| improved insights into the transcriptomes of the human hookworm necator americanus--fundamental and biotechnological implications. | hookworms of humans are blood-feeding parasitic nematodes of major socio-economic significance in a wide range of countries. they cause a neglected tropical disease (ntd) called "hookworm disease" (=necatoriasis and/or ancylostomiasis). necator americanus is the most widely distributed hookworm of humans and is a leading cause of iron deficiency anaemia, which can cause physical and mental retardation and deaths in children as well as adverse maternal-foetal outcomes. currently, there is a signi ... | 2009 | 18977428 |
| an update on the use of helminths to treat crohn's and other autoimmunune diseases. | this review updates our previous one (reddy and fried, parasitol research 100: 921-927, 2007) on crohn's disease and helminths. the review considers the most recent literature on trichuris suis therapy and crohn's and the significant literature on the use of necator americanus larvae to treat crohn's and other autoimmune disorders. the pros and cons of helminth therapy as related to autoimmune disorders are discussed in the review. we also discuss the relationship of the bacterium campylobacter ... | 2009 | 19050918 |
| anthelmintic activity of cyclotides: in vitro studies with canine and human hookworms. | hookworm infection is a leading cause of maternal and child morbidity in countries of the tropics and subtropics, as well as being an important parasite in companion-animal medicine. the cyclotides are a novel family of cyclic cystine knot containing peptides from plants that have been shown to possess anthelmintic activity against haemonchus contortus and trichostrongylus colubriformis, two important gastrointestinal nematodes of sheep. in the current study we demonstrated the in vitro effects ... | 2009 | 19059189 |
| spatial heterogeneity of parasite co-infection: determinants and geostatistical prediction at regional scales. | multiple parasite infections are widespread in the developing world and understanding their geographical distribution is important for spatial targeting of differing intervention packages. we investigated the spatial epidemiology of mono- and co-infection with helminth parasites in east africa and developed a geostatistical model to predict infection risk. the data used for the analysis were taken from standardised school surveys of schistosoma mansoni and hookworm (ancylostoma duodenale/necator ... | 2009 | 19073189 |
| human helminth co-infection: analysis of spatial patterns and risk factors in a brazilian community. | individuals living in areas endemic for helminths are commonly infected with multiple species. despite increasing emphasis given to the potential health impacts of polyparasitism, few studies have investigated the relative importance of household and environmental factors on the risk of helminth co-infection. here, we present an investigation of exposure-related risk factors as sources of heterogeneity in the distribution of co-infection with necator americanus and schistosoma mansoni in a regio ... | 2008 | 19104658 |
| case of creeping disease treated with ivermectin. | we report a case of creeping disease treated successfully with ivermectin. a 46-year-old man presented with a 1-month history of pruriginous linear erythema on his right thigh after a visit to indonesia. although he had no history of eating raw fish or meat, he walked along the river and in the jungle without wearing shoes. creeping disease caused by animal hookworm was strongly suspected. the presence of parasite larvae was not confirmed in biopsied skin specimens. in enzyme-linked immunosorben ... | 2009 | 19284451 |
| necator americanus infection: a possible cause of altered dendritic cell differentiation and eosinophil profile in chronically infected individuals. | hookworms survive for several years (5 to 7 years) in the host lumen, inducing a robust but largely ineffective immune response. among the most striking aspects of the immune response to hookworm (as with many other helminths) is the ablation of parasite-specific t cell proliferative response (hyporesponsiveness). while the role of the adaptive immune response in human helminth infection has been well investigated, the role of the innate immune responses (e.g., dendritic cells and eosinophils) h ... | 2009 | 19308259 |
| geohelminth infection and re-infection after chemotherapy among slum-dwelling children in durban, south africa. | the prevalences and intensities of ascaris lumbricoides, trichuris trichiura and hookworm (probably necator americanus) infection were measured in the young children (aged 2-10 years) living in 10 urban slums in durban, south africa. re-infection was assessed at 4-6 and 12 months post-treatment. the baseline prevalences of a. lumbricoides and t. trichiura were 81.7%-96.3% and 54.5%-86.2%, respectively, and the corresponding geometric mean intensities were 960 and 91 eggs/g faeces. most (85%) of ... | 2009 | 19341539 |
