Hepatica Infection Research Articles

Seroprevalence and associated risk factors for Fasciola hepatica in sheep in Nile Delta of Egypt

Fascioliasis is a globally distributed zoonotic parasitic disease that affects ruminants, including sheep. This study conducted from January to December 2023, aimed to determine the prevalence of Fasciola hepatica in sheep across three governorates in Egypt's Nile Delta and to assess associated risk factors. A total of 455 serum samples were analyzed using a commercial ELISA kit, revealing antibodies against F. hepatica in 22.2 % of the tested sheep. There was no significant association between locality or sex and the seroprevalence of F. hepatica in sheep; however, the highest prevalence was observed in Kafr ElSheikh and in female sheep.Concerning risk factors, poor conditioned sheep aged between 1 and 2 years showed 2.1 and 3.8 times higher of infection probability than others. In addition, the risk of F. hepatica infection in sheep increased significantly in winter season (OR = 6.6, 95 %CI: 2.6–16.8), in absence of prophylactic treatment (OR = 2.2, 95 %CI: 1.3–3.3) and in presence of snail (OR = 3, 95 %CI: 3–5.4). The existence of antibodies against F. hepatica in examined sheep raising in Nile Delta indicating that the disease is reported in the studied areas and needs to be managed on farms through control and preventative measures.

Seroprevalence and assessment the associated risk factors for Fasciola hepatica infection in water buffaloes in Egypt.

Fasciolosis is a zoonotic neglected parasitic disease that affects a variety of hosts, resulting in substantial economic losses. The epidemiological information about fasciolosis in water buffaloes in Egypt is very scarce. Hence, the present study aimed to determine the seroprevalence of F. hepatica in water buffaloes using commercial ELISA kits in three governorates at north of Egypt and to estimate the associated risk factors for F. hepatica infection. The total seroprevalence of F. hepatica in buffaloes was 15.4% (63/410), with a higher seroprevalence in Kafr Elsheikh governorates 17.9% (25/140) than in other areas. Fasciolosis was more likely in older buffaloes (OR = 3.4, 95%CI:1.5-7.8), throughout the winter season (OR = 5.3, 95%CI:1.9-14.7). Moreover, the absence of prophylactic treatment (OR = 2.3, 95%CI:1.2-4.2) increased the risk of F. hepatica infection in buffaloes, particularly in animals suffered from diarrhea (OR = 3.8, 95%CI:1.4-10.6). The present study confirmed the prevalence of F. hepatica in water buffaloes in north of Egypt. Consequently, the implementation of preventive and control for the parasite and its intermediate host are very necessary to decrease the economic losses and public health hazard.

Capillaria hepatica (syn. Calodium hepaticum) infection and factors influencing infection carriage in rats (Rattus spp.) in Hong Kong

Capillaria hepatica (syn. Calodium hepaticum) (Bancroft, 1893) is a nematode, which colonises the liver of a wide range of hosts including humans. The worldwide prevalence of infection in the genus Rattus can be as high as 100% and the Norway rat (R. norvegicus) and black rat (R. rattus) are considered the main host species. This study is the first to investigate the epidemiology of C. hepatica infection in wild rats trapped in various geographical locations in Hong Kong. Four species of trapped rats were identified, with 65% being R. norvegicus, followed by 30% R. tanezumi (Asian house rat), 4% R. andamanensis (Sikkim rat), and 1% Niviventer huang (South China white-bellied rat). The overall prevalence of C. hepatica infection was 36.7% (81/221) (95% CI 30.4–43.4) and R. norvegicus was the most common rat species trapped during this study, with the highest prevalence of C. hepatica infection. Two risk factors for host infection were skin wounds and geographical region, whilst sex, body weight, stage of development, and presence of ectoparasites were not risk factors for this infection. Gross hepatic lesions were absent in 17% of infected rats and when present, were not pathognomonic for the infection. Infected rats lacked severe hepatic inflammation or fibrosis, indicating that rats tolerate the infection well. Egg production was observed in the livers of 69% of infected rats, which emphasizes their role as reservoirs of this zoonotic parasite. Several infected rats in this study were trapped inside residential buildings, which highlights the zoonotic risk of C. hepatica to humans following the potential ingestion of embryonated eggs from contaminated food, water, or soil.

