Trematodiasis Research Articles

The life cycle of a zoonotic parasite reassessed: Experimental infection of Melanoides tuberculata (Mollusca: Thiaridae) with Centrocestus formosanus (Trematoda: Heterophyidae).

Centrocestus formosanus is a foodborne intestinal trematode that is native to Asia and has been introduced into the Americas and Europe. Although there are several studies of C. formosanus in definitive vertebrate hosts (birds and mammals, including humans), and in intermediate vertebrate hosts (fish and amphibians), there is little published information regarding interaction with its transmitting mollusc. In this study we studied the miracidial development of C. formosanus using a mouse as a source of eggs. Adult parasites were maintained in water in order to develop miracidia in intrauterine eggs. Miracidia appeared at 12 days of incubation, with no hatching observed for up to 40 days. Subsequently, we placed dead C. formosanus containing eggs with miracidia individually in contact with 48 specimens of Melanoides tuberculata, and observed the absence of the parasites after 1h of exposure, suggesting that they were ingested by the snails. Of the 33 experimentally-infected snails that were alive after 84–89 days post-infection (DPI), seven (21%) shed cercariae. We detected young C. formosanus rediae in 21/33 (64%) M. tuberculata at 90 DPI. To our knowledge, this report is the first to show that, in the life cycle of C. formosanus, infection of molluscs occurs passively by ingestion of eggs, followed by a long intramolluscan phase. We compare these data with those described for other Heterophyidae, and discuss on the phylogenetic background of the pattern of miracidial development verified in these parasites.

Bridging the Gap between TGF-β/Smad Signalling and Tumorigenesis Arising from Clonorchis sinensis Induced Hepatic Fibrosis

Clonorchiasis is a parasitic infection caused by food borne trematode, Clonorchis sinensis that is mainly prevalent in Asian countries, including South Korea, China, northern Vietnam, Japan, as well as far-eastern Russia, in which over 35 million people are the casualties. Clonorchiasis is characterized by the development of hepatic fibrosis. Upon chronic liver injury following the C. sinensis infection, hepatic fibrosis develops into cholangiocarcinoma with a concomitant genetic and epigenetic mutations. Cholangiocarcinoma represents important clinical manifestation of C. sinensis infection and causes high rate of morbidity. TGF- β/Smad signalling is known to initiate hepatic fibrosis following the hepatic injury. However, little is known about the role of TGF- β/Smad signalling during C. sinensis induced hepatic injury and the underlying contribution of TGF- β/Smad signalling in the development of cholangicarcinoma. The expression dynamic of TGF-β/Smad signalling and their role in the development of hepatic fibrosis in C. sinensis infected BALB/c mice have been investigated. Concomitantly but irrespective to C. sinensis infection, the role of hepatic epithelial TGF-β during hepatic fibrosis and the development of cholangiocarcinoma arising from hepatic epithelial cells have also been dissected. Both findings will be reviewed in this paper. Thereby, the link between TGF-β/Smad signalling, hepatic fibrosis during C sinensis infection, and cholangiocarcinoma could be drawn clearly.Keywords: Clonorchis sinensis, TGF-β/Smad signalling, Hepatic fibrosis, Cholangiocarcinoma

Morphological effects on helminth parasites caused by herbicide under experimental conditions.

Helminth parasites have been studied as potential accumulators for different pollutants. Echinostoma paraensei is a foodborne trematode whose vertebrate host, the rodent Nectomys squamipes, is naturally exposed to environmental pesticides. However, little information exists regarding the pesticide's effects on helminths. This study investigated the morphological effects on the trematode, E. paraensei, after experimental Roundup® herbicide exposure, in concentrations below those recommended for agricultural use. After two hours of exposure, scanning electron microscopy (SEM) showed changes to the tegument, such as furrowing, shrinkage, peeling, spines loss on the peristomic collar, and histopathological evidence of altered cells in the cecum and acinus vitelline glands with vacuoles and structural changes to the muscular layers. Glycidic content was decreased, primarily in the connective tissue. As E. paraensei is an intestinal parasite of the semi-aquatic wild rodent, N. squamipes, it is predisposed to pesticide exposure resulting from agricultural practices. Therefore, we emphasize the need to evaluate its impact on helminth parasites, due to their pivotal role in regulating host populations.

