Gigantica Infection Research Articles

Fasciola hepatica - Convoluted life forms and names.

Infection of ruminants and humans with Fasciola gigantica is attracting increasing attention due to its economic impact and public health significance. However, little is known of innate immune responses during F. gigantica infection. Here, we investigated the expression profiles of genes involved in Toll-like receptors (TLRs) and NOD-like receptors (NLRs) signaling pathways in buffaloes infected with 500 F. gigantica metacercariae. Serum, liver and peripheral blood mononuclear cell (PBMC) samples were collected from infected and control buffaloes at 3, 10, 28, and 70 days post infection (dpi). Then, the levels of 12 cytokines in serum samples were evaluated by ELISA. Also, the levels of expression of 42 genes, related to TLRs and NLRs signaling, in liver and PBMCs were determined using custom RT2 Profiler PCR Arrays. At 3 dpi, modest activation of TLR4 and TLR8 and the adaptor protein (TICAM1) was detected. At 10 dpi, NF-κB1 and Interferon Regulatory Factor signaling pathways were upregulated along with activation of TLR1, TLR2, TLR6, TLR10, TRAF6, IRF3, TBK1, CASP1, CD80, and IFNA1 in the liver, and inflammatory response with activated TLR4, TLR9, TICAM1, NF-κB1, NLRP3, CD86, IL-1B, IL-6, and IL-8 in PBMCs. At 28 dpi, there was increase in the levels of cytokines along with induction of NLRP1 and NLRP3 inflammasomes-dependent immune responses in the liver and PBMCs. At 70 dpi, F. gigantica activated TLRs and NLRs, and their downstream interacting molecules. The activation of TLR7/9 signaling (perhaps due to increased B-cell maturation and activation) and upregulation of NLRP3 gene were also detected. These findings indicate that F. gigantica alters the expression of TLRs and NLRs genes to evade host immune defenses. Elucidation of the roles of the downstream effectors interacting with these genes may aid in the development of new interventions to control disease caused by F. gigantica infection.

Expression profiles of genes involved in TLRs and NLRs signaling pathways of water buffaloes infected with Fasciola gigantica

Infection of ruminants and humans with Fasciola gigantica is attracting increasing attention due to its economic impact and public health significance. However, little is known of innate immune responses during F. gigantica infection. Here, we investigated the expression profiles of genes involved in Toll-like receptors (TLRs) and NOD-like receptors (NLRs) signaling pathways in buffaloes infected with 500F. gigantica metacercariae. Serum, liver and peripheral blood mononuclear cell (PBMC) samples were collected from infected and control buffaloes at 3, 10, 28, and 70days post infection (dpi). Then, the levels of 12 cytokines in serum samples were evaluated by ELISA. Also, the levels of expression of 42 genes, related to TLRs and NLRs signaling, in liver and PBMCs were determined using custom RT2 Profiler PCR Arrays. At 3 dpi, modest activation of TLR4 and TLR8 and the adaptor protein (TICAM1) was detected. At 10 dpi, NF-κB1 and Interferon Regulatory Factor signaling pathways were upregulated along with activation of TLR1, TLR2, TLR6, TLR10, TRAF6, IRF3, TBK1, CASP1, CD80, and IFNA1 in the liver, and inflammatory response with activated TLR4, TLR9, TICAM1, NF-κB1, NLRP3, CD86, IL-1B, IL-6, and IL-8 in PBMCs. At 28 dpi, there was increase in the levels of cytokines along with induction of NLRP1 and NLRP3 inflammasomes-dependent immune responses in the liver and PBMCs. At 70 dpi, F. gigantica activated TLRs and NLRs, and their downstream interacting molecules. The activation of TLR7/9 signaling (perhaps due to increased B-cell maturation and activation) and upregulation of NLRP3 gene were also detected. These findings indicate that F. gigantica alters the expression of TLRs and NLRs genes to evade host immune defenses. Elucidation of the roles of the downstream effectors interacting with these genes may aid in the development of new interventions to control disease caused by F. gigantica infection.

