Recent developments in the epidemiology, diagnosis, and treatment of Fasciola infection

Global distribution of zoonotic digenetic trematodes: a scoping review

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Advances in diagnostic approaches to Fasciola infection in animals and humans: An overviews

Fasciolosis, caused by Fasciola hepatica and F. gigantica, is an impediment to the livestock industry’s expansion and has a massively negative socio-economic impact due to its widespread prevalence in livestock. It is a waterborne zoonosis affecting human populations in the countries where rural economies are associated with livestock rearing. Conventional diagnosis of Fasciola infection is done by detecting parasite eggs in the faeces of infected animals or by immunological methods. Accurate and quick immunodiagnosis of Fasciola infection in animals and humans is based on the detection of antibodies and specific antigens expressed in the prepatent stage of the parasite. Both molecular and serodiagnostic tests developed thus far have enhanced the reliability of Fasciola diagnosis in both man and animals but are not widely available in resource-poor nations. A pen-side diagnostic test based on a lateral flow assay or a DNA test like loop-mediated isothermal amplification (LAMP) would be simple, fast, and cost-effective, enabling clinicians to treat animals in a targeted manner and avoid the development of drug resistance to the limited flukicides. This review focuses on the recent advances made in the diagnosis of this parasite infection in animals and humans.

In vitro and in vivo studies on a group of chalcones find promising results as potential drugs against fascioliasis

About a third of the world population is infected by helminth parasites implicated in foodborne trematodiasis. Fascioliasis is a worldwide disease caused by trematodes of the genus Fasciola spp. It generates huge economic losses to the agri-food industry and is currently considered an emerging zoonosis by the World Health Organization (WHO). The only available treatment relies on anthelmintic drugs, being triclabendazole (TCBZ) the drug of choice to control human infections. The emergence of TCBZ resistance in several countries and the lack of an effective vaccine to prevent infection highlights the need to develop new drugs to control this parasitosis. We have previously identified a group of benzochalcones as inhibitors of cathepsins, which have fasciolicidal activity in vitro and are potential new drugs for the control of fascioliasis. We selected the four most active compounds of this group to perform further preclinical studies. The compound's stability was determined against a liver microsomal enzyme fraction, obtaining half-lives of 34-169 min and low intrinsic clearance values (<13 μL/min/mg), as desirable for potential new drugs. None of the compounds were mutagenic or genotoxic and no in vitro cytotoxic effects were seen. Compounds C31 and C34 showed the highest selectivity index against liver fluke cathepsins when compared to human cathepsin L. They were selected for in vivo efficacy studies observing a protective effect, similar to TCBZ, in a mouse model of infection. Our findings strongly encourage us to continue the drug development pipeline for these molecules.

Fasciola hepatica Infection in Horses in Three Governorates in Northern Egypt: Prevalence and Risk Factors

Fasciola hepatica is a trematode parasite that affects wide range of mammalian hosts including horses. There are no epidemiological data on fasciolosis in Egyptian horses. Hence, the present study aimed to evaluate the seroprevalence of F. hepatica in horses using ELISA as well as assess the associated risk factors for fasciolosis infection. A total of 400 sera samples of horses from three Egyptian governorates were examined. The overall seroprevalence rate in horses was 13% and the disease was more prevalent in Qalubia (14.17%) and Gharbia (16.67%) which are located at Nile Delta. The likelihood of having F. hepatica seropositivity was higher in mixed-breed animals and stallions (OR = 3.97, 95%CI: 1.10-14.28 and OR = 2.07, 95%CI: 1.09-3.93, respectively), and in older horses more than 10 years (OR = 5.69, 95% CI: 1.98-16.36). Horses were more likely to be seropositive with F. hepatica when kept in outdoor housing (OR= 1.53, 95%CI: 0.78-3), during autumn (OR = 3.80, 95%CI: 1.17-12.32) and in the presence of snails (OR = 2.72, 95%CI: 1.34-5.52). Therefore, the obtained data contributes to the understanding of the epidemiology of Fasciola species, assess in establishment of management programmes to reduce disease and public health risks.

Single Amino Acid Polymorphisms in the Fasciola hepatica Carboxylesterase Type B Gene and Their Potential Role in Anthelmintic Resistance

The expression of the Fasciola hepatica carboxylesterase type B (CestB) gene is known to be induced upon exposure to the anthelmintic triclabendazole (TCBZ), leading to a substantial rise in enzyme-specific activity. Furthermore, the nucleotide sequence of the CestB gene displays variations that can potentially result in radical amino acid substitutions at the ligand binding site. These substitutions hold the potential to impact both the ligand-protein interaction and the catalytic properties of the enzyme. Thus, the objective of our study was to identify novel CestB polymorphisms in TCBZ-resistant parasites and field isolates obtained from a highly endemic region in Central Mexico. Additionally, we aimed to assess these amino acid polymorphisms using 3D modeling against the metabolically oxidized form of the anthelmintic TCBZSOX. Our goal was to observe the formation of TCBZSOX-specific binding pockets that might provide insights into the role of CestB in the mechanism of anthelmintic resistance. We identified polymorphisms in TCBZ-resistant parasites that exhibited three radical amino acid substitutions at positions 147, 215, and 263. These substitutions resulted in the formation of a TCBZSOX-affinity pocket with the potential to bind the anthelmintic drug. Furthermore, our 3D modeling analysis revealed that these amino acid substitutions also influenced the configuration of the CestB catalytic site, leading to alterations in the enzyme's interaction with chromogenic carboxylic ester substrates and potentially affecting its catalytic properties. However, it is important to note that the TCBZSOX-binding pocket, while significant for drug binding, was located separate from the enzyme's catalytic site, rendering enzymatic hydrolysis of TCBZSOX impossible. Nonetheless, the observed increased affinity for the anthelmintic may provide an explanation for a drug sequestration type of anthelmintic resistance. These findings lay the groundwork for the future development of a molecular diagnostic tool to identify anthelmintic resistance in F. hepatica.