Prevalence of liver flukes infections and hydatidosis in slaughtered sheep and goats in Nishapour, Khorasan Razavi, Iran.

Background:Food-borne trematode infections and hydatidosis are endemic diseases caused by helminths in Iran that are responsible for great economic loss and getting public health at risk.Aim:Aim of this study was to determine the prevalence of fasciolosis, dicrocoeliasis, and hydatidosis infections in slaughtered sheep and goats in Nishapour, Khorasan Razavi province of Iran.Materials and Methods:A survey was implemented on 130,107 sheep and goats slaughtered at an abattoir in Nishapour (Neyshbur) city, north central Khorasan Razavi Province, Iran, to determine the prevalence of fascioliasis, dicrocoeliosis and presence of hydatidosis.Results:During a 1-year period of study, among 130,107 of sheep and goats slaughtered at Nishapour abattoir, 1064 and 7124 livers were condemned totally and partially, respectively. A total of 255 (0.19%), 181 (0.12 %), and 7751 (5.95%) of livers were condemned due to cysts of Echinococcus granulosus, flukes of Fasciola spp., and Dicrocoelium dendriticum, respectively. Totally, 1932 (1.48%) lungs were condemned due to hydatidosis. The significant seasonal pattern was seen for fasciolosis, dicrocoeliosis, and hydatidosis, statistically (p<0.01).Conclusion:According to this study, it seems that Neyshabour is considered as an endemic region for Fasciola spp. and D. dendriticum infections and D. dendriticum is the most widespread liver fluke found in sheep and goats.

Travel-Related Parasitic Infections in Travellers to Southeast Asia and Western Pacific Countries.

In the last decades, there has been a significant increase in international human mobility with increase in the prosperity, travel possibilities, and number of refugees. In the first half of 2016, the Asian continent showed the fastest growth in the number of tourists. Such increase is seen due to the interest in Asian history, culture, and cuisine. In the globalizing world, human mobility causes changes in the epidemiology of diseases and the spread of various infections across continents. Parasitic infections that may pose a risk for travellers to the Asia-Pacific are malaria, leishmaniasis, filariasis, foodborne trematode infections, schistosomiasis, soil-transmitted infections, and tourist diarrhea. Consulting a travel medical expert and using health services such as pre-travel vaccination and chemoprophylaxis will reduce the risk of infectious diseases among travelers.

Human Parasitology and Parasitic Diseases: Heading Towards 2050.

By 2050 our civilized planet may be comprised predominantly of networked megacities embedded in warm subtropical and tropical climates, and under stress from climate change and catastrophic weather events. Urban slum areas in these cities, including those found in wealthier middle- and high-income nations (blue marble health), will be especially vulnerable to disease. Moreover, regional conflicts fought over shifting and limited resources, including water, will collapse health systems infrastructures to further promote disease emergence and reemergence. Thus while by 2050 we might congratulate ourselves for successfully eliminating some key parasitic and neglected tropical diseases such as dracunculiasis, lymphatic filariasis, onchocerciasis, and human African trypanosomiasis, there could be a commensurate rise in other parasitic diseases based on the scenarios highlighted above. Of particular concern are urban and newly urbanized helminth infections, including schistosomiasis and some soil-transmitted helminth infections, as well zoonotic helminthiases, such as toxocariasis, food-borne trematodiases, and cysticercosis. Protozoan infections persisting in urban environments, including leishmaniasis, Chagas disease, malaria, and intestinal protozoan infections, will also remain, as will zoonotic diseases such as toxoplasmosis. Our best hope to counteract the parasitic diseases emerging in our steaming 21st century megacities is to develop new and innovative technologies through gene editing, systems biology, and immunology, and the new single-celled OMICs. However, success on this front will require our ability to contain the globalization of antiscience beliefs and sentiments.

Fasciola spp: Mapping of the MF6 epitope and antigenic analysis of the MF6p/HDM family of heme-binding proteins.

