Paramphistomosis of Ruminants: An Emerging Parasitic Disease in Europe

Morphological and molecular data confirm the occurrence of Paramphistomum leydeni (Trematoda: Paramphistomidae) in ruminants from Southern Brazil

Species belonging to the family Paramphistomidae Fischoeder, 1901, commonly known as "rumen flukes", are a group of parasites frequently related to Brazilian livestock production. They inhabit the digestive tract of ruminants and have recognized pathogenicity during the early stages of infection, which can be responsible for economic losses. These trematodes are often associated with Southern Brazil, a region heavily focused on animal farming, which also makes it ideal for the life cycle of paramphistomes. Despite their aforementioned importance, studies regarding their distribution, molecular taxonomy and biology are still scarce in the country. In the present study, rumen flukes collected from cattle (n = 22) and sheep (n = 3) from 9 batches of ruminants from the cities of Jaguarão, Pelotas and Rio Grande, state of Rio Grande do Sul, Brazil, between May and July 2022, were subjected to morphological and molecular study. The microscopic analysis of histological and manual cuts revealed diagnostical traits compatible with Paramphistomum leydeni Näsmark, 1937, including the presence of tegumental papillae, pharynx of the liorchis type and acetabulum of the leydeni type. Molecular data corroborated the morphological identification, with ITS-2 and cox-1 sequences here obtained presenting 100% and 96.8-99.8% similarity, respectively, to P. leydeni samples previously characterized in different countries from Asia, Europe, and South America. Intensity of infection ranged from 5 to 458 and 1 to3 specimens of P. leydeni in sampled cattle and sheep, respectively. The present study contributes to a better understanding of the taxonomy of the flukes involved in cattle and sheep paramphistomosis in Brazil, suggesting that P. leydeni could be the main paramphistome species found in ruminants in the studied region.

The prevalence and infection rates of amphistome species in intermediate snail hosts: a systematic review and meta-analysis

The systematic review and meta-analysis were conducted to determine the estimates of the prevalence and infection rates of natural and experimental infections of amphistome species in intermediate host snails (IHs) across different continents. A search of peer-reviewed literature on natural and experimental infections of freshwater snails with amphistome species was conducted from four electronic databases from 1984 to 2023. The estimates of the prevalence and/or infection rates were based on 36 eligible peer-reviewed articles, which met the inclusion criteria and reported on natural and experimental infections of amphistome species in freshwater snails. The results showed that a total of 1,67,081 snail species from the peer-reviewed articles were examined for natural infections and 7,659 snail species for experimental infections. The overall pooled prevalence of amphistome infections from naturally infected snails was 2% (95% CI: 0-4), while the overall pooled prevalence of amphistome infections from infections was 40% (95% CI: 18-64). The highest pooled prevalence of natural infection was 3%, which was recorded in Europe (95% CI: 1-7%). The highest overall prevalence of naturally infected amphistome was 6% (95% CI: 0-20%) for Paramphistomum epiclitum. The Americas had the highest pooled prevalence of experimental amphistome infection among freshwater snails (66%; 95% CI: 26-96%). The highest pooled infection rate of 65% (95% CI: 12-100%) was recorded for Paramphistomum cervi in experimental infections. Galba truncatula was the only snail that qualified for meta-analysis for natural infection with Calicophoron daubneyi, with a pooled prevalence of 3% (95% CI: 1-8%). Galba truncatula infected with C. daubneyi and P. cervi, and Bulinus tropicus infected with Calicophoron microbothrium in the experimental infection qualified for the meta-analysis, with an overall infection rate of 66% (95% CI: 34-92%) and 30% (95% CI: 0-74%), respectively. The pooled prevalence of amphistome species infection in the intermediate host (IH) snails based on detection techniques was higher with PCR compared to the dissection and shedding of cercariae. The results from the quality effects model revealed a high heterogeneity and publication bias between studies. This meta-analysis provided valuable insights into the prevalence and infection rates of amphistome species in snail IHs across different geographical regions.

Amphistome Infection and Species Diversity of Freshwater Snails Collected from Selected Wildlife Drinking Water Sources in Matebeleland Region of Zimbabwe

This study aimed at determining the identity of freshwater snails collected from selected water habitats frequented by wildlife as source of drinking water in the Matebeleland region of Zimbabwe and further screening the identified snails for natural infections with amphistomes using PCR. A total of 487 freshwater snails were collected from six areas in the Matebeleland region of Zimbabwe for identification and screening of amphistome infection. Eight freshwater snail species were morphologically identified and Biomphalaria pfeifferi, Bul. tropicus, Bul. truncatus, Bul. globosus, and L. (R.) natalensis were confirmed using the COI gene. Bulinus tropicus and Phy. acuta were the most abundant species at 33.9% (165/487) and 31.2% (155/487), respectively. DNA of amphistome was detected in 11.9% (58/487) of the collected snails. The highest infection rate was detected in Bul. globosus (44.4%). West Nicholson recorded the highest infection rate (33.9%), and infection was not detected in L. (R.) natalensis, Phy. acuta, and Bellamya spp. Amphistome DNA from M. tuberculata was successfully sequenced and identified as Calicophoron microbothrium. An additional band was detected in M. tuberculata, Bul. tropicus, and Bul. trancatus, which showed a 96.42% similarity to Paragonimus sp. sequence in the GenBank.

Tegumental surface change in Paramphistomum epiclitum caused by Bombax ceiba flowers and black pepper seed extract

Rumen flukes, parasites of the superfamily Paramphistomoidea, are found in cattle rumen. Heavy infections can cause symptoms such as diarrhea, weight loss, and poor body condition, resulting in a decrease in milk and meat production. This study compares the tegumental surface change of Paramphistomum epiclitum as a response to ethanolic extracts of Bombax ceiba flowers and black pepper seeds. Adult flukes were subjected to various concentrations of crude extracts, including 12.5, 25, 50, 100, and 200 μg/mL for 12, 18, and 24 h incubation. Scanning electron microscopy (SEM) exhibited that the ethanolic extracts of both Bombax ceiba flowers and black pepper seeds caused tegumental surface changes in adult P. epiclitum. Based on the results, Bombax ceiba flower extract has anthelmintic activity, compared with black pepper seed extract, towards adult P. epiclitum due to the deformation of the tegument at lower concentrations than black pepper extract.

Epidemiology of rumen fluke infection in selected buffalo farms in perak, malaysia: prevalence, molecular species identification, and associated risk factors

Rumen flukes cause heavy economic losses in the ruminant industry worldwide, especially in tropical and subtropical countries. This study estimated the prevalence of rumen flukes in buffaloes, identified the species diversity, and determined risk factors associated with rumen fluke prevalence in Perak, Peninsular Malaysia. A cross-sectional study was conducted, and 321 faecal samples were collected from six buffalo farms. A structured questionnaire was developed, and farmers were interviewed to obtain information regarding risk factors associated with rumen fluke infection. The faecal samples were examined using sedimentation and Flukefinder® techniques. Genomic DNA was extracted from the fluke eggs recovered using the Flukefinder® method, and the internal transcribed spacer 2 (ITS2) fragment was amplified and sequenced to facilitate species identification. The results showed that the overall prevalence of rumen fluke across the sampled farms was 40.2% (129/321). Three rumen fluke species were identified, namely, Fischoederius elongatus, F. cobboldi, and Orthocoelium streptocoelium. Several management factors had a significant association (P < 0.05) with rumen fluke prevalence, including production type, cleaning of the stable, drinking water system, flooding around the farm, grazing system, pasture sharing with other livestock, and deworming program. This work constitutes the first attempt to understand the epidemiology of rumen fluke infection in the region and suggests that good farm management, pasture management, choosing appropriate drugs, and proper husbandry practices may improve buffalo health and production in areas where rumen flukes are prevalent.