Genetic variation and population structure of Fasciola hepatica: an in silico analysis

Fasciola hepatica is a trematode leading to heavy economic setbacks to the livestock sector globally. The population's genetic information and intimate kinship level are frequently assessed using analysis of mitochondrial DNA. In this analysis, we retrieved cox1 (n = 247) and nad1 (n = 357) sequences of F. hepatica from the NCBI GenBank database and aligned the sequences with the respective reference sequences using MEGA software. The median joining network was drawn using PopArt software while neutrality and diversity indices were estimated with the help of DnaSp software. Neighbor-joining phylogenetic tree was constructed using the MEGA software package. A total of 46 and 98 distinctive haplotypes were observed for cox1 and nad1 genes, respectively. Diversity indices indicated high haplotype and nucleotide diversities in both genes. Positive Tajima's D and Fu's Fs values were found for the entire population of both the genes under study. The cox1 and nad1 gene segments in this study showed high Tajima's D values, suggesting a low likelihood of future population growth. The Tajima's D value of the nad1 gene sequence is lower (2.14910) than that of the cox1 gene sequence (3.40314), which suggests that the former is growing at a slower rate. However, the region-wise analysis revealed that both the cox1 and nad1 genes showed deviation from neutrality suggesting a recent population expansion as a result of an excess of low-frequency polymorphism. Furthermore, the overall host-wise analysis showed positive and significant Tajima's D values for the cox1 and nad1 gene sequences. To the best of our knowledge, this is the first attempt to provide insights into genetic variations and population structure of F. hepatica at a global scale using cox1 and nad1 genes. Our findings suggest the existence of specific variants of F. hepatica in different parts of the world and provide information on the molecular ecology of F. hepatica. The results of this study also mark a critical development in upcoming epidemiological investigations on F. hepatica and will also contribute to understanding the global molecular epidemiology and population structure of F. hepatica.

The global prevalence of human fascioliasis: a systematic review and meta-analysis

Background

Fascioliasis is a parasitic zoonosis that can infect humans and be a source of significant morbidity. The World Health Organization lists human fascioliasis as a neglected tropical disease, but the worldwide prevalence of fascioliasis data is unknown.

Objective

We aimed to estimate the global prevalence of human fascioliasis.

Data sources and methods

We performed a systematic review and prevalence meta-analysis. We used the following inclusion criteria: articles published in the English, Portuguese, or Spanish languages from December 1985 to October 2022 and studies assessing the prevalence of Fasciola in the general population with an appropriate diagnostic methodology, including longitudinal studies, prospective and retrospective cohorts, case series, and randomized clinical trials (RCTs). We excluded animal studies. Two reviewers independently reviewed the selected studies for methodological quality, performing critical standard measures from JBI SUMARI. A random-effects model was conducted of the summary extracted data on the prevalence proportions. We reported the estimates according to the GATHER statement.

Results

In all, 5617 studies were screened for eligibility. Fifty-five studies from 15 countries were selected, including 154,697 patients and 3987 cases. The meta-analysis revealed a pooled prevalence of 4.5% [95% confidence interval (CI): 3.1-6.1; I² = 99.4%; T² = 0.07]. The prevalence in South America, Africa, and Asia was 9.0%, 4.8%, and 2.0%, respectively. The highest prevalence was found in Bolivia (21%), Peru (11%), and Egypt (6%). Subgroup analysis showed higher prevalence estimates in children, in studies from South America, and when Fas2-enzyme-linked immunosorbent assay (ELISA) was used as a diagnostic method. A larger study sample size (p = 0.027) and an increase in female percentage (p = 0.043) correlated with a decrease in prevalence. Multiple meta-regression showed a higher prevalence for hyperendemic than hypoendemic (p = 0.002) or mesoendemic (p = 0.013) regions.

Conclusion

The estimated prevalence and projected disease burden of human fascioliasis are high. Study findings support that fascioliasis continues to be a globally neglected tropical disease. Strengthening epidemiological surveillance and implementing measures to control and treat fascioliasis is imperative in the most affected areas.

Transcriptomic analysis supports a role for the nervous system in regulating growth and development of Fasciola hepatica juveniles

Fasciola spp. liver flukes have significant impacts in veterinary and human medicine. The absence of a vaccine and increasing anthelmintic resistance threaten sustainable control and underscore the need for novel flukicides. Functional genomic approaches underpinned by in vitro culture of juvenile Fasciola hepatica facilitate control target validation in the most pathogenic life stage. Comparative transcriptomics of in vitro and in vivo maintained 21 day old F. hepatica finds that 86% of genes are expressed at similar levels across maintenance treatments suggesting commonality in core biological functioning within these juveniles. Phenotypic comparisons revealed higher cell proliferation and growth rates in the in vivo juveniles compared to their in vitro counterparts. These phenotypic differences were consistent with the upregulation of neoblast-like stem cell and cell-cycle associated genes in in vivo maintained worms. The more rapid growth/development of in vivo juveniles was further evidenced by a switch in cathepsin protease expression profiles, dominated by cathepsin B in in vitro juveniles and by cathepsin L in in vivo juveniles. Coincident with more rapid growth/development was the marked downregulation of both classical and peptidergic neuronal signalling components in in vivo maintained juveniles, supporting a role for the nervous system in regulating liver fluke growth and development. Differences in the miRNA complements of in vivo and in vitro juveniles identified 31 differentially expressed miRNAs, including fhe-let-7a-5p, fhe-mir-124-3p and miRNAs predicted to target Wnt-signalling, which supports a key role for miRNAs in driving the growth/developmental differences in the in vitro and in vivo maintained juvenile liver fluke. Widespread differences in the expression of neuronal genes in juvenile fluke grown in vitro and in vivo expose significant interplay between neuronal signalling and the rate of growth/development, encouraging consideration of neuronal targets in efforts to dysregulate growth/development for parasite control.

