Parasites

This paper deals with the effects of agronomic practices on parasite life cycles, and the design of integrated crop protection strategies. Cropping systems have a large effect on the size of the primary inoculum and its localisation, on the development and spread of epidemics, and on the coordination of the life cycle of cultivated plants and that of their parasites. They can disrupt ecological equilibria, either favouring or disfavouring the pathogens. By combining information concerning the effects of agricultural techniques on diseases and the physiological effects of diseases on growth and crop production, it is now possible to develop new crop management systems, in which the use of non-chemical methods for preventing diseases is a priority. However, the current knowledge need to be completed by studies on other scales, particularly of the effect of cropping systems on the genetics of disease populations integrating more completely the 'long-term' dimension of sustainable agriculture. To cite this article:

173 fecal specimens from captive Capercaillies and 92 fecal specimens from free-living Capercaillies were examined bacteriologically. With all specimens the bacteriological examination was limited to the aerobic bacteria which can be isolated by the usual methods and to Clostridium perfringens. The occurrence of fungi and parasites was examined as well. The present paper compares the results of these examinations. The identifiable fecal flora of free-living Capercaillies consists of few species with low colony numbers. In about half of the specimens Bacillus spp. are the main aerobic component while only a small number of the fecal specimens contain Escherichiu coli and Streptococcus spp. None of the literature to date has stated that Streptococcus spp. do not belong to the autochthonous fecal or intestinal flora of an avian species. Clostridium perfringens cannot be isolated. The identifiable fecal flora of captive Capercaillies consists of many species with high colony numbers. Almost all fecal specimens contain Escherichia coli and various Bacillus spp. Streptococcus spp. can be isolated frequently, other enterobacteriaceae and Clostridium perfringens are present. The results of the examinations for fungi and parasites only differ slightly from those in wild birds.

Dog parks represent a recent trend in western countries, enabling owners to spend quality time with their pets in a controlled environment. Despite their growing popularity, few studies have been performed to date on these parks to investigate dog intestinal parasitic infections and soil contamination. The present study examined 369 faecal and 18 soil samples collected from 3 dog parks in Greater Lisbon, Portugal. Additionally, 102 interviews were performed with dog owners to assess dog-walking behaviours and parasite risk. In total, 33% of the faecal dog samples were infected with at least one parasitic agent: hookworms (16.5%), Cryptosporidium spp. (11.9%), Giardia spp. (11.4%), Toxascaris leonina (1.1%), Cystoisospora spp. (1.1%), Toxocara spp. (0.5%), and Sarcocystis sp. (0.3%). The soil of all the parks was contaminated with hookworm eggs. This is the first study performed in a European urban area to assess canine faecal contamination and parasitic agents in dog parks. Our resu...

Numerous studies have indicated that aquatic pollution affects parasite populations and communities. However, the responses of individual taxa and functional groups to specific contaminants, and their effect sizes, have yet to be assessed quantitatively. We began by summarizing general trends in the literature, and found that reports of significant changes in parasitism were most commonly observed in response to eutrophication and metal contamination. Among parasite taxa, significant changes were most commonly reported for acanthocephalans, digeneans and microparasites. We then conducted a quantitative metaanalysis of the effects of pollution on parasitism in aquatic animals. We calculated signed standardized effect sizes (as Cohen's d) for all published studies that provided the necessary descriptive statistics, and compared them among major contaminant types (pesticides, hydrocarbons, polychlorinated biphenyls, pulp mill effluent, metals, sewage, eutrophication, and acidification) and parasite taxa (Acanthocephala, Cestoda, Digenea, Monogenea, Nematoda and microparasites). Effect sizes were not significantly different from zero for many parasite/contaminant interactions, and tended to be highly variable within individual taxa. However, consistently strong, significant negative effects were noted in Digenea and Monogenea, especially in response to metal pollution. Significant effect sizes were typically negative, indicating that pollutants have negative effects on parasite populations. Contaminants also had a slightly negative effect on community richness. When parasites were grouped into heteroxenous (with >1 obligatory host in life cycle) vs. monoxenous (1 obligatory host in life cycle) taxa, the latter were more susceptible to a wide range of pollutants. Similarly, directly exposed (external parasites and the free-living transmission stages of internal parasites) and freshwater taxa were more susceptible to a wider range of pollutants than indirectly exposed (internal parasites) and marine taxa. This meta-analysis represented a first attempt to consider the size of the effect of pollution on parasites, and highlighted the potential of susceptible parasite taxa, communities, and functional groups for use in the biological assessment of pollution. For instance, our results indicate that freshwater monogeneans and digeneans are good candidates as potential biological indicators of pollution in aquatic ecosystems.