MF6p/FhHDM-1 is a small cationic heme-binding protein which is recognized by the monoclonal antibody (mAb) MF6, and abundantly present in parenchymal cells and secreted antigens of Fasciola hepatica. Orthologs of this protein (MF6p/HDMs) also exist in other causal agents of important foodborne trematodiasis, such as Clonorchis sinensis, Opisthorchis viverrini and Paragonimus westermani. Considering that MF6p/FhHDM-1 is relevant for heme homeostasis in Fasciola and was reported to have immunomodulatory properties, this protein is expected to be a useful target for vaccination. Thus, in this study we mapped the epitope recognized by mAb MF6 and evaluated its antigenicity in sheep. The sequence of the MF6p/FhHDM-1 ortholog from F. gigantica (MF6p/FgHDM-1) was also reported. By means of ELISA inhibitions with overlapping synthetic peptides, we determined that the epitope recognized by mAb MF6 is located within the C-terminal moiety of MF6p/FhHDM-1, which is the most conserved region of MF6p/HDMs. By immunoblotting analysis of parasite extracts and ELISA inhibitions with synthetic peptides we also determined that mAb MF6 reacted with the same intensity with F. hepatica and F. gigantica, and in decreasing order of intensity with C. sinensis, O.viverrini and P. westermani orthologs. On the contrary, mAb MF6 showed no reactivity against Dicrocoelium dendriticum and Schistosoma mansoni. The study of the recognition of peptides covering different regions of MF6p/FhHDM-1 by sera from immunized sheep revealed that the C-terminal moiety is the most antigenic, thus being of potential interest for vaccination. We also demonstrated that the production of antibodies to MF6p/FhHDM-1 in sheep infected by F. hepatica occurs relatively early and follows the same pattern as those produced against L-cathepsins.

Effects of dietary intake of garlic on intestinal trematodes.

The current strategy for the control of helminth infections relies on chemotherapy. However, resistance appearance is promoting the necessity of developing new drugs against trematodes. Herein, potential trematocidal effects of garlic (Allium sativum) are investigated in the context of intestinal foodborne trematodes, employing the Echinostoma caproni-mouse model. Daily administration of dietary doses of garlic was conducted in three groups of mice: (i) before infection (prophylaxis), (ii) after infection (therapeutic) and (iii) both, before and after infection (continuous). A fourth group of mice, not exposed to garlic, was used as control. No differences in worm recovery, fecundity and local cytokine expression profiles were found with respect to control infections. However, considerable alterations in tegument structure, including swelling, furrowing, vacuolization and changes in secretory bodies were detected in garlic-exposed parasites using scanning and transmission electron microscopy. Protein secretion was markedly reduced in response to garlic, whereas up-regulation of several proteins, such as major vault protein and tER-ATPase, was observed in treated worms. The results presented herein provide new insights in the anthelminthic activity of bioactive garlic compounds and the manner that parasites respond to toxins.

Risk mapping of clonorchiasis in the People’s Republic of China: A systematic review and Bayesian geostatistical analysis

BackgroundClonorchiasis, one of the most important food-borne trematodiases, affects more than 12 million people in the People’s Republic of China (P.R. China). Spatially explicit risk estimates of Clonorchis sinensis infection are needed in order to target control interventions.MethodologyGeoreferenced survey data pertaining to infection prevalence of C. sinensis in P.R. China from 2000 onwards were obtained via a systematic review in PubMed, ISI Web of Science, Chinese National Knowledge Internet, and Wanfang Data from January 1, 2000 until January 10, 2016, with no restriction of language or study design. Additional disease data were provided by the National Institute of Parasitic Diseases, Chinese Center for Diseases Control and Prevention in Shanghai. Environmental and socioeconomic proxies were extracted from remote-sensing and other data sources. Bayesian variable selection was carried out to identify the most important predictors of C. sinensis risk. Geostatistical models were applied to quantify the association between infection risk and the predictors of the disease, and to predict the risk of infection across P.R. China at high spatial resolution (over a grid with grid cell size of 5×5 km).Principal findingsWe obtained clonorchiasis survey data at 633 unique locations in P.R. China. We observed that the risk of C. sinensis infection increased over time, particularly from 2005 onwards. We estimate that around 14.8 million (95% Bayesian credible interval 13.8–15.8 million) people in P.R. China were infected with C. sinensis in 2010. Highly endemic areas (≥ 20%) were concentrated in southern and northeastern parts of the country. The provinces with the highest risk of infection and the largest number of infected people were Guangdong, Guangxi, and Heilongjiang.Conclusions/SignificanceOur results provide spatially relevant information for guiding clonorchiasis control interventions in P.R. China. The trend toward higher risk of C. sinensis infection in the recent past urges the Chinese government to pay more attention to the public health importance of clonorchiasis and to target interventions to high-risk areas.

