Showing papers in "Advances in Parasitology in 2018"

Molecular Epidemiology of Anisakis and Anisakiasis: An Ecological and Evolutionary Road Map.

Abstract: This review addresses the biodiversity, biology, distribution, ecology, epidemiology, and consumer health significance of the so far known species of Anisakis, both in their natural hosts and in human accidental host populations, worldwide. These key aspects of the Anisakis species' biology are highlighted, since we consider them as main driving forces behind which most of the research in this field has been carried out over the past decade. From a public health perspective, the human disease caused by Anisakis species (anisakiasis) appears to be considerably underreported and underestimated in many countries or regions around the globe. Indeed, when considering the importance of marine fish species as part of the everyday diet in many coastal communities around the globe, there still exist significant knowledge gaps as to local epidemiological and ecological drivers of the transmission of Anisakis spp. to humans. We further identify some key knowledge gaps related to Anisakis species epidemiology in both natural and accidental hosts, to be filled in light of new 'omic' technologies yet to be fully developed. Moreover, we suggest that future Anisakis research takes a 'holistic' approach by integrating genetic, ecological, immunobiological, and environmental factors, thus allowing proper assessment of the epidemiology of Anisakis spp. in their natural hosts, in human populations, and in the marine ecosystem, in both space and time.

Evolution, Systematics, and Biogeography of the Triatominae, Vectors of Chagas Disease.

Abstract: In this chapter, we review and update current knowledge about the evolution, systematics, and biogeography of the Triatominae (Hemiptera: Reduviidae)-true bugs that feed primarily on vertebrate blood. In the Americas, triatomines are the vectors of Trypanosoma cruzi, the etiological agent of Chagas disease. Despite declining incidence and prevalence, Chagas disease is still a major public health concern in Latin America. Triatomines occur also in the Old World, where vector-borne T. cruzi transmission has not been recorded. Triatomines evolved from predatory reduviid bugs, most likely in the New World, and diversified extensively across the Americas (including the Caribbean) and in parts of Asia and Oceania. Here, we first discuss our current understanding of how, how many times, and when the blood-feeding habit might have evolved among the Reduviidae. Then we present a summary of recent advances in the systematics of this diverse group of insects, with an emphasis on the contribution of molecular tools to the clarification of taxonomic controversies. Finally, and in the light of both up-to-date phylogenetic hypotheses and a thorough review of distribution records, we propose a global synthesis of the biogeography of the Triatominae. Over 130 triatomine species contribute to maintaining T. cruzi transmission among mammals (sometimes including humans) in almost every terrestrial ecoregion of the Americas. This means that Chagas disease will never be eradicated and underscores the fact that effective disease prevention will perforce require stronger, long-term vector control-surveillance systems.

Climate Change and the Neglected Tropical Diseases.

Abstract: Climate change is expected to impact across every domain of society, including health. The majority of the world's population is susceptible to pathological, infectious disease whose life cycles are sensitive to environmental factors across different physical phases including air, water and soil. Nearly all so-called neglected tropical diseases (NTDs) fall into this category, meaning that future geographic patterns of transmission of dozens of infections are likely to be affected by climate change over the short (seasonal), medium (annual) and long (decadal) term. This review offers an introduction into the terms and processes deployed in modelling climate change and reviews the state of the art in terms of research into how climate change may affect future transmission of NTDs. The 34 infections included in this chapter are drawn from the WHO NTD list and the WHO blueprint list of priority diseases. For the majority of infections, some evidence is available of which environmental factors contribute to the population biology of parasites, vectors and zoonotic hosts. There is a general paucity of published research on the potential effects of decadal climate change, with some exceptions, mainly in vector-borne diseases.

Update on Pathogenesis of Opisthorchiasis and Cholangiocarcinoma.

Abstract: Infection with the food-borne liver fluke Opisthorchis viverrini causes cholangiocarcinoma (CCA). Whereas the cause of CCA in the West remains obscure, the principal risk factor in Thailand is opisthorchiasis. Here, we review recent findings on the pathogenesis of opisthorchiasis and CCA focusing on helminth molecules/toxic metabolites, host-parasite interaction, endocytosis, immunopathology/inflammatory responses, free radical production, molecular genetic alterations, and multifactorial including coinfections driving to CCA development.