Dynamic expression of cytokine and transcription factor genes during experimental Fasciola gigantica infection in buffaloes

BackgroundDetermining the mechanisms involved in the immune-pathogenesis of the tropical liver fluke, Fasciola gigantica, is crucial to the development of any effective therapeutic intervention. Here, we examined the differential gene expression of cytokines and transcription factors in the liver of F. gigantica-infected buffaloes, over the course of infection.MethodsWater buffaloes (swamp type) were infected orally with 500 F. gigantica encysted metacercariae. Liver tissue samples were collected 3, 10, 28, 42, 70 and 98 days post-infection (dpi). Levels of gene expression of nine cytokines (IFN-γ, TGF-β, IL-1β, IL-4, IL-6, IL-10, IL-12B, IL-13 and IL-17A) and four transcription factors (T-bet, GATA-3, Foxp3 and ROR-γτ) were determined using quantitative real-time PCR (qRT-PCR). We evaluated any correlation between gene expression of these immune-regulatory factors and the severity of liver pathology.ResultsHistopathological examination revealed that cellular infiltration, hemorrhage and fibrosis without calcification in the liver parenchyma of infected buffaloes, increased over the course of infection. This progressive pathology was attributed to dysregulated and excessive inflammatory responses induced by infection. The early infection phase (3–10 dpi) was marked by a generalized immunosuppression and elevated TGF-β expression in order to facilitate parasite colonization. A mixed Th1/Th2 immune response was dominant from 28 to 70 dpi, to promote parasite survival while minimizing host tissue damage. During late infection (98 dpi), the response was biased towards Th1/Treg in order to inhibit the host’s Th2 protective response and promote chronic infection. Both IL-10 and IL-17A and the Th17/Treg balance, played key roles in mediating the inflammatory and immunoregulatory mechanisms in the liver during chronic fasciolosis.ConclusionsOur data showed distinct CD4+ T helper (Th) polarization and cytokine dysregulation in response to F. gigantica infection in water buffaloes over the course of infection. Characterizing the temporal expression profiles for host immune genes during infection should provide important information for defining how F. gigantica adapts and survives in the liver of buffaloes and how host immune responses influence F. gigantica pathogenicity.

Seroprevalence of Fasciola gigantica infection in bovines using cysteine proteinase dot enzyme-linked immunosorbent assay

Aim:The objective of the present study was to know the seroprevalence status of Fasciola gigantica infection in cattle and buffaloes using cysteine proteinase (CP) antigen in dot enzyme-linked immunosorbent assay (ELISA) format under field conditions.Materials and Methods:As per the standard protocol, the sera were collected from the blood of 112 cattle and 38 buffaloes of coastal areas of Navsari district, South Gujarat, India. The indirect ELISA was performed on the strip of nitrocellulose paper blotted with 1 µl of CP antigen, to detect F. gigantica seropositive animals.Results:The native CP of F. gigantica revealed a single visible band on 10% sodium dodecyl sulfate-polyacrylamide gel electrophoresis. There was no any noted cross-reaction between the selected antigen and sera of Gastrothylax crumenifer-infected animals in ELISA. Out of 150 screened bovines, the sera of 47 (31.33%) were found to be reactive in dot-ELISA, with a prevalence rate of 31.25% and 31.58% in cattle and buffaloes, respectively. The seropositive bovines with heavy, moderate, and light level of infection were 44.68%, 34.04%, and 21.28%, respectively (p<0.05 between heavy and light; p>0.05 between moderate and heavy or light). The share of F. gigantica seropositive and negative animals was 31% and 69%, respectively. The optical density at 450 nm of pooled sera of seropositive bovines with heavy, moderate, and light reactivity in plate-ELISA was significantly higher with field or reference ­negative sera.Conclusion:The CP-based dot-ELISA can be useful for field veterinarians for quick and timely isolation of the animals requiring urgent flukicide therapy.