| an enzymatically inactivated hemoglobinase from necator americanus induces neutralizing antibodies against multiple hookworm species and protects dogs against heterologous hookworm infection. | hookworms digest hemoglobin from erythrocytes via a proteolytic cascade that begins with the aspartic protease, apr-1. ac-apr-1 from the dog hookworm, ancylostoma caninum, protects dogs against hookworm infection via antibodies that neutralize enzymatic activity and interrupt blood-feeding. toward developing a human hookworm vaccine, we expressed both wild-type (na-apr-1(wt)) and mutant (na-apr-1(mut)-mutagenesis of the catalytic aspartic acids) forms of na-apr-1 from the human hookworm, necator ... | 2009 | 19380510 |
| coinfections with schistosoma haematobium, necator americanus, and entamoeba histolytica/entamoeba dispar in children: chemokine and cytokine responses and changes after antiparasite treatment. | the effect of polyparasite infections on cytokine and chemokine responses as well as the effect of antiparasite treatment was studied in children without parasite infection (the g0 group), in children singly infected with schistosoma haematobium (the g1 group), and in children multiply infected with s. haematobium/schistosoma mansoni, entamoeba histolytica/entamoeba dispar, and necator americanus (the g3+ group). linear regression analysis disclosed a significant risk for coinfection with hookwo ... | 2009 | 19392635 |
| [relevance of helminths in the prevention and healing of immune diseases]. | the incidence of immune diseases has had a steady significant increase in the industrialized countries since the end of the last century. epidemiological data suggest that prevention of exposure to helminths may be one of the factors promoting the rise in these diseases. animal models of immune diseases support this concept by showing that these parasites can prevent and reverse developed diseases. helminths strongly modulate the host's immune system inducing regulatory immune cells and pathways ... | 2009 | 19418721 |
| proteolytic degradation of hemoglobin in the intestine of the human hookworm necator americanus. | blood-feeding parasites use mechanistically distinct proteases to digest hemoglobin (hb), often as multienzyme cooperative cascades. we investigated the roles played by 3 distinct proteases from adults of the human hookworm necator americanus. the aspartic protease na-apr-1 and the cysteine protease na-cp-3 were expressed in catalytically active form in yeast, and the metalloprotease na-mep-1 was expressed in catalytically active form in baculovirus. antibodies to all 3 proteases were used to im ... | 2009 | 19434933 |
| identification of the nuclear receptor daf-12 as a therapeutic target in parasitic nematodes. | nematode parasitism is a worldwide health problem resulting in malnutrition and morbidity in over 1 billion people. the molecular mechanisms governing infection are poorly understood. here, we report that an evolutionarily conserved nuclear hormone receptor signaling pathway governs development of the stage 3 infective larvae (il3) in several nematode parasites, including strongyloides stercoralis, ancylostoma spp., and necator americanus. as in the free-living caenorhabditis elegans, steroid ho ... | 2009 | 19497877 |
| dose-response assay templates for in vitro assessment of resistance to benzimidazole and nicotinic acetylcholine receptor agonist drugs in human hookworms. | with the implementation of mass drug administration programs for the control of human hookworms, there is a need to monitor for the emergence of drug resistance. we have therefore examined in vitro assays for monitoring sensitivity to benzimidazoles (egg hatch assay) and nicotinic acetylcholine receptor agonist drugs (motility and morphology assays), with a view to developing tools for monitoring drug sensitivity in the field. we have performed assays with necator americanus and ancylostoma ceyl ... | 2009 | 19556583 |
| nutritional status, body composition, and intestinal parasitism among the mbyá-guaraní communities of misiones, argentina. | indigenous communities in argentina represent socially and economically neglected populations. they are living in extreme poverty and environmental degradation conditions. new information about health status and socio-environmental features is urgently needed to be applied in future sanitary policies. present study describes the nutritional status, body composition, and intestinal parasitism among mbyá-guaraní children from three communities in the misiones province. anthropometric parameters we ... | 2010 | 19642206 |
| human helminth co-infection: no evidence of common genetic control of hookworm and schistosoma mansoni infection intensity in a brazilian community. | strong statistical associations between soil-transmitted helminths and schistosomes are frequently observed in co-endemic human populations, although the underlying explanations remain poorly understood. this study investigates the contribution of host genetics and domestic environment to hookworm and schistosoma mansoni infection intensity and evaluates the role of genetic and non-genetic factors in co-variation of infection intensity. detailed genealogical information allowed assignment of 130 ... | 2010 | 19699204 |