Light and scanning electron microscopy study of in vitro effects of artesunate in newly excysted metacercariae of Echinostoma paraensei (Trematoda: Digenea)

Chemotherapy of food-borne trematodes relies on two drugs, praziquantel and tricabendazole, and there is growing interest in finding alternative therapies. Plant oil extracts have long been used in traditional Chinese medicine as sources of bioactive compounds with antiparasitic activity. Species of the genus Echinostoma are used as good models to test effective compounds against food-borne trematodes. This study evaluated the anthelmintic activity of crude artesunate extracts in vitro on newly excysted metacercariae of Echinostoma paraensei by light and scanning electron microscopy (SEM). The flukes were incubated with 1 μg/mL, 10 μg/mL, 25 μg/mL, 50 μg/mL and 100 μg/mL of artesunate for 4, 12, 24, 48 and 72 h. When the exposure time and concentration of artesunate increased, there were changes in motor activity, tegument damage and death. Blebs and swelling were the most common damages quantified on the tegument. The in vitro study reproduced results described for other immature flukes incubated with artemisinin derivatives. Excysted metacercariae of E. paraensei constitute a good model to study in vitro drug effects.

Transcriptome profiling of gene expression during immunisation trial against Fasciola hepatica: identification of genes and pathways involved in conferring immunoprotection in a murine model

BackgroundFasciolosis remains a significant food-borne trematode disease causing high morbidity around the world and affecting grazing animals and humans. A deeper understanding concerning the molecular mechanisms by which Fasciola hepatica infection occurs, as well as the molecular basis involved in acquiring protection is extremely important when designing and selecting new vaccine candidates. The present study provides a first report of microarray-based technology for describing changes in the splenic gene expression profile for mice immunised with a highly effective, protection-inducing, multi-epitope, subunit-based, chemically-synthesised vaccine candidate against F. hepatica.MethodsThe mice were immunised with synthetic peptides containing B- and T-cell epitopes, which are derived from F. hepatica cathepsin B and amoebapore proteins, as novel vaccine candidates against F. hepatica formulated in an adjuvant adaptation vaccination system; they were experimentally challenged with F. hepatica metacercariae. Spleen RNA from mice immunised with the highest protection-inducing synthetic peptides was isolated, amplified and labelled using Affymetrix standardised protocols. Data was then background corrected, normalised and the expression signal was calculated. The Ingenuity Pathway Analysis tool was then used for analysing differentially expressed gene identifiers for annotating bio-functions and constructing and visualising molecular interaction networks.ResultsMice immunised with a combination of three peptides containing T-cell epitopes induced high protection against experimental challenge according to survival rates and hepatic damage scores. It also induced differential expression of 820 genes, 168 genes being up-regulated and 652 genes being down-regulated, p value <0.05, fold change ranging from −2.944 to 7.632. A functional study of these genes revealed changes in the pathways related to nitric oxide and reactive oxygen species production, Interleukin-12 signalling and production in macrophages and Interleukin-8 signalling with up-regulation of S100 calcium-binding protein A8, Matrix metallopeptidase 9 and CXC chemokine receptor 2 genes.ConclusionThe data obtained in the present study provided us with a more comprehensive overview concerning the possible molecular pathways implied in inducing protection against F. hepatica in a murine model, which could be useful for evaluating future vaccine candidates.