Human Parasitology and Parasitic Diseases: Heading Towards 2050.

Abstract: 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.

Expanding the Vector Control Toolbox for Malaria Elimination: A Systematic Review of the Evidence

Abstract: Background: Additional vector control tools (VCTs) are needed to supplement insecticide-treated nets (ITNs) and indoor residual spraying (IRS) to achieve malaria elimination in many settings. To identify options for expanding the malaria vector control toolbox, we conducted a systematic review of the availability and quality of the evidence for 21 malaria VCTs, excluding ITNs and IRS. Methods: Six electronic databases and grey literature sources were searched from January 1, 1980 to September 28, 2015 to identify systematic reviews, Phase I–IV studies, and observational studies that measured the effect of malaria VCTs on epidemiological or entomological outcomes across any age groups in all malaria-endemic settings. Eligible studies were summarized qualitatively, with quality and risk of bias assessments undertaken where possible. Of 17,912 studies screened, 155 were eligible for inclusion and were included in a qualitative synthesis. Results: Across the 21 VCTs, we found considerable heterogeneity in the volume and quality of evidence, with 7 VCTs currently supported by at least one Phase III community-level evaluation measuring parasitologically confirmed malaria incidence or infection prevalence (insecticide-treated clothing and blankets, insecticide-treated hammocks, insecticide-treated livestock, larval source management (LSM), mosquito-proofed housing, spatial repellents, and topical repellents). The remaining VCTs were supported by one or more Phase II (n = 13) or Phase I evaluation (n = 1). Overall the quality of the evidence base remains greatest for LSM and topical repellents, relative to the other VCTs evaluated, although existing evidence indicates that topical repellents are unlikely to provide effective population-level protection against malaria. Conclusions: Despite substantial gaps in the supporting evidence, several VCTs may be promising supplements to ITNs and IRS in appropriate settings. Strengthening operational capacity and research to implement underutilized VCTs, such as LSM and mosquito-proofed housing, using an adaptive, learning-by-doing approach, while expanding the evidence base for promising supplementary VCTs that are locally tailored, should be considered central to global malaria elimination efforts.

Epidemiology of Opisthorchis viverrini Infection

Abstract: Opisthorchiasis in the Lower Mekong Subregion is a parasitic disease caused by the liver fluke Opisthorchis viverrini. This parasite has a well-documented distribution in Thailand, Lao PDR, Cambodia, Myanmar and Southern Vietnam. In this chapter, we describe the current knowledge of the epidemiology of O. viverrini infection, highlighting advances in control efforts made in the last four decades in Thailand and identifying ongoing gaps in our epidemiological knowledge which need to be filled to support efforts to permanently overcome the heavy morbidity and mortality burden caused by these parasites within their endemic regions.

Opisthorchis viverrini proteome and host-parasite interactions

Abstract: The omics technologies have improved our understanding of the molecular events that underpin host–parasite interactions and the pathogenesis of parasitic diseases. In the last decade, proteomics and genomics in particular have been used to characterize the surface and secreted products of the carcinogenic liver fluke Opisthorchis viverrini and revealed important roles for proteins at the host–parasite interface to ensure that the flukes can migrate, feed and reproduce in a hostile environment. This review summarizes the advances made in this area, primarily focusing on discoveries enabled by the publication of the fluke secreted proteomes over the last decade. Protein families that will be covered include proteases, antioxidants, oncogenic proteins and the secretion of exosome-like extracellular vesicles. Roles of these proteins in host–parasite interactions and pathogenesis of fluke-induced hepatobiliary diseases, including cholangiocarcinogenesis, are discussed. Future directions for the application of this knowledge to control infection and disease will also be discussed.

Parasites of the Giant Panda: A Risk Factor in the Conservation of a Species.