Ovicidal activity of diaryl dichalcogenides and ivermectin on Fasciola hepatica: A novel candidate for a blending-based therapeutic strategy

Fasciolosis is a food and waterborne disease caused by Fasciola spp., representing a global health burden to various hosts, including humans and other animals. This study investigates the in vitro activity of tellurium- and selenium-containing diaryl dichalcogenides: diacetal ditelluride (LQ07), diacetal diselenide (LQ62), and diacetyl diselenide (LQ68) alone and in combination with ivermectin (IVM) against eggs of Fasciola hepatica. The eggs were exposed for 12 h with each organochalcogen (OC) (0.1 - 2 mmol l-1) and IVM (0.01 - 2 mmol l-1) following an incubation of 15 days, allowing embryonation. The inhibitory concentration of 50 % (IC50) of each OC or IVM was tested with the IC10, IC30, and IC50 of IVM or each OC, respectively. LQ07, LQ62, and LQ68, as well as IVM, demonstrated a concentration-dependent ovicidal activity. The peak ovicidal activity of 99.74 % was achieved when IVM was tested at 2.0 mmol l-1. LQ62 and LQ68 demonstrated greater ovicidal activity, having an IC50 < 0.32 mmol l-1 being 6.25-fold more toxic than IVM alone. The percentage of dead eggs was significantly higher in the IVM group (early mortality), as Se-containing OCs led to the (miracidia) embryonation of the eggs with no hatching (late mortality). Blending Se-containing OCs and IVM showed an additive effect of up to 27 % against F. hepatica eggs. The present data contribute to the potential use of blending-based therapeutic strategies to combat F. hepatica infections in eradication programs worldwide. The combinations may also act against multidrug-resistant strains, reinstating drug-based parasite control.

Early stage Fasciola hepatica infection in growing cattle: impact on weight gain and liver weight determined in flukicide efficacy studies.

Although the negative impact of liver fluke (Fasciola hepatica) infection on production and health in cattle is generally accepted, results of individual research have been variable, ranging from important negative impacts on the animal to minimal or no impact. To add information on the impact of F. hepatica infection in growing cattle, weight gain and liver weight of young experimentally infected animals from seven controlled efficacy studies were analyzed. In each study, fluke naïve animals were inoculated with approximately 450 to 500 F. hepatica encysted metacercariae, blocked on body weight and randomly assigned into one untreated group (controls) and groups which were administered an experimental flukicide when the flukes were 4 weeks old (migrating) and sacrificed 8 weeks thereafter (12 weeks after inoculation). Data of groups which demonstrated >90% reduction of fluke counts following treatment and groups left untreated (total 103 and 47 animals, respectively) were compared. There was a significant (p < 0.0001) negative association between fluke count and weight gain while fluke count and liver weight and fluke count and relative liver weight were positively associated (p < 0.0001). Over the 8-week post-treatment period, flukicide-treated cattle had almost 15% more weight gain than the controls (50.9 kg vs. 44.4 kg; p = 0.0003). Absolute and relative liver weight was significantly (p < 0.0001) lower in flukicide-treated compared to untreated cattle. Overall, this analysis provided evidence of a substantial negative effect of early (migrating) liver fluke infection on the growth of young cattle, likely due to pathology of the liver and associated reduction in its function as the central organ for bioenergy and protein metabolism.

Anthelmintic effects of some medicinal plants on different life stages of Fasciola hepatica: Evidence on oxidative stress biomarkers, and DNA damage.

