidal activity at a dose of 6 mg/kg, which was equivalent to the triclabendazole content. The fasciolicidal activity of fosfatriclaben was similar to commercial oral (Fasimec®) and intramuscular (Endovet®) triclabendazole formulations at a dose of 12 mg/kg. In the in vivo experiments, all formulations administered intramuscularly reduced egg excretion by 100%, and formulations F1, F2, and F3 presented fasciolicidal activities of 100%, 100%, and 99.6%, respectively.

Secondary Structure Analysis of Fasciola from Semi-wild Ruminants of Northeast India

PURPOSE

The objective of this study is to study the secondary structure analysis of Fasciola flukes from a rare mithun host from Manipur. Fascioliasis, a neglected tropical trematodiasis, is poorly studied in India and is widely believed to be predominantly caused by F. gigantica. Through this study, we want to assess the flukes from the rare semi-wild ruminants of Northeast India. This study is important as the mithun population is semi-wild and its population is declining in Manipur.

METHODS

Sample collected from the difficult and challenging terrain of Northeast India. The sample was collected from mithun and observed under the microscope. DNA was isolated, sequenced, and analyzed using various bioinformatics tools. The secondary structure analysis of the Internal Transcribed Spacer 2 (ITS2) region was also performed.

RESULTS

The secondary structure species tree corroborated the Bayesian inference and, hence, strengthened the phylogeny reconstructed. The annotated ITS2 sequence and RNA secondary of the Manipur isolate displayed the typical four-helix or four-domain model. Helix III reveals the presence of the UGGU motif with other deviations like UGG and GGU.

CONCLUSION

This is an in-depth analysis of the secondary structure of Fasciola species. The present study has demonstrated the usefulness of ITS2 and its secondary structures for characterizing parasites. The information on fascioliasis in the mithun's population presents itself useful with regards to their conservation strategy as their populations in both Manipur and Nagaland are dwindling.

Fasciola spp. in Southeast Asia: A systematic review

BACKGROUND

Fasciolosis is an emerging public health threat in a number of regions worldwide. To date, we lack an overview of both its occurrence and distribution in Southeast Asia across all actors involved in the life cycle, which impedes the development of disease control measures. Therefore, our objective was to collect recent information on the distribution and the prevalence of Fasciola spp. and the associated risk factors for infection in humans, animals, snails and plant carriers in Southeast Asia.

METHODOLOGY

Bibliographic and grey literature databases as well as reference lists of important review articles were searched for relevant records published between January 1st, 2000, and June 30th, 2022. The systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for reporting systematic reviews. A total of 3,887 records were retrieved, of which 100 were included in the final analysis.

PRINCIPAL FINDINGS

The studies focused mainly on one host species (96.0%), with Fasciola spp. infection in animals being the most studied (72.0%), followed by humans (21.0%). Based on the used inclusion and exclusion criteria, reports were retrieved describing the presence of Fasciola spp. infection in seven out of 11 countries in Southeast Asia. Depending on the diagnostic tool applied, the prevalence of Fasciola spp. infection ranged between 0.3% and 66.7% in humans, between 0% and 97.8% in animals, and between 0% and 66.2% in snails. There were no studies reporting the presence of metacercariae on plant carriers.

CONCLUSIONS/SIGNIFICANCE

Our study reconfirms that Fasciola spp. infections are widespread and highly prevalent in Southeast Asia, but it remains difficult to accurately assess the true occurrence of Fasciola spp. in absence of well-designed surveys covering all hosts. As next steps we propose to assess the occurrence of the infection across all actors involved in the transmission, to identify associated risk factors and to estimate the burden of the disease to support national and international decision makers.

Amphistomes

Amphistomes, commonly referred to as 'stomach' or 'rumen' flukes because of the localization of these flukes in the stomach of ruminants, are digenetic trematodes distinguished by the absence of an oral sucker and the position of the ventral sucker or acetabulum at the posterior end of the body. The body is characterized by a leaf-like fleshy structure, pink or red with a large posterior sucker. Amphistomes are an important group of parasites since they cause 'amphistomiasis' (variously known as paramphistomosis/amphistomosis), a serious disease of great economic importance in ruminants worldwide. These parasites have a broad spectrum of definitive hosts together with a wide geographical distribution. Though they form a continuous evolutional lineage from fishes to mammals, amphistomes mainly inhabit the rumen and reticulum of ruminant mammals, while some species occur in the large intestine or parenteric sites of ruminants, pigs, equines and man.