Abstract: The giant panda, with an estimated population size of 2239 in the world (in 2015), is a global symbol of wildlife conservation that is threatened by habitat loss, poor reproduction and limited resistance to some infectious diseases. Of these factors, some diseases caused by parasites are considered as the foremost threat to its conservation. However, there is surprisingly little published information on the parasites of the giant panda, most of which has been disseminated in the Chinese literature. Herein, we review all peer-reviewed publications (in English or Chinese language) and governmental documents for information on parasites of the giant pandas, with an emphasis on the intestinal nematode Baylisascaris schroederi (McIntosh, 1939) as it dominates published literature. The purpose of this chapter is to: (i) review the parasites recorded in the giant panda and describe what is known about their biology; (ii) discuss key aspects of the pathogenesis, diagnosis, treatment and control of key parasites that are reported to cause clinical problems and (iii) conclude by making some suggestions for future research. This chapter shows that we are only just 'scratching the surface' when it comes to parasites and parasitological research of the giant panda. Clearly, there needs to be a concerted research effort to support the conservation of this iconic species.

Taxonomy, Ecology and Population Genetics of Opisthorchis viverrini and Its Intermediate Hosts.

Abstract: There have been considerable advances in our understanding of the systematics and ecology of Opisthorchis viverrini; however, this new knowledge has not only clarified but also complicated the situation. We now know that what was once considered to be a single species is, in fact, a species complex, with the individual species being confined to specific wetland areas. There is also a strong genetic association between the members of the O. viverrini species complex and their Bithynia snail intermediate hosts. Although this does not negate data collected before the recognition of this situation, it does lead to the caveat that regional and temporal variations in data collected may be related to the species examined. The advances in ecology have generally been spatially limited and have led, in part, to contradictory results that may well be related to nonrecognition of the species studied. It may also be related to natural temporal and spatial variation related, for example, to habitat characteristics. To understand the variation present, it will be necessary to conduct long-term (several years at least) sampling projects after defining the genetic characteristics of O. viverrini sensu lato and its Bithynia snail intermediate hosts.

Parasite Dispersal From the Ornamental Goldfish Trade

Abstract: Goldfish, Carassius auratus Linnaeus, 1758, are immensely popular ornamental cyprinid fish, traded in more than 100 countries. For more than 500 years, human translocation has facilitated the spread of goldfish globally, which has enabled numerous and repeated introductions of parasite taxa that infect them. The parasite fauna assemblage of goldfish is generally well documented, but few studies provide evidence of parasite coinvasion following the release of goldfish. This review provides a comprehensive synopsis of parasites that infect goldfish in farmed, aquarium-held, native, and invasive populations globally and summarises evidence for the cointroduction and coinvasion of goldfish parasites. More than 113 species infect goldfish in their native range, of which 26 species have probably coinvaded with the international trade of goldfish. Of these, Schyzocotyle acheilognathi (Cestoda: Bothriocephalidae), Ichthyophthirius multifiliis (Ciliophora: Ichthyophthiriidae), Argulus japonicus (Crustacea: Argulidae), Lernaea cyprinacea (Crustacea: Ergasilidae), Dactylogyrus anchoratus, Dactylogyrus vastator and Dactylogyrus formosus (Monogenea: Dactylogyridae) are common to invasive goldfish populations in more than four countries and are considered a high risk of continued spread. Coinvasive parasites include species with direct and complex life cycles, which have successfully colonised new environments through utilisation of either new native hosts or suitable invasive hosts. Specifically, I. multifiliis, A. japonicus and L. cyprinacea can cause harm to farmed freshwater fish species and are important parasites to consider for biosecurity. These species may threaten other aquatic animal industries given their low host specificity and adaptable life histories. Future attention to biosecurity, management and border detection methods could limit the continued spread of exotic parasites from the ornamental trade of goldfish.

Monogenean Parasite Cultures: Current Techniques and Recent Advances.