| antigen-driven basophil activation is indicative of early necator americanus infection in ige-seronegative patients. | parasitic worms induce a strong, polarized t(h)2-type immune response. the kinetics of gastrointestinal nematode-induced t(h)2-type responses, especially in the context of primary infection, have been extensively studied in experimental infection models but not in human subjects. | 2009 | 19800679 |
| systems metabolic effects of a necator americanus infection in syrian hamster. | hookworms (ancylostoma duodenale and necator americanus) are blood-feeding intestinal nematodes that infect approximately 700 million people worldwide. to further our understanding of the systems metabolic response of the mammalian host to hookworm infection, we employed a metabolic profiling strategy involving the combination of (1)h nmr spectroscopic analysis of urine and serum and multivariate data analysis techniques to investigate the biochemical consequences of a n. americanus infection in ... | 2009 | 19810771 |
| immunologic profiles of persons recruited for a randomized, placebo-controlled clinical trial of hookworm infection. | data from epidemiologic studies suggest that hookworm infections, in establishing an immunologic phenotype conducive to parasite survival, may protect against the development of allergic disease. we describe immunologic findings from a clinical study designed to investigate the safety of iatrogenic hookworm infection in participants with allergic rhinitis. the low, relatively safe level of hookworm infection used in this study was immunogenic, inducing eosinophilia and a significant specific igg ... | 2009 | 19861631 |
| alterations in the expression level of a putative aspartic protease in the development of angiostrongylus cantonensis. | aspartic proteases are a family of proteinases with catalytic aspartate residues in the active site. these enzymes have been reported to initialize the degradation of host hemoglobin in blood-feeding helminths. after identifying an expressed sequence tag representing an aspartic protease from an angiostrongylus cantonensis young adult dataset, this sequence was found to encode a protein with a predicted molecular mass of 46 kda. it also showed good homologies to aspartic proteases from caenorhab ... | 2010 | 19945419 |
| metabolic alterations in the hamster co-infected with schistosoma japonicum and necator americanus. | co-infection with hookworm and schistosomes is a common phenomenon in sub-saharan africa, as well as in parts of south america and southeast asia. as a first step towards understanding the metabolic response of a hookworm-schistosome co-infection in humans, we investigated the metabolic consequences of co-infection in an animal model, using a nuclear magnetic resonance (nmr)-based metabolic profiling technique, combined with multivariate statistical analysis. urine and serum samples were obtaine ... | 2010 | 19951707 |
| experimental hookworm infection: a randomized placebo-controlled trial in asthma. | epidemiological studies suggest that hookworm infection protects against asthma, and therefore that hookworm infection may have a direct or an indirect therapeutic potential in this disease. we now report the first clinical trial of experimental hookworm infection in people with allergic asthma. | 2010 | 20030661 |
| crystallization and preliminary x-ray analysis of na-saa-2 from the human hookworm parasite necator americanus. | human hookworms are among the most pathogenic soil-transmitted helminths. these parasitic nematodes have co-evolved with the host and are able to maintain a high worm burden for decades without killing the human host. however, it is possible to develop vaccines against laboratory-challenge hookworm infections using either irradiated third-state infective larvae (l3) or enzymes from the adult parasites. in an effort to control hookworm infection globally, the human hookworm vaccine initiative, a ... | 2010 | 20124715 |
| molecular cloning, biochemical characterization, and partial protective immunity of the heme-binding glutathione s-transferases from the human hookworm necator americanus. | hookworm glutathione s-transferases (gsts) are critical for parasite blood feeding and survival and represent potential targets for vaccination. three cdnas, each encoding a full-length gst protein from the human hookworm necator americanus (and designated na-gst-1, na-gst-2, and na-gst-3, respectively) were isolated from cdna based on their sequence similarity to ac-gst-1, a gst from the dog hookworm ancylostoma caninum. the open reading frames of the three n. americanus gsts each contain 206 a ... | 2010 | 20145100 |