Transcriptomic and proteomic profiling of peptidase expression in Fasciola hepatica eggs developing at host's body temperature

Fasciola hepatica is a global parasite of livestock which also causes a neglected zoonosis in humans. The parasite’s communication with the host during its complicated lifecycle is based on an ingenious enzymatic apparatus which includes a variety of peptidases. These enzymes are implicated in parasite migration, pathogenesis of the disease, and modification of host immune response. Although the dynamics of proteolytic machinery produced by intra-mammalian F. hepatica life stages has been previously investigated in great detail, peptidases of the eggs so far received little scientific attention. In this study, we performed a comparative RNA-seq analysis aimed at identification of peptidases expressed in F. hepatica eggs, cultured at 37 °C to represent gall bladder retained eggs, for different time periods and employed mass spectrometry in order to identify and quantify peptidases translated in F. hepatica egg lysates. We demonstrated that F. hepatica eggs undergo significant molecular changes when cultured at the physiological temperature of the definitive host. Egg transcriptome is subject to numerous subtle changes while their proteome is even more variable. The peptidase profile is considerably modified on both transcriptome and proteome level. Finally, we measured and classified proteolytic activities in extracts from F. hepatica eggs using a library of fluorogenic substrates and peptidase class-selective inhibitors. Activities of threonine peptidases were detected constantly, while the cysteine peptidases prevailing in freshly laid eggs are substituted by aspartic peptidase and metallopeptidase activities in the later stages of egg development.

Geospatial analysis of the associations between environmental contamination with livestock feces and children with chronic fascioliasis in the Anta province of Cusco, Peru

Fasciola hepatica is a neglected parasitic infection with significant human health and livestock industry impact. The Andean Altiplano harbors an estimated 50% of the Fasciola’s world infection burden. There is scarce data regarding the spatial associations between different Fasciola hosts. In this project, we aimed to determine the geospatial relationships between Fasciola eggs passed in feces of different livestock species and the risk of infection among each household as a unit. We used data from a cross-sectional study evaluating children and livestock feces for Fasciola infection around households in three districts of Anta province, in the Cusco region of Peru. Each sample was geographically tagged and evaluated for fascioliasis using microscopy methods. A total of 2070 households were included, the median age was 9.1 years (6.7–11.8), 49.5% were female, and 7.2% of the households had at least one infected child. A total of 2420 livestock feces samples were evaluated. The infection rate in livestock samples was 30.9%. The highest infection rate was found in sheep with 40.8%, followed by cattle (33.8%), and swine (26.4%). The median distance between a household with an infected child to a positive animal sample was 44.6 meters (IQR 14.7–112.8) and the distance between a household with no infected children to a positive animal sample was 62.2 meters (IQR 18.3–158.6) (p = 0.025). The multivariable logistic regression adjusted by presence of poor sanitation, unsafe water consumption, altitude, and presence of multiple infected children per household demonstrated an association between household infection and any cattle feces at a 50 meters radius (Uninfected: OR 1.42 (95%CI 1.07–1.89), p = 0.017. Infected: OR 1.89 (95%CI 1.31–2.73), p = 0.001), positive cattle feces at a 100 meters radius (OR 1.35 (95% CI 1.08–1.69), p = 0.008), and negative cattle feces at a 200 meters radius (OR 1.08 (95% CI 1.01–1.15), p = 0.022). We identified potential hot and cold spots for fascioliasis in the Anta province. An association between environmental contamination with feces from different livestock species and infected children in rural households was found in our study. Local health authorities may apply this strategy to estimate the risk of infection in human populations and apply targeted interventions.

Fasciola hepatica is the parasite that causes fascioliasis in the Andes region. The factors associated with transmission of the disease among humans have not been well described in the area studied. In this study, we evaluate the spatial relationships between infected households and the environmental burden of Fasciola eggs passed by different livestock in the Cusco region of Peru. We geographically marked and tested for fascioliasis feces provided by children and livestock. Infected and uninfected cattle as well as sheep feces were more likely to be in proximity to human households with infected children than to households without infected children. We were able to identify and map the areas of higher and lower infections rates. This information and strategy may be used in the control of the disease.

Stage-specific miRNAs regulate gene expression associated with growth, development and parasite-host interaction during the intra-mammalian migration of the zoonotic helminth parasite Fasciola hepatica

Background

MiRNAs are small non-coding RNAs that post-transcriptionally regulate gene expression in organisms ranging from viruses to mammals. There is great relevance in understanding how miRNAs regulate genes involved in the growth, development, and maturation of the many parasitic worms (helminths) that together afflict more than 2 billion people.

Results

Here, we describe the miRNAs expressed by each of the predominant intra-mammalian development stages of Fasciola hepatica, a foodborne flatworm that infects a wide range of mammals worldwide, most importantly humans and their livestock. A total of 124 miRNAs were profiled, 72 of which had been previously reported and three of which were conserved miRNA sequences described here for the first time. The remaining 49 miRNAs were novel sequences of which, 31 were conserved with F. gigantica and the remaining 18 were specific to F. hepatica. The newly excysted juveniles express 22 unique miRNAs while the immature liver and mature bile duct stages each express 16 unique miRNAs. We discovered several sequence variant miRNAs (IsomiRs) as well as miRNA clusters that exhibit strict temporal expression paralleling parasite development. Target analysis revealed the close association between miRNA expression and stage-specific changes in the transcriptome; for example, we identified specific miRNAs that target parasite proteases known to be essential for intestinal wall penetration (cathepsin L3). Moreover, we demonstrate that miRNAs fine-tune the expression of genes involved in the metabolic pathways that allow the parasites to move from an aerobic external environment to the anerobic environment of the host.

Conclusions

These results provide novel insight into the regulation of helminth parasite development and identifies new genes and miRNAs for therapeutic development to limit the virulence and pathogenesis caused by F. hepatica.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-022-08644-z.

Molecular characteristics and genetic diversity of Fasciola hepatica from sheep in Xinjiang, China

Introduction

Fasciola hepatica is a trematode infecting ruminants worldwide and occasionally affecting other animal species, including humans. It causes significant economic losses. Geographic distribution and patterns of infection must be considered before control and management measures are developed for this parasite. DNA molecular markers are useful for the identification of flukes and elucidation of their genetic evolution. Therefore, the population structure of F. hepatica was studied using this method in sheep in Xinjiang, China.