Serum levels of cytokines in water buffaloes experimentally infected with Fasciola gigantica

Fasciola gigantica infection in water buffaloes causes significant economic losses especially in developing countries. Although modulation of the host immune response by cytokine neutralization or vaccination is a promising approach to control infection with this parasite, our understanding of cytokine's dynamic during F. gigantica infection is limited. To address this, we quantified the levels of serum cytokines produced in water buffaloes following experimental infection with F. gigantica. Five buffaloes were infected via oral gavage with 500 viable F. gigantica metacercariae and blood samples were collected from buffaloes one week before infection and for 13 consecutive weeks thereafter. The levels of 10 cytokines in serum samples were simultaneously determined using ELISA. F. gigantica failed to elicit the production of various pro-inflammatory cytokines, including interleukin-1β (IL-1β), IL-2, IL-6, IL-12, and IFN-γ. On the other hand, evidence of a Th2 type response was detected, but only early in the course of parasite colonization and included modest increase in the levels of IL-10 and IL-13. The results also revealed suppression of the immune responses as a feature of chronic F. gigantica infection in buffaloes. Taken together, F. gigantica seems to elicit a modest Th2 response at early stage of infection in order to downregulate harmful Th1- and Th17-type inflammatory responses in experimentally infected buffaloes. The full extent of anti-F. gigantica immune response and its relation to pathogenesis requires further study.

Transcriptomic responses of water buffalo liver to infection with the digenetic fluke Fasciola gigantica

BackgroundFasciola gigantica, the tropical liver fluke, infects buffaloes in Asian and African countries and causes significant economic losses and poses public health threat in these countries. However, little is known of the transcriptional response of buffaloes to infection with F. gigantica. The objective of the present study was to perform the first transcriptomic analysis of buffalo liver infected by F. gigantica. Understanding the mechanisms that underpin F. gigantica infection in buffaloes will contribute to our ability to control this parasite.MethodsWe challenged buffaloes with 500 viable F. gigantica metacercariae and collected liver samples through a time course at 3, 42 and 70 days post-infection (dpi). Then, we performed gene expression analysis on liver samples using RNA sequencing (RNA-Seq) Illumina technology and confirmed the RNA-Seq data by quantitative RT-PCR analysis.ResultsTotals of 496, 880 and 441 differentially expressed transcripts were identified in the infected livers at 3, 42 and 70 dpi, respectively. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that transcriptional changes in the liver of infected buffaloes evolve over the course of infection. The predominant response of buffaloes to infection was mediated by certain pathways, such as MHC antigen processing and presentation, Toll-like receptor 4 (TLR4), transforming growth factor beta (TGF-β), and the cytochrome P450. Hepatic drug metabolizing enzymes and bile secretion were also affected.ConclusionsFasciola gigantica can induce statistically significant and biologically plausible differences in the hepatic gene expression of infected buffaloes. These findings provide new insights into the response of buffaloes to F. gigantica over the course of infection, which may be useful in determining pathways that can modulate host-parasite interaction and thus potentially important for clearance of the parasite.

Small Ruminant Fasciolosis and its Direct Financial Loss in Dessie Municipal Abattoir North Eastern Ethiopia

A cross sectional study was conducted from November 2016 to April 2017 on 384 small ruminants brought for slaughter to Dessie Municipal Abattoir from Dessie and its surroundings. Coprological and postmortem examinations were employed. The objectives of the study were to determine the prevalence of fasciolosis and associated risk factors, the test agreement between fecal examination by sedimentation and post mortem examination; and the direct financial loss due to liver condemnation. Of 384 fecal samples collected during ante mortem, 54 were positive for egg of Fasciola with an overall prevalence of 14.1% (54/384) based on coprological examination. The prevalence was 14.5% (50/294) in sheep and 10% (4/40) in goats. An overall prevalence of 18.8% (72/384) was found based on liver examination. There was no statistically significant difference (P>0.05) in infection rate between the two species and sex. The difference in infection rate in body condition, age and fecal consistency was statistically significant (P=0.000, 0.034 and 0.031 respectively). The dominant species of Fasciola was F. hepatica 9.9%, followed by 3.39, 3.13 and 2.34% by immature Fasciola, F. gigantica and mixed infection respectively. The mean fluke burden was 28.28 ranging between 3 and 96 flukes per infected liver and the fluke burden was highest in animals with mixed infection followed by animals infected by F. hepatica. The sensitivity of the sedimentation technique to detect Fasciola eggs was 75% compared to postmortem examination of liver and a considerable agreement (kappa=0.830) was obtained between the tests. An annual loss of 25230 Birr loss was estimated in Dessie Municipal Abattoir. Study on public health implication of the parasites is recommended.