| the effect of tribendimidine and its metabolites against necator americanus in golden hamsters and nippostrongylus braziliensis in rats. | the antinematode effect of tribendimidine (tbd) and its metabolites has been studied. a total of 107 hamsters were each infected with 250 necator americanus third stage infective larvae (nal3) for 25 days. in the first test, 75 hamsters were divided equally into 15 groups for determination of ed(50) and ed(90.) among them, five groups were treated orally with tbd or its metabolite, p-(1-dimethylamino ethylimino)aniline (aminoamidine, deacylated amidantel, bay d 9216, dadt), at single doses of 1, ... | 2010 | 20155372 |
| necator americanus and ancylostoma duodenale in guam, leyte, and okinawa, with a note on hookworm egg sizes. | | 1946 | 20277205 |
| neutralizing antibodies to the hookworm hemoglobinase na-apr-1: implications for a multivalent vaccine against hookworm infection and schistosomiasis. | the aspartic protease of necator americanus, na-apr-1, is a vaccine antigen that induces antibodies that neutralize hemoglobin proteolysis in the gut of the worm. to define the epitopes recognized by these antibodies, monoclonal antibodies (mabs) were raised and assessed for neutralizing activity. three immunoglobulin (ig) g1 mabs bound to the intestine of n. americanus and inhibited na-apr-1 enzymatic activity. overlapping fragments of na-apr-1 were expressed, and one (apr-1/5b) was recognized ... | 2010 | 20367477 |
| hyperendemic h. pylori and tapeworm infections in a u.s.-mexico border population. | a higher incidence of infectious disease has been documented in u.s. regions bordering mexico compared with non-border areas. we assessed the prevalence of important gastrointestinal infections in ciudad juarez, mexico, and el paso, texas, the largest binational community along the u.s.-mexico border. | 2010 | 20433039 |
| massively parallel sequencing and analysis of the necator americanus transcriptome. | the blood-feeding hookworm necator americanus infects hundreds of millions of people worldwide. in order to elucidate fundamental molecular biological aspects of this hookworm, the transcriptome of the adult stage of necator americanus was explored using next-generation sequencing and bioinformatic analyses. | 2010 | 20485481 |
| advances in metabolic profiling of experimental nematode and trematode infections. | metabonomics, which is the combination of metabolic profiling of biological samples using spectroscopic methods, together with multivariate data analysis, is a powerful approach for biomarker recovery. moreover, metabonomics holds promise to enhance our understanding of host-parasite interactions at the metabolic level, and therefore provides a framework for discovery of novel targets for diagnostics, drugs and vaccines. in this review, we summarise progress made to date with metabolic profiling ... | 2010 | 20627148 |
| copro-molecular identification of infections with hookworm eggs in rural lao pdr. | the prevalence of hookworm eggs in fecal samples, by modified cellophane thick-smear technique, was found to be 30.0% (61/203 samples) in lahanam village, savannakhet province, lao pdr. the hookworm eggs were morphologically heterogeneous, so that identification was confirmed by copro-pcr with specific primers for hookworms and trichostrongylus spp.; 12 samples were positive for necator americanus, 19 for ancylostoma spp., with one mixed infection of both. sequencing of the ancylostoma spp. copr ... | 2010 | 20673938 |
| hookworm (necator americanus) larval enzymes disrupt human vascular endothelium. | knowledge of the molecular mechanisms used by necator americanus larvae to penetrate the human skin and the vasculature would aid the development of effective vaccines against this important pathogen. in this work, the impact of n. americanus exsheathing fluid (ef) and excretory/secretory products (es) on the endothelial barrier was examined using human umbilical vein endothelial cells (huvec). cellular responses were assessed by investigating molecular changes at cell-cell junctions and by dete ... | 2010 | 20810819 |
| potency testing for the experimental na-gst-1 hookworm vaccine. | over the next decade, a new generation of vaccines will target the neglected tropical diseases (ntds). the goal of most ntd vaccines will be to reduce the morbidity and decrease the chronic debilitating nature of these often-forgotten infections – outcomes that are hard to measure in the traditional potency testing paradigm. the absence of measurable correlates of protection, a lack of permissive animal models for lethal infection, and a lack of clinical indications that do not include th ... | 2010 | 20923271 |
| developing vaccines to combat hookworm infection and intestinal schistosomiasis. | hookworm infection and schistosomiasis rank among the most important health problems in developing countries. both cause anaemia and malnutrition, and schistosomiasis also results in substantial intestinal, liver and genitourinary pathology. in sub-saharan africa and brazil, co-infections with the hookworm, necator americanus, and the intestinal schistosome, schistosoma mansoni, are common. the development of vaccines for these infections could substantially reduce the global disability associat ... | 2010 | 20948553 |