In-herd prevalence of Fasciola hepatica and Calicophoron / Paramphistomum spp. infections in German dairy cows with comparison of two coproscopical methods and establishment of real-time pyrosequencing for rumen fluke species differentiation

Infections with liver and rumen flukes are among the most frequent parasitic diseases in cattle worldwide. In Europe, the predominant liver fluke species is Fasciola hepatica, and the recently rapidly spreading rumen flukes are mostly Calicophoron daubneyi and occasionally Paramphistomum leydeni. In this study, 1638 faecal samples from individual dairy cows from 24 northern and 18 southern German farms as well as one central German farm, all preselected for potential F. hepatica infection, were examined to determine in-herd prevalences of liver and rumen fluke infections. Furthermore, individual faecal egg counts (FECs) were determined in the northern and central German cows. On farms with patent F. hepatica infections, the mean in-herd prevalence was 15.8% in northern Germany, 41.6% in southern Germany and 14.0% in the central German farm. Rumen fluke infections resulted in high in-herd prevalences in all regions with a mean prevalence of 46.0% in northern, 48.4% in southern and 40.0% in central Germany. Individual FECs varied between 0.1 and 4.1 (mean 0.4) eggs per gram faeces (EPG) for F. hepatica and between 0.1 and 292.4 (mean 16.9) EPG for rumen flukes. Mean in-herd prevalence and mean FECs did not differ significantly between mono- and coinfected farms for either fluke species. Comparison of the classical sedimentation technique and the Flukefinder® method on a subset of 500 faecal samples revealed a similar number of positive samples, however, Flukefinder® mean FECs were three to four times higher for liver and rumen fluke eggs, respectively, with an increasing gap between EPG levels with rising egg counts. Fluke egg size measurement confirmed P. leydeni eggs on average to be larger in length and width (161.0 µm x 87.1 µm) than those of C. daubneyi (141.8 µm x 72.9 µm). However, due to overlap of measurements, morphological species identification based on egg size proved unreliable. For accurate identification, a real-time pyrosequencing approach was established, offering the advantage over classical Sanger sequencing of unambiguously identifying rumen fluke mixed species infections. Real-time pyrosequencing confirmed C. daubneyi (78.1% [50/64]) as the predominant rumen fluke species in Germany, while P. leydeni was detected in 12.5% (8/64) of sampled cows. A total of 9.4% (6/64) cows were infected with both C. daubneyi and P. leydeni, representing the first finding of a mixed infection in domestic ruminants in Europe to date.

Prevalence and geographical distribution of amphistomes of African wild ruminants: A scoping review

This review summarizes published records on the prevalence, species diversity, geographical distribution, mixed infections, co-infections with other trematodes and intermediate hosts (IHs) of amphistomes (rumen flukes) of wild ruminants in Africa. Literature search was conducted on Google Scholar, PubMed and JSTOR, using a combination of predetermined search terms and Boolean operators. Of the 54 African countries searched, results showed that occurrence of amphistome infections in wild ruminants have only been reported in 23 countries. A total of 38 amphistome species consisting of the following 11 genera were recorded, viz Bilatorchis, Calicophoron, Carmyerius, Choerecotyloides, Cotylophoron, Explanatum, Gastrothylax, Gigantocotyle, Leiperocotyle, Paramphistomum and Stephanopharynx. These were recorded in 39 wild ruminant species, belonging to the Bovidae family. The genus Carmyerius recorded the highest number of species (n = 13) across nine countries Africa. However, Calicophoron species (n = 9) were more widely distributed, occurring in 17 countries across all regions of Africa. Species of this genus collectively infected 27 wild ruminant species. However, at a species level, Cotylophoron cotylophorum infected the highest number of wild ruminant species. Prevalence of infection based on post-mortem examination ranged from 1.89% in African Buffalo to 100% in Defassa waterbuck from Egypt and Zambia, respectively. The most common mixed infections recorded were those between amphistomes of the same or different genus. Snail intermediate hosts (IHs) were described for 10/38 amphistome species, and these were predominantly species from Plarnobidae family. Despite the richness in diversity of amphistomes infecting wild ruminants in Africa, there is need to further confirm identity of snail IHs and the amphistome species using both morphological and molecular techniques. Furthermore, more studies are recommended to assess the burden of amphistomosis in commercially reared wildlife/game farming, mixed game and livestock farming systems in Africa.

First Molecular Identification of Calicophoron daubneyi (Dinnik, 1962) and Paramphistomum leydeni (Nasmark, 1937) in Wild Ruminants from Romania

Rumen flukes are geographically widespread trematodes affecting wild and domestic ruminants. The juvenile forms, which are found in the small intestine, are more pathogenic compared to the adults. Severe diarrhoea and weight loss are the major clinical signs, and the disease might be fatal in severely infested individuals. In the last decade, paramphistomosis has been described as an emerging parasitic disease in Europe. This study aimed to identify the rumen fluke species in wild ruminants from western Romania. Fifty-two pre-stomachs obtained from roe deer (Capreolus capreolus) that were hunted on 14 hunting grounds from Timiș and Arad counties were examined for the presence of paramphistomes. Three (9.09%) out of 33 samples were positive in Timiș County, and one (5.26%) out of 19 samples was positive in Arad County. Subsequent PCR testing revealed that three samples were positive for Calicophoron daubneyi and one for Paramphistomum leydeni. The presence of C. daubneyi and P. leydeni in roe deer has not been previously reported in Romania. Two Paramphistomum species-C. daubneyi and P. leydeni-were revealed as the main species of rumen flukes in roe deer from forests in Romania.

Species identity and phylogeny of Paramphistomoidea Fischoeder, 1901 occurring in cattle and sheep in North Cameroon

Paramphistomidae and Gastrothylacidae are parasitic flatworms occurring in wild and domestic ruminants in different parts of the world especially in Asia and Africa. In Central Africa, few studies have been done using molecular techniques to resolve taxonomical groupings and understand the epizootiology of these parasites. In this study, we molecularly characterized two hundred adult flukes collected from the fore stomachs of cattle and sheep in the Adamawa region of the northern Cameroon. PCR and sequencing of the nuclear ITS-2 of the ribosomal DNA gene and a portion of the mitochondrial cox-1 locus revealed the presence of at least nine species belonging to the genera of Cotylophoron, Calicophorn, Orthocoelium and Carmyerius. In Zebu cattle, we identified Ca. microbothrium, Ca. clavula, Ca. phillerouxi, Co. cotylophorum, Co. fuelleborni, O. scoliocoelium, Car. gregarius, Car. graberi and Car. mancupatus and one yet unknown Paramphistomoidea sp, whereas in sheep, only Ca. microbothrium was found. The present study also strongly suggests cross-hybridization between the two Cotylophoron species coexisting in cattle. These results have implications for the diagnosis and control of rumen flukes in the region and point to the need for accurate species identification to understand parasite distribution and population genetics.

Comparison of Mini-FLOTAC, Flukefinder and sedimentation techniques for detection and quantification of Fasciola hepatica and Calicophoron daubneyi eggs using spiked and naturally infected bovine faecal samples

BACKGROUND

Fasciolosis (Fasciola hepatica) and paramphistomosis (Calicophoron daubneyi) are two important infections of livestock. Calicophoron daubneyi is the predominant Paramphistomidae species in Europe, and its prevalence has increased in the last 10-15 years. In Italy, evidence suggests that the prevalence of F. hepatica in ruminants is low in the southern part, but C. daubneyi has been recently reported at high prevalence in the same area. Given the importance of reliable tools for liver and rumen fluke diagnosis in ruminants, this study evaluated the diagnostic performance of the Mini-FLOTAC (MF), Flukefinder(R) (FF) and sedimentation (SED) techniques to detect and quantify F. hepatica and C. daubneyi eggs using spiked and naturally infected cattle faecal samples.

METHODS

Briefly, negative bovine faecal samples were artificially spiked with either F. hepatica or C. daubneyi eggs to achieve different egg count levels: 10, 50 and 100 eggs per gram (EPG) of faeces. Moreover, ten naturally infected cattle farms from southern Italy with either F. hepatica and/or C. daubneyi were selected. For each farm, the samples were analysed individually only with MF technique and as pools using MF, FF and SED techniques. Bayesian latent class analysis (LCA) was used to estimate sensitivity and accuracy of the predicted intensity of infection as well as the infection rate in the naturally infected farms.

RESULTS

The outcome of this study showed that the highest number of eggs (F. hepatica and C. daubneyi) recovered was obtained with MF, followed by FF and SED in spiked infected samples at 50 and 100 EPG, while at lower infection levels of 10 EPG, FF gave the best results. Moreover, the sensitivity for all the techniques included in the study was estimated at > 90% at infection levels > 20 EPG for both F. hepatica and C. daubneyi eggs. However, MF was the most accurate of the three techniques evaluated to estimate fluke infection intensity. Nevertheless, all three techniques can potentially estimate infection rate at farm level accurately.

CONCLUSIONS

Optimization and standardization of techniques are needed to improve the FEC of fluke eggs.