Multihost parasites can infect different types of hosts or even different host species. Epidemiological models have shown the importance of the diversity of potential hosts for understanding the dynamics of infectious disease (e.g., the importance of reservoirs), but the consequences of this diversity for virulence and transmission evolution remain largely overlooked. Here, I present a general theoretical framework for the study of life-history evolution of multihost parasites. This analysis highlights the importance of epidemiology (the relative quality and quantity of different types of infected hosts) and between-trait constraints (both within and between different hosts) to parasite evolution. I illustrate these effects in different transmission scenarios under the simplifying assumption that parasites can infect only two types of hosts. These simple but contrasted evolutionary scenarios yield new insights into virulence evolution and the evolution of transmission routes among different hosts. Because many of the pathogens that have large public-health and agricultural impacts have complex life cycles, an understanding of their evolutionary dynamics could hold substantial benefits for management.

In the present study, a tetraphylleadean larval cestode Scolex pleuronectis Müller, 1788 was determined in the intestine of shore rockling Gaidropsarus mediterraneus, Atlantic horse mackerel Trachurus trachurus, blotched picarel Spicara flexuosa, grass goby Zosterissesor ophiocephalus and round goby Neogobius melanostomus. Fish were collected by commercial fishermen in Sinop coasts of the Black Sea in April and May 2014. Infection prevalence and mean intensity values were determined as 12.5% and 2.00 ± 0.0 in shore rockling; 4.76% and 1.00 ± 0.0 in Atlantic horse mackerel; 20.0% and 6.80 ± 3.20 in botched picarel; 20.00% and 4.00 ± 0.0 in grass goby and, 1.44% and 55.00 ± 0.0 in round goby. Our results showed that this parasite species can be found widely at its larval stage in many bony fish species in the Black Sea.

Cophylogenetic studies examine the relationship between host and parasite evolution. One aspect of cophylogenetic studies that has had little modern discussion is parasites with multiple definitive hosts. Parasite species with multiple host species are anomalous as, under a codivergence paradigm, speciation by the hosts should cause speciation of their parasites. We discuss situations such as cryptic parasite species, recent host switching or failure to speciate that may generate multi-host parasites. We suggest methods to identify which of the mechanisms have led to multi-host parasitism. Applying the suggested methods may allow multi-host parasites to be integrated more fully into cophylogenetic studies. q

This study was conducted to evaluate effectiveness of an integrated management intervention in the control of endo- and ectoparasites of pigs kept by smallholder farmers in Mbeya Rural and Mbozi districts of southern highlands of Tanzania. A repeated cross-sectional group randomization design was employed, with 10 villages in the intervention group and six villages in the control group. The intervention consisted of improving pig confinement, feeds and feeding practices, and strategic anthelmintic treatment of pigs with oxfendazole, to primarily control Taenia solium (porcine) cysticercosis and nematodes; and with ivermectin to control ectoparasites and nematodes. Blood and faecal samples, ectoparasite specimens and skin scrapings were collected at baseline and two follow-up rounds, at an interval of seven months. A total of 482, 460 and 421 pigs were sampled in 221, 196 and 139 households at baseline, first and second follow-up visits respectively. Sero-prevalence of PC, prevalence and burden of gastrointestinal (GI) nematodes and prevalence of ectoparasites were determined using Ag-ELISA, McMaster faecal egg counting technique and body searches/skin scrapings, respectively. Mann Whitney test was used to measure intervention effect by comparing changes from baseline values of prevalence and faecal egg counts between the two groups. No significant difference (p > 0.05) was observed between the two groups, in changes from baseline of sero-prevalence of PC. The intervention significantly reduced prevalence of Trichuris suis (p = 0.044) and mean faecal egg counts of Ascaris suum (p = 0.02) from baseline to first follow-up. The intervention showed a substantial effect on the prevalence of ectoparasites as it significantly reduced overall prevalence of ectoparasites (p = 0.026), lice (p = 0.045), ticks (p = 0.049) and mites (p = 0.013) from baseline to first follow-up, and prevalence of ectoparasites, lice and mites from baseline to second follow-up (p = 0.052, p = 0.03, p = 0.017 respectively). This study has demonstrated a moderate effect of the intervention on controlling GI nematodes and ectoparasites, but no effect on sero-prevalence of PC. The reported ineffectiveness of the intervention against PC is probably an underestimation because serology is not able to provide quantitative data. It may also be a result of reduced compliance as this was a field study. Nevertheless, further studies are needed to better understand transmission dynamics of PC and explore One Health approaches including treatment of the human population against taeniosis to better secure public health.