| a case of severe anemia by necator americanus infection in korea. | this report describes clinical and parasitological findings of an 82-yr-old female patient who lived in a local rural village and suffered from severe chronic anemia for several years. she was transferred to the national police hospital in seoul for management of severe dyspnea and dizziness. at admission, she showed symptoms or signs of severe anemia. gastroduodenoscopy observed hyperemic mucosa of the duodenum and discovered numerous moving roundworms on the mucosa. endoscopy isolated seven of ... | 2010 | 21165298 |
| short report: human trichostrongylus colubriformis infection in a rural village in laos. | in lahanam village, savannakhet province, laos, 125 of 253 villagers (49.4%) were found by fecal examination to harbor hookworm eggs. the eggs were heterogeneous in morphology and size, suggesting infections of mixed nematode species. to confirm the hookworm egg species, on a voluntary basis, 46 hookworm egg-positive participants were treated with albendazole, and post-treatment adult worms were collected from purged fecal samples. the common human hookworm was found in only 3 participants; 1 ca ... | 2011 | 21212201 |
| high throughput multiplex pcr and probe-based detection with luminex beads for seven intestinal parasites. | polymerase chain reaction (pcr) assays for intestinal parasites are increasingly being used on fecal dna samples for enhanced specificity and sensitivity of detection. comparison of these tests against microscopy and copro-antigen detection has been favorable, and substitution of pcr-based assays for the ova and parasite stool examination is a foreseeable goal for the near future. one challenge is the diverse list of protozoan and helminth parasites. several existing real-time pcr assays for the ... | 2011 | 21292910 |
| a pentaplex real-time polymerase chain reaction assay for detection of four species of soil-transmitted helminths. | soil-transmitted helminth infections remain a major public health burden in low- and middle-income countries. the traditional diagnosis by microscopic examination of fecal samples is insensitive and time-consuming. in this study, a pentaplex real-time polymerase chain reaction (pcr) was evaluated for the simultaneous detection of ancylostoma, necator americanus, ascaris lumbricoides, and strongyloides stercoralis. the results were compared with those obtained by conventional parasitological diag ... | 2011 | 21292911 |
| effect of hookworm infection on wheat challenge in celiac disease--a randomised double-blinded placebo controlled trial. | the association between hygiene and prevalence of autoimmune disease has been attributed in part to enteric helminth infection. a pilot study of experimental infection with the hookworm necator americanus was undertaken among a group of otherwise healthy people with celiac disease to test the potential of the helminth to suppress the immunopathology induced by gluten. | 2011 | 21408161 |
| bugs as drugs, part two: worms, leeches, scorpions, snails, ticks, centipedes, and spiders. | in this second of a two-part series analyzing the evidence for the use of organisms as medicine, the use of a number of different "bugs" (worms, leeches, snails, ticks, centipedes, and spiders) is detailed. several live organisms are used as treatments: leeches for plastic surgery and osteoarthritis and the helminths trichuris suis and necator americanus for inflammatory bowel disease. leech saliva is the source of a number of anticoagulants, including the antithrombin agent hirudin and its synt ... | 2011 | 21438646 |
| incidence and risk factors of hookworm infection in a rural community of central thailand. | a cohort study to identify incidence and risk factors of hookworm infection was conducted in a rural community, central thailand from november 2005 to february 2007. stool specimens were examined for hookworm eggs using wet preparation, kato thick smear, and water-ethyl acetate sedimentation technique. the incidence rate of hookworm infection was 7.5/100 person-years. the independent risk factors for acquiring hookworm infection were barefoot walking (incidence rate ratio [irr] = 4.2, 95% confid ... | 2011 | 21460016 |
| assessment of the anthelmintic efficacy of albendazole in school children in seven countries where soil-transmitted helminths are endemic. | the three major soil-transmitted helminths (sth) ascaris lumbricoides, trichuris trichiura and necator americanus/ancylostoma duodenale are among the most widespread parasites worldwide. despite the global expansion of preventive anthelmintic treatment, standard operating procedures to monitor anthelmintic drug efficacy are lacking. the objective of this study, therefore, was to define the efficacy of a single 400 milligram dose of albendazole (alb) against these three sth using a standardized p ... | 2011 | 21468309 |