Epidemiology and Geographical Distribution of Human Trematode Infections

Digenetic trematodes infecting humans are more than 109 species that belong to 49 genera all over the world. According to their habitat in the definitive hosts, they are classified as 6 blood flukes (Schistosoma japonicum. S. mekongi, S. malayensis, S. mansoni, S. intercalatum, and S. haematobium), 15 liver flukes (Fasciola hepatica, F. gigantica, Clonorchis sinensis, Opisthorchis viverrini, O. felineus, Dicrocoelium dendriticum, D. hospes, Metorchis bilis, M. conjunctus, M. orientalis, Amphimerus sp., A. noverca, A. pseudofelineus, Pseudamphistomum truncatum, and P. aethiopicum), nine lung flukes (Paragonimus westermani, P. heterotremus, P. skrjabini, P. skrjabini miyazakii, P. kellicotti, P. mexicanus, P. africanus, P. uterobilateralis, and P. gondwanensis), 30 heterophyid intestinal flukes (Metagonimus yokogawai, M. takahashii, M. miyatai, M. suifunensis, M. katsuradai, M. pusillus, M. minutus, Heterophyes heterophyes, H. nocens, H. dispar, Haplorchis taichui, H. pumilio, H. yokogawai, H. vanissinus, Centrocestus formosanus, C. armatus, C. cuspidatus, C. kurokawai, Procerovum calderoni, P. varium, Pygidiopsis genata, P. summa, Stictodora fuscata, S. lari, Stellantchasmus falcatus, Heterophyopsis continua, Acanthotrema felis, Apophallus donicus, Ascocotyle longa, and Cryptocotyle lingua), 24 echinostome intestinal flukes (Echinostoma revolutum, E. cinetorchis, E. mekongi, E. paraensei, E. ilocanum, E. lindoense, E. macrorchis, E. angustitestis, E. aegyptica, Isthmiophora hortensis, I. melis, Echinochasmus japonicus, E. perfoliatus, E. lilliputanus, E. caninus, E. jiufoensis, E. fujianensis, Artyfechinostomum malayanum, A. sufrartyfex, A. oraoni, Acanthoparyphium tyosenense, Echinoparymphium recurvatum, Himasthla muehlensi, and Hypoderaeum conoideum), 23 miscellaneous intestinal flukes (Brachylaima cribbi, Caprimolgorchis molenkampi, Phaneropsolus bonnei, P. spinicirrus, Cotylurus japonicus, Fasciolopsis buski, Gastrodiscoides hominis, Fischoederius elongatus, Watsonius watsoni, Gymnophalloides seoi, Gynaecotyla squatarolae, Microphallus brevicaeca, Isoparorchis hypselobagri, Nanophyetus salmincola, N. schikobalowi, Neodiplostomum seoulense, Fibricola cratera, Plagiorchis muris, P. vespertilionis, P. harinasutai, P. javensis, P. philippinensis, and Prohemistomum vivax), one throat fluke (Clinostomum complanatum), and one pancreatic fluke (Eurytrema pancreaticum). The mode of transmission to humans includes contact with cercariae contaminated in water (schistosomes) or ingestion of raw or improperly cooked food, including fish (liver flukes, heterophyid flukes, echinostomes, and throat flukes), snails (echinostomes, brachylaimids, and gymnophallid flukes), amphibia, reptiles (neodiplostomes), aquatic vegetables (fasciolids and amphistomes), and insect larvae or adults (lecithodendriids, plagiorchiids, and pancreatic flukes). Praziquantel has been proven to be highly effective against almost all kinds of trematode infections except Fasciola spp. Epidemiological surveys and detection of human infections are required for a better understanding of the prevalence, intensity of infection, and geographical distribution of each trematode species.

Echinostomes and Other Intestinal Trematode Infections

Intestinal trematodes are among the most common types of parasitic worms. About 76 species belonging to 14 families have been recorded infecting humans. Infection commonly occurs when humans eat raw or undercooked foods that contain the infective metacercariae. These parasites are diverse in regard to their morphology, geographical distribution and life cycle, which make it difficult to study the parasitic diseases that they cause. Many of these intestinal trematodes have been considered as endemic parasites in the past. However, the geographical limits and the population at risk are currently expanding and changing in relation to factors such as growing international markets, improved transportation systems, new eating habits in developed countries and demographic changes. These factors make it necessary to better understand intestinal trematode infections. This chapter describes the main features of human intestinal trematodes in relation to their biology, epidemiology, host-parasite relationships, pathogenicity, clinical aspects, diagnosis, treatment and control.