Prevalence of flukes (Fasciola hepatica and paramphistomids) in cattle in south-eastern Mexico

The objective of this study was to determine the risk factors and prevalence of trematodes in south-eastern Mexico. The prevalence of trematodes was determined in 1010 bovines. The study was carried out from October 2018 (n=291) to December 2019 (n=719). Only in 2019 rumen and liver fluke eggs were differentiated. Faecal samples (n=311) were obtained from farms in southeast Mexico located in Tabasco, Chiapas and Campeche. In addition, the presence of flukes in liver and rumen from slaughtered cattle in abattoirs was recorded with a total of 408 samples. A logistic procedure was used to obtain the prevalence and the effect of main risk factors such as land physiography (flooded areas and hills), year, sex, animals' age and type of sample obtained (eggs in faeces and flukes). The general prevalence of flukes in cattle was 32.3 % in 2018 and 41.7 % in 2019. Prevalence of F. hepatica (liver fluke) was 18.6 % (134/719) and that of paramphistomids (rumen fluke) was 33.4 % (240/719). The infected cattle from the slaughterhouse indicated a lower prevalence of F. hepatica (1 %) and rumen fluke (26.7 %) than in farms detected by egg in faeces (41.8 % and 42.1 %, respectively). The physiographic zone was decisive in the presence of F. hepatica and rumen fluke, while sex did not represent a risk factor (P > 0.05). The environmental conditions of the Mexican southeast favour the presence of both liver and rumen fluke.

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.

Morphological and molecular identification of lymnaeid snail and trematodes cercariae in different water bodies in Perak, Malaysia

Lymnaeid snails play a crucial role in the transmission of trematode cercariae as an intermediate host that can infect humans, ruminants like buffalo, and other animals, resulting in serious economic losses. The purpose of the study was to identify the morphological and molecular characteristics of snails and cercariae collected from water bodies near buffalo farms that were integrated with palm oil in Perak, Malaysia. The presence or absence of snails in 35 water bodies was examined via cross-sectional study. From three marsh wetlands, 836 lymnaeid snails were gathered in total. Each snail's shell was morphologically identified to determine its family and species. The cercarial stage inside each snail's body was observed using the crushing method and trematode cercariae types were determined. In addition, the target gene Cytochrome c oxidase subunit 1 (Cox1) and the ribosomal internal transcribed spacer 2 (ITS2) region were used to identify the snail species and cercarial types according to the species level. The findings indicated that the collected snails belong to the family lymnaeidae and Radix rubiginosa species. In snails, the cercarial emergence infection rate was 8.7%. Echinostome, xiphidiocercariae, gymnocephalous, brevifurcate-apharyngeate distome cercariae (BADC), and longifurcate-pharyngeal monostome cercariae (LPMC) are the five morphological cercarial types that were observed. The cercariae were identified using morphological and molecular techniques, and they are members of the four families which are Echinostomatidae, Plagiorchiidae, Fasciolidae, and Schistosomatidae. Interestingly, this is the first study on R. rubiginosa and several trematode cercariae in Perak water bodies near buffalo farms that are integrated with palm oil. In conclusion, our research shown that a variety of parasitic trematodes in Perak use R. rubiginosa as an intermediate host.

Multispecies helminth parasitism of grazing dairy cows in Germany and Austria, examined in the housing period

Helminth composition and burden data for dairy cows have not been reported for >40 years for Germany and even less information is available for Austria. In the context of two recent studies, helminth parasitism was studied in 32 cows (23 from six farms in Bavaria and Tyrol; 9 from one farm in Saxony) from pasture-based dairy farms necropsied during the housing period. Helminths were enumerated and identified based on morphological characters (all helminths but rumen flukes) or molecular techniques (rumen flukes). Thirteen species of gastrointestinal nematodes and two species each of liver flukes (Fasciola hepatica, Dicrocoelium dendriticum) and rumen flukes (Calicophoron daubneyi, Paramphistomum leydeni) were recorded; no lungworms were recovered from any cow. Early fourth-stage (inhibited) larval Ostertagia species nematodes (210 to 140,600) were recovered from all cows, 31 each had adult Ostertagia ostertagi/Ostertagia lyrata (40 to 2020) and Trichostrongylus axei (10 to 53,400), 23 Oesophagostomum radiatum (1 to 242) and 20 Cooperia punctata (10 to 3330). Other nematodes present in descending order of prevalence were: Cooperia oncophora/Cooperia surnabada, Ostertagia leptospicularis/Ostertagia kolchida, Oesophagostomum venulosum, Bunostomum phlebotomum, Chabertia ovina, Nematodirus helvetianus, Trichostrongylus longispicularis, Haemonchus contortus and Aonchotheca bilobata. The cows from Bavaria and Tyrol harbored more total gastrointestinal nematodes than that from Saxony (geometric mean adult plus inhibited larval nematodes, 6510 vs. 2051, respectively). However, in both cohorts of cows abomasal nematodes accounted for ∼97% of the total nematode burden with inhibited larval Ostertagia species nematodes contributing over 70% of the total gastrointestinal nematode burden and ∼ 96% of the Ostertagia species burden. Approximately 44%, 37% and 19% of the cows harbored <5000, 5000 to 10,000 or > 10,000 total gastrointestinal nematodes, respectively. Fecal nematode egg and coproculture nematode larval counts significantly correlated with the cows' total adult nematode burden (r_s = 0.354, p < 0.05, and r_s = 0.608, p < 0.001, respectively). Although the magnitude of nematode burden to exert production effects on dairy cows is not well defined and may vary relative to several factors including nutritional supplementation, the level of mixed parasitism found in this investigation supports consideration of grazing dairy cows in helminth control measures, especially at the time of housing in autumn.

First recorded outbreak of Paramphistomum cervi in Andaman local goats (Capra aegagrus hircus) from Bay island of India: A brief communication

This communication reports an outbreak of immature paramphistomiosis in Andaman local goats (Capra aegagrus hircus) along with report of mortality and gross as well as histopathological changes. During the month of September, 2021 there was report of 38.57% mortality in goats which was investigated in depth. Outbreak occurred at South Andaman district where goats were reared under semi intensive managerial system and allowed to graze in the morning in surrounding marshy land. The affected animals showed the symptoms of immature amphistomiasis; it was further confirmed on necropsy and identification of causative organism as Paramphistomum cervi based on its typical morphological features. Histopathological examination showed damaged structure of rumen with typical degenerative changes and initiation of necrotic changes of cells with infiltration of inflammatory cells. We report the outbreak of immature amphistomiasis for the first time from Andaman and Nicobar archipelago along with the causative agent.

Morphological and Molecular Identification of Lymnaeid snail and Trematodes Cercariae in Different Water Bodies in Perak, Malaysia.. [DOI: 10.21203/rs.3.rs-2423733/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Lymnaeid snails are vital in transmitting trematode cercariae as an intermediate host that can infect buffalo and other ruminants and humans, causing significant economic losses. The study aimed to conduct morphological and molecular identification of snails and cercariae collected from the selected buffalo farms under palm oil integration in Perak, Malaysia. A cross-sectional study was conducted, and 35 water were investigated for the presence or absence of snails. A total of 836 lymnaeid snails were collected from three marshes wetlands. To identify the snail family and species, morphological identification was performed on each snail’s shell, and to identify trematode cercariae types; the crushing method was used to observe the cercarial stage inside each snail’s body. In addition, the Internal Transcribed Spacer 2 (ITS2) region and Cytochrome c oxidase subunit 1 (cox1) was used as the target gene to identify the snail species and cercarial types up to the species level. The result showed that the collected snails belong to the family Lymnaeidae and Radix rubiginosa species. The infection rate by cercarial emergence in snails was 8.73%. Five morphological cercarial types were observed which include: echinostome, xiphidiocercariae, gymnocephalous, brevifurcate-apharyngeate distome, and vivax. Using molecular methods, the identified cercariae belong to the three families, including Echinostomatidae, Plagiorchiidae, and Fasciolidae. This is the first report on R. rubiginosa and different types of trematodes cercariae in buffalo farms under palm oil integration in Perak. Our finding confirmed that R. rubiginosa could serve as an intermediate host for a range of parasitic trematodes in Perak.

Changes in the Populations of Two Lymnaeidae and Their Infection by Fasciola hepatica and/or Calicophoron daubneyi over the Past 30 Years in Central France

Field investigations were carried out during three periods (from 1976 to 1997, in 2013-2014, and in 2020-2021) on 39 cattle-raising farms on acidic soils to track changes in the populations of two Lymnaeidae (Galba truncatula and Omphiscola glabra) and their infection with Fasciola hepatica and/or Calicophoron daubneyi. Compared to the survey between 1976 and 1997 on these farms, there was a significant decrease in the number of the two lymnaeid populations and the size of the G. truncatula populations in both 2013-2014 and 2020-2021. This decline was significantly faster in the last nine years than it was before 2013. The area of habitats colonized by G. truncatula showed no significant variation over the years, while that of habitats with O. glabra significantly decreased in the period covered by the three surveys. The prevalence of F. hepatica infection in snails significantly decreased over the years, while C. daubneyi infection increased over time in both lymnaeid species. These changes are due to the use of triclabendazole to treat fasciolosis in ruminants since the 1990s, and are probably a consequence of the successive heatwaves that have occurred since 2018 in the region.