Material and Methods

The molecular characteristics, genetic relationships within the population and dispersal patterns of F. hepatica isolates were analysed based on the cox1 and nad1 genes. The population structure of F. hepatica from three regions of Xinjiang was explored and a neutrality test was conducted.

Results

The cox1 and nad1 genes have 21 and 42 variable sites, respectively, which can be classified into 34 and 33 haplotypes. Median-joining network and phylogenetic tree analyses showed that there was no significant variation in F. hepatica isolates between the three geographical regions. Analysis of variance revealed that the genetic variation of F. hepatica was mainly present within the populations. The neutrality test indicated that the populations were relatively stable but the Hami population may have undergone short-term expansion.

Conclusion

This study revealed for the first time the molecular characteristics, genetic diversity and dispersal patterns of F. hepatica isolates from sheep in Xinjiang, thus providing new insights into the genetic variation and haplotype diversity of F. hepatica from indigenous sheep.

Spatial visualization of drug uptake and distribution in Fasciola hepatica using high-resolution AP-SMALDI mass spectrometry imaging

Understanding drug penetration, distribution, and metabolization is fundamental for understanding drug efficacy. This also accounts for parasites during antiparasitic treatment. Recently, we established matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) in blood flukes and liver flukes. This label-free technique is capable of visualizing the molecular distribution of endogenous and exogenous molecules, such as drug compounds. Here, we conducted atmospheric-pressure scanning microprobe MALDI MSI (AP-SMALDI MSI) of tissue sections of adult Fasciola hepatica that have been treated in vitro with 100 µM of triclabendazole (TCBZ), the drug of choice for treatment of fasciolosis, and its main metabolite triclabendazole sulfoxide (TCBZ-SO). Measurements covered an m/z mass range of 250–1,000 and provided a high spatial resolution using a pixel size of 10 µm. To support the interpretation of drug distribution, we first identified endogenous lipids that mark characteristic tissues such as the gastrodermis, the tegument, and the parenchyma. The obtained results suggested an early tegumental route of TCBZ uptake within 20 min, followed by spreading throughout the parasite after 4 h, and an even distribution in most tissues after 12 h. This coincided with a strong reduction of parasite vitality. TCBZ-SO treatment demonstrated the accumulation of this metabolite in the same tissues as the parent drug compound. These data demonstrate the auspicious potential of MALDI MSI to visualize uptake and distribution patterns of drugs or drug-candidate compounds in parasites, which might contribute to preclinical drug discovery in liver fluke research and beyond.

Case Report: Fascioliasis Hepatica Precisely Diagnosed by Metagenomic Next-Generation Sequencing and Treated With Albendazole

The clinical manifestations of fascioliasis hepatica in humans are unspecific. Traditional diagnosis relies on evidence of live parasites or eggs in the bile or feces. However, due to similar imaging manifestations, they are often misdiagnosed as malignant tumors. Here, we report a case of a 43-year-old woman with fever and space-occupying liver disease. Liver biopsy, parasite-specific antibody screening, and stool testing did not find any pathogens. Therefore, metagenomic next-generation sequencing (mNGS) and routine microbiological examinations were performed. Finally, Fasciola hepatica was only identified by mNGS. The body temperature of the patient and the eosinophil count remained normal, and the space-occupying liver lesions were significantly absorbed after more than 7 months of treatment with albendazole. The details of this case highlight the timely use of mNGS to identify parasites and judge therapeutic effects after treatment, providing important help for clinical decision-making.

Diagnosis and Risk Factors of Bovine and Human Fascioliasis in Cattle Farms from a Venezuelan Andean Rural Area

INTRODUCTION

Fascioliasis is caused in Venezuela by the trematode Fasciola hepatica, affecting herbivorous and human. The Venezuelan Andean region is endemic for bovine fascioliasis and its presence in humans is not known. The objective of this work was to detected positive cases of bovine and human fascioliasis by coprological and immunological techniques and determine the possible risk factors, in eight cattle farms of a Venezuelan Andean rural area.

METHODS

We studied 143 samples of feces and sera of bovines, and 34 samples of feces and sera of humans. Feces were examined by several coprologic techniques, while sera were evaluated by ELISA using two antigens: crude extract (CE) and surface proteins (SP) of F. hepatica, which were previously standardized and validated.

RESULTS

The frequency of fascioliasis in bovines was 21% by coprology, and 49.7% by SP-ELISA. The human detection was 0% by coprology, and 29.4% by SP-ELISA. There were statistical significative differences between cattle farms, regarding to the positive results by coprology and by SP-ELISA. About the possible risk factors, statistical association was found only with the presence of snails near or in the farms and consumption of non-channeled water (river, ditch or spring), both for cattle and for humans.

CONCLUSION

The results showed that the studied area is endemic for bovine fascioliasis, the human has been in contact with F. hepatica and there are risk factors for the transmission of the parasite in the studied farms.

Human Fascioliasis (Liver Fluke Disease) in Hawai'i: Case Report and Review of Human Fascioliasis Acquired in the United States

Fascioliasis is a foodborne zoonotic infection caused by the trematode liver flukes: Fasciola hepatica and Fasciola gigantica (F. gigantica). Infections may cause acute and chronic hepatobiliary tract diseases in herbivore animals and humans. Fascioliasis is present worldwide, particularly in regions where sheep and cattle are raised. The global burden of human fascioliasis is estimated to be 2.7 million. Human infections are rare in the United States, and most infections were acquired abroad. In the 1950s, several human cases of F. gigantica infection were reported from Hawai'i, but no subsequent cases have been reported until the case described here. This case report describes a man from Hawai'i Island who ate raw wild watercress, and 22 days later, developed acute phase fascioliasis with fever, acute hepatitis, peripheral eosinophilia, and hypodense lesions seen on liver diagnostic imaging. Immunodiagnostic tests were positive for Fasciola species. Based on earlier reports from Hawai'i, F. gigantica infection was likely. Clinical abnormalities resolved after treatment with triclabendazole. Physicians should consider fascioliasis in immigrants and travelers from endemic areas with acute hepatitis and eosinophilia after eating raw wild watercress or chronic hepatobiliary disease. Hepatobiliary imaging and serological testing are useful for diagnosis. Oral triclabendazole is the preferred treatment. Animal fascioliasis appears to be spreading in the United States, and the popularly perceived health benefits of eating raw wild watercress and other aquatic plants may lead to more human infections. The rarity of human infections in Hawai'i suggests that it is safe to eat commercially grown watercress cultivated in Hawai'i.