Fasciolosis caused by Fasciola hepatica is a major public health and economic problem worldwide. Due to the lack of a successful vaccine and emerging resistance to the drug triclabendazole, alternative phytotherapeutic approaches are being investigated. This study investigated the in vitro anthelmintic activity of Lavender (Lavandula angustifolia) and carob (Ceratonia siliqua L.) essential oils (EOs) against F. hepatica. The in vitro study was based on an egg hatch assay (EHA), adult motility inhibition assays, DNA damage, reactive oxygen species (ROS) level along with several oxidative stress biomarkers including glutathione peroxidase (GSH), and glutathione-S-transferase (GST), superoxide dismutase (SOD) and malondialdehyde (MDA). To this end, different concentrations of L. angustifolia and C. siliqua EOs (1, 5, 10, 25 and 50 mg/mL) were used to assess anthelmintic effects on different life stages including egg, and adults of F. hepatica for 24 hrs. The results indicated that these EOs play a significant role as anthelminthics, and the effect was dependent on time and concentration. The in vitro treatment of F. hepatica worms with both L. angustifolia and C. siliqua EOs increased DNA damage, ROS production and induction of oxidative stress (decreased SOD, GST and GSH, and increased MDA), significantly compared to control. Therefore, it can be concluded that L. angustifolia and C. siliqua EOs have the potential to be used as novel agents for the control and treatment of F. hepatica infections. Further studies are required to investigate their pharmacological potential and effectiveness in vivo for the treatment of parasitic infections.

Estimation of diagnostic sensitivity and specificity of abattoir registrations and bulk tank milk ELISA as herd-level tests for Fasciola hepatica using Bayesian latent class modelling

The common liver fluke, Fasciola hepatica, is a trematode parasite found worldwide, typically with a focal distribution due to its requirement for suitable climatic and environmental conditions to complete its lifecycle. Bovine fasciolosis causes suboptimal production and economic losses, including liver condemnation at slaughter. The lack of reliable diagnostic methods is a disadvantage to the increasing demand for surveillance and control. The aim of this study was to evaluate the diagnostic accuracy of bulk tank milk (BTM) antibody testing and aggregated abattoir registrations (AAR) of liver fluke as herd-level tests for F. hepatica infection using Bayesian latent class models. Data from the abattoirs in 2019–2021 and BTM, sampled in the winter of 2020/2021, were collected from 437 herds on the southwest coast of Norway. The BTM samples were analysed with the SVANOVIR® F. hepatica-Ab ELISA test, with results given as an optical density ratio (ODR), and later dichotomized using the recommended cut-off value from the test manufacturer (ODR ≥0.3). Based on the BTM ELISA test, 47.8% of the herds tested positive. The AAR test was defined as the herd-level proportion of female slaughtered animals registered with liver fluke infection during the study period. For this test, three cut-offs were used (a proportion of 0.05, 0.1 and 0.2). The herds were split into two subpopulations (“Coastal” and “Inland”), which were expected to differ in true prevalence of F. hepatica infection based on climate-related and geographical factors. The diagnostic accuracies of both tests were estimated using Bayesian latent class models with minimally informative priors. Post-hoc analysis revealed that the maximum sum of sensitivity (Se) and specificity (Sp) of the tests was achieved with a herd-level proportion of ≥0.1 registered with liver fluke as the AAR test. Using this cut-off, the median estimate for the diagnostic accuracy of the BTM ELISA was 90.4% (84.0–96.2 95% Posterior Credible Interval (PCI)) for Se and 95.3% (90.6–100% PCI) for Sp, while the median estimate of Se for AAR was 87.5% (81.4–93.1% PCI) and the median estimate of Sp for AAR was 91.0% (85.2–96.5% PCI). The cut-off evaluation of the SVANOVIR® F. hepatica-Ab ELISA test for BTM confirmed the manufacturer's recommended cut-off of ODR ≥0.3 to denote positive and negative herds. This study suggests that AAR and BTM ELISA test can be used as herd-level tools to monitor liver fluke infection, so that appropriate interventions against infection can be implemented as necessary.