A survey of sheep and/or cattle farmers in the UK shows confusion over the diagnosis and control of rumen fluke and liver fluke

Calicophoron daubneyi (rumen fluke) is an emerging parasitic infection of livestock across Europe. Despite increasing in prevalence, little is known about the level of awareness of rumen fluke or current control practices used by UK farmers. Fasciola hepatica (liver fluke) is a common parasitic infection of cattle and sheep in the UK. Co-infections with these parasites can present in sheep and cattle, but the only drug with reported efficacy against rumen fluke is oxyclozanide. Between December 2019 and March 2020, 451 sheep and/or cattle farmers completed an online questionnaire, capturing their awareness and current means of control for liver fluke and rumen fluke. Most respondents (70%) were aware of rumen fluke, with 14% recording its presence on their farms and 18% having previously treated for rumen fluke. Almost all respondents (99%) were aware of liver fluke and higher numbers of respondents reported its presence on farm (67%) with 88% having previously treated for liver fluke. Respondents who were aware of rumen fluke said they were concerned about the parasite (81%), although rumen fluke was less of a concern than liver fluke (p < 0.05). Of respondents who reported rumen fluke presence on their farm, 42% cited incorrect diagnostic methods, including those traditionally used to detect liver fluke. Respondents were more likely to treat annually for liver fluke, as opposed to rumen fluke (p < 0.05). The most frequently used drug for the treatment of liver fluke infection was triclabendazole (53% sheep treatments, 34% cattle treatments) and only a minority of farmers treated with a product effective against rumen fluke (oxyclozanide; 42% cattle treatments, 35% sheep treatments). A small proportion of farmers stated that they used a non-flukicide drug to treat sheep for liver fluke infection (1.6% sheep treatments). These results demonstrate a broad awareness of liver and rumen fluke in sheep and cattle, but reveal confusion amongst farmers about their diagnosis and treatment, highlighting the need to provide best practice advice to the livestock industry for the control of both parasites.

Prevalence of Ruminant Paramphistomosis and Comparative Histopathology of the Infected Rumens in Narowal District, Punjab, Pakistan

The present study reports the prevalence of Paramphistomum spp. in small and large ruminants and their association with the histopathology of the infected rumens. A total of 384 animals were screened for Paramphistomum spp. The animals found positive for Paramphistomum spp. were divided into three groups according to the worm load/5 cm2 (G1: 10 - 20 worms/5 cm2 = Low, G2: 20 - 40 worms/5 cm2 = Medium, and G3: >41 worms/5 cm2 = High). Tissue slides were prepared from samples of the rumen (1 cm2) taken from animals positive for ruminal fluke to determine the histological parameters, including epithelial length or thickness, length and width of the ruminal papilla, and thickness of tunica submucosa and mucularis externae. The overall prevalence of Paramphistomum spp. in the ruminant population of district Narowal was 56.25 % with a significant (P < 0.05) variation among different species of ruminants. The highest prevalence was in cattle, followed in order by buffalo, goat, and sheep. Epithelium thickness was significantly correlated with parasite load in large ruminants and the most significant (P < 0.05) decrease in epithelium thickness was in Group B (31.12 ± 1.82 μm) and Group C (31.07 ± 1.68 μm) and a same trend was recorded in small ruminants. Histopathological changes due to Paramphistomum spp. are reported for the first time, which explained the histomorphological and physiological changes in Paramphistomum-infected rumens which might be associated with lowered feed efficiency and productivity in ruminants.

The effect of naturally acquired rumen fluke infection on animal health and production in dairy and beef cattle in the UK

The incidence of paramphistomosis, caused by the rumen fluke, Calicophoron daubneyi, has greatly increased within Europe in the last 15–20 years. However, the production impacts of this disease are poorly understood. This study firstly aimed to investigate the prevalence of rumen fluke in England and Northern Ireland (NI) by conducting an abattoir survey of dairy and beef cattle which also allowed the impact of rumen fluke on carcass weight, conformation and fat classification to be assessed. Secondly, an experiment aimed to assess the impact of C. daubneyi infection on diarrhea score, production loss and welfare in dairy heifers, while also evaluating the impacts of treating infected heifers with oxyclozanide. Rumen fluke prevalence was greater in NI than in England, with 53.8% (95% CI 51.9 - 55.9%) of the NI cattle carcases sampled being infected compared to 16.3% (95% CI 15.8 - 16.8%) and 17.9% (95% CI 17.4 - 18.4%) detected at the two abattoirs in England. However, there was no significant difference (P > 0.05) in the cold carcass weight between infected and non-infected cattle. Similarly, carcass conformation and fat classification were unaffected (P > 0.05) by the presence of rumen fluke. In the second experiment, daily live weight gain (DLWG), diarrhea score and welfare score were also unaffected (P > 0.05) by rumen fluke infection and by oxyclozanide treatment against rumen fluke. The farms in this experiment were managed to a high standard and animals had no intercurrent disease. Therefore, these findings suggest that on well–managed farms, production losses (growth rates) should not be compromised as a result of sub-clinical rumen fluke infection.

Rumen Fluke in Cattle and Buffaloes in Asia: A Review

Rumen fluke is a parasitosis that infects ruminant animals across a wide geographical range of countries. It is a severe infection in temperate and tropical climate regions of Asia, Australia, Africa, and Europe, which cause significant economic losses. In this review, the available information to date on rumen fluke species infecting cattle and buffaloes in Asian countries is evaluated. The citation search was performed through specific keywords, literature published from 1964 to 2021, retrieved from electronic databases: Scopus, Web of Science, Pub Med, Education Resources Information Center (ERIC), Science Direct, Elsevier, and Google Scholar. Twenty-six (26) rumen fluke species belonging to two families: Paramphistomidae 61.5% (16/26) and Gastrothylacidae 38.4% (10/26), were reported in cattle and buffaloes in fourteen Asian countries. Paramphistomum cervi and Cotylophoron cotylophorum are the most prevalent species with broader distribution in countries than the other genera. The coprological prevalence varies from 0.8% to 98.17% and 0.86% to 78.4% in cattle and buffaloes, respectively. The prevalence of rumen fluke by fluke counts method range between 6.45% to 90.6% and 4.29% to 75.07% in cattle and buffaloes, respectively. The sedimentation method and fluke count are reliable tests for detecting rumen fluke in live and slaughtered animals. In conclusion, the rumen fluke should be considered a critical production disease that affects cattle and buffaloes in Asia. Further studies are necessary to determine the rumen fluke-snail associations, develop diagnostic tests to detect prepatent infections in the definitive host, determine the economic importance of rumen fluke, and determine the efficacy of different anthelmintic in the treatment of patent infections in the definitive host.

Rumen and Liver Fluke Infections in Sheep and Goats in Northern and Southern Germany

Simple Summary

Little is known about the distribution of rumen and liver flukes in sheep and goats in Germany or about the occurring rumen fluke species. These fluke infections can be detected by the parasite’s eggs in the host animal’s feces. Therefore, fecal samples from 223 sheep farms and 143 goat farms from northern and southern Germany were examined. The eggs of rumen flukes were detected on 2.2% of the samples, the eggs of common liver flukes on 2.7%, and the eggs of small liver flukes on 21.1% of the examined sheep farms. The rumen flukes were identified as the emerging species Calicophoron daubneyi. No rumen fluke eggs were detected on any of the goat farm samples, but common and small liver fluke eggs were detected in 5.6% and 7.0% of the goat herds, respectively. Differences in the geographical distribution of rumen and liver flukes between and within the two regions were identified. Rumen flukes were more frequently found in the north, while the two liver fluke species were more frequently found in the south of Germany. Sheep sharing the pasture with other ruminants were more likely to be infected with rumen flukes.