Abstract: Global expansion in fish production and trade of aquatic ornamental species requires advances in aquatic animal health management. Aquatic parasite cultures permit diverse research opportunities to understand parasite-host dynamics and are essential to validate the efficacy of treatments that could reduce infections in captive populations. Monogeneans are important pathogenic parasites of captured captive fishes and exhibit a single-host life cycle, which makes them amenable to in vivo culture. Continuous cultures of oviparous monogenean parasites provide a valuable resource of eggs, oncomiracidia (larvae) and adult parasites for use in varied ecological and applied scientific research. For example, the parasite-host dynamics of Entobdella soleae (van Beneden and Hesse, 1864) and its fish host, Solea solea (Linnaeus, 1758), is one of the most well-documented of all monogeneans following meticulous, dedicated study. Polystoma spp. cultures provide an intriguing model for examining evolution in monogeneans because they exhibit two alternative phenotypes depending on the age of infection of amphibians. Furthermore, assessments of the ecological, pathological and immunological effects of fish parasites in aquaculture have been achieved through cultures of Gyrodactylus von Nordmann, 1832 spp., Benedenia seriolae (Yamaguti, 1934), Neobenedenia Yamaguti, 1963 spp. and Zeuxapta seriolae (Meserve, 1938). This review critically examines methods to establish and maintain in vivo monogenean monocultures on finfish, elasmobranchs and amphibians. Four separate approaches to establish cultures are scrutinised including the collection of live infected hosts, cohabiting recipient hosts with infected stock, cohabiting hosts with parasite eggs or oncomiracidia (larvae) and direct transfer of live adult parasites onto new fish hosts. Specific parasite species' biology and behaviour permits predictive collection of parasite life stages to effectively maintain a continuous culture, while environmental parameters can be altered to manipulate parasite generation time. Parasite virulence and biosecurity are vital components of a well-managed culture to ensure appropriate animal welfare and uncontaminated surrounding environments. Contemporary approaches and techniques are reviewed to ensure optimised monogenean cultures, which ultimately can be used to further our understanding of aquatic parasitology and identify mechanisms to limit infestations in public aquaria, ornamental trade and intensive aquaculture.

100 Years of Mass Deworming Programmes: A Policy Perspective From the World Bank's Disease Control Priorities Analyses.

Abstract: For more than 100 years, countries have used mass drug administration as a public health response to soil-transmitted helminth infection. The series of analyses published as Disease Control Priorities is the World Bank's vehicle for exploring the cost-effectiveness and value for money of public health interventions. The first edition was published in 1993 as a technical supplement to the World Bank's World Development Report Investing in Health where deworming was used as an illustrative example of value for money in treating diseases with relatively low morbidity but high prevalence. Over the second (2006) and now third (2017) editions deworming has been an increasingly persuasive example to use for this argument. The latest analyses recognize the negative impact of intestinal worm infection on human capital in poor communities and document a continuing decline in worm infection as a result of the combination of high levels of mass treatment and ongoing economic development trends in poor communities.

Immune Response to Opisthorchis viverrini Infection and Its Role in Pathology

Abstract: Human liver fluke infection caused by Opisthorchis viverrini is a major public health problem in Mekong countries such as Thailand, Laos, Cambodia, Vietnam, and Myanmar with over 10 million infected through consumption of fish containing infective metacercariae With no tissue migration phase and living entirely within the larger secondary (intrahepatic) bile ducts, liver flukes are only exposed to a biliary mucosal immune response, while their excretory and secretory products also stimulate chronic inflammation of biliary epithelium Neither mucosal nor tissue immune responses appear to cause parasite death or protect against newly established flukes, as evidenced by the persistence of infection for decades in the body and rapid reinfection following treatment Experimental studies suggest that specific immune suppressive mechanisms may promote parasite persistence, therefore allowing continued secretion of parasite products that damage the biliary epithelium, both directly through mechanical damage and mitogenicity and through innate and adaptive inflammatory responses Chronic infection is associated with several hepatobiliary diseases, specifically gallbladder and bile duct inflammation (cholecystitis and cholangitis), periductal fibrosis, and cholangiocarcinoma, the fatal bile duct cancer Various studies have linked the chronic immune response to parasite antigens to both fibrosis and many steps in the carcinogenic process Here, we review research-based understandings of the basic immune response to liver fluke infection and its roles in host protection and immunopathogenesis from available literature and also from recent studies conducted by the authors

Recent Advances in the Diagnosis and Detection of Opisthorchis viverrini Sensu Lato in Human and Intermediate Hosts for Use in Control and Elimination Programs.