In vitro assessment of the anthelmintic activity of copper oxide and zinc oxide nanoparticles on egg and adult stages of Fasciola hepatica: evidence on oxidative stress biomarkers, and DNA damage

ObjectivesFasciolosis is of significant economic and public health importance worldwide. The lack of a successful vaccine and emerging resistance in flukes to the drug of choice, triclabendazole, has initiated the search for alternative approaches. In recent years, metallic nanoparticles have been extensively investigated for their anthelmintic effects. This study investigates the in vitro anthelmintic activity of copper oxide and zinc oxide nanoparticles against Fasciola hepatica.MethodsThe in vitro study was based on egg hatchability test (EHA), adult motility inhibition tests, DNA damage, ROS levels, as well as several biomarkers of oxidative stress, including glutathione peroxidase (GSH) and glutathione S-transferase (GST), superoxide dismutase (SOD) and malondialdehyde (MDA). For this purpose, different concentrations of copper oxide nanoparticles (CuO-NPs) and Zinc oxide nanoparticles (ZnO-NPs) (1, 4, 8, 12, and 16 ppm) were used to evaluate the anthelmintic effect on different life stages, including egg and adults of Fasciola hepatica, over 24 h.ResultsIn vitro treatment of F. hepatica worms with both CuO-NPs and ZnO-NPs could significantly increase ROS production and oxidative stress induction (decreased SOD, GST and GSH and increased MDA) compared to control group.ConclusionsBased on the results, it seems that CuO-NPs and ZnO-NPs may be effective in the control and treatment of F. hepatica infection. Further research is needed to investigate their potential for in vivo use in the treatment of parasitic infections.

Living tape worms in the duodenal lumen: A rare case report

Fascioliasis is an infection caused by a trematode of the liver, Fasciola hepatica, which affects sheep, goats and cattle. Humans become accidental hosts through drinking contaminated water or ingesting raw green vegetables that has been contaminated with encysted metacercariae, which is the infective form. Fascioliasis has a hepatic phase and a biliary phase, each displaying different clinical signs and symptoms. Common signs and symptoms of the hepatic phase are abdominal pain, fever, eosinophilia, and abnormal liver function tests. The biliary phase of the disease usually presents with intermittent right upper quadrant pain with or without cholangitis or cholestasis. However, it is very rare to find a living flukes in the common bile duct (CBD) and duodenal lumen as it usually lives in gall-bladder and smaller biliary tracts. Here we report a case of human infestation of Fasciola hepatica, who presented with respiratory tract infection with abdominal pain &amp; dyspeptic symptoms and eventually during evaluation, an upper gastro-intestinal endoscopy revealed several flat worms at the second part of the duodenum. The worms were sent to microbiology department for identification. The organisms were confirmed to be Fasciola hepatica. The patient was given tablet Nitazoxanide 500mg 12 hourly for 7 days. The symptoms reduced in intensity after two days of nitazoxanide. The patient was then discharged with an advice of a stool routine examination after one month of completion of nitazoxanide. As fasciolosis is non endemic in our country, a high degree of suspicion is required to ensure early detection and management of such cases. Patients with abdominal pain, altered liver function tests &amp; eosinophilia should always be evaluated for a suspected Fasciola hepatica infection and should be kept as a differential in these cases. Bangladesh Crit Care J March 2024; 12 (1): 54-57

Exploring the utility of circulating miRNAs as diagnostic biomarkers of fasciolosis

Effective management and control of parasitic infections on farms depends on their early detection. Traditional serological diagnostic methods for Fasciola hepatica infection in livestock are specific and sensitive, but currently the earliest detection of the parasite only occurs at approximately three weeks post-infection. At this timepoint, parasites have already entered the liver and caused the tissue damage and immunopathology that results in reduced body weight and loss in productivity. Here, we investigated whether the differential abundance of micro(mi)miRNAs in sera of F. hepatica-infected sheep has potential as a tool for the early diagnosis of infection. Using miRNA sequencing analysis, we discovered specific profiles of sheep miRNAs at both the pre-hepatic and hepatic infection phases in comparison to non-infected sheep. In addition, six F. hepatica-derived miRNAs were specifically identified in sera from infected sheep. Thus, a panel of differentially expressed miRNAs comprising four sheep (miR-3231-3p; miR133-5p; 3957-5p; 1197-3p) and two parasite miRNAs (miR-124-3p; miR-Novel-11-5p) were selected as potential biomarkers. The expression of these candidates in sera samples from longitudinal sheep infection studies collected between 7 days and 23 weeks was quantified using RT-qPCR and compared to samples from age-matched non-infected sheep. We identified oar-miR-133-5p and oar-miR-3957-5p as promising biomarkers of fasciolosis, detecting infection as early as 7 days. The differential expression of the other selected miRNAs was not sufficient to diagnose infection; however, our analysis found that the most abundant forms of fhe-miR-124-3p in sera were sequence variants (IsomiRs) of the canonical miRNA, highlighting the critical importance of primer design for accurate diagnostic RT-qPCR. Accordingly, this investigative study suggests that certain miRNAs are biomarkers of F. hepatica infection and validates miRNA-based diagnostics for the detection of fasciolosis in sheep.