Abstract

Paramphistomidosis has recently been identified as an emerging parasitosis in Europe. This study estimated the prevalence of rumen flukes, Fasciola hepatica and Dicrocoelium dendriticum, in small ruminants in Germany and identified occurring rumen fluke species and potential predictors for fluke infections. Pooled fecal samples from 223 sheep farms and 143 goat farms in northern and southern Germany were examined by the sedimentation technique, and molecular species identification was performed on rumen-fluke-positive samples. In sheep, a flock prevalence of 2.2% was detected for rumen flukes. Calicophoron daubneyi was identified on four of five positive farms, while species identification failed in one flock. No rumen fluke eggs were detected in the examined goat herds. F. hepatica eggs were detected in 2.7% of the sheep flocks, while the herd prevalence was 5.6% in goats. Higher prevalence values of 21.1% (sheep) and 7.0% (goats) were observed for D. dendriticum. Mixed grazing with other ruminants and previously identified infections with rumen flukes and/or F. hepatica were identified as predictors for paramphistomidosis. The distribution of the three trematode species followed a geographical pattern associated with conditions favoring the relevant intermediate hosts. C. daubneyi is an established parasite in German sheep at a currently low prevalence.

The winner takes it all: dominance of Calicophoron daubneyi (Digenea: Paramphistomidae) among flukes in Central European beef cattle

In Europe, paramphistomosis caused by Paramphistomum spp. was historically regarded as being of minor importance. However, Calicophoron daubneyi has recently been recognized as an emerging pathogen in Europe due to its increasing prevalence and negative impact on livestock production. In search for paramphistomid flukes, 5573 beef cattle fecal samples from 115 farms across the whole Czech Republic were examined from March 2019 to June 2021. The eggs of paramphistomid flukes were identified in 29.9% of samples. Internal transcribed spacer 2 sequences from 90 adult flukes and 125 fecal samples collected across Czech Republic confirmed C. daubneyi infection in the Czech beef cattle. Ninety mitochondrial DNA sequences obtained from adult C. daubneyi specimens revealed 13 individual haplotypes, two of them recorded for the first time. Although C. daubneyi is a new parasite in beef cattle herds in the Czechia, it clearly dominates the parasitological findings in the country's beef cattle. The common occurrence of C. daubneyi in most of the beef cattle herds indicates environmental conditions suitable also for the life cycle of Fasciola hepatica and risk of its emergence.

Pasture rewetting in the context of nature conservation shows no long-term impact on endoparasite infections in sheep and cattle

BACKGROUND

Nature conservation with reduced drainage of pastures has been increasingly promoted in agriculture in recent years. However, moisture on pastures is a crucial factor for the development of free-living stages of many parasite species in ruminants. Hence, for the first time, we conducted a field study between 2015 and 2017 at the German North Sea coast to investigate the long-term effect of pasture rewetting (since 2004) on endoparasite infections in sheep and cattle.

METHODS

We examined faecal samples of 474 sheep and 646 cattle from five farms in spring, summer and autumn each year for the presence of endoparasite infections. Animals were kept on conventionally drained, undrained and rewetted pastures. The association between pasture rewetting and endoparasite infection probability was analysed in generalized linear mixed models and including further potential confounders.

RESULTS

Infection frequencies for gastrointestinal strongyles, Eimeria spp. and Strongyloides papillosus were significantly higher in sheep (62.9%, 31.7% and 16.7%) than in cattle (39.0%, 19.7% and 2.6%). Fasciola hepatica was detected with a frequency of 13.3% in sheep and 9.8% in cattle, while rumen fluke frequency was significantly higher in cattle (12.7%) than in sheep (3.8%). Nematodirus spp., lungworms (protostrongylids, Dictyocaulus viviparus), Moniezia spp., Trichuris spp. and Dicrocoelium dendriticum were identified in less than 7% of samples. Co-infection with more than three endoparasite taxa was present significantly more often in sheep than in cattle. We identified significant positive correlations above 0.2 for excretion intensities between S. papillosus with strongyles, Eimeria spp. and Nematodirus spp. in sheep and between strongyles and Nematodirus spp. in cattle. Pasture rewetting had no long-term effect on endoparasite infections, neither in sheep nor in cattle. Interestingly, F. hepatica infections decreased significantly in sheep and cattle from 2015 (10.9% and 13.9%) to 2017 (1.4% and 2.1%).

CONCLUSIONS

Pasture rewetting for nature conservation did not increase endoparasite infection probability in ruminants in the long term. This finding should be confirmed in ongoing studies aimed at further animal welfare parameters. The rapid decrease in F. hepatica infections over 3 years may suggest climatic impact or competition with rumen flukes in addition to potential anthelmintic treatment after feedback of the results to the farmers.

DNA barcoding of rumen flukes (Paramphistomidae) from bovines in Germany and Austria

Rumen flukes have received growing veterinary attention in western and central Europe during the past two decades because of an increase in prevalence of infection in cattle and sheep, including cases of severe clinical disease. Historically, rumen fluke infections in Europe were assumed to be caused mainly by Paramphistomum cervi (or species, which were later considered to be synonymous with P. cervi), but more recently molecular studies demonstrated Calicophoron daubneyi to be the predominating species. For the present investigation, adult rumen flukes isolated from 23 cattle originating from ten farms in Germany (Saxony [1], Baden-Württemberg [4], Bavaria [5]) and one farm in Austria (Tyrol) were analyzed to establish partial sequences of the mitochondrial cytochrome c oxidase subunit I (COI) and the complete sequence of the nuclear internal transcribed spacer 2 (ITS2). Flukes of five animals (dairy cows from three farms in Bavaria) were determined as P. leydeni, and flukes of 18 animals (dairy cows or cattle from cow-calf operations from eight farms in Saxony [1], Baden-Württemberg [4], Bavaria [2], and Tyrol [1]) were identified as C. daubneyi. Based on the molecular analysis of adult rumen flukes collected from cattle, the results of this investigation confirm the common occurrence of C. daubneyi in Germany and reveal the first definitive findings of P. leydeni in Germany and C. daubneyi in Austria.

Exploration of factors associated with spatial-temporal veterinary surveillance diagnoses of rumen fluke (Calicophoron daubneyi) infections in ruminants using zero-inflated mixed modelling

Rumen fluke (Calicophoron daubneyi) has emerged as a prominent parasite of ruminants in Europe over the past decades. Epidemiological questions remain regarding this observed increase in prevalence as well as the prospect for future paramphistomosis risk. This study aimed to identify factors associated with the temporal−spatial prevalence of rumen fluke as measured by veterinary surveillance in a temperate region using zero-inflated negative binomial mixed modelling. Modelling revealed that summer rainfall, raindays and sunshine hours and mean winter temperature as significant positively associated climate variables for rumen fluke prevalence over space and time (P < 0.05). Rumen fluke prevalence was also higher in counties with higher cattle/sheep densities and was positively associated with rumen fluke case rates in the previous years (P < 0.05). Equivalent models for fasciolosis prevalence revealed no significant association with winter temperature and sunshine hours, (P > 0.05). These results confirm a strong association between rainfall and the prevalence of both fluke species in a temperate environment, likely due to the role of Galba truncatula as their intermediate snail host. It also highlights the potential added importance of winter temperature and sunshine hours in rumen fluke epidemiology when compared to liver fluke.

Rumen (Calicophoron/Paramphistomum spp.) and Liver Flukes (Fasciola hepatica) in Cattle-Prevalence, Distribution, and Impact of Management Factors in Germany

Simple Summary

Paramphistomidosis is a parasitic disease of ruminants caused by so-called rumen flukes. To determine the current prevalence in German cattle, faecal samples from 614 herds were examined for parasite eggs. In addition, the occurring rumen fluke species were determined, resulting in Calicophoron daubneyi and Paramphistomum leydeni. In the course of the work, the occurrence of the common liver fluke, causing fasciolosis, was also documented. Rumen fluke eggs could be detected in 5.5% of German cattle farms, liver flukes in 9.5%. In 2.1% of the farms, both fluke types occurred. Regional differences between northern and southern Germany were detected. Cattle grazing and fed with fresh grass were more likely to be infected with rumen and liver flukes than cattle without such access. Cattle from organic farms were also more likely to have fluke infections than those from conventional farms, in suckler cows, however, this association only applied to rumen flukes.

Abstract

This study was carried out to determine the prevalence of rumen flukes on German cattle farms via the sedimentation technique, and to identify the rumen fluke species occurring in Germany. Additionally, the prevalence of patent Fasciola hepatica infections was determined. Furthermore, a short questionnaire was answered by the farmers. A prevalence of 5.5% and 9.5% was detected for rumen flukes and liver flukes, respectively. Coinfections occurred on 2.1% of farms. In northern Germany, the rumen fluke prevalence was higher than in southern Germany, while for liver fluke the distribution was reversed. Rumen flukes were mostly identified as Calicophoron daubneyi, but in four cases, sequencing revealed Paramphistomum leydeni for the first time in Germany. Grazing and feeding of fresh grass, as well as organic farming, were significantly associated with rumen and liver fluke occurrence. In contrast, suckler cow husbandry only had an influence on the occurrence of rumen flukes, but not liver flukes. Trematode eggs could be detected in both, farms with and without deworming. Since there were only a few studies about Paramphistomidosis in Germany, more attention should be paid to these parasitic diseases for animal welfare and animal health reasons.