Abstract: Opisthorchiasis is a neglected tropical disease, caused by infection with the fish-borne trematode Opisthorchis viverrini sensu lato that afflicts more than 10million people in Southeast Asia, including Thailand, Lao PDR, Vietnam and Cambodia. The disease is characterized by a chronic infection that induces hepatobiliary inflammation, especially periductal fibrosis, which can be detected by ultrasonography. This chronic inflammation eventually leads to cholangiocarcinoma (CCA), a usually fatal bile duct cancer that develops in approximately 1% of O. viverrini-infected individuals. In Thailand alone, CCA kills up to 20,000 people every year and is therefore of substantial public health importance. Its socioeconomic impacts on impoverished families and communities are considerable. To reduce O. viverrini-associated morbidity and CCA, the primary intervention measures focus on opisthorchiasis control and elimination. Accurate diagnoses of O. viverrini infection, in both mammalian, snail and fish intermediate hosts, are important for achieving these goals. Despite extensive efforts over several decades to find sensitive and specific diagnostics for opisthorchiasis, a simple and robust diagnostic method is still required. Here we review earlier and current developments in the search for new diagnostics for opisthorchiasis, with practical applications in the research laboratory, the clinic and the field. Of the methods currently available, the urine antigen assay shows considerable potential for the diagnosis and screening of opisthorchiasis. Nevertheless, these new assays require validation, determination of their cost-effectiveness when applied for mass screening in an endemic setting in support of policy decisions for national public health programs aimed at the control and elimination of opisthorchiasis.

Reservoir Animals and Their Roles in Transmission of Opisthorchis viverrini.

Abstract: Although any fish-eating mammals could be potential definitive hosts of Opisthorchis viverrini, only a few, especially cats and dogs, are actually known reservoir hosts for this parasite. Both animals usually get infected via consuming raw or undercooked contaminated fish, fish dishes or food remains from households. The infected animals sustain parasite egg spread via open environment defecation. Cats are the most important reservoir with higher prevalence rates of O. viverrini infection than dogs in endemic areas. Usually Opisthorchis-infected animals do not exhibit apparent clinical symptoms or specific abnormalities in laboratory examinations. Pathological findings in these animal reservoirs are basically similar to those seen in humans and experimental animals, namely periductal inflammation, biliary hyperplasia and periductal fibrosis. However, O. viverrini-associated cholangiocarcinoma has not yet been reported in the reservoir animals at present. Praziquantel is a treatment of choice not only for humans but also for animal reservoirs. Integrated control of opisthorchiasis in animal reservoirs is based on holistic approaches such as EcoHealth/One Health concepts. In fact integrated control of opisthorchiasis in humans in ecosystem has also proved successful, for example, the Lawa model for opisthorchiasis control in the endemic area of Khon Kaen, Thailand. Other feral and wild animals in endemic areas might also be potential reservoirs, and this requires more investigation. In addition, genetic diversity and evolution of the flukes might also influence zoonotic capability.

Social Influence in Liver Fluke Transmission: Application of Social Network Analysis of Food Sharing in Thai Isaan Culture

Abstract: In northeastern Thai (Isaan) culture traditional raw fish dishes and raw fish-eating habits are common. Eating and sharing meals together among the community's members, especially relatives and neighbours, are a common practice in both daily life and social gathering events. Fish are a significant protein source and are associated with variety of traditional recipes. Cyprinid fish are one of the most preferred fish by Isaan villagers for daily consumption because they are accessible and affordable. Consumption of these fish probably causes the persistence of high endemicity of human liver fluke infection, particularly with Opisthorchis viverrini, in northeast Thailand. Because the consumption of raw cyprinid fish is a well-documented risk factor for liver fluke infection, sharing of risky raw fish dishes may influence disease transmission through a community. Social network analysis was used to investigate fish and fish-based meal sharing among household members in Isaan villages in liver fluke endemic areas. The findings from three studies confirmed the persistence of traditional Isaan raw fish consumption and food-sharing practice. Social connections via food sharing among villagers played an important role in liver fluke infection and transmission dynamics as a risk factor. Thus these sociocultural factors should be taken into account in designing strategies for control of opisthorchiasis and other food-borne illnesses at the community level.