Re-infection with Fasciola gigantica 6-month post-treatment with triclabendazole in cattle from mobile pastoralist husbandry systems at Lake Chad

At Lake Chad in central Africa, livestock fascioliasis caused by Fasciola gigantica represents a major veterinary health problem, particularly in cattle reared in mobile pastoralist husbandry systems. We assessed re-infection after a single dose of triclabendazole with fascioliasis in cattle in a mobile pastoralist setting towards the end of the dry season. Within the cattle herds of 14 groups of mobile pastoralists, 375 cattle were randomly selected. A faecal sample was obtained from each animal to determine the prevalence of F. gigantica. Animals were administered a single oral dose of triclabendazole (12mg/kg). A second faecal sample was obtained 6-month post-treatment after cattle had returned from the annual migration cycle. Faecal samples were fixed in sodium acetate-acetic acid-formalin (SAF), and examined for F. gigantica using the sedimentation technique. From the 375 cattle enrolled at baseline, 198 animals (53%) in 12 groups of mobile pastoralists were re-sampled at the 6-month follow-up. Baseline prevalence did not differ noteworthy between animals lost to follow-up and those re-examined. At baseline, bovine fascioliasis prevalence in cattle with follow-up data was 41.9% (95% confidence interval (CI) 35.2–48.9%). At the 6-month post-treatment follow-up, the prevalence was 46.0% (95% CI 39.2–52.9%), ranging between 0% and 75% at the herd level. The mean faecal egg counts at the unit of the herd were higher at follow-up compared to baseline. The observed persistent high prevalence of F. gigantica infection in cattle shows that a single pre-rainy season treatment does not prevent rapid re-infection despite the partial migration away from the high-risk areas at Lake Chad into drier areas. A locally adapted strategic control package for fascioliasis in cattle in the Lake Chad area ought to integrate targeted triclabendazole treatment and seasonal transhumance practices.

Cross-sectional study of Fasciola gigantica and other trematode infections of cattle in Edu Local Government Area, Kwara State, north-central Nigeria.

BackgroundTrematode infections of livestock are of global veterinary and public health importance causing serious economic losses. Majority of data on burden of trematode infections in Nigeria are based on abattoir surveys and there are very few data on herd level risk factors. The present study investigated the prevalence of, and herd level risk factors for, fasciolosis and other trematode infections in cattle in Edu Local Government Area (LGA).MethodsA cross-sectional survey used two-stage study design to investigate cattle belonging to 65 households. Two questionnaires were administered for household-level and individual cattle-level data. Faecal and blood samples were obtained from the cattle. Logistic regression analyses were performed to determine risk factors for infections.ResultsOf 686 faecal samples analysed, 74.9 %, 16.1 %, 7.3 % and 1.2 % were positive for infections with Fasciola gigantica, paramphistomes, Dicrocoelium hospes and Schistosoma bovis respectively. Fasciola gigantica had higher prevalence in adult cattle (77.3 %) than weaners (62.5 %). Majority of co-infections was a combination of F. gigantica with paramphistomes 84/130 (64.6 %). Most (58.9 %) of the cattle belonged to FAMACHA© score 2. The mean packed cell volume (PCV) was 34.4 %. The sensitivity and specificity of FAMACHA© for anaemia (PCV < 24 %) were 18.2 and 96.9 %, respectively. Positive correlation was obtained between faecal egg counts for F. gigantica and paramphistomes (R = 0.15, P = 0.0001). Adult cattle were more likely to be infected with F. gigantica (odds ratio, OR: 1.94; Confidence Interval, CI: 1.19–3.16) than weaners. Cattle belonging to household heads aged between 40–59 years were more likely infected with paramphistomes (OR: 1.95; CI: 1.02–3.74) than those belonging to other age groups. Cattles from herds with size ≥ 100 were more likely infected with D. hospes than those from smaller herds (OR: 6.98; CI: 2.94–16.6).ConclusionThis study revealed high prevalence of infection with F. gigantica in Kwara State. The co-infections by F. gigantica and paramphistomes with a positive correlation should be considered during anthelmintic therapy. There is a need to optimise and validate the FAMACHA© for use in cattle based on breeds and variation in colour of ocular mucous membrane. Risk factors identified could assist in tailoring control strategies for various trematode infections to particular groups of farmers and cattle.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-016-1737-5) contains supplementary material, which is available to authorized users.