Plasma cytokines during acute human fascioliasis

Fascioliasis is a foodborne trematode endemic worldwide. Children under 15 years have the highest prevalence of infection. We hypothesized that acute fascioliasis would be associated with more pronounced cytokine changes than in chronic disease or no helminth infections. To test this hypothesis, 33 children who lived in the Peruvian highlands were classified into 3 groups: acute fascioliasis, chronic fascioliasis, and no helminth infection. Type Th1, Th2, and Th17 cytokines were measured in plasma by cytometric bead array. Children with acute infection had higher levels of IL-5 and IL-17 compared with controls (p < 0.001 and p < 0.007, respectively). The increased IL-5 plasma concentration in children with acute infection was associated with the eosinophilia found in that group.

Stunting in pre-school and school-age children in the Peruvian highlands and its association with Fasciola infection and demographic factors

Fascioliasis is a zoonotic trematode infection that is endemic in the highlands of Peru. Chronic fascioliasis can be asymptomatic and remain undiagnosed for years. Chronic malnutrition in children, as manifested by stunting, leads to delayed cognitive development and lost productivity. We hypothesized that fascioliasis is among the factors associated with stunting in children from endemic areas. We conducted a cross-sectional study among children attending pre-school and school in 26 communities in the Anta province in the Cusco region of Peru. We conducted interviews to collect information on demographic, socioeconomic, and medical history. Blood was collected and tested for complete cell count and FAS2 ELISA for Fasciola antibodies. Three stool samples per participant were tested for parasites by Kato-Katz and Lumbreras rapid sedimentation methods. Chronic fascioliasis was determined by the presence of ova in stool. Children's height, weight, and age were recorded and used to calculate height for age Z scores (HAZ). Three thousand children participated in the study. Nine percent (264) of children had at least one positive test for Fasciola infection, 6% (164) had chronic fascioliasis, and 3% (102) had only positive antibody tests. The median HAZ was -1.41 (IQR: -2.03 to -0.81) and was similar in males and females. Twenty six percent (776) of children had stunting with HAZ < -2. Children with chronic fascioliasis had a lower median HAZ than children without Fasciola (-1.54 vs. -1.4, p = 0.014). History of treatment for malnutrition, history of treatment for anemia, having other helminths in stool, lower socioeconomic score, living at a higher elevation, and fewer years of schooling of both parents were associated with a lower HAZ score. In a multiple regression analysis, older age and a lower socioeconomic score were associated with a lower HAZ score. While fascioliasis and other helminths were associated with lower HAZ, they were not independent of the socioeconomic score.

Recognition Pattern of the Fasciola hepatica Excretome/Secretome during the Course of an Experimental Infection in Sheep by 2D Immunoproteomics

Excretory/secretory products released by helminth parasites have been widely studied for their diagnostic utility, immunomodulatory properties, as well as for their use as vaccines. Due to their location at the host/parasite interface, the characterization of parasite secretions is important to unravel the molecular interactions governing the relationships between helminth parasites and their hosts. In this study, the excretory/secretory products from adult worms of the trematode Fasciola hepatica (FhES) were employed in a combination of two-dimensional electrophoresis, immunoblot and mass spectrometry, to analyze the immune response elicited in sheep during the course of an experimental infection. Ten different immunogenic proteins from FhES recognized by serum samples from infected sheep at 4, 8, and/or 12 weeks post-infection were identified. Among these, different isoforms of cathepsin L and B, peroxiredoxin, calmodulin, or glutathione S-transferase were recognized from the beginning to the end of the experimental infection, suggesting their potential role as immunomodulatory antigens. Furthermore, four FhES proteins (C2H2-type domain-containing protein, ferritin, superoxide dismutase, and globin-3) were identified for the first time as non-immunogenic proteins. These results may help to further understand host/parasite relationships in fasciolosis, and to identify potential diagnostic molecules and drug target candidates of F. hepatica.

Efficacy of a multivalent vaccine against Fasciola hepatica infection in sheep

In this work we report the protection found in a vaccination trial performed in sheep with two different vaccines composed each one by a cocktail of antigens (rCL1, rPrx, rHDM and rLAP) formulated in two different adjuvants (Montanide ISA 61 VG (G1) and Alhydrogel®(G2)). The parameters of protection tested were fluke burden, faecal egg count and evaluation of hepatic lesions. In vaccinated group 1 we found a significant decrease in fluke burden in comparison to both unimmunised and infected control group (37.2%; p = 0.002) and to vaccinated group 2 (Alhydrogel®) (27.08%; p = 0.016). The lower fluke burden found in G1 was accompanied by a decrease in egg output of 28.71% in comparison with the infected control group. Additionally, gross hepatic lesions found in vaccine 1 group showed a significant decrease (p = 0.03) in comparison with unimmunised-infected group. The serological study showed the highest level for both IgG1 and IgG2 in animals from group 1. All these data support the hypothesis of protection found in vaccine 1 group.