Clonorchis sinensis and Clonorchiasis: The Relevance of Exploring Genetic Variation.

Abstract: Parasitic trematodes (flukes) cause substantial mortality and morbidity in humans. The Chinese liver fluke, Clonorchis sinensis, is one of the most destructive parasitic worms in humans in China, Vietnam, Korea and the Russian Far East. Although C. sinensis infection can be controlled relatively well using anthelmintics, the worm is carcinogenic, inducing cholangiocarcinoma and causing major suffering in ~15 million people in Asia. This chapter provides an account of C. sinensis and clonorchiasis research-covering aspects of biology, epidemiology, pathogenesis and immunity, diagnosis, treatment and control, genetics and genomics. It also describes progress in the area of molecular biology (genetics, genomics, transcriptomics and proteomics) and highlights challenges associated with comparative genomics and population genetics. It then reviews recent advances in the sequencing and characterisation of the mitochondrial and nuclear genomes for a Korean isolate of C. sinensis and summarises salient comparative genomic work and the implications thereof. The chapter concludes by considering how advances in genomic and informatics will enable research on the genetics of C. sinensis and related parasites, as well as the discovery of new fluke-specific intervention targets.

Opisthorchiasis and the Microbiome.

Abstract: The liver flukes Opisthorchis viverrini, O. felineus, and Clonorchis sinensis are closely related fish-borne trematodes endemic in East Asia, Eurasia, and Siberia. Following ingestion, the parasites locate to the biliary tree, where chronic infection frequently leads to cholangiocarcinoma (CCA). Infection with C. sinensis or O. viverrini is classified as a Group 1 carcinogen by the International Agency for Research on Cancer. Infection with O. felineus may also be carcinogenic. The mechanism(s) by which infection with these liver flukes culminates in CCA remain elusive, although they are likely to be multi-factorial. Not yet well studied is the influence of opisthorchiasis on the microbiome of the host despite reports that helminth parasites are capable of affecting the microbiome, potentially modulating gastrointestinal inflammation in response to the appearance of pathogenic strains of bacteria. Here, we review recent findings related to opisthorchiasis and the microbiome and related issues. In the hamster, a tractable model of infection with liver fluke and of infection-induced biliary morbidity and CCA, infection with O. viverrini perturbs the microbiome of the gastrointestinal tract, including increasing numbers of Lachnospiraceae, Ruminococcaceae, Lactobacillaceae, and others, while decreasing Porphyromonadaceae, Erysipelotrichaceae, and Eubacteriaceae. In addition, a complex microbial community associates with the parasites within the biliary tree, including Helicobacter pylori and related bacteria. Moreover, higher rates of infection with Helicobacter occur in Thailand in persons with opisthorchiasis in a liver fluke infection intensity-dependent manner. Experimental infection of hamsters with Opisthorchis felineus results in increased alpha diversity of the microbiota diversity in the biliary tract. In humans, infection with O. felineus modifies the composition of the biliary microbiome, with increasing numbers of species of Klebsiella, Aggregatibacter, Lactobacillus, Treponema, and others. Several phylotypes of Archaea occurred solely in bile from persons infected with O. felineus.

Integrative EcoHealth/One Health Approach for Sustainable Liver Fluke Control: The Lawa Model.

Abstract: The Lawa model is a successful integrative and sustainable means of controlling opisthorchiasis in Thailand. The model integrates the EcoHealth and One Health holistic approaches with systems thinking to target the interruption of Opisthorchis viverrini transmission. Using the six principles of EcoHealth and emphasizing the three domains of One Health (human-animal-ecosystem), the program targets each step of the parasite life cycle, thus maximizing the chances of interrupting the life cycle of the parasite. The main drivers of success are the village health volunteers and health-promoting hospitals, together with the support of the government and academia. The success of the model has led to continuous expansion, adoption nationally and internationally and application to the control of other neglected tropical diseases as well as noncommunicable diseases.