Correlation between the Fasciola hepatica infection rate (number of parasites in the liver parenchyma) and the antibody titration, detected by ELISA assay.

This study aimed to demonstrate the existence of a possible correlation between the level of liver fluke infection in cattle caused by Fasciola hepatica and the titers of anti-parasite antibodies in the blood. 113 blood samples were taken from non-dewormed pasture cattle in the communal slaughterhouse of the Jijel city in order to determine the serological titration of anti-fluke antibodies by the ELISA method. After slaughtering the animals studied, a count of parasites present in the inspected livers was carried out in order to assess the level of parasitic infection. The prevalence of bovine fasciolosis (due to Fasciola hepatica) based on counting the number of flukes in the inspected livers was around 61.06%, while the seroprevalence obtained is 55.75%. The sensitivity and specificity of the ELISA test used in this study were, respectively, 91.3% and 100%. A very strong correlation (r = 0.93 to p < 0.0001) was statistically demonstrated between the antibody titers and the number of flukes in the inspected livers. According to the results of this study, there is a strong statistical correlation between serum antibody titers and the number of flukes present in the liver (the higher the number of parasites in the liver, the higher the level of anti-flukes antibodies in the blood).

Eosinophilic Liver Abscess: A Case of Locally Acquired Fasciola hepatica in Alberta, Canada.

Fasciola hepatica is a trematode causing acute and chronic infection. A 33-year-old Canadian woman with eosinophilic liver abscesses and no relevant travel was diagnosed with F hepatica infection. F hepatica is reported in livestock in Alberta. This is the first case of locally acquired fascioliasis in Canada in >100 years.

Comparative evaluation of real-time PCR and ELISA for the detection of human fascioliasis

Fascioliasis is a zoonotic parasitic infection caused by Fasciola species in humans and animals. Despite significant advances in vaccination and new therapeutic agents, little attention has been paid to validating methods for the diagnosis of fascioliasis in humans. Serological techniques are convenient assays that significantly improves the diagnosis of Fasciola infection. However, a more sensitive method is required. The aim of this study was to compare the Real-Time PCR technique with the indirect-ELISA for the detection of Fasciola hepatica in human. Using a panel of sera from patients infected with Fasciola hepatica (n = 51), other parasitic infections (n = 7), and uninfected controls (n = 12), we optimized an ELISA which employs an excretory–secretory antigens from F. hepatica for the detection of human fascioliasis. After DNA extraction from the samples, molecular analysis was done using Real-Time PCR technique based on the Fasciola ribosomal ITS1 sequence. Of 70 patient serum samples, 44 (62.86%) samples were identified as positive F. hepatica infection using ELISA and Real-Time PCR assays. There was no cross-reaction with other parasitic diseases such as toxoplasmosis, leishmaniasis, taeniasis, hydatidosis, trichinosis, toxocariasis, and strongyloidiasis. The significant difference between the agreement and similarity of the results of patients with indirect ELISA and Real-Time PCR was 94.4% and 99.2%, respectively (Cohen’s kappa ≥ 0.7; P = 0.02). Based on the Kappa agreement findings, the significant agreement between the results of ELISA and Real-Time PCR indicates the accuracy and reliability of these tests in the diagnosis of F. hepatica in humans.