Phylogenetic analysis reveals cryptic species diversity within minute intestinal fluke, Stellantchasmus falcatus Onji and Nishio, 1916 (Trematoda, Heterophyidae)

To examine the taxonomic boundaries in the Stellantchasmus populations in different hosts and reveal the cryptic speciation of the Stellantchasmus in Thailand based on both morphological and molecular approaches. Stellantchasmus falcatus (S.falcatus) s.l. was collected from different hosts throughout Thailand. The worms were examined and measured. The nuclear ITS2 gene and the mitochondrial COI gene were used to investigate the S.falcatus s.l. from Dermogenus pusillus and Liza subviridis. Stellantchasmus was one of food-borne trematode that widely distribute throughout Thailand. The comparison of S.falcatus s.l. from Dermogenus pusillus and Liza subviridis indicated a genetic divergence of nuDNA with 3.6% and mtDNA with 19.3%, respectively. Morphological characteristics were fairly different in the ratio of body size, length of prepharynx, and ratio of organ size. Our results provide initial evidence that S.falcatus s.l. from different hosts tend to be a different species based on both molecular and morphological characters. Cryptic species complexes are generally found among parasites that tend to have large populations and/or rapid evolution. The degree of genetic diversity existing would suggest the practice of targeted regimes to design and minimize these lections of anthelmintic resistance in the future.

Genomes of Fasciola hepatica from the Americas Reveal Colonization with Neorickettsia Endobacteria Related to the Agents of Potomac Horse and Human Sennetsu Fevers.

Food borne trematodes (FBTs) are an assemblage of platyhelminth parasites transmitted through the food chain, four of which are recognized as neglected tropical diseases (NTDs). Fascioliasis stands out among the other NTDs due to its broad and significant impact on both human and animal health, as Fasciola sp., are also considered major pathogens of domesticated ruminants. Here we present a reference genome sequence of the common liver fluke, Fasciola hepatica isolated from sheep, complementing previously reported isolate from cattle. A total of 14,642 genes were predicted from the 1.14 GB genome of the liver fluke. Comparative genomics indicated that F. hepatica Oregon and related food-borne trematodes are metabolically less constrained than schistosomes and cestodes, taking advantage of the richer millieux offered by the hepatobiliary organs. Protease families differentially expanded between diverse trematodes may facilitate migration and survival within the heterogeneous environments and niches within the mammalian host. Surprisingly, the sequencing of Oregon and Uruguay F. hepatica isolates led to the first discovery of an endobacteria in this species. Two contigs from the F. hepatica Oregon assembly were joined to complete the 859,205 bp genome of a novel Neorickettsia endobacterium (nFh) closely related to the etiological agents of human Sennetsu and Potomac horse fevers. Immunohistochemical studies targeting a Neorickettsia surface protein found nFh in specific organs and tissues of the adult trematode including the female reproductive tract, eggs, the Mehlis’ gland, seminal vesicle, and oral suckers, suggesting putative routes for fluke-to-fluke and fluke-to-host transmission. The genomes of F. hepatica and nFh will serve as a resource for further exploration of the biology of F. hepatica, and specifically its newly discovered trans-kingdom interaction with nFh and the impact of both species on disease in ruminants and humans.

Clonorchis sinensis, an oriental liver fluke, as a human biological agent of cholangiocarcinoma: a brief review.

Parasitic diseases remain an unarguable public health problem worldwide. Liver fluke Clonorchis sinensis is a high risk pathogenic parasitic helminth which is endemic predominantly in Asian countries, including Korea, China, Taiwan, Vietnam, and the far eastern parts of Russia, and is still actively transmitted. According to the earlier 8th National Survey on the Prevalence of Intestinal Parasitic Infections in 2012, C. sinensis was revealed as the parasite with highest prevalence of 1.86% in general population among all parasite species surveyed in Korea. This fluke is now classified under one of the definite Group 1 human biological agents (carcinogens) by International Agency of Research on Cancer (IARC) along with two other parasites, Opisthorchis viverrini and Schistosoma haematobium. C. sinensis infestation is mainly linked to liver and biliary disorders, especially cholangiocarcinoma (CCA). For the purposes of this mini-review, we will only focus on C. sinensis and review pathogenesis and carcinogenesis of clonorchiasis, disease condition by C. sinensis infestation, and association between C. sinensis infestation and CCA. In this presentation, we briefly consider the current scientific status for progression of CCA by heavy C. sinensis infestation from the food-borne trematode and development of CCA.