Opisthorchiasis-Induced Cholangiocarcinoma: How Innate Immunity May Cause Cancer

Abstract: Innate, inflammatory responses towards persistent Opisthorchis viverrini (OV) infection are likely to contribute to the development of cholangiocarcinoma (CCA), a liver cancer that is rare in the West but prevalent in Greater Mekong Subregion countries in Southeast Asia. Infection results in the infiltration of innate immune cells into the bile ducts and subsequent activation of inflammatory immune responses that fail to clear OV but instead may damage local tissues within the bile ducts. Not all patients infected with OV develop CCA, and so tumourigenesis may be dependent on multiple factors including the magnitude of the inflammatory response that is activated in infected individuals. The purpose of this review is to summarize how innate immune responses may promote tumourigenesis following OV infection and if such responses can be used to predict CCA onset in OV-infected individuals. It also hypothesizes on the role that Helicobacterspp., which are associated with liver fluke infections, may play in activation of the innate the immune system to promote tissue damage and persistent inflammation leading to CCA.

The Socioeconomic Burden of Cholangiocarcinoma Associated With Opisthorchis viverrini Sensu Lato Infection in Northeast Thailand: A Preliminary Analysis.

Abstract: The northeast of Thailand, which is the poorest region of the country, has the highest incidence of cholangiocarcinoma (CCA) worldwide This is associated with infection with the liver fluke Opisthorchis viverrini Although an estimated 20,000 people die every year of this disease, the socioeconomic impact of this mortality on the victims' family and the community in which he or she lived remains unknown Here, we provide background information on the socioeconomic groups most effected by CCA and provide a qualitative estimate of the likely financial burden on the family and community Most victims of CCA are small-scale farmers Mortality occurs most commonly in males between the ages of 40 and 65, having either children or grandchildren to support Costs can be divided between premortality with the family paying for transport and accommodation to the hospital, as well as costs not covered by the Thai Universal Health Coverage scheme The main costs, however, are likely to be postmortem with loss of income and potentially the loss of a major contributor to farm work What is urgently required is a quantitative estimate of the costs of CCA and long-term studies of the families and communities affected to determine where and how the burden of CCA falls

The Evolutionary Biology, Ecology and Epidemiology of Coccidia of Passerine Birds

Abstract: Coccidia are intracellular parasites of the phylum Apicomplexa that cause a range of pathologies collectively termed coccidiosis. Species of coccidia of commercial importance have been well studied, with the effect of other species on passerine birds receiving increasing attention. In this chapter, we review the literature on coccidia in passerines, with a particular focus on wild populations. The taxonomy and life cycle of passerine coccidia are covered, as is their impact on the health of passerines, their epidemiology and their role in parasite-mediated natural and sexual selection. Coccidia can pose a significant threat to the health of wild passerine populations, and high rates of mortality have been observed in some studies. We examine some of the genetic factors that influence host resistance to coccidia and discuss how these parasites may be important in relation to sexually selected traits. General patterns are beginning to emerge with regard to the epidemiology of the parasites, and the influence of different aspects of the host's ecology on the prevalence and intensity of coccidia is being revealed. We examine these, as well exceptions, in addition to the phenomenon of diurnal oocyst shedding that can bias studies if not accounted for. Finally, we discuss potential future directions for research on coccidia in passerines and the importance of understanding parasite ecology in the management of threatened species.

Exploring Structural and Physical Properties of Schistosome Eggs: Potential Pathways for Novel Diagnostics?