IDENTIFIKASI Fasciola hepatica PADA SAPI DI SLEMAN YOGYAKARTA

Due to the economic value of beef cattle and dairy cattle, efforts need to be made to increase and prevent Fasciola hepatica infection. Fasciola hepatica infection in cattle can cause losses. This research aims to identify Fasciola hepatica in cattle in Sleman DI Yogyakarta. Identification of Fasciola hepatica is carried out by microscopic examination of feces using the formol-ether sedimentation method. Data analysis was carried out descriptively. Data are presented in the form of prevalence tables and images of Fasciola hepatica eggs. As many as 50% of male cattle and 50% of female cattle aged more than 12 months have Fasciola hepatica infection. Fasciola hepatica infection in cattle in Sleman DI Yogyakarta is 20% .

The Detection of Circulating Antigen Glutathione S-Transferase in Sheep Infected with Fasciola hepatica with Double-Antibody Sandwich Signal Amplification Enzyme-Linked Immunosorbent Assay

Fasciolosis is a global zoonotic parasitic disease caused by F. hepatica infection that is particularly harmful to cattle and sheep. A biotin–streptavidin signal amplification ELISA (streptavidin-ELISA/SA-ELISA) based on circulating antigens can allow for the early detection of F. hepatica-infected animals and is suitable for batch detection. It is considered to be a better means of detecting F. hepatica infection than traditional detection methods. In this study, using the serum of sheep artificially infected with F. hepatica, the cDNA expression library of F. hepatica was screened, 17 immunodominant antigen genes of F. hepatica were obtained, and glutathione s-transferase (GST) was selected as the candidate detection antigen. Firstly, the GST cDNA sequence was amplified from F. hepatica, followed by the preparation of recombinant protein GST (rFhGST). Then, monoclonal and polyclonal antibodies against rFhGST were prepared using the GST protein. Afterward, the immunolocalization of the target protein in the worm was observed via confocal microscopy, and it was found that the GST protein was localized in the uterus, intestinal tract, and body surface of F. hepatica. Finally, a double-antibody sandwich SA-ELISA based on the detection of circulating antigens was established. There was no cross-reaction with positive sera infected with Dicrocoelium lanceatum (D. lanceatum), Haemonchus contortus (H. contortus), Neospora caninum (N. caninum), or Schistosoma japonicum (S. japonicum). Forty serum and fecal samples from the same batch of sheep in Nong’an County, Changchun City, Jilin Province, China were analyzed using the established detection method and fecal detection method. The positive rate of the SA-ELISA was 17.5%, and the positive rate of the fecal detection method was 15%. The detection results of this method were 100% consistent with commercial ELISA kits. A total of 152 sheep serum samples were tested in Nong’an County, Changchun City, Jilin Province, and the positive rate was 5.92%. This study laid the foundation for the development of serological detection preparations for F. hepatica infection based on the detection of circulating antigens.

Evaluation of LAMP for Fasciola hepatica detection from faecal samples of experimentally and naturally infected cattle

Fasciola hepatica causes liver fluke disease in production animals and humans worldwide. Faecal egg counts (FEC) are the most common diagnostic tool for the diagnosis of liver fluke disease. However, FEC has low sensitivity and is often unreliable for the detection of patent infection. In this study, loop-mediated isothermal amplification (LAMP) was optimised and evaluated for the detection of Fasciola hepatica infection, with the aim of increased sensitivity and making it suitable for on-farm application. LAMP was initially conducted under laboratory conditions, optimised to enable visual detection using calcein dye. DNA extraction based on bead-beating was developed to enable on-farm application. LAMP results were compared to FEC and polymerase chain reaction (PCR). Under laboratory conditions, LAMP was conducted using two incubation methods: a conventional PCR thermocycler and a field-deployable LAMP instrument. When compared to a ‘rigorous’ FEC protocol consisting of multiple counts using a comparatively large volume of faeces and with infection confirmed post-mortem, LAMP was highly sensitive and specific (using silica membrane DNA extraction sensitivity 88 %, specificity 100 %; using sieving and beat-beating DNA extraction sensitivity 98.9 %, specificity 100 %). When applied on-farm, LAMP was compared to conventional FEC, which suggested high sensitivity but low specificity (sensitivity 97 %, specificity 37.5 %). However, further analysis, comparing field LAMP results to laboratory PCR, suggested that the low specificity was likely the outcome of the inability of conventional FEC to detect all true F. hepatica positive samples. Based on the high sensitivity and specificity of LAMP compared to a ‘rigorous’ FEC protocol and its ability to be used in field settings, the study demonstrates the potential of LAMP for diagnosing F. hepatica infection in agriculture.