Genotoxic potential of Fasciolagigantica infection in experimentally infected rabbits.

A number of parasitic platyhelminthes are known to cause genotoxicity in humans and animals. However no such information is available on tropical liver fluke, Fasciola gigantica, which incurs huge economic losses worldwide. In the present study the genotoxic potential of F. gigantica infection in rabbits, experimentally infected with the metacercarial cysts of this parasite, has been investigated using the standard comet assay and micronucleus (MNi) test on the isolated hepatocytes and the whole blood from the infected rabbits. The tail length of the comet in both hepatocytes and reticulocytes from the infected animals was significantly prominent (p<0.05) as compared to the controls. About 61.17% of the hepatocytes from the infected rabbits were positive for MNi formation. A number of blood cells also showed cellular deformities, which were recognised as spicule type, schistocytes, tear drop type, acanthocytes and dumbbell type. It is possible that during the establishment of host-parasite relationship the worms might have released some products which could have contributed to the induction of cellular and DNA damage. However, long term studies are required to understand the serious implications of such an effect caused by F. gigantica, though hepatic carcinoma has not been reported so far due to fasciolosis, however, considering the present results the possibility may not be rule out for the disease progression in this direction.

Gastrointestinal helminthosis: prevalence and associated determinants in goats of Jabalpur, India.

A total of 632 faecal samples of goats of Jabalpur district of Madhya Pradesh state were examined during three years of the study period (November 2012-October 2015), out of which 82.75% sampleswere positive for helminthic infections. Among various helminths, maximum prevalence was of strongyles (32.59%) followed by amphistomes (14.40%), Moniezia spp. (12.50%), Strongyloides spp. (0.79%), Trichuris spp. (0.47%) and Fasciolagigantica (0.32%). Year wise prevalence revealed a highly significant (p<0.01) decrease in prevalence of helminths. Except Trichuris and Moniezia spp., the effect of year was significant for prevalence of all other gastro-intestinal helminths observed during the study. Significantly higher (p<0.05) helminth infections were observed in monsoon (87.97%) as compared tothat of winter (81.48%) or summer (79.03%) season. The seasonal difference in prevalence was found significant for strongyles, Strongyloides spp., amphistomes and Moniezia spp. There was no significant variation in Trichuris spp. and Fasciola gigantica infections in relation to season. Age wise prevalence of helminths was non-significantly higher in kids (83.13%) than in adults (82.62%). Except Moniezia spp., age wise observations did not reveal any significant difference (p>0.05) in prevalence of other gastrointestinal helminths.