Mapping the Spatial Distribution of the Rumen Fluke Calicophoron daubneyi in a Mediterranean Area

Rumen flukes (Calicophoron daubneyi) represent a growing threat to the animal health, productivity and welfare of ruminants. The present study aimed to assess the spatial distribution of C. daubneyi infections in ruminants and to develop a predictive model of the environmental suitability for rumen flukes in a Mediterranean area. A cross-sectional coprological survey was conducted in 682 sheep, 73 goat and 307 cattle farms located in the Basilicata region (southern Italy). Faecal samples collected were analysed using the FLOTAC technique. Geographical Information Systems (GIS) and statistical models were developed to determine environmental risk factors and to delimitate the areas at highest risk of infections in small ruminants. The results showed 7.9% (95% CI 6.05–10.27) of sheep farms, 2.7% (95% CI 0.48–10.44) of goat farms and 55.0% (95% CI 49.62–60.99) of cattle farms were infected by C. daubneyi. The areas with high predicted risk were situated in the western part of the region. The soil texture, land use and the presence of streams and brooks were the variables statistically significant (p < 0.05) in explaining the C. daubneyi distribution in the study area. The study confirms the importance of geospatial technology in supporting parasite control strategies in livestock and demonstrates that a combined use of different geostatistical techniques can improve the prediction of the C. daubneyi infection risk in ruminants.

Prevalence of gastrointestinal helminths in ruminants in Ukraine: a 5-year meta-analysis

The production of environmentally friendly livestock products is currently receiving much attention, especially in the European Union. The problem of monitoring the quality and safety of meat and milk in modern conditions is relevant not only for Ukraine but also for the world community. The scientific substantiation of the methods of research on meat for sale subject to invasive diseases is especially important, as the product may pose risks to the consumer. One of the criteria for assessing the welfare of a herd is the prevalence of helminthiases in cattle. Ruminant parasitoses in Ukraine have always been and remain a separate, often significant, problem for veterinary specialists. Helminths have evolved to use a wide range of ecological niches. In this study, we tried to quantify the prevalence of helminthiases among ruminants (cattle, sheep and goats) in Ukraine. The relevant studies were searched for in the online databases. The meta-analysis included 15 publications from January 2015 to December 2020 which reported the spread of parasites in Ukraine. The research results show that the infestation of ruminants with gastrointestinal helminths on the territory of Ukraine is 56.7%. Egger’s regression test revealed no significant publication bias. During the period of pastured farming, stable parasitocenoses are formed in the body of ruminants. The parasitoses are caused by helminths (gastrointestinal strongyles, liver flukes, paramphistomas, dicrocelia). They are recorded in monoinvasions or mixed invasions. Ruminants, according to helminthological examination in different climatic zones, are constantly infested with trematodes. In Ukraine, the presence of three species of flukes has been confirmed in ruminants: Fasciola hepatica, Dicrocoelium dendriticum and Paramphistomum cervi. Parasitization by those species negatively affects the profitability of dairy farming. Trematodes cause significant economic losses: reduced milk productivity of cows, reduced live weight gain of young animals, negative impact on reproduction. At the same time, fascioliasis is socially significant and dangerous to humans. According to the analyzed literature sources, two types of cestodes have been registered in Ukraine: Moniezia benedeni and M. expansa. The epizootic situation regarding nematodes is just as fraught. That is the most numerous group of helminths, their fauna is represented by the following species: Strongyloides papillosus, Nematodirus spathiger, Bunostomum spp., Oesophagostomum radiatum, Haemonchus contortus, Toxocara vitulorum, Trichuris skrjabini, T. ovis and T. globulosa. It is proven that in cattle parasitocenoses are recorded more often than monoinvasions. The highest rates of prevalence of infection were observed when polyinvasion included gastrointestinal strongyles, namely from the order Strongylida. Strongyloides papillosus is the most common taxonomic representative, while Fasciola hepatica has the lowest prevalence of infection, especially in sheep. Updated data on helminthiasis will expand the screening strategy to maintain the health of farm ruminants and reduce economic losses.

Modulation of Rumen Microbes Through Extracellular Vesicle Released by the Rumen Fluke Calicophoron daubneyi

Parasite derived extracellular vesicles (EVs) have been proposed to play key roles in the establishment and maintenance of infection. Calicophoron daubneyi is a newly emerging parasite of livestock with many aspects of its underpinning biology yet to be resolved. This research is the first in-depth investigation of EVs released by adult C. daubneyi. EVs were successfully isolated using both differential centrifugation and size exclusion chromatography (SEC), and morphologically characterized though transmission electron microscopy (TEM). EV protein components were characterized using a GeLC approach allowing the elucidation of comprehensive proteomic profiles for both their soluble protein cargo and surface membrane bound proteins yielding a total of 378 soluble proteins identified. Notably, EVs contained Sigma-class GST and cathepsin L and B proteases, which have previously been described in immune modulation and successful establishment of parasitic flatworm infections. SEC purified C. daubneyi EVs were observed to modulate rumen bacterial populations by likely increasing microbial species diversity via antimicrobial activity. This data indicates EVs released from adult C. daubneyi have a role in establishment within the rumen through the regulation of microbial populations offering new routes to control rumen fluke infection and to develop molecular strategies to improve rumen efficiency.

A Universal Approach to Molecular Identification of Rumen Fluke Species Across Hosts, Continents, and Sample Types

Rumen fluke are parasitic trematodes that affect domestic and wild ruminants across a wide range of countries and habitats. There are 6 major genera of rumen fluke and over 70 recognized species. Accurate species identification is important to investigate the epidemiology, pathophysiology and economic impact of rumen fluke species but paramphistomes are morphologically plastic, which has resulted in numerous instances of misclassification. Here, we present a universal approach to molecular identification of rumen fluke species, including different life-cycle stages (eggs, juvenile and mature fluke) and sample preservation methods (fresh, ethanol- or formalin-fixed, and paraffin wax-embedded). Among 387 specimens from 173 animals belonging to 10 host species and originating from 14 countries on 5 continents, 10 rumen fluke species were identified based on ITS-2 intergenic spacer sequencing, including members of the genera Calicophoron, Cotylophoron, Fischeroedius, Gastrothylax, Orthocoelium, and Paramphistomum. Pairwise comparison of ITS-2 sequences from this study and GenBank showed >98.5% homology for 80% of intra-species comparisons and <98.5% homology for 97% of inter-species comparisons, suggesting that some sequence data may have been entered into public repositories with incorrect species attribution based on morphological analysis. We propose that ITS-2 sequencing could be used as a universal tool for rumen fluke identification across host and parasite species from diverse technical and geographical origins and form the basis of an international reference database for accurate species identification.

Rumen Fluke in Great Britain

Calicophoron daubneyi is the primary rumen fluke (RF) found in Europe in ruminants and infection is more common in cattle than in sheep. The incidence of RF has appeared to increase greatly throughout Europe in the last 10-15 years, with outbreaks of clinical paramphistomosis confirmed in ruminants in many countries, including Great Britain and Ireland. Clinical disease, due to immature stages developing in the small intestine, appears infrequently but can occur, usually in the autumn or winter within weeks of beginning to graze wet pasture. Although disease due to adult RF has not been proven, subclinical production losses have been attributed to adult RF infection by some researchers. As the intermediate host for RF and the liver fluke (Fasciola hepatica) is the mud snail (Galba truncatula), similar habitats and environmental conditions favour both parasites. There may, however, be differences in parasite development and interactions within both the final and intermediate hosts. No anthelminthic product is licensed for treatment of ruminants for RF in the UK. However, oxyclozanide, licensed for the treatment of adult F. hepatica infection, has been shown to have activity, but it may be more effective against the adult than the immature stages. The future prevalence of RF due to climate change and limited treatment options is unpredictable. Infection and clinical disease could become more common and RF is worthy of further research.