Diagnosis of Human Trematode Infections

Digenetic trematodes form a major group of human parasites, affecting a large number of humans, especially in endemic foci. Over 100 species have been reported infecting humans, including blood, lung, liver and intestinal parasites. Traditionally, trematode infections have been diagnosed by parasitological methods based on the detection and the identification of eggs in different clinical samples. However, this is complicated due to the morphological similarity between eggs of different trematode species and other factors such as lack of sensitivity or ectopic locations of the parasites. Moreover, the problem is currently aggravated by migratory flows, international travel, international trade of foods and changes in alimentary habits. Although efforts have been made for the development of immunological and molecular techniques, the detection of eggs through parasitological techniques remains as the gold standard for the diagnosis of trematodiases. In the present chapter, we review the current status of knowledge on diagnostic techniques used when examining feces, urine, and sputum and also analyze the most relevant characteristics used to identify eggs with a quick key for the identification of eggs.

Evaluation of the ovicidal activity and fasciolicidal activity of the extract of ethyl acetate from Artemisia ludoviciana Nutt. spp. mexicana and of artemisinin against adult parasites of Fasciola hepatica

The objective of this work was to evaluate the effect of the ethyl acetate extract from A. ludoviciana (EALM) and artemisinin against adult parasites and eggs of F. hepatica. For the ovicidal assay, cell culture plates with 24 wells were used, and 90 to 110 F. hepatica eggs were placed in each well. The eggs were exposed to concentrations of 100, 200, 300, 400, and 500 mg/L EALM and incubated for 16 days. Additionally, triclabendazole (TCBZ) was used as a reference drug at concentrations of 10 and 50 mg, and the response of artemisinin at concentrations of 10 and 20 mg was simultaneously assessed. Adult flukes were exposed to concentrations of 125, 250, 375, and 500 mg/L EALM. The results of the ovicidal action of EALM on the eggs showed that concentrations greater than 300 mg/L were significant, with ovicidal percentages greater than 60% observed on day 16 of incubation (p < 0.05). The maximum efficiency of EALM on adult flukes was reached 72 h post-exposure at a concentration of 125 mg/L (p < 0.05).

Effects of temperature on the life history traits of intermediate host snails of fascioliasis: A systematic review

BACKGROUND

The impact of climate change has led to variations in various biological processes, leading to altered transmission dynamics of infectious diseases, including snail-borne diseases (SBDs). Fascioliasis is one of the neglected zoonotic tropical snail-borne diseases caused by the trematode of the genus Fasciola. This review focused on laboratory experimental and model studies that evaluate the potential effect of temperature change on the ecology and biology of the intermediate host snails (IHS) of Fasciola.

METHODS

A literature search was conducted on Google Scholar, EBSCOhost, and PubMed databases using predefined medical subject heading terms, Boolean operators, and truncation symbols in combination with direct keywords: Fasciolosis AND Temperature, Lymnaea OR Austropeplea OR Radix OR Galba OR Fossaria OR Pseudosuccinea AND growth, fecundity, AND survival at the global scale. Other search terms used were (Fascioliasis AND Temperature), (Lymnaea AND Temperature), (Austropeplea AND Temperature), (Fossaria AND Temperature), (Galba AND Temperature), (Pseudosuccinea AND Temperature), and (Radix AND Temperature).

RESULTS

The final synthesis included thirty-five published articles. The studies reviewed indicated that temperature rise may alter the distribution, and optimal conditions for breeding, growth, and survival of IHS, ultimately resulting in changing the transmission dynamics of fascioliasis. The literature also confirmed that the life history traits of IHS and their interaction with the liver fluke parasites are driven by temperature, and hence climate change may have profound outcomes on the population size of snails, parasite density, and disease epidemiology.

CONCLUSION

We concluded that understanding the impact of temperature on the growth, fecundity, and survival of IHS may broaden our knowledge of the possible effects of climate change and hence inform fascioliasis control programs.