This paper, based on a recent comprehensive sampling of insects, is the first report of Laboulbeniales from the New England region since the 1930s. We present 7 new records of laboulbenialean parasites on Staphylinidae (rove beetles) and Coccinellidae (lady beetles) from the Boston Harbor Islands National Recreation Area. These are Clonophoromyces nipponicus Terada & I.I. Tav., Hesperomyces virescens Thaxt., Ilyomyces cf. mairei F. Picard, Laboulbenia philonthi Thaxt., Peyritschiella protea Thaxt., Stichomyces conosomatis Thaxt., and Teratomyces actobii Thaxt. One of these parasite species, C. nipponicus, has not been found previously outside of its type locality in Japan. Examination of Roland Thaxter's 1891-1932 slides led to the designation of lectotypes for L. philonthi, P. protea, S. conosomatis, and T. actobii. The following synonymy is established: Teratomyces brevicaulis Thaxt. = T. actobii. In addition, we discovered new localities for H. virescens (from Canada, Cuba, Guatemala, and Japan) and L. philonthi (from

Parasitic diseases are prevalent in developing countries, especially among poor communities in the tropics. In Côte d'Ivoire, previous studies have recorded high prevalence for intestinal parasite infestations. This paper focuses on investigating the presence of gastro-intestinal parasites in rural populations from 3 villages located near the Tai National Park (TNP) and among researchers and research assistants working in TNP. Screening of 586 stool samples by Ritchie method and Merthiolate-Iodine-Formaldehyde concentration technique has revealed the presence of 21 parasites including 12 helminths and 9 protozoa. The overall parasite prevalence was high (69.1%). We found the highest and lowest prevalence in Gouléako 1 (81.43%) and Paule Oula (64.58%) villages respectively. The age group [7-14] has been more infested with a peak of infestations during rainy season. Polyparasitism is very marked with 89% of individuals harboring at least two species of parasites. The intestinal parasites inventory, detected in rural populations living near the PNT, allowed us to add six species to the list of parasites identified in the human population of Côte d'Ivoire. These are Oesophagostomum sp., Capillariidae Gen. sp., 2 Dicrocoelium sp., Trichostrongylus sp., Strongyloides fuelleborni and Balantidium coli.

Introduction: Intestinal parasitic infection has been a significant problem in HIV patients, worldwide. In this study, we aimed to measure the prevalence and identify the factors associated with intestinal parasitic infection in people infected with HIV and attending National Public Health Laboratory in Kathmandu, Nepal, for CD4 T-cell count. Methodology: An analytical cross-sectional study in 745 HIV-infected people attending for CD4 T-cell count was conducted. Results: The prevalence of intestinal parasitic infection was 22.4% (95% CI 19.5 to 25.5). In univariate analysis, age, sex, longer time since diagnosis of HIV, CD4 T-cell count of <200/µL, diarrhoea, marital status, and being under tuberculosis (TB) treatment were significantly associated with increased odds of intestinal parasite infection. However, in the logistic regression model, only the CD4 T-cell count of <200/µL (adjusted OR=4.2, 95% CI 2.5 to 7.0), diarrhoea (adjusted OR=2.8, 95% CI 1.8 to 4.3) and being under TB treatment (adjusted OR=2.9, 95% CI 1.8 to 4.6) remained as significant predictors. On stratification, CD4 T-cell count of <200/ µL was independently associated with higher odds of protozoal as well as helminthes infection. The parasites Cryptosporidium and Cyclospora were observed only in participants with CD4 T-cell counts <200/µL. Conclusions: Both protozoal and helminthic intestinal parasitic infections are common in HIV-infected people seeking care in healthcare facilities. The poor immune status as indicated by low CD4 T-cell count and TB may account for such a high risk of parasitic infection.