Transcriptome and Secretome Analysis of Intra-Mammalian Life-Stages of Calicophoron daubneyi Reveals Adaptation to a Unique Host Environment

Paramphistomosis, caused by the rumen fluke, Calicophoron daubneyi, is a parasitic infection of ruminant livestock, which has seen a rapid rise in prevalence throughout Western Europe in recent years. After ingestion of metacercariae (parasite cysts) by the mammalian host, newly excysted juveniles (NEJs) emerge and invade the duodenal submucosa, which causes significant pathology in heavy infections. The immature flukes then migrate upward, along the gastrointestinal tract, and enter the rumen where they mature and begin to produce eggs. Despite their emergence, and sporadic outbreaks of acute disease, we know little about the molecular mechanisms used by C. daubneyi to establish infection, acquire nutrients, and avoid the host immune response. Here, transcriptome analysis of four intramammalian life-cycle stages, integrated with secretome analysis of the NEJ and adult parasites (responsible for acute and chronic diseases, respectively), revealed how the expression and secretion of selected families of virulence factors and immunomodulators are regulated in accordance with fluke development and migration. Our data show that while a family of cathepsins B with varying S2 subsite residues (indicating distinct substrate specificities) is differentially secreted by NEJs and adult flukes, cathepsins L and F are secreted in low abundance by NEJs only. We found that C. daubneyi has an expanded family of aspartic peptidases, which is upregulated in adult worms, although they are under-represented in the secretome. The most abundant proteins in adult fluke secretions were helminth defense molecules that likely establish an immune environment permissive to fluke survival and/or neutralize pathogen-associated molecular patterns such as bacterial lipopolysaccharide in the microbiome-rich rumen. The distinct collection of molecules secreted by C. daubneyi allowed the development of the first coproantigen-based ELISA for paramphistomosis which, importantly, did not recognize antigens from other helminths commonly found as coinfections with rumen fluke.

In vitro screening as an anthelmintic discovery pipeline for Calicophoron daubneyi: nutritive media and rumen environment-based approaches

Paramphistomosis can lead to morbidity and mortality of ruminant livestock within tropical and sub-tropical climates. In recent decades, rumen fluke has become an emerging infection in temperate climates across Western Europe, with Calicophoron daubneyi, the primary species present. Clinical outbreaks with C. daubneyi larvae are reported and adults might be responsible for production losses. There is not currently a widely licensed anthelmintic product available to control C. daubneyi. In this study, three existing flukicide anthelmintics were tested for efficacy against mature C. daubneyi, comparing a standard in vitro culturing assay and a new more relevant rumen fluid based in vitro compound screening protocol. The new rumen based screen confirmed that oxyclozanide was active against adult C. daubneyi and identified activity with praziquantel. The study highlighted the downstream value of incorporating relevant in vitro screening for anthelmintic discovery pipelines.

Prevalence and risk factors associated with amphistome parasites in cattle in Iran

Amphistomiasis, a neglected trematode infection of ruminants, has recently come up as an important reason for economic losses. The aim of this study was to determine the prevalence of bovine amphistomiasis and associated risk factors such as: age, gender, breed, season, water source, pastureland and grazing system. Between January 2016 and 2017, a total of 1,000 faecal samples and 1,000 rumens of cattle were collected from slaughterhouse of Zabol, Iran ante-mortem and post-mortem, respectively, and examined. The overall prevalence was 34.6% and 19.5% in terms of amphistome adults and eggs respectively. The identified amphistome species and their prevalence were Paramphistomumcervi (13.3%), Cotylophoroncotylophorum (19.5%), Gastrothylaxcrumenifer (5.9%) and Carmyeriusspatiosus (2.7%). The correlation between prevalence and season, age, breed, water source, pastureland and grazing system was significant (p < .0001). The presented information about the prevalence of amphistomes of cattle and individual and management risk factors can be used to design appropriate control measures.

Efficacy of Oxyclozanide and Closantel against Rumen Flukes (Paramphistomidae) in Naturally Infected Sheep

Simple Summary

Paramphistomosis, caused by ruminal trematodes, is currently considered an emergent disease in Europe due to the progressive increase of prevalence and reports of acute cases in ruminants. Thus, finding effective control methods such as efficient drugs against paramphistomids is currently a priority. Although some drugs have been found effective for treating paramphistomid infections in cattle, data in sheep are currently limited. A single administration of oxyclozanide (15 mg/kg) or closantel (10 mg/kg) has been proven efficient in cattle, but it has not been tested in sheep; thus, the aim of the present study was to assess the effectiveness of these treatment protocols against paramphistomids in naturally infected sheep. The treatment with oxyclozanide was very efficient since it significantly reduced the paramphistomid egg output in more than 90% during 11 weeks after treatment. In contrast, closantel showed low efficacies throughout the study. The results of this study support the use of a single oral dose of oxyclozanide at 15 mg/kg for treating paramphistomid infections in sheep, whereas a single oral dose of closantel at 10 mg/kg is not effective.

Abstract

Paramphistomosis is considered an emergent disease of ruminants in Europe. Some drugs have been found effective for treating paramphistomid infections in cattle, but data in sheep are currently limited. Thus, faecal samples from 25 adult sheep naturally infected with paramphistomids were collected weekly to test the efficacy of oxyclozanide and closantel. Three groups were performed: nine animals orally treated with a single dose of oxyclozanide (15 mg/kg bodyweight (BW) integrated the G-OXI group, whereas eight sheep orally treated with a single dose of closantel (10 mg/kg BW) were placed in a group called G-CLS. Eight untreated controls constituted the group G-CON. Oxyclozanide showed efficacies up to 90% until week 11 post-treatment, with a maximum efficacy of 98.3%, and significant differences were found between G-OXI and G-CON until the 26th week post-treatment. Closantel was insufficiently active (0–81%) throughout the study and differences compared to G-CON were never found. The present study reveals that oxyclozanide given at a single oral dose of 15 mg/kg BW is highly effective against adult rumen flukes in sheep. In addition, the use of a single oral dose of closantel at 10 mg/kg BW is not recommended for treating paramphistomid infections in sheep.

Gastrointestinal parasite infections in fighting bulls in South Thailand

Background and Aim:

Bullfighting is booming in South Thailand, attracting tourists, and stimulating local economies. The bulls are well raised and practiced, but in many cases, the owners lack knowledge and understanding of the prevention of animal diseases, including parasitic infections. This study aimed to determine the occurrence of gastrointestinal (GI) parasite infection in fighting bulls.

Materials and Methods:

A total of 1501 fecal samples were collected from bulls aged 2-5 years visiting the animal hospital of Prince of Songkla University during 2016-2019. The formalin ethylether concentration method was used to detect GI parasites in feces.

Results:

The overall rate of GI parasite infection was 94.27%. Rumen fluke eggs were detected in 97.17% of all infected animals, followed in prevalence by strongyles (26.29%), Eurytrema spp. (2.83%), Fasciola spp. (2.47%), Trichuris spp. (0.35%), and Moniezia spp. (0.14%). Two protozoan genera were identified, Balantidium coli (6.64%) and Eimeria spp. (3.53%). Coinfection was observed in 33.99%. The five most common coinfections were rumen fluke with strongyles (20.85%), B. coli (4.66%), Eimeria spp. (1.55%), Eurytrema spp. (1.34%), and Fasciola spp. (1.06%).

Conclusion:

In addition to high GI parasite infection rates, zoonotic parasites were observed. Therefore, it is recommended that farmers should follow good sanitation and prevention practices to control parasitic infections in bulls, and proper hygienic precautions should be taken by the owners. Implementation of deworming programs using appropriateanthelmintic drugs as well as rotation of anthelmintic drug that have different chemical agent to prevent further drug resistance should be considered. The promotion of bull health management is highly recommended to protect humans from zoonotic diseases.

Evaluation of anthelmintic drugs against egg development of rumen flukes recovered from cattle raised in the humid tropics of Mexico

Paramphistomosis is a parasitic disease endemic in ruminants nearly worldwide. In the present study, an in vitro screening of the main anthelmintics used in Mexico was carried out to determine the mean lethal dose for rumen fluke eggs from cattle in a humid, warm region. Rumen flukes were obtained from cattle slaughtered in the states of Tabasco and Chiapas in Mexico. Eggs were collected using a 37-μm sieve and quantified. Then, an in vitro incubation study was performed: 100 eggs were placed into the wells of polystyrene microtiter plates. Anthelmintic products were tested on the eggs at concentrations ranging from 0.0015 to 3.0 mg/ml for rafoxanide, 0.0025 to 10.20 mg/ml for nitroxinil and 0.0015 to 3 mg/ml for closantel to determine the median lethal dose (LD50) and maximum lethal dose (LD99). A control group (water) was included in each plate. Three different species of rumen flukes (Calicophoron brothriophoron, Calicophoron clavula and Paramphistomum cervi) belonging to five isolates were identified. Nitroxinil had the highest efficacy against rumen fluke eggs, with an LD50 of 0.11 to 65 μg/ml, whereas rafoxanide showed the lowest efficacy with an LD50 ranging from 500 to 1713 μg/ml. Closantel showed high variability in the LD50 among the different analysed isolates (17 to 122 μg/ml). The evaluated flukicidal drugs presented differential efficacy against the development of rumen fluke eggs. The efficacy of the drugs will vary depending on the geographical area of origin of the animals.