Abstract: In this era of increasing demand for sensitive techniques to diagnose schistosomiasis, there is a need for an increased focus on the properties of the parasite eggs. The eggs are not only directly linked to the morbidity of chronic infection but are also potential key targets for accurate diagnostics. Eggs were the primary target of diagnostic tools in the past and we argue they could be the target of highly sensitive tools in the future if we focus on characteristics of their structure and shell surface that could be exploited for enhanced detection. In this review, we discuss the current state of knowledge of the physical structures of schistosome eggs and eggshells with a view to identifying pathways to a comprehensive understanding of their role in the host-parasite relationship and pathogenesis of infection, and pathways to new strategies for development of diagnostics.

Opisthorchis viverrini Draft Genome - Biomedical Implications and Future Avenues.

Abstract: Opisthorchiasis is a neglected tropical disease of major proportion, caused by the carcinogenic, Asian liver fluke, Opisthorchis viverrini. This hepatobiliary disease is known to be associated with malignant cancer (cholangiocarcinoma, CCA) and affects millions of people in Southeast Asia. No vaccine is available, and only one drug (praziquantel) is routinely employed against the parasite. Despite technological advances, little is known about the molecular biology of the fluke itself and the disease complex that it causes in humans. The advent of high-throughput nucleic acid sequencing and bioinformatic technologies is enabling researchers to gain global insights into the molecular pathways and processes in parasites. The principal aims of this chapter are to (1) review molecular research of O. viverrini and opisthorchiasis; (2) provide an account of recent advances in the sequencing and characterization of the genome and transcriptomes of O. viverrini; (3) describe the complex life of this worm in the biliary system of the definitive (human) host and how the fluke interacts with this host and causes disease at the molecular level; (4) discuss the implications of systems biological research and (5) consider how progress in genomics and informatics might enable explorations of O. viverrini and related worms and the discovery of new interventions against opisthorchiasis and CCA.

An Important Milestone in Parasitology: Celebrating a Hundred Volumes of Advances in Parasitology.

Abstract: Beginning in 1963, the founding rationale of Advances in Parasitology was to provide authentic, well-documented reviews by leading experts, about the progress being made in their area of specialism to inform the wider cadre of parasitologists, disseminating this information across allied disciplines and all users. Some 55 years later, the Series has accumulated over 667 published articles, with just over 650 authors contributing either alone or in collaboration, and has successfully served the parasitological needs of medical, veterinary and wildlife scientific communities with equity, notwithstanding treatises on vectors or intermediate hosts, as well as 'honorary parasites' such as viruses, bacteria and fungi. The first production of Advances in Parasitology united the publishing offices of Academic Press in the USA (New York) and the UK (London), maintaining Webster or Oxford writing styles, but unlike its production, all seven editors, beginning with Professor Ben Dawes, have been UK-based. While Advances in Parasitology is now published by Elsevier from their London Office, it still follows the tradition of hard backed book production, in either eclectic or thematic volume formats. But now, following academic imperatives, the Series supports online posting, allowing chapter(s) to be downloaded ahead of final production of the hard back volume. With the 100th volume of Advances in Parasitology, in eclectic format like the very first, there is good reason to celebrate and reflect on the academic impact and enduring legacy of this Series. Seen not only as a yardstick of publishing success but also as a testament, in part, to our fascination with parasites, these cursorily simple yet wonderfully complex organisms that often cause undue harm and much suffering, is still as vibrant, expanding and relevant as ever before.

RNA Interference as an Approach to Functional Genomics Genetic Manipulation of Opisthorchis viverrini

Abstract: The availability of genome and transcriptome data of the liver fluke Opisthorchis viverrini provides the foundation for exploration of gene function and its effect on host-parasite interactions and pathogenesis of O. viverrini-associated bile duct cancer. Functional genomics approaches address the function of DNA at levels of the gene, RNA transcript and protein product using informative manipulations of the genome, epigenome, transcriptome, proteome, microbiome and metabolome. Advances in functional genomics for O. viverrini have thus far focused on RNA interference. The flukes have been transfected with double-stranded RNAs aiming to silence target gene expression. In general, this approach for functional genomics investigation of this pathogen has been found to be tractable and efficient: suppression of messenger RNA expression in O. viverrini results in reduction of protein activity and phenotypic changes. Future perspectives for functional genomics of this liver fluke and close phylogenetic relatives are also discussed.