Association between Opisthorchis viverrini and Leptospira spp. infection in endemic Northeast Thailand

Opisthorchiasis caused by Opisthorchis viverrini is an important foodborne trematodiasis in Thailand, Laos and Cambodia. Interestingly, the opisthorchiasis endemic region overlaps with an area of leptospirosis emergence. Here we report an association between opisthorchiasis and leptospirosis in Thailand. Of 280 sera collected from villagers living around the Lawa wetland complex in Khon Kaen province, 199 (71%) were seropositive for leptospirosis by immunochromatography. Individuals with O. viverrini infection had a significantly higher rate of leptospirosis than those without (P=0.001). Significant higher leptospirosis prevalence was found in males than females (P=0.002). However, females but not males with O. viverrini infection showed a significantly higher seroprevalence of leptospirosis. Twenty-one of 35 environmental samples from the lake (water, mud and fish skin mucus) were positive for Leptospira spp. DNA sequencing, sequence alignment, and phylogenetic analysis of some positive nested PCR products revealed both pathogenic and intermediate pathogenic strains of Leptospira in the samples. Strikingly, O. viverrini metacercariae from the fish were positive for L. interrogans. These results suggest a close association between opisthorchiasis and leptospirosis. Contact with water, mud or eating raw fish harboring liver fluke metacercariae may be risk factors for Leptospira infection.

Conservation and diversification of the transcriptomes of adult Paragonimus westermani and P. skrjabini.

BackgroundParagonimiasis is an important and widespread neglected tropical disease. Fifteen Paragonimus species are human pathogens, but two of these, Paragonimus westermani and P. skrjabini, are responsible for the bulk of human disease. Despite their medical and economic significance, there is limited information on the gene content and expression of Paragonimus lung flukes.ResultsThe transcriptomes of adult P. westermani and P. skrjabini were studied with deep sequencing technology. Approximately 30 million reads per species were assembled into 21,586 and 25,825 unigenes for P. westermani and P. skrjabini, respectively. Many unigenes showed homology with sequences from other food-borne trematodes, but 1,217 high-confidence Paragonimus-specific unigenes were identified. Analyses indicated that both species have the potential for aerobic and anaerobic metabolism but not de novo fatty acid biosynthesis and that they may interact with host signaling pathways. Some 12,432 P. westermani and P. skrjabini unigenes showed a clear correspondence in bi-directional sequence similarity matches. The expression of shared unigenes was mostly well correlated, but differentially expressed unigenes were identified and shown to be enriched for functions related to proteolysis for P. westermani and microtubule based motility for P. skrjabini.ConclusionsThe assembled transcriptomes of P. westermani and P. skrjabini, inferred proteins, and extensive functional annotations generated for this project (including identified primary sequence similarities to various species, protein domains, biological pathways, predicted proteases, molecular mimics and secreted proteins, etc.) represent a valuable resource for hypothesis driven research on these medically and economically important species.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-016-1785-x) contains supplementary material, which is available to authorized users.

A prospective view of animal and human Fasciolosis.

SummaryFasciolosis, a food‐borne trematodiasis, results following infection with the parasites, Fasciola hepatica and Fasciola gigantica. These trematodes greatly affect the global agricultural community, infecting millions of ruminants worldwide and causing annual economic losses in excess of US $3 billion. Fasciolosis, an important zoonosis, is classified by WHO as a neglected tropical disease with an estimated 17 million people infected and a further 180 million people at risk of infection. The significant impact on agriculture and human health together with the increasing demand for animal‐derived food products to support global population growth demonstrate that fasciolosis is a major One Health problem. This review details the problematic issues surrounding fasciolosis control, including drug resistance, lack of diagnosis and the threat that hybridization of the Fasciola species poses to future animal and human health. We discuss how these parasites may mediate their long‐term survival through regulation and modulation of the host immune system, by altering the host immune homeostasis and/or by influencing the intestinal microbiome particularly in respect to concurrent infections with other pathogens. Large genome, transcriptome and proteomic data sets are now available to support an integrated One Health approach to develop novel diagnostic and control strategies for both animal and human disease.