Effects of triclabendazole and nitroxynil on EPG, hematological parameters and body weight against fascioliasis in goats at government goat development farm, Sylhet, Bangladesh

The study was conducted to evaluate the effects of triclabendazole and nitroxynil against fascioliasis in goat for a period of 28 days on 20 black bengal goats. Among hundred goats, twenty were selected for this study which was suffering from liver fluke (Fasciola gigantica) infection and were marked by tagging. Twenty goats were randomly divided into four groups (A, B, C and D) where each group comprising of five goats. Group A were treated with tablet fasinex (triclabendazole, Novartis Ltd, Bangladesh) orally at the dose rate of 12 mgkg-1body weight, group B were treated with acinex (triclabendazole, ACI Ltd, Bangladesh) orally at the dose rate of 12 mgkg-1body weight and group C were treated with nitronex injection (nitroxynil, Renata Ltd, Bangladesh) subcutaneously at the dose rate of 10 mgkg-1 body weight. Goats of group D was kept as infected control group without giving any treatment. A significant (P&lt;0.01) reduction of egg per gram (EPG) count was found on 7th, 14th, 21st and 28th days of treated goats of group A, B and C, respectively. The EPG count of control group were significantly (P&lt;0.01) increased 7 day onwards up to experimental period. Reduction of mean EPG on 7th, 14th, 21st and 28th day after treatment in group A, B and C were 81.48%, 81.25% and 83.04%, respectively, whereas in control group the mean EPG were 22.43%. Of the hematological parameters, TEC, Hb and PCV values were lower on day 0 but turned to increase (p&lt;0.01) on day 28 of the study. On the other hand, ESR and TLC were higher before treatment (day 0) but decreased significantly (p&lt;0.01) on day 28.The body weight increased significantly (P&lt;0.01) after treatments in group A, B and C respectively except untreated control. This result may indicate that three commercial anthelmintics contain triclabendazole and nitroxynil against fascioliasis in goat and nitroxynil have higher efficacies on egg per gram (EPG), hematological parameters and body weight against fascioliasis in goat. Additional detailed studies are required to prevent and control of fascioliasis in goats by using a routine prophylactic anthelmintics measurement.International Journal of Natural Sciences (2015), 5(2) 46-51

Vaccine potential of recombinant cathepsinL1G against Fasciola gigantica in mice

In this study, we characterized and investigated the vaccine potential of FgCatL1G against Fasciola gigantica infection in mice. Recombinant mature FgCatL1G (rmFgCatL1G) was expressed in Escherichia coli BL21. The vaccination was performed in Imprinting Control Region (ICR) mice (n=10) by subcutaneous injection with 50μg of rmFgCatL1G combined with Freund’s adjuvant. Two weeks after the second boost, mice were infected with 15 metacercariae by the oral route. The percents of protection of rmFgCatL1G vaccine were estimated to be 56.5% and 58.3% when compared with non vaccinated-infected and adjuvant-infected controls, respectively. Antibodies in the immune sera of vaccinated mice were shown by immunoblot to react with the native FgCatL1s in the extract of all stages of parasites and rmFgCatL1H, recombinant pro – FgCatL1 (rpFgCatL1). By immunohistochemistry, the immune sera also reacted with FgCatL1s in the caecal epithelial cells of the parasites. The levels of IgG1 and IgG2a in the immune sera, which are indicative of Th2 and Th1 immune responses, were also increased with IgG1 predominating. The levels of serum glutamic oxaloacetic transaminase (SGOT) and serum glutamic pyruvic transaminase (SGPT) in rmFgCatL1G-immunized group showed no significant difference from the control groups, but pathological lesions of livers in rmFgCatL1G-immunized group showed significant decrease when compared to the control groups. This study indicates that rmFgCatL1G has a vaccine potential against F. gigantica in mice, and this potential will be tested in larger livestock animals.

Fasciola gigantica enolase is a major component of worm tegumental fraction protective against sheep fasciolosis

Infection of cattle and sheep with the parasite Fasciola gigantica is a cause of important economic losses throughout Asia and Africa. Many of the available anthelmintics have undesirable side effects, and the parasite may acquire drug resistance as a result of mass and repeated treatments of livestock. Accordingly, the need for developing a vaccine is evident. Triton-soluble surface membrane and tegumental proteins (TSMTP) of 60, 32, and 28kDa previously shown to elicit protective immunity in mice against challenge F. gigantica infection were found to be strongly immunogenic in sheep eliciting vigorous specific antibody responses to a titer>1:16,000 as assessed by enzyme-linked immunosorbent assay. Furthermore, the 60kDa fraction induced production of antibodies able to bind to the surface membrane of newly excysted juvenile flukes and mediate their attrition in antibody-dependent complement- and cell-mediated cytotoxicity assays, and significant (P<0.05) 40% protection of sheep against F. gigantica challenge infection. Amino acid micro sequencing of the 60 kDa-derived tryptic peptides revealed the fraction predominantly consists of F. gigantica enolase. The cDNA nucleotide and translated amino acid sequences of F. gigantica enolase showed homology of 92% and 95%, respectively to Fasciola hepatica enolase, suggesting that a fasciolosis vaccine might be effective against both tropical and temperate liver flukes.