Liver condemnation due to bovine and buffalo fasciolosis in Antioquia province, Colombia

Background: Fasciola hepatica affects cattle and buffaloes, causing decreased production and liver condemnation at the slaughterhouse level. Objective: To determine liver condemnation frequency, temporal distribution, and associated factors, as well as the spatial distribution and economic impact of F. hepatica infection, based on post mortem inspection in cattle and buffaloes processed between 2010 and 2019 in one of the main slaughterhouses in Colombia. Methods: An observational, descriptive, and cross37 sectional study was carried out, with a convenience non-probability sampling. The temporal distribution of the frequency of liver condemnations was analyzed, the Pearson ꭕ2 test was used to determine the association between the dependent variable (i.e. presence/absence of adult parasites of F. hepatica) and the frequency rates between months and years, and the monthly rainfall data was compared with the accumulated monthly frequency. The association between the dependent variable and the type of production (i.e. industrial-type bovine cattle—intended for milk production, commercial44 type bovine cattle —intended for meat production), weight, and sex (odds ratios, OR and confidence intervals, 95%CI) was explored. Descriptive maps of the municipalities that presented at least one positive case of F. hepatica in 2019 and of the weighted prevalences, both for bovines and buffaloes, were designed. Only losses due to liver condemnation between 2010 and 2019 were considered for the analysis of the economic impact. Results: A total of 1,947,233 animals were processed during the study period, with an overall frequency of fasciolosis of 3.1%. Industrial-type cattle presented a 7.4% higher risk of developing F. hepatica compared to commercial-type cattle (OR=0.074; 95%CI: 0.07-0.08). Likewise, male cattle presented 3.88 times more risk compared to females (OR=3.88; 95%CI: 3.49-4.33). Economic losses due to liver condemnation were estimated at US$1,129,660 for the study period. Conclusion: The frequency of condemnations in Colombia occurs throughout the year, although it increases in the rainy season. The economic losses, only estimated by liver condemnation due to fasciolosis, are important. However, it is necessary to explore such losses considering other productive indicators and in larger animal populations. Fasciola hepatica was reported for the first time in the country in buffaloes. This work demonstrates the importance of systematizing the information generated by animal slaughterhouses.

Fasciola hepatica infection modifies IgG1 specific immune response to foot-and-mouth disease virus induced by vaccination

Fasciola hepatica, a worldwide distributed helminth, has a robust immunoregulatory effect in the host, increasing the susceptibility to secondary infections. Foot and mouth disease (FMD) is a highly contagious acute vesicular viral disease effectively controlled by vaccination in endemic regions. Despite the evidence of immunoregulatory effects, the impact of fasciolosis on the immune response induced by FMD vaccination in cattle has never been assessed. Our objective was to evaluate whether the infection by F. hepatica in cattle influences the long-term immunity elicited by the currently used commercial FMD-inactivated vaccines. Aberdeen Angus steers negative for F. hepatica were vaccinated twice against FMD virus (FMDV) during the first 6 months of age using a commercial oil vaccine formulated with A24/Cruzeiro and O1/Campos strains. When maternal antibodies against F. hepatica were weaned (18––20 months of age) animals were divided into groups of 12 and infected or mock-infected with 500 metacercariae/animal. Individual serum samples were collected at 0-, 28-, 59-, 87- and 157-days post-infection (dpi). Indirect ELISAs were used to detect A24/Cruzeiro specific bovine IgG and IgG subtypes. The total IgG antibody levels and avidity against FMDV did not show significant differences between all the groups. The commercial vaccine induced higher IgG2 than IgG1 titers in vaccinated animals. Anti-FMDV IgG1 levels significantly decreased in the infected group at 28 dpi. In addition, the avidity of IgG1 FMDV-specific antibodies at day 28 in the infected group was reduced compared to the control. These results show that F. hepatica infection modified anamnestic responses against FMDV, reducing serum IgG1 titers and avidity. To our knowledge, this is the first report of immune-regulation of F. hepatica altering the immune response of FMD vaccines, one of the most globally used animal vaccines.