Loop-Mediated Isothermal Amplification as Point-of-Care Diagnosis for Neglected Parasitic Infections

The World Health Organisation (WHO) has placed twenty diseases into a group known as neglected tropical diseases (NTDs), twelve of them being parasitic diseases: Chagas’ disease, cysticercosis/taeniasis, echinococcosis, food-borne trematodiasis, human African trypanosomiasis (sleeping sickness), leishmaniasis, lymphatic filariasis, onchocerciasis (river blindness), schistosomiasis, soil-transmitted helminthiasis (ascariasis, hookworm, trichuriasis), guinea-worm and scabies. Such diseases affect millions of people in developing countries where one of the main problems concerning the control of these diseases is diagnosis-based due to the most affected areas usually being far from laboratories having suitable infrastructure and/or being equipped with sophisticated equipment. Advances have been made during the last two decades regarding standardising and introducing techniques enabling diagnoses to be made in remote places, i.e., the loop-mediated isothermal amplification (LAMP) technique. This technique’s advantages include being able to perform it using simple equipment, diagnosis made directly in the field, low cost of each test and the technique’s high specificity. Using this technique could thus contribute toward neglected parasite infection (NPI) control and eradication programmes. This review describes the advances made to date regarding LAMP tests, as it has been found that even though several studies have been conducted concerning most NPI, information is scarce for others.

Glutathione-S-transferase: an important diagnostic antigen of liver amphistome Gigantocotyle explanatum, infecting the Indian water buffalo

The foodborne trematodiases pose a significant health problem to the animals as well as the human population living in close proximities with the livestock and are still considered as the neglected tropical diseases by the World Health Organisation. The digenetic trematode, Gigantocotyle explanatum infecting the liver of Indian water buffalo, Bubalus bubalis, has been identified as one of the most common helminth parasite responsible for the disease, amphistomosis, in livestock. Despite huge abattoir prevalence, the epidemiological data and the actual economic losses incurred due to this parasite alone are yet to be established probably due to the limitations of routinely used diagnostic tests. The gold standard for the confirmation of such infections under field conditions is still the fecal egg count (FEC). However, the poor sensitivity and cumbersome nature of these tests necessitates the development of a more sensitive, reliable and easy to perform workflow/method. Immunological diagnosis of helminthic infections is still considered as an alternative to the FEC. Therefore, efforts have been made to utilize glutathione-S-transferase (GST), a vitally significant molecule of the adult G. explanatum, for the serodiagnosis of amphistomosis under both laboratory and field conditions. The GST antigen was first affinity purified from the somatic extract of the adult worms since its highest level was recorded in the somatic extracts followed by eggs and the excretory/secretory products. A five-fold affinity purified native GST antigen of about 25 kDa was found to be highly immunogenic as evident from high titre (1:25,600) of the polyclonal antibodies raised in the rabbits. The immunoblotting results revealed differential presence of GST in the adult worms, their eggs and excretory/secretory products. The immunolocalization studies revealed that the vitelline glands are the major source of GST in liver amphistome. Further, we were able to successfully screen animals naturally infected with G. explanatum using anti GST polyclonal antibodies in dot blot assay. High levels of both circulating GST antigen and anti GST antibodies were detected in the serum of the animals naturally infected with G. explanatum, while no cross reactivity was observed with the tropical liver fluke, F. gigantica which often infects the buffalo liver concurrently. The findings of the present study indicate that GST could be used as an important antigen for the diagnosis of G. explanatum infection in Indian water buffaloes.

Mass Drug Administration of Triclabendazole for Fasciola Hepatica in Bolivia

Human infection with Fasciola hepatica leads to obstruction of the common bile duct by adult worms and disease characterized by biliary colic, epigastric pain, and nausea. Recommended treatment is a single dose of triclabendazole (TCBZ) (10 mg/kg). Because in the 1990s the Bolivian Altiplano bordering Lake Titicaca was thought to have the highest prevalence of human fascioliasis worldwide, the Bolivian Ministry of Health instituted TCBZ mass drug administration (MDA). From 2008 to 2016 (excepting 2015), one dose of 250 mg was administered, usually in September/October, to each resident of highly endemic regions willing to participate. This is apparently the first reported use of MDA for Fasciola. The proportion of persons in key regions receiving TCBZ MDA was 87% in 2016. In 2017, we resurveyed key regions, and found that the MDA program had been dramatically successful. Whereas Fasciola prevalence was reported as 26.9% in Huacullani/Tiahuanaco and 12.6% in Batallas in 1999, there was 0.7% prevalence in Huacullani/Tiahuanaco and 1% in Batallas in 2017. However, lessons from schistosomiasis control efforts suggest that for sustained control of Fasciola infection, Fasciola MDA needs to be maintained and coupled with measures to control infection in the intermediary snail and in the animal hosts of F. hepatica.

Economic impact of the liver condemnation of cattle infected with Fasciola hepatica in the Peruvian Andes

Fasciolosis is a zoonotic food- and waterborne infection related to great economic losses on ruminant production. In order to determine the prevalence of bovine liver condemnations due to fasciolosis in an abattoir at the Central Andes of Peru, we evaluated the records of an authorized slaughterhouse in Huancayo, at 3300 m above sea level, over 16 months. Subsequently, the average weights of condemned viscera and carcasses were also estimated to determine the direct and indirect economic losses. Fasciolosis was the main cause of liver condemnation, with a prevalence of 55.72% (3926/7046; CI 95%: 56.88-54.56%). The livers infected were more than double the amount of livers supplied to markets in this period. Although the average price of liver in the Peruvian Andes is very cheap, approximately 16.45 tons of livers were destroyed, estimating a direct economic loss of US$ 35,080 (CI 95%: US$ 29,178-40,938). The indirect loss due to decreased body weight gain (calculated using 10% of the average weight of a healthy animal carcass) was estimated at US$ 354,570 (CI 95%: US$ 387,908-US$ 321,227). Fasciolosis is an important zoonotic disease that threatens food security in the Andean region, with major repercussions on the income of the livestock industry and the availability of cheap protein sources.