A retrospective study of the prevalence of bovine fasciolosis at major abattoirs in Botswana.

A retrospective study covering a period of ten years (2001–2010) was conducted using postmortem meat inspection records of the Department of Veterinary Services in Gaborone to determine the prevalence of bovine fasciolosis in Botswana. Meat inspection records of monthly and annual returns from the two main export abattoirs in the country were examined, as well as the data collected on the total number of cattle slaughtered and the number of livers condemned due to Fasciola gigantica infection. Only 1250 of the approximately 1.4 million cattle slaughtered were infected with F. gigantica (0.09%, 95% confidence intervals [CI] 0.0% – 0.3%). No distinct seasonal pattern was observed in condemnation rates of livers. However, the pattern of distribution of fasciolosis was higher (but not significant) in cattle that originated from areas with high rainfall and more permanent water bodies than those from relatively low rainfall areas with a transitory water system. It is recommended that a longitudinal survey should be carried out at the abattoirs and farms to determine the prevalence of the disease in cattle of different ages, sex and breed as well as the place of origin in the country. The present study indicated that the prevalence of fasciolosis in cattle is low and the disease is therefore of less significance in Botswana than other African countries for which information is available.

Immunodiagnosis of Fasciola gigantica Infection Using Monoclonal Antibody-Based Sandwich ELISA and Immunochromatographic Assay for Detection of Circulating Cathepsin L1 Protease.

BackgroundTropical fasciolosis caused by Fasciola gigantica infection is one of the major diseases infecting ruminants in the tropical regions of Africa and Asia including Thailand. Parasitological diagnosis of fasciolosis is often unreliable and possesses low sensitivity. Therefore, the detection of circulating parasite antigens is thought to be a better alternative for diagnosis of fasciolosis, as it reflects the real parasite burden.MethodsIn this study, we have produced a monoclonal antibody (MoAb) against recombinant F. gigantica cathepsin L1 (rFgCatL1), and developed both sandwich enzyme-linked immunosorbent assay (sandwich ELISA) and immunochromatographic (IC) test for rapid detection of circulating cathepsin L1 protease (CatL1) in the sera from mice experimentally and cattle naturally infected with Fasciola gigantica. MoAb 4E3 and biotinylated rabbit anti-recombinant CatL1 antibody were selected due to their high reactivities and specificities.ResultsThe lower detection limits of sandwich ELISA and IC test were 3 pg/ml and 0.256 ng/ml, respectively. Sandwich ELISA and IC test could detect F. gigantica infection from day 1 to 35 post infection. In experimental mice, the sensitivity, specificity and accuracy were 95%, 100% and 98.6% (for sandwich ELISA), and 93%, 100% and 98.2% (for IC test), while in natural cattle they were 98.3%, 100% and 99.5% (for sandwich ELISA), and 96.7%, 100% and 99.1% (for IC test).ConclusionsThese two assay methods showed high efficiencies and precisions for diagnosis of fasciolosis by F. gigantica.