Cysteine proteases play numerous indispensable roles in the biology of parasitic organisms. Aside from previously known general catabolic functions and protein processing, cysteine proteases may be key to parasite immunoevasion, excystment/encystment, exsheathing and cell and tissue invasion. Parasite cysteine proteases are unusually immunogenic and have been exploited as serodiagnostic markers and vaccine targets. Although host homologues exist, parasite cysteine proteases have distinct structural and biochemical properties including, pH optima and stability, the alteration in peptide loops or domain extensions, diverse substrate specificity and cellular location. The disparate nature of parasite cysteine protease compared to the host orthologous proteins has opened opportunities for chemotherapy. This review will highlight recent research on the 'papain-like' class of cysteine proteases, the most abundant family, and the newly discovered class of asparaginyl-endopeptidases. Cysteine protease classification will be re-examined in light of the diversity uncovered within parasitic organisms.

The factors that determine parasite assemblages among the clariid fishes of Lake Victoria, Tanzania were studied between August 2003 and February 2005. Six hundred and fifty-six fish belonging to seven species were necropsied and examined for parasites, from which 31 species of metazoan parasites were recorded. The community was dominated by the nematodes both in species and numbers. Most species were generalists with only two trematodes, Diplostomum mashonense and Tylodelphys species, being specialists of Clarias gariepinus. Ten species were considered core and predictable. Parasite species richness, number of individuals per host and Shannon -Wiener diversity indices were generally high. At the compound community level, a mean number of 7.8 parasites were shared among different species of fish and the maximum number of parasites species per fish at the infracommunity level was seven. Levels of similarity in parasite species richness at the component community level ranged from 29.6 to 61.5%. The study concludes that parasite communities in clariid fishes of Lake Victoria are structured by ecological factors. At the infracommunity level, host size, diet and vagility promoted a richer parasite community. At the compound level, two factors were crucial, namely the intermixing of the waters in the lake and the predominant and mobile C. gariepinus.

Trypanosomes and leishmania, the causative agents of several tropical diseases, possess a unique redox metabolism which is based on trypanothione. The bis(glutathionyl)spermidine is the central thiol that delivers electrons for the synthesis of DNA precursors, the detoxification of hydroperoxides and other trypanothione-dependent pathways. Many of the reactions are mediated by tryparedoxin, a distant member of the thioredoxin protein family. Trypanothione is kept reduced by the parasite-specific flavoenzyme trypanothione reductase. Since glutathione reductases and thioredoxin reductases are missing, the reaction catalyzed by trypanothione reductase represents the only connection between the NADPH-and the thiolbased redox metabolisms. Thus, cellular thiol redox homeostasis is maintained by the biosynthesis and reduction of trypanothione. Nearly all proteins of the parasite-specific trypanothione metabolism have proved to be essential.