First morphometric and molecular characterization of Fasciola spp. in Northwest Tunisia

The aim of this study was to characterize the Tunisian Fasciola spp. flukes by morphometric and molecular analyses. Flukes were collected from livers of sheep slaughtered in Sejnane slaughterhouses (Bizerte gouvernorate, Northwest Tunisia) between January and March 2021.Five morphometric parameters were determined for all the liver flukes, as follows: (i) total body length (BL), (ii) distance between ventral sucker and the tail (VS-T), (iii) distance between oral sucker and ventral sucker (OS-VS), (iv) abdomen diameter (AD), (v) tail diameter (TD) and the body length to width ratio (BL/BW). Molecular identification of the fluke specimens was carried out by polymerase chain reaction, restriction fragment polymorphism (PCR-RFLP) of a 680 bp sequence of the internal transcribes spacer 1 (ITS1) gene and by amplification, sequencing, and phylogenetic analysis of a 500 bp sequence of the ITS2 gene. Morphometric measurements showed that the mean of the total body length of the adult flukes was 21.1 ± 2.7 mm with minimum and maximum lengths of 13 and 31 mm, respectively. The PCR-RFLP analysis revealed a single profile consisting of three bands of approximately 370, 100, and 60 bp. Fasciola sequences described in the present study (GenBank numbers: OQ457027 and OQ457028) showed 99.58-100% identity to Fasciola hepatica. In conclusion, the results of this study show that molecular and phylogenetic analyses confirm the presence of a single species of F. hepatica in the Sejnane region Northwest of Tunisia. However, further studies are needed to identify the occurrence of Fasciola species in other Tunisian regions.

Triclabendazole resistance in Fasciola hepatica: First report in sheep from the Santa Cruz province, Argentinian Patagonia

In the fall of 2022, decreased triclabendazole (TCBZ) efficacy against F. hepatica was suspected in a sheep farm located in the Santa Cruz province, Argentinian Patagonia. Since TCBZ-resistance in F. hepatica has never been reported in this province, this study aimed to confirm potential TCBZ-resistance in F. hepatica and to evaluate the efficacy of closantel (CLO) and nitroxinil (NTX), through faecal egg count reduction test (FECRT), and the efficacy of albendazole (ABZ) through the in vitro egg hatch test (EHT) in sheep. Sixty-eight (68) animals were selected from a herd of eighty (80) female Merino naturally infected with F. hepatica based on eggs per gram of F. hepatica (EPGFh) counts and assigned into four (4) groups (n = 17 per group): Group Control, animals did not receive anthelmintic treatment; Group TCBZ, animals were orally treated with TCBZ (12 mg/kg); Group CLO, animals were orally treated with CLO (10 mg/kg); and Group NTX, animals were subcutaneously treated with NTX (10 mg/kg). The fluke egg output was monitored on days 0 and 21 post-treatment. For the EHT, liver fluke eggs were isolated from faecal samples (approx. 50 g) collected from animals of the control group. TCBZ efficacy against liver fluke was 53.4%, confirming the presence of TCBZ-resistant isolates on the farm. CLO and NTX were highly effective (100%) for the treatment of F. hepatica on this farm. The EHT was carried out in two different laboratories, in which was observed an ABZ efficacy of 95.8 (Bariloche) and 96.5% (Tandil). These results indicate the ABZ susceptibility of this F. hepatica isolate and the inter-laboratory precision of the test.

Genetic characterization and regional distribution of lymnaeid snails in northern Patagonia, Argentina

Lymnaeid snails serve as intermediate hosts for Fasciola hepatica (Linnaeus, 1758), the etiological agent of fasciolosis, which is a widespread livestock disease in Argentina. Determining their geographic distribution and identifying the snail species involved in the transmission of fasciolosis can provide crucial information for designing strategic control programs. In this context, this work aimed at genetically characterizing the species of lymnaeid snails collected in different water bodies of northern Patagonia, Argentina. To this end, 689 snails were collected in 12 sites in the provinces of Neuquén, Río Negro and Chubut, in areas where fasciolosis is endemic. According to the morphological characteristics of their valves, they were identified as Galba spp. Twenty-three of these specimens were further identified using the nuclear sequences of the internal transcribed spacers ITS-1 and ITS-2 and 18S rRNA. The results confirmed the identity of all the analyzed snails as Galba viatrix and provided evidence that studying the variable region V2 of the 18S rRNA gene is not enough to differentiate closely related species, as observed in lymnaeid snails. Both the fact that G. viatrix was the only species identified in the endemic area surveyed and previous evidence of the high prevalence of F. hepatica infestation in grazing animals in the region suggest that this species is the main intermediate host of F. hepatica. The correct identification of lymnaeid snail species has great importance to determine risk zones and develop appropriate control measures to reduce transmission, according to the different ecological characteristics of each species.