Multigene typing and phylogenetic analysis of Fasciola from endemic foci in Iran

Fasciolosis is a public health problem originally transmitted from livestock. Although molecular analysis of the nuclear and mitochondrial genes allow discrimination between the two known species of Fasciola, F. hepatica and F. gigantica, these markers do not permit the detection of hybrid forms. On the other hand, molecular analysis of the pepck and pold genes from Fasciola do permit the detection of hybrid isolates and this study has not yet been performed on specimens from human and domesticated animals in Iran. Therefore, the aim of this study was to molecularly analyze Fasciola isolates using both conventional and the two new genetic markers mentioned above. Fifty-three adult Fasciola worms were isolated from the livers of 28 domesticated animals, including sheep, cattle and goat. Moreover, an adult worm was obtained from the bile duct of an infected woman during endoscopic retrograde cholangio-pancratography (ERCP). Targeted fragments from the ITS-1, NDI and COX1 genes were amplified using specific primers. PCR products were sequenced and genetically analyzed using MEGA v.7 and DnaSP software. Additionally, the pepck and pold regions were amplified and analyzed using multiplex PCR and RLFP-PCR, respectively. Multiple alignment of sequenced fragments showed highest similarity among the ITS-1 sequences isolated from all four hosts in comparison to the other genes. Furthermore, sequence diversity across the COX1 was higher than the NDI and ITS-1. Diversity among sequences isolated from cattle was higher than those from sheep and goat in all three genes. Tajima's D and Fu's Fs were negative and statistically significant for all the genes except ITS-1. Phylogenetic trees showed that the human F. hepatica isolate was closer to sheep isolates. The results of the pepck and pold analyses showed that all isolates were F. hepatica and there were no hybrid forms among samples. The molecular analyses corroborated this finding.

Case Report: Hepatic Fascioliasis in a Young Afghani Woman with Severe Wheezing, High-Grade Peripheral Eosinophilia, and Liver Lesions: A Brief Literature Review

A 23-year-old recent emigrant from Afghanistan presented in August 2017 with severe wheezing and dyspnea that required hospital admission. Her illness was associated with marked peripheral blood eosinophilia (9,900-15,600/µL; 45.2-68%), as well as mild nausea, epigastric pain, and decreased appetite. She had lived until 3 months earlier in close proximity to cattle in her home in Kabul and did not recall eating watercress or other leafy plants associated with Fasciola hepatica transmission. Computerized tomography scanning showed bilateral ground-glass lung consolidations and multiple distinctive hypo-attenuating linear, tubuliform, and nodular liver lesions, including a large subcapsular hematoma. Numerous tests for rheumatological and malignant disorders were negative. Fasciola hepatica infestation was suspected on epidemiological, clinical, and radiographic grounds, and was confirmed by immunoblotting at the Centers for Disease Control (CDC). Multiple stool ova and parasite examinations were negative and endoscopic retrograde cholangiopancreatography did not identify trematodes. Her acute respiratory illness resolved with asthma-targeted therapies and her eosinophilia resolved with triclabendazole, which was obtained from CDC via an FDA Investigational New Drug application. Fascioliasis is uncommon in the United States, but the prolonged warfare and civil strife in Afghanistan and adjacent areas may lead to increased incidence outside the endemic region. Her case also demonstrates how hepatic imaging features of fascioliasis can be pathognomonic in clinical scenarios with eosinophilia and appropriate epidemiology and clinical features. We also highlight her relatively unusual presentation with symptoms of Loeffler-like syndrome alone.

Reference gene analysis and its use for kinase expression profiling in Fasciola hepatica

The liver fluke Fasciola hepatica causes fasciolosis, a foodborne zoonosis affecting humans and livestock worldwide. A reliable quantification of gene expression in all parasite life stages relevant for targeting by anthelmintics in the mammalian host is fundamental. The aim of this study was to define a set of stably expressed reference genes for qRT-PCR in Fasciola studies. We determined the expression stabilities of eight candidate reference genes by the algorithms NormFinder, geNorm, BestKeeper, and comparative ΔCT method. The most stably expressed reference genes for the comparison of intra-mammalian life stages were glutamyl-prolyl-tRNA synthetase (Fheprs) and tubulin-specific chaperone D (Fhtbcd). The two best reference genes for analysis of in vitro-cultured juveniles were Fhtbcd and proteasome subunit beta type-7 (Fhpsmb7). These genes should replace the housekeeping gene gapdh which is used in most Fasciola studies to date, but in fact was differentially expressed in our analysis. Based on the new reference genes, we quantified expression of five kinases (Abl1, Abl2, PKC, Akt1, Plk1) discussed as targets in other parasitic flatworms. Distinct expression patterns throughout development were revealed and point to interesting biological functions. We like to motivate using this set of validated reference genes for future F. hepatica research, such as studies on drug targets or parasite development.

Evaluation of nitazoxanide treatment following triclabendazole failure in an outbreak of human fascioliasis in Upper Egypt

Background

Fascioliasis is a neglected zoonosis with major public health implications in humans. Although triclabendazole (TCBZ) is the drug of choice, there are records of TCBZ failure worldwide. TCBZ-resistant fascioliasis is treated with alternative approved drugs including nitazoxanide (NTZ), with varying levels of efficacy. Data on NTZ efficacy after TCBZ failure in Egypt is scarce. This study evaluated the efficacy of NTZ in cases of TCBZ failure during an outbreak of fascioliasis in Assiut governorate of Upper Egypt.

Methodology/Principal findings

This prospective study included 67 patients from the outpatient clinic in Manfalout locality of Assiut governorate with clinical manifestations of acute fascioliasis. These included high eosinophilia (> 6% eosinophils in peripheral blood), positive anti-Fasciola antibodies, and hepatic focal lesions (HFL) or ascites on abdominal ultrasound or computed tomography. All patients initially received TCBZ at recommended doses. Patients were followed up after 1 month to assess response. According to the responses, patients were categorized as non-responders and responders. The non-responders received a trial of NTZ and were re-assessed for response based on clinical manifestations, eosinophil count, and abdominal ultrasound. Patients not responding to NTZ received additional doses of TCBZ.

One month after initial TCBZ treatment, 37 patients responded well to TCBZ, while 30 patients failed to respond with persistence of fever, abdominal pain, high eosinophilia, and HFL. Most non-responders were male (56.7%); females predominated among TCBZ responders (62.2%). The mean age of the non-responders was relatively lower, at 20.57 ± 14.47 years (p = 0.004). Following NTZ therapy, HFL disappeared in 9/30 (30%) patients and eosinophil counts normalized in only 2 (6.7%) patients, indicating an overall efficacy of 36.6%. The remaining cases received additional doses of TCBZ with complete clinical, pathological, and radiological resolution.