INTESTINAL PARASITE INFECTION IN HUE UNIVERSITY HOSPITAL IN 2013-2014 BY DIRECT EXAMINATION AND IMMUNOLOGICAL DIAGNOSTICS

Introduction: Intestinalparasite infections still are very common in tropical country such as Vietnam. Therefore evaluation of the prevalence of them should be done. Materials and methods: A crosssectional descriptivestudy were carried out to use the wet mount direct examination, Kato and ELISA technique for evaluation the rate of intestinal parasite infections, interviewed them to reveal their life’s hygenic condition, knowledge and risk behaviour of intestinal parasite infections in 640 patients attending to the in Hue University of hospital. Result: The rate of soiltransmitted intestinal helminth were lower than the foodborne infection of cestode and trematode such as: Taenia solium/saginata 3.64%, Clonorchis sinensis 2.73%. The rate of positive antibody of rare intestinal parasite were Fasciola gigantica 40.68%, E. histolytica/dispar 43.75%, Toxocara canis 32.43%, Gnasthostoma spinigerum 37.5%, Taenia solium 51.43%, Strongyloidesstercoralis 16.67%. Most of people has hygenic life condition with hygenic water available. The popular knowledge of intestinal parasite diseases of transmission, pathology, prevention and treatment were concentrate on oiltransmittedintestinal helminth.There were high rate of platyhelminths infectious behaviourssuch as: eating raw water plant 75.6%, eating raw beef 80.6%, eating raw pork 72.2%, eating raw fish 11.8%, bare foot 34.2%. Conclusions: The result of our study showed that the higher rate of foodborne cestode and trematode than soiltransmittedhelminth correspond tothe hygenic life condition, the knowledge of the diseases and risk behavior of intestinal parasites infection. Key words: Helminth, cestode, trematode

Rare trematode infestation in irritable bowel syndrome: Pathogen or commensal?

AbstractA healthy young adult male presented with complaints of frequent (&gt;3/day) formed stools and passage of excessive mucous in stool for 3 months. He did not complain of nocturnal motions, recent diarrhea, blood in stool, straining, weight loss, or pain abdomen. Stool test was normal. He was counseled and treated as a case of irritable bowel syndrome. Due to inadequate relief with empirical therapy, colonoscopy was performed in a subsequent visit. Club-shaped small, round organisms with moving proboscis were seen in the cecum. Organism was later identified as a trematode Gastrodiscoides hominis, a rare foodborne trematode. The patient was treated with praziquantel, without complete relief. Trematode infection might not be the cause of symptoms.

In vivo and in vitro effects of the herbicide Roundup® on developmental stages of the trematode Echinostoma paraensei

The exposure of wildlife and humans to toxic residues of Roundup® through agricultural practices or the food chain has been reported since the herbicide was found contaminating rivers. Glyphosate, N-(phosphonomethyl)glycine acid, is a nonselective post-emergent herbicide and is formulated as an isopropylamine salt with the surfactant taloamine polyethoxylate (POEA) representing the commercial formulation of Roundup®. There is little knowledge about the effects of the herbicide on helminth parasites, particularly those whose life cycle is related to water bodies. Here we investigated the effects of the Roundup® on the food-borne trematode Echinostoma paraensei in experimental conditions using different developmental stages (eggs, miracidia, cercariae, metacercariae, newly excysted larvae (NEL), helminths at seven days and helminths at fourteen days). Three different herbicide concentrations were tested based on concentrations typically applied in the field: 225, 450 and 900 mg/L. Specimens were analyzed in vitro for hatching miracidia, mortality and excystment rate of metacercariae and in vivo for parasitic load and egg production. There was a significant difference in the hatching miracidia rate only for the newly embryonated eggs. The mortality of specimens and excystment rate of metacercariae were concentration-dependent. There was a significant difference in the miracidia mortality with respect to concentration until 56.3 mg/L. The same effect was observed for cercariae, and mortality was observed from 15 min onwards at concentrations of 225–900 mg/L. At low concentrations, mortality was detected after 30 min. The effects of the herbicide concentration on NEL and on helminths at seven and fourteen days showed a significant difference after 24 h. There was no significant difference in parasitic load and egg production after infection of rodents with exposed metacercariae. All developmental stages of the trematode E. paraensei were affected by Roundup® exposure under experimental conditions. These results suggest that dynamics of transmission of the trematode could be affected in the natural environments. The study also reinforces the usefulness of this trematode as a good model organism to test pesticides regarding human and environmental health.