A phylogenetic study of the cecal amphistome Zygocotyle lunata (Trematoda: Zygocotylidae), with notes on the molecular systematics of Paramphistomoidea

Zygocotyle lunata inhabits the caecum of birds and mammals from the American continent. This amphistome parasite is easily maintained in the laboratory and serves as a model organism in life-cycle studies, but it has seldom been studied using molecular data. Neither the position of Z. lunata in the superfamily Paramphistomoidea nor the monophyly of the Zygocotylidae has been evaluated with molecular phylogenetic methods. In the present study, adult specimens of Z. lunata obtained experimentally in mice from Brazil were submitted to molecular studies. Partial sequences of nuclear (1261 bp of 28S and 418 bp of 5.8S-ITS-2) and mitochondrial (1410 bp of cytochrome c oxidase 1, cox1) markers were compared with published data. In the most well-resolved phylogeny, based on 28S sequences, Z. lunata clustered in a well-supported clade with Wardius zibethicus, the only other species currently included in the Zygocotylidae, thus confirming the validity of this family. Divergence of 28S sequences between these species was 2.2%, which falls in the range of intergeneric variation (0.9-5.6%) observed in the other two monophyletic groups in the 28S tree, i.e., representatives of Gastrodicidae and Neotropical cladorchiids (Cladorchiidae). Analysis of ITS-2 and two parts of the cox1 gene placed Z. lunata within poorly resolved clades or large polytomies composed of several paramphistomoid families, without clarifying higher-level phylogenetic relationships. The cox1 of a Brazilian isolate of Z. lunata is 99.6% similar to a Canadian isolate, confirming the pan-American distribution of the species. Finally, our phylogenetic reconstructions of Paramphistomoidea revealed a complex scenario in the taxonomic composition of some amphistome families, which highlights a need for further integrative studies that will likely result in rearrangements of traditional morphology-based classifications.

Occurrence of fluke infection in beef cattle around Phayao Lake, Phayao, Thailand

Background and Aim:

Ruminant flukes, including Fasciola spp. and Paramphistomum spp., are recognized as the significant parasites in livestock worldwide. Cattle infected by these fluke results in slower growth rate and productivity losses contributing to economic losses. In case of Fasciola spp., the parasite is considered as an important zoonotic parasite. This study aimed to investigate the prevalence of fluke invasion in beef cattle around Phayao Lake, Phayao, Thailand, between January 2019 and June 2019.

Materials and Methods:

A total of 311 fecal samples from beef cows reared nearby Phayao Lake were examined for the presence of fluke eggs by formalin-ethyl acetate sedimentation and subsequently identified by morphology together with methylene blue staining.

Results:

The overall prevalence of fluke invasion in beef cattle around Phayao Lake was 33.8% (105/311). The prevalence of rumen fluke and liver fluke was 25.4% (79/311) and 8.4% (26/311), respectively. Mixed infection of both species was found at 1.9% (6/311).

Conclusion:

Age of cattle was observed to be associated with invasion rate of all flukes, particularly in the ages over 4 years, which was the highest group of invasion. However, other risk factors, including gender, breed, and location of animals, were not found to be related. This study provides the current status of natural fluke invasion among the beef cattle in Phayao, Thailand, which could be critical for designing the control program of these parasites.

Molecular classification of rumen fluke eggs in fecal specimens from Suphanburi Province, Thailand, based on cytochrome C oxidase subunit 1

Rumen fluke infections have been known to cause paramphistomiasis in both wild and domestic animals worldwide. Occasionally, coinfections of rumen flukes (Carmyerius, Fischoederius, and Paramphistomum) with liver flukes (Fasciola) have been observed due to the similar life cycles that these two species share. This study involved an alternative approach that was developed to classify and distinguish rumen fluke eggs from other genera by using the polymerase chain reaction (PCR) method based on cytochrome c oxidase subunit 1 (COI). Thirty-eight fecal specimens of Bos taurus from Suphanburi Province, Central Thailand were examined using the formalin-ether sedimentation technique. PCR detection was then performed using COI-specific primers that were developed in this study. The results showed that this primer set can classify and distinguish the egg specimens into a separate clade of the genera comprising Gastrothylax, Carmyerius, Fischoederius, Paramphistomum, Explanatum, and Fasciola. Moreover, epidemiological mapping revealed coinfections of three genera of rumen flukes at some collection sites, leading to the need to further investigate Paramphistomoidea infection along with Fasciolidae infection within the endemic area. This data is important for monitoring the outbreak of these parasites in Suphanburi Province, Thailand. It can be applied for initiating surveillance programs of paramphistomiasis and fascioliasis in veterinary studies.

Morphological and molecular identification with frequency analysis of Calicophoron microbothrioides in central Chile

This research aimed to determine the presence of paramphistomids in cattle slaughtered in a slaughterhouse of the Ñuble Region of Chile, to identify flukes and to analyze the frequency of these parasites in the Maule, Ñuble, and Biobío administrative regions of Chile. Between October of 2016 and April of 2017, rumens of 494 cattle were examined for flukes in the forestomachs. Worms were identified morphologically and, in addition, molecular analysis of the internal transcriber spacer region 2 of the fluke's DNA was done and phylogenetic analyses were performed with Bayesian inference in 14 worms. The frequency was analyzed by locality (low- or highlands) and age. The overall frequency was 11.24%. The district with the highest frequency of presentation was Chillán Viejo (30.8%). Districts in the lowlands had similar frequencies to those in the mountain lands (p=0.1). The frequency of flukes was significantly higher in adult animals than in young ones (p<0.01). We obtained a 460 bp-length fragment of DNA that was identical to the sequences previously identified as Paramphistomum cervi and Calicophoron microbothrioides, and performed morphological analyses confirmed that our samples belonged to C. microbothrioides. This is the first published study of C. microbothrioides in Chile.

An in vitro confirmation of the ethonopharmacological use of Senna plants as anthelmintic against rumen fluke Paramphistomum gracile

BACKGROUND

Paramphistomosis is a pathogenic disease of domesticated ruminants, causing great economic loss in dairy industry and meat production. It is considered as a neglected tropical disease with highest prevalence throughout tropical and subtropical regions, particularly in Africa, Asia, Europe, and Australia. There are few trematocidal drugs available in the market. Most are resistant and have elevated side effects. Therefore, alternative trematocidal drugs need to discover. This study was conducted to evaluate three plants leaf extracts (from Senna alata, S. alexandrina, and S. occidentalis) as effective remedies against gastrointestinal trematode parasite (Paramphistomum gracile) of ruminants. Live adult parasites were collected in 0.1 M phosphate-buffered saline (PBS) from fresh autopsied goat's rumen. Parasites were incubated in leaf extracts of S. alata, S. alexandrina and, S. occidentalis individually and in combination (1:1) ratio at 37 ± 1°C. Treatment media contain extracts at different concentrations (10, 20 and 40 mg/mL) in 10 mL of 0.1 M PBS with 1% dimethylsulphoxide (DMSO). Parasites in control group were incubated in PBS without extract. The efficacy of three Senna extracts was evaluated on the basis of dose-dependent motility and mortality of the trematode. Immediately after paralysis, all treated parasites were collected for histology, SEM and biochemical study.

RESULTS

Dose-dependent efficacy was observed in terms of motility and time of mortality in all treated parasites after exposure in various concentrations of the Senna plant extracts. S. occidentalis and S. alexandrina showed better efficacy in combination than comparing with individual treatment groups. Histological study and scanning electron microscopic observations revealed conspicuous deformity of surface architecture in all treated parasites. Scanning electron micrographs also revealed shrinkage, vacuolization, infoldings and blebbings on the body surface of treated worms. Activities of tegumental enzymes were inhibited in all treatment groups compared to control.

CONCLUSION

The overall findings from this study revealed that all three Senna leaf extracts individually and in combination showed potential antitrematocidal activity against Paramphistomum gracile by damaging body tegument and neural propagation. Thus, this study confirmed that all three Senna extracts can be considered as a potential drug-like candidate in indigenous system of traditional medicine against trematode infections in livestock.