| structure of a two-cap-domain protein from the human hookworm parasite necator americanus. | major proteins secreted by the infective larval stage hookworms upon host entry include ancylostoma secreted proteins (asps), which are characterized by one or two cap (cysteine-rich secretory protein/antigen 5/pathogenesis related-1) domains. the cap domain has been reported in diverse phylogenetically unrelated proteins, but has no confirmed function. the first structure of a two-cap-domain protein, na-asp-1, from the major human hookworm parasite necator americanus was refined to a resolution ... | 2011 | 21543848 |
| proteases in blood-feeding nematodes and their potential as vaccine candidates. | parasitic nematodes express and secrete a variety of proteases which they use for many purposes including the penetration of host tissues, digestion of host protein for nutrients, evasion of host immune responses and for internal processes such as tissue catabolism and apoptosis. for these broad reasons they have been examined as possible parasite control targets. blood-feeding nematodes such as the barber-pole worm haemonchus contortus that infect sheep and goats and the hookworms, ancylostoma ... | 2011 | 21660664 |
| the effect of egg embryonation on field-use of a hookworm benzimidazole-sensitivity egg hatch assay in yunnan province, people's republic of china. | current efforts to control human soil-transmitted helminths (sths) involve the periodic mass administration of benzimidazole drugs to school aged children and other at- risk groups. given that high levels of resistance to these drugs have developed in roundworms of livestock, there is a need to monitor drug efficacy in human sths. the current study aimed to evaluate an in vitro egg hatch assay for measuring the sensitivity of human hookworms to benzimidazole drugs in an isolated field setting in ... | 2011 | 21738805 |
| prevention of soil-transmitted helminth infection. | soil-transmitted helminths (sths) form one of the most important groups of infectious agents and are the cause of serious global health problems. the most important sths are roundworms (ascaris lumbricoides), whipworms (trichuris trichiura) and hookworms (necator americanus or ancylostoma duodenale); on a global level, more than a billion people have been infected by at least one species of this group of pathogens. this review explores the general concepts of transmission dynamics and the enviro ... | 2011 | 21731306 |
| Necator americanus and helminth co-infections: further down-modulation of hookworm-specific type 1 immune responses. | Helminth co-infection in humans is common in tropical regions of the world where transmission of soil-transmitted helminths such as Ascaris lumbricoides, Trichuris trichiura, and the hookworms Necator americanus and Ancylostoma duodenale as well as other helminths such as Schistosoma mansoni often occur simultaneously. | 2011 | 21909439 |
| suppression of inflammatory immune responses in celiac disease by experimental hookworm infection. | we present immunological data from two clinical trials where the effect of experimental human hookworm (necator americanus) infection on the pathology of celiac disease was evaluated. we found that basal production of interferon- (ifn-)γ and interleukin- (il-)17a from duodenal biopsy culture was suppressed in hookworm-infected participants compared to uninfected controls. increased levels of cd4+cd25+foxp3+ cells in the circulation and mucosa are associated with active celiac disease. we show th ... | 2011 | 21949691 |
| Non-dietary therapeutic clinical trials in coeliac disease. | Coeliac disease is a permanent immunological intolerance to gluten proteins in genetically predisposed individuals. The only management is life-long strict adherence to a gluten-free diet. Unfortunately, compliance with gluten-free diet is very difficult in practice due to the widespread presence of gluten in Western diets. For this reason, about 50% of coeliacs following a gluten-free diet continue to suffer from symptoms and present with autoantibodies and/or villous atrophy while on a gluten- ... | 2012 | 22153524 |
| a history of hookworm vaccine development. | the human hookworms necator americanus and ancylostoma duodenale remain among the most common infections of humans in areas of rural poverty in the developing regions of the world, with an estimated 1 billion people infected with one or more of these parasites. herein, we review the nearly 100 years of research, development, animal testing, and fieldwork that have led to our current progress in recombinant hookworm vaccines. we begin with the identification of hookworm at the start of the 20th c ... | 2011 | 22064562 |
| Acquired hookworm immunity in the golden hamster (Mesocricetus auratus) elicited by living Necator americanus third-stage infective larvae. | The aim of the study is to demonstrate and understand the acquired immunity in golden hamsters (Mesocricetus auratus) elicited by primary Necator americanus infective third-stage larvae (L3) infection. Hamsters infected with 150 L3 for 1, 2, 3, 6 and 10weeks, were challenged with the same number of L3 and sacrificed 25days post challenge. The primarily infected hamsters exhibited 99-100% protection against subsequent L3 challenge compared to un-infected naive hamsters. The acquired immunity was ... | 2012 | 22024448 |
| [one case with mixed infection of giardia lamblia, clonorchis sinensis, and necator americanus]. | | 2011 | 21972592 |
| [Aetiology of intestinal parasites in a sample of students from Mozambique]. | The purpose of this survey is to assess the prevalence of intestinal parasites in a population of Mozambican students. Ninety five faecal samples were collected at the three schools in Marrere, Mozambique, for a period of about one week. Observations of fresh and Giemsa-stained samples were performed at the laboratory of the Geral de Marrere Hospital; observation after concentration (FEA) was performed later at the Microbiology Laboratory of the S. Maria Nuova Hospital (Reggio Emilia, Italy). Th ... | 2011 | 22037436 |
| in vitro and in vivo efficacy of monepantel (aad 1566) against laboratory models of human intestinal nematode infections. | few effective drugs are available for soil-transmitted helminthiases and drug resistance is of concern. in the present work, we tested the efficacy of the veterinary drug monepantel, a potential drug development candidate compared to standard drugs in vitro and in parasite-rodent models of relevance to human soil-transmitted helminthiases. | 2011 | 22216366 |
| application of a real-time pcr method for detecting and monitoring hookworm necator americanus infections in southern china. | to develop a quantitative pcr method for detecting hookworm infection and quantification. | 2012 | 23593570 |
| neglected tropical diseases of oceania: review of their prevalence, distribution, and opportunities for control. | among oceania's population of 35 million people, the greatest number living in poverty currently live in papua new guinea (png), fiji, vanuatu, and the solomon islands. these impoverished populations are at high risk for selected ntds, including necator americanus hookworm infection, strongyloidiasis, lymphatic filariasis (lf), balantidiasis, yaws, trachoma, leprosy, and scabies, in addition to outbreaks of dengue and other arboviral infections including japanese encephalitis virus infection. pn ... | 2013 | 23383349 |
| peptide-based subunit vaccine against hookworm infection. | hookworms infect more people than hiv and malaria combined, predominantly in third world countries. treatment of infection with chemotherapy can have limited efficacy and re-infections after treatment are common. heavy infection often leads to debilitating diseases. all these factors suggest an urgent need for development of vaccine. in an attempt to develop a vaccine targeting the major human hookworm, necator americanus, a b-cell peptide epitope was chosen from the apical enzyme in the hemoglo ... | 2012 | 23056500 |
| lipid core peptide targeting the cathepsin d hemoglobinase of schistosoma mansoni as a component of a schistosomiasis vaccine. | the self-adjuvanting lipid core peptide (lcp) system offers a safe alternative vaccine delivery strategy, eliminating the need for additional adjuvants such as cpg alum. in this study, we adopted the lcp as a scaffold for an epitope located on the surface of the cathepsin d hemoglobinase (sm-catd) of the human blood fluke schistosoma mansoni. sm-catd plays a pivotal role in digestion of the fluke's bloodmeal and has been shown to be efficacious as a subunit vaccine in a murine model of human sch ... | 2013 | 24231271 |
| identification and characterization of alternative splicing in parasitic nematode transcriptomes. | alternative splicing (as) of mrna is a vital mechanism for enhancing genomic complexity in eukaryotes. spliced isoforms of the same gene can have diverse molecular and biological functions and are often differentially expressed across various tissues, times, and conditions. thus, as has important implications in the study of parasitic nematodes with complex life cycles. transcriptomic datasets are available from many species, but data must be revisited with splice-aware assembly protocols to fac ... | 2014 | 24690220 |
| rapid detection and identification of human hookworm infections through high resolution melting (hrm) analysis. | hookworm infections are still endemic in low and middle income tropical countries with greater impact on the socioeconomic and public health of the bottom billion of the world's poorest people. in this study, a real-time polymerase chain reaction (pcr) coupled with high resolution melting-curve (hrm) analysis was evaluated for an accurate, rapid and sensitive tool for species identification focusing on the five human hookworm species. | 2012 | 22844538 |
| epidemiological and genetic data supporting the transmission of ancylostoma ceylanicum among