Geographic expansion of Fasciola hepatica (Linnaeus, 1758) due to changes in land use and cover in Brazil

Fasciolosis is caused by parasites of the genus Fasciola, affecting animals and humans worldwide. In South America, the disease is a result of infection with Fasciola hepatica and although animal infections are more frequently reported, the full extent of the impact on human health due to underdiagnosis remains uncertain. This study analyzed changes in land use and the distribution of F. hepatica in bovine livers in Brazil over 18 years. Data on land use and land cover were collected from the Mapbiomas Project. Data on 414,481,963 slaughtered cattle and condemned livers due to F. hepatica infection were obtained from 4,433 municipalities. Joinpoint analysis was used to study the time series, and the Susceptible-Infected-Recovered (SIR) model was utilized to explore the behavior of F. hepatica infection. In the North, pasture areas significantly increased (P = 0.000001), while forested areas decreased (P = 0.000001). The midwestern and northern regions concentrated the highest number (>290 million) of cattle slaughtered in Brazil. More than 2 million bovine livers were infected by F. hepatica. The infected cattle originated from 194 municipalities in 2002, increasing to 747 in 2020. We consider that the changes in land use and intense cattle transportation may have caused the expansion of F. hepatica. The SIR model analyzed the spread of the disease looking at all six biomes: Caatinga, Amazon Forest, Cerrado, Pantanal, Atlantic Forest, and Pampa. Moreover, this infection not only threatens the health of animals but is also a major concern to biodiversity and vulnerable human communities in South America. Emblematic biomes such as the Amazon basin already face challenges with logging, desertification, and loss of biodiversity. Therefore, strategies for mitigating infection should include controlling illegal pasture areas, establishing health inspections of animal transport, quarantine of newly arrived animals, and livestock zoning, as well as clear One Health policies.

Efficacy of flukicides against Fasciola hepatica and first report of triclabendazole resistance on German sheep farms

Fasciola hepatica infections lead to severe health problems and production losses in sheep farming, if not treated effectively. Triclabendazole has been used extensively over decades due to its unique efficacy range against all definitive hostfluke stages but published data about the susceptibility of F. hepatica to anthelmintics in Germany are lacking. This study aimed to identify current F. hepatica infections in German sheep flocks by coproscopic examinations and to evaluate the efficacy of anthelmintics with a focus on triclabendazole in a field study conducted from 2020 to 2022. Initial screening included 71 sheep farms, many of them with known history of fasciolosis. In this highly biased sample set, the frequency of F. hepatica infection at individual sheep and farm level were 12.8% and 35.2%, respectively. Additionally, eggs of Paramphistominae were found at frequencies of 4.8% and 15.5% at individual sheep and farm level, respectively. Due to low egg shedding intensity, faecal egg count reduction (FECR) tests could only be conducted on a few farms. The efficacy of triclabendazole was tested on 11 farms and albendazole on one farm, including 3–53 sheep/farm. Individual faecal samples were collected before and two weeks after treatment to evaluate the FECR using the sedimentation or FLUKEFINDER® or a modified FLUKEFINDER® method. On all farms a coproantigen reduction test was conducted in parallel. Lacking efficacy of triclabendazole even at double dosage was shown on one farm associated with a high number of animal losses due to acute fasciolosis. On this farm, the Fasciola miracidium development test was additionally performed, revealing a high in vitro ovicidal activity of albendazole while closantel was effective in vivo. On all other farms, sufficient efficacy of triclabendazole was observed. In conclusion, triclabendazole resistance appears not to be widespread on German sheep farms but, when present, can have serious effects on animal health.