Serological diagnosis of fasciolosis (Fasciola hepatica) in humans, cattle, and sheep: a meta-analysis

Fasciola hepatica can cause problems in both animals and humans. Fasciolosis can be diagnosed through the indirect ELISA immunodiagnostic test. Serological diagnosis of Fasciola is based on recombinant antigens secreted by this worm. We used PubMed and Google Scholar databases to review the published literature on 'antigens with immunogenic potential' used in serological tests to identify antibodies against F. hepatica in humans, cattle, and sheep. Studies that investigated diagnostic tests with common reference standards were included in the sensitivity and/or specificity bivariate meta-analysis. In the quality and susceptibility to bias analysis of the 33 included studies, 26 fulfilled at least six (75%) of the eight QUADAS criteria and were considered good-quality papers. We found that most of the studies used native excretory-secretory antigens and recombinant cathepsin in ELISA tests for serological diagnosis of fascioliasis in humans, cattle, and sheep. The meta-analysis revealed that all antigens demonstrated good accuracy. The best results in terms of sensitivity [0.931-2.5% confidence interval (CI) and 0.985-97.5% CI] and specificity (0.959-2.5% CI and 0.997-97.5% CI) were found in human FhES. FhrCL-1, FhES, and FhrSAP-2 antigens gave the best results for the serum diagnosis of human and animal fasciolosis.

Cloning and expression of Fasciola hepatica enolase gene and efficacy of recombinant protein in the serodiagnosis of sheep fasciolosis

Fasciolosis caused by Fasciola hepatica is a disease of zoonotic importance that is common worldwide and can cause serious problems in farm animals, some wild animals and humans. The development of diagnostic kits for the correct diagnosis of fasciolosis in sheep is important in terms of preventing yield losses. With this study, it is aimed to clone and express the enolase gene to be isolated from adult F. hepatica and to determine the effectiveness of the recombinant antigen in the serodiagnosis of sheep fasciolosis. For this aim, primers were designed to amplify the enolase gene from the F. hepatica enolase sequence, mRNA was isolated from F. hepatica adult fluke obtained from an infected sheep followed by cDNA was obtained. Enolase gene was amplified by PCR and the product was cloned and then expressed. The efficiency of the purified recombinant protein was displayed by Western blot (WB) and ELISA using positive and negative sheep sera. As a result, the sensitivity and specificity rates of the recombinant FhENO antigen were 85% and %82.8 by WB while the rates were 90% and 97.14% by ELISA, respectively. At the same time, in sheep blood sera samples collected from the Elazig and Siirt provinces of Turkey, 100 (50%) of 200 sera were found to be positive by WB and 46 (23%) were found to be positive by ELISA. The most important problem in ELISA was the high cross-reaction rate of the recombinant antigen used, as in WB. In order to prevent the cross-reactions, it will be useful to compare the genes encoding the enolase protein of parasites from the closely related parasite family, and select the regions where there are no common epitopes, and clone them and test the purified protein.

Identification and prevalence of fluke infection in yak and Tibetan sheep around Qinghai Lake, China

Liver flukes (Fasciola spp.) and rumen flukes (Paramphistomum spp.) are significant parasites in livestock worldwide, and Fasciola spp. are considered an important zoonotic parasite. To our knowledge, there are no reports on fluke species identification and epidemiological prevalence in yak and Tibetan sheep around Qinghai Lake, China. Therefore, this study aimed to identify the major fluke species and determine the prevalence of fluke infections among yak and Tibetan sheep in this area. A total of 307 fecal samples were collected and fluke eggs identified using morphology and molecular methods. Our study is the first to display that the predominant fluke species were F. hepatica and P. leydeni in yak and Tibetan sheep around Qinghai Lake. The overall prevalence of fluke infections in yak and Tibetan sheep was 57.7% (177/307). Specifically, the prevalences of F. hepatica and P. leydeni were 15.0% (46/307) and 31.6% (97/307), respectively, and the co-infection of both species was 11.1% (34/307). No significant difference existed in the prevalence of overall fluke infection between yak and Tibetan sheep (p < 0.05). However, F. hepatica prevalence was significantly different in yak and Tibetan sheep (p < 0.05) but not P. leydeni. The findings of this study provide useful information about the current status of natural fluke invasion in yak and Tibetan sheep around Qinghai Lake, which could be important for monitoring and controlling these parasites in the region.