Epidemiological Studies of Fascioliosis (Fasciola gigantica Infection) in Cattle

Epidemiological Studies of Fascioliosis (Fasciola gigantica Infection) in Cattle

Effects of climatic factors on prevalence of developmental stages of Fasciola gigantica infection in Lymnaea snails (Lymnaea auricularia var rufescens) in Bangladesh

The present study was conducted to investigate the prevalence of developmental stages of Fasciola gigantica infection in Lymnaea snails and their populations in Sylhet region of Bangladesh. A total of 1865 Lymnaea snails were collected and examined, of which 56 (3%) were found to having infected with developmental stages of Fasciola gigantica. Only 4.08% infected of 515 snails were collected from Biswanath Upazilla followed by 3.16% of 443 from Beanibazar, 2.53% of 396 from Balaganj then 2.40% of 292 Jaintapur Upazilla and the lowest 1.83% of 219 from Sylhet Sadar. Month-wise data, the prevalence of snail infections was observed to be the highest in May (5.06%) and August (5.61%) and the lowest in March (0.74%) and February (0.68%). However there was no infection observed through November to January. Seasonal prevalence of the developmental stages of F. gigantica infection in Lymnaea snails was also studied. Highest prevalence (4.63%) was recorded during rainy season and lowest prevalence (0.76%) was recorded during winter season. The study revealed that the developmental stages of F. gigantica infection in snail populations decreases from November to January and increases from February to October and highest in August and September in Sylhet region of Bangladesh.

Epidemiological studies on some trematode parasites of ruminants in the snail intermediate hosts in three districts of Uttar Pradesh, Jabalpur and Ranchi

Seasonal prevalence of 5 trematode parasites in the 4 snail species, viz. Lymnaea auricularia, L. luteola, Gyraulus convexiusculus and Indoplanorbis exustus for the years 2012-2014 was studied in 3 districts of Uttar Pradesh and in Jabalpur and Ranchi districts of Madhya Pradesh and Jharkhand, respectively. Intramolluscan larval stages of Fasciola gigantica, Explanatum explanatum, Paramphistomum epiclitum, Fischoederius elongatus and Schistosoma spindale were identified using ITS-2, 28S rDNA, 12S mitochondrial (mt) DNA and Cox I markers. F. gigantica infection in L. auricularia had a significant (P&lt;0.05) occurrence in the winter season followed by rains. Seasonality of P. epiclitum transmission in I. exustus was observed with significant occurrence of its infection in the rainy season followed by a sharp decline in other seasons. Prevalence of S. spindale infection in I. exustus was insignificant in 3 districts of Uttar Pradesh but highly prevalent in other 2 districts. Infection with F. elongatus in L. luteola was recorded in different seasons. G. convexiusculus were screened for E. explanatum and Gastrothylax crumenifer infection and a significant rate of infection with E. explanatum was observed in the rainy season. Climatic factors including temperature and rainfall influence the distribution of snail populations and transmission of trematode infections by these snail intermediate hosts.

Fasciola gigantica infection in large ruminants in northern Laos: smallholder knowledge and practices

High prevalence of Fasciola spp. infection in smallholder large ruminant farming systems has been confirmed in many regions of South-East Asia, yet information on trematode knowledge and any control practices of large ruminant farmers is lacking. We surveyed smallholder farmers (n = 326) in northern Laos on knowledge of liver fluke and its management in their large ruminants, identifying 93.1% of farmers had no knowledge and 6.9% minimal knowledge of the parasite and impacts on large ruminant production. The survey further confirmed anecdotal reports that control or prevention measures were lacking, with none of the surveyed producers using effective anthelminthic treatments or grazing strategies to control Fasciola spp. This was despite 20.6% of farmers having reported observing leaf-shaped parasites in the liver of their cattle or buffalo when slaughtered in the past. With increasing demand for red meat in the region, subsistence smallholder farmers are able to supply this market and increase their income. Athough the production impact of fascioliasis in large ruminants in these farming systems still needs to be quantified, farmer knowledge and control of fascioliasis in this region is likely to increase livestock productivity and improve rural livelihoods. This would help to address regional rural poverty and food insecurity, but requires improved knowledge to address the identified knowledge and practice gaps on presence, impact and control of fasciolosis. The majority (95.4%) of surveyed farmers indicated a desire to learn more about fascioliasis in large ruminants, suggesting that extension methods used in the past need adapting to result in more effective knowledge transfer and changed practices in future.