Leishmania parasites of several species cause cutaneous and visceral disease to millions of people worldwide, and treatment for this vector-borne protozoan parasite typically involves administration of highly toxic antimonial drugs. Snake venoms are one of the most concentrated enzyme sources in nature, displaying a broad range of biological effects, and several drugs now used in humans were derived from venoms. In this study, we compared the effects of the venoms of the South American rear-fanged snakes Philodryas baroni (PbV), Philodryas olfersii olfersii (PooV) and Philodryas patagoniensis (PpV), and the North American rear-fanged snakes Hypsiglena torquata texana (HttV) and Trimorphodon biscutatus lambda (TblV), on the growth of Leishmania major, a causative agent of cutaneous leishmaniasis. Different concentrations of each venom were incubated with the log-phase promastigote stage of L. major. TblV showed significant anti-leishmanial activity (IC 50 of 108.6 mg/mL) at its highest concentrations; however, it induced parasite proliferation at intermediate concentrations. PpV was not very active in decreasing the parasitic growth, and a high final concentration (1.7 mg/mL) was necessary to inhibit proliferation by only 51.5% AE 3.6%. PbV, PooV and HttV, at final concentrations of 562, 524 and 438 mg/mL respectively, had no significant effect on L. major growth. The phospholipase A 2 of TblV (trimorphin) was isolated and assayed as for crude venom, and it also exhibited dose-dependent biphasic effects on the parasite culture, with potent cytotoxicity at higher concentrations (IC 50 of 0.25 mM; 3.6 mg/mL) and stimulation of proliferation at very low concentrations. Anti-leishmanial activity of TblV appears to be solely due to the action of trimorphin. This is the first report of anti-leishmanial activity of rear-fanged snake venoms, and these results suggest novel possibilities for discovering new protein-based drugs that might be used as possible agents against leishmaniasis as well as tools to study the biology of Leishmania parasites.

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

The objective of this study was to assess the physicochemical parameters and waterborne parasites in selected recreational lakes from Malaysia. Samples were collected from seven stations of Recreational Lake A (RL-A) and six stations of Recreational Lake B (RL-B). The samples were processed to detect the presence of Giardia spp. and Cryptosporidium spp. using immunomagnetic separation kit, helminth eggs or ova by bright field microscopy and Acanthamoeba spp. by cultivation in non-nutrient agar. Chemical parameters such as ammonia, chlorine, fluoride, nitrate and nitrite and physical parameters such as dissolved oxygen, electrical conductivity, pH, salinity, temperature and total dissolved solid were also measured. Both lakes were freshwater with salinity ranging from 0.05 to 0.09 ppt. Most stations of these lakes were contaminated with Cryptosporidium spp., Giardia spp., Ascaris spp. and hookworm. Schistosoma spp. was found in RL-B only, while Acanthamoeba spp. was found in all stations. Of all sampling sites, station 5 of RL-B is the most contaminated. Linear regression and correlation analysis revealed that Giardia spp. and Schistosoma spp. showed a significant negative correlation with turbidity (p <0.01). Based on the preliminary data obtained, it is clearly shown that there is a necessity to implement the detection of waterborne parasites and physicochemical analysis in Malaysia. Future work on heavy metals (chromium, copper, mercury and zinc) is recommended to enhance the overall water quality monitoring and to take appropriate safety measures to ensure maintenance of good water standards.

Our understanding of human evolutionary and population history can be advanced by ecological and evolutionary studies of our parasites. Many parasites flourish only in the presence of very specific human behaviors and in specific habitats, are wholly dependent on us, and have evolved with us for thousands or millions of years. Therefore, by asking when and how we first acquired those parasites, under which environmental and cultural conditions we are the most susceptible, and how the parasites have evolved and adapted to us and we in response to them, we can gain considerable insight into our own evolutionary history. As examples, the tapeworm life cycle is dependent on our consumption of meat, the divergence of body and head lice may have been subsequent to the development of clothing, and malaria hyperendemicity may be associated with agriculture. Thus, the evolutionary and population histories of these parasites are likely intertwined with critical aspects of human biology and cu...

Microscopic examination of stool specimens is the cornerstone of detection of intestinal parasites in parasitology laboratories. In Europe, fresh, nonpreserved stool specimens are generally used for examination. Because intestinal parasites are shed intermittently, patients are asked to deliver multiple stool samples for examination. The limitation of this diagnostic approach is that detection of the vegetative stages of protozoa may be missed because of delays in processing and/or low compliance with the request to submit multiple stool samples. To overcome this limitation, a diagnostic test that combines multiple sampling (on 3 consecutive days), a fixative (SAF; sodium acetate acetic acid formalin), a concentration method and an easy-to-use permanent stain (chlorazol black dye) was developed for use in routine clinical practice. The results of the test, called the &quot;Triple Faeces Test&quot; (TFT), were compared with those of the conventional diagnostic method, i.e. ether sedi...

Michel Serres’s Le Parasite is a foundational text not only for the understanding of Serres’s own imposing and timely thought but also for key debates in contemporary posthumanism, object oriented thought, new materialisms, ecology, ontology and politics.
However, the reader seeking to come to terms with the book faces a three-fold problem. To begin with, Serres dialogues with a forbidding array of intertexts ranging from ancient Greek and Roman literature and philosophy through medieval and early modern French to more recent texts. Without a knowledge of key passages from these intertexts it is simply impossible to appreciate Serres’s argument, an argument which is, itself, quite intentionally parasitic on the texts with which it interacts.
The second problem for the reader is that, although both the original French and subsequent English translation of Le Parasite contain a list of intertexts as an appendix bearing the title “Histoires, animaux” (“Stories, animals”), the list is incomplete. Thirdly, and to compound the problem, Serres does not systematically mention the particular text with which he is interacting at any given point, nor indeed that he is interacting with a particular text at all. It is left to the reader to pick up the allusions and reactions for herself. The English translation provides footnotes to some but not all of these references, but the reader is nevertheless left to track down the intertexts and read the relevant passages. This leaves a great deal of work to do in order to access and appreciate the brilliant and important moves that Serres is making in Le Parasite.
The current document has been prepared to save some – perhaps most – of that extra effort. The reader will find herein not only a comprehensive list of Serres’s intertexts but also both French and English versions of the key passages with which he interacts. Each passage given below is accompanied by references to the pages of the French (Grasset, 1980) and English (Minnesota Press, 2007) editions of Le Parasite where Serres alludes to it or mentions it directly.

Paragonimus westermani is commonly known as lung fluke is native to Asia and South America. It was first isolated from two tigers that died in the zoo in Europe in 1878. It was isolated from humans after many years in Formosa. The parasite is known to cause a food-borne infection known as Paragonimiasis which causes a sub-acute inflammatory disease of lung. It has a wide geographical distribution. More than 30 species of trematodes belonging to the genus Paragonimus are known to infect both humans and animals. Out of these 10 are known to infect humans and this species is also known as oriental lung fluke.

The purpose of the African Chiroptera Report is to collate published information on, and collate specimen records of, African bats. The advent of the internet provides an opportunity for large amounts of information to be easily and economically updated and accessible, which is particularly important for taxonomic information. The electronic, web-based nature of the information is intended to allow information on African bats to be corrected/updated more frequently than a printed format allows, and to be available to users in an affordable form that can be manipulated to their specific requirements. It is hoped this tool will facilitate research and conservation planning, and possibly stimulate interactions across different areas of research. The report is generated from data collated in the African Chiroptera Database and will hopefully grow and develop with the addition of new and corrected information.
The incorporation of information other than taxonomic (see the various section headings in the description of the layout below), is still patchy in its execution across the taxa. Information that may answer specific requirements of a user, i.e. more information about the voucher specimens, or specimen collectors, has been drawn from across the database and is presented in separate appendices. Published identification keys for African bat species, have, where necessary, been updated to include current names, and are presented in appendix 5. In appendix 6 images of type specimens are included as they become available.

A re-translation of Michel Serres's “The Parasite” by Randolph Burks, based on Lawrence Schehr's translation. It was high time “The Parasite” saw a revision. Here it is. Schehr's translation has been substantially altered in style and content.

Faecal samples were individually collected from pet (n = 63) and zoo (n = 83) birds representing 14 orders and 63 species. All the samples were examined by faecal flotation technique. In a subgroup of samples (n = 75), molecular assays were also used to detect Cryptosporidium oocysts and Giardia duodenalis cysts. Overall, 35.6% of the birds harboured parasites (42.2% of zoo birds and 27% of pet birds), including Strongyles-Capillarids (8.9%), Ascaridia (6.8%), Strongyles (5.5%), G. duodenalis Assemblage A (5.3%), Coccidia (4.1%), Cryptosporidium (4%), Porrocaecum (2.7%), Porrocaecum-Capillarids (2%), and Syngamus-Capillarids (0.7%). The zoonotic G. duodenalis Assemblage A and Cryptosporidium were exclusively found in Psittaciformes, with prevalences of 10.3% and 7.7% within this bird group. Zoo birds were more likely to harbor mixed infections (OR = 14.81) and symptomatic birds to be parasitized (OR = 4.72). Clinicians should be aware of the public health implications posed by zoonotic G. duodenalis Assemblages and Cryptosporidium species in captive birds.

Parasites play an important role in the structure and function of arctic ecosystems, systems that are currently experiencing an unprecedented rate of change due to various anthropogenic perturbations, including climate change. Ungulates such as muskoxen, caribou, moose and Dall&#39;s sheep are also important components of northern ecosystems and are a source of food and income, as well as a focus for maintenance of cultural traditions, for northerners. Parasites of ungulates can influence host health, population dynamics and the quality, quantity and safety of meat and other products of animal origin consumed by people. In this article, we provide a contemporary view of the diversity of nematode, cestode, trematode, protozoan and arthropod parasites of ungulates in arctic and subarctic North America and Greenland. We explore the intricate associations among host and parasite assemblages and identify key issues and gaps in knowledge that emerge in a regime of accelerating environment...

Parasites (ectoparasites or endoparasites) are a major cause of diseases in man, his live‐ stock and crops, leading to poor yield and great economic loss. To overcome some of the major limitations of chemical control methods such as rising resistance, environmen‐ tal and health risks, and the adverse effect on non‐target organisms, biological control (biocontrol) is now at the forefront of parasite (pests) control. Biocontrol is now a core component of the integrated pest management. Biocontrol is defined as " the study and uses of parasites, predators and pathogens for the regulation of host (pest) densities ". Considerable successes have been achieved in the implementation of biocontrol strate‐ gies in the past. This chapter presents a review of the history of biocontrol, its advantages and disadvantages; the different types of biological control agents (BCAs) including predators, parasites (parasitoids) and pathogens (fungi, bacteria, viruses and virus‐like particles, protozoa and nematodes); the effect of biocontrol on native biodiversity; a few case studies of the successful implementation of biocontrol methods and the challenges encountered with the implementation of biocontrol and future perspectives.

"Michel Serres’ concept of ‘the parasite’ provides for a sustained rethinking of basic categories in social science. As an example of post-Kantian philosophy, Serres critiques the classical logic of identity as based on a ‘third man’ argument. This third space – personified as the parasite – is essential to thinking communication and transformation in systems. Parasitism operates through the logic of taking without giving or ‘abuse value’. But the parasite nevertheless makes exchange possible by creating connections between otherwise incommensurable forms of ordering. Human relations oscillate through periods of disequilibrium, often involving scapegoating and exclusion, as parasitic cascades emerge. However, parasites in the form of jokers and quasi-objects create powerful mechanisms for creating collectivity and individuality. The ‘dark organizational theory’ of Serres allows for adequate descriptions of these processes.
"

Protease function is essential to many biological systems and processes. In parasites, proteases are essential for host tissue degradation, immune evasion, and nutrition acquisition. Helminths (worms) depend on several classes of proteases for development, host tissue invasion and migration, and for degradation of host hemoglobin and serum proteins. The protozoa, which cause malaria, depend on both cysteine and aspartic proteases to initiate host hemoglobin digestion. Other types of proteases are involved in erythrocyte cell invasion and cell exit. Surface metalloproteases in kinetoplastids are implicated in the evasion of complement-mediated cell lysis and cell entry. Cysteine proteases in Entamoeba facilitate invasion of the host colon. Giardia utilizes a cysteine protease for both encystation and excystation. This review will summarize published data using protease inhibitors as tools to identify the function of parasite proteases in the development, virulence, and pathogenesis of parasites; as well as the role of endogenous parasite protease inhibitors in regulation.

J. L. Austin's claim that language ‘used not seriously’ is ‘parasitic’ upon ‘normal use’ has proved a puzzle to literary scholars, who have often taken this to mean that they are not allowed to apply the insights of speech-act theory to their own object of research. This article explores how, when read together, Michel Serres’ definition of the parasite as a ‘thermal exciter’ and Deleuze's concept of ‘minor literature’ bring out the hidden potential inherent in Austin's claim. More specifically, the article argues that Austin's reference to literature as a parasitic entity might become a promising conceptual gift, allowing us to generate a new model for approaching the world-shaping potential of literary texts.

Eicosanoids are lipid mediators with multiple functions in vertebrate tissues and invertebrate organisms. In this review the roles of eicosanoids--mostly prostaglandins (PGs), thromboxanes and leukotrienes--in parasite physiology and host-parasite interactions are discussed. PGs are present in the saliva of blood-sucking arthropods facilitating feeding by increasing local blood flow and prolonged attachment of ticks by immune suppression. Release of various eicosanoids has also been demonstrated for a number of protozoan and metazoan endoparasites. These substances appear to play a role in penetration, immune suppression, inflammation or modulation of haemostasis, enabling parasite invasion and establishment. Moreover, endogenous eicosanoids serve various functions in parasite metabolism and physiology. In many parasitic infections eicosanoids are involved in host pathology, e.g. granuloma formation, coagulopathy, secretory diarrhoea, or fever. Immune suppression by induction of PG ...

Zoonotic parasites are important causes of endemic and emerging human disease in northern North America and Greenland (the North), where prevalence of some parasites is higher than in the general North American population. The North today is in transition, facing increased resource extraction, globalisation of trade and travel, and rapid and accelerating environmental change. This comprehensive review addresses the diversity, distribution, ecology, epidemiology, and significance of nine zoonotic parasites in animal and human populations in the North. Based on a qualitative risk assessment with criteria heavily weighted for human health, these zoonotic parasites are ranked, in the order of decreasing importance, as follows: Echinococcus multilocularis, Toxoplasma gondii, Trichinella and Giardia, Echinococcus granulosus/canadensis and Cryptosporidium, Toxocara, anisakid nematodes, and diphyllobothriid cestodes. Recent and future trends in the importance of these parasites for human health in the North are explored. For example, the incidence of human exposure to endemic helminth zoonoses (e.g. Diphyllobothrium, Trichinella, and Echinococcus) appears to be declining, while water-borne protozoans such as Giardia, Cryptosporidium, and Toxoplasma may be emerging causes of human disease in a warming North. Parasites that undergo temperature-dependent development in the environment (such as Toxoplasma, ascarid and anisakid nematodes, and diphyllobothriid cestodes) will likely undergo

Disease is a major cause of natural selection affecting human evolution, whether through a sudden pandemic or persistent morbidity and mortality. Recent contributions in the field of ancient pathogen genomics have advanced our understanding of the antiquity and nature of human-pathogen interactions through time. Technical advancements have facilitated the recovery, enrichment, and high-throughput sequencing of pathogen and parasite DNA from archived and archaeological remains. These time-stamped genomes are crucial for calibrating molecular clocks to infer the timing of evolutionary events, while providing finer-grain resolution to phylogenetic reconstructions and complex biogeographical patterns. Additionally, genome scale data allow better identification of substitutions linked to adaptations of the pathogen to their human hosts. As methodology continues to improve, ancient genomes of humans and their diverse microbiomes from a range of eras and archaeological contexts will enable...

This collection of articles provides an account of six presentations delivered at the 19th International Conference of the World Association for the Advancement of Veterinary Parasitology (WAAVP) (held in New Orleans, Louisiana, USA, from 10 to 14 August 2003) in a symposium session on Molecular Systematics and Diagnosis, organised and chaired by R.B. Gasser and D.S. Zarlenga. The focus was on recent advances in molecular tools for specific and genotypic identification, diagnosis, systematics and population genetics, with special emphasis on investigations of parasitic nematodes and protists.

The hard clam, Mercenaria mercenaria, has been affected by severe mortality episodes associated with the protistan parasite QPX (Quahog Parasite Unknown) for several years. Despite the commercial importance of hard clams in the United States, molecular bases of defense mechanisms in M. mercenaria, especially during QPX infection, remain unknown.