Conclusions/Significance

Nitazoxanide was partially effective in TCBZ failure in acute human fascioliasis in Upper Egypt. Further studies with larger samples are highly encouraged and further research is urgently needed to find new therapeutic alternatives to TCBZ.

Fascioliasis is a neglected zoonosis with major public health implications in humans. Triclabendazole (TCBZ) is the drug of choice, but alternative approved drugs are necessary in cases of TCBZ failure. Nitazoxanide (NTZ) is an alternative used in such cases. However, the efficacy of NTZ in TCBZ-failure cases among patients in Egypt remains unclear. In this study, the efficacy of NTZ was evaluated in cases of TCBZ failure during an outbreak of human fascioliasis in Assiut governorate of Upper Egypt. This study enrolled 67 patients diagnosed with fascioliasis based on clinical, laboratory, and radiological findings. These patients were referred from the outpatient clinic in Manfalout locality of Assiut governorate in Egypt. All patients received TCBZ at recommended doses as initial treatment. Those failing to respond were treated with NTZ at standard doses; following therapy, lesions in the liver and high eosinophil counts were resolved in 30% and 6.7% patients, respectively, indicating an overall efficacy of 36.6%. Therefore, in this outbreak of human fascioliasis in Upper Egypt, NTZ was found to be partially effective in cases with TCBZ failure.

Prevalence of bovine fascioliasis in a new-emerging focus of human fascioliasis in BoyerAhmad district, southwest of Iran

BACKGROUND

The prevalence of fascioliasis in a population of cattle in a new-emerging focus of human fascioliasis in Boyer-Ahmad District, in the southwest of Iran, was investigated, using an ELISA system and coprological methods.

METHODS

Blood, as well as stool samples, were collected from 150 dairy cattle consisted of 82 (54.7%) males and 68 (45.3%) females, aged from 1 to 8 years, selected from different pastures. The stool samples were evaluated by direct wet mount microscopic examination as well as sedimentation methods. Moreover, modified Telemann was used for detecting of Fasciola eggs. Anti-Fasciola antibodies in the cattle sera samples were determined, using a Fasciola excretory-secretory antigen-specific ELISA.

RESULTS

Anti-Fasciola antibodies were detected in 64 (42.4%) of the subjects by ELISA. Out of 64 seropositive cases, 29 (45.3%) were female and 35 (54.6%) were male. No significant association was found between sex and seropositivity to fascioliasis. Considering the age of the cattle, the highest prevalence of fascioliasis (23%) was found in the 5-year old age group. However, the difference between the age of the cattle and seropositivity to fascioliasis was not statistically significant (P > 0.05). Fasciola eggs were not detected in fecal samples of any of the studied cattle, while Paramphistomide, as well as Dicrocoelium dendriticum eggs, were detected in 6 (4%) and 17 (11.3%) of the subjects, respectively.

CONCLUSION

Findings of the current study provide basic information about bovine fascioliasis in a new focus of human fascioliasis in Iran, which is needed for effective control of this parasitic infection in such areas.

Diagnosis of Human Trematode Infections

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

Cathepsin L Inhibitors with Activity against the Liver Fluke Identified From a Focus Library of Quinoxaline 1,4-di-N-Oxide Derivatives

Infections caused by Fasciola species are widely distributed in cattle and sheep causing significant economic losses, and are emerging as human zoonosis with increasing reports of human cases, especially in children in endemic areas. The current treatment is chemotherapeutic, triclabendazole being the drug of preference since it is active against all parasite stages. Due to the emergence of resistance in several countries, the discovery of new chemical entities with fasciolicidal activity is urgently needed. In our continuous search for new fasciolicide compounds, we identified and characterized six quinoxaline 1,4-di-N-oxide derivatives from our in-house library. We selected them from a screening of novel inhibitors against FhCL1 and FhCL3 proteases, two essential enzymes secreted by juvenile and adult flukes. We report compounds C7, C17, C18, C19, C23, and C24 with an IC₅₀ of less than 10 µM in at least one cathepsin. We studied their binding kinetics in vitro and their enzyme-ligand interactions in silico by molecular docking and molecular dynamic (MD) simulations. These compounds readily kill newly excysted juveniles in vitro and have low cytotoxicity in a Hep-G2 cell line and bovine spermatozoa. Our findings are valuable for the development of new chemotherapeutic approaches against fascioliasis, and other pathologies involving cysteine proteases.

Cathepsin L3 From Fasciola hepatica Induces NLRP3 Inflammasome Alternative Activation in Murine Dendritic Cells

The production of IL-1-family cytokines such as IL-1β and IL-18 is finely regulated by inflammasome activation after the recognition of pathogens associated molecular pattern (PAMPs) and danger associated molecular patterns (DAMPs). However, little is known about the helminth-derived molecules capable of activating the inflammasome. In the case of the helminth trematode Fasciola hepatica, the secretion of different cathepsin L cysteine peptidases (FhCL) is crucial for the parasite survival. Among these enzymes, cathepsin L3 (FhCL3) is expressed mainly in the juvenile or invasive stage. The ability of FhCL3 to digest collagen has demonstrated to be critical for intestinal tissue invasion during juvenile larvae migration. However, there is no information about the interaction of FhCL3 with the immune system. It has been shown here that FhCL3 induces a non-canonical inflammasome activation in dendritic cells (DCs), leading to IL-1β and IL-18 production without a previous microbial priming. Interestingly, this activation was depending on the cysteine protease activity of FhCL3 and the NLRP3 receptor, but independent of caspase activation. We also show that FhCL3 is internalized by DCs, promoting pro-IL-1β cleavage to its mature and biologically active form IL-1β, which is released to the extracellular environment. The FhCL3-induced NLRP3 inflammasome activation conditions DCs to promote a singular adaptive immune response, characterized by increased production of IFN-γ and IL-13. These data reveal an unexpected ability of FhCL3, a helminth-derived molecule, to activate the NLRP3 inflammasome, which is independent of the classical mechanism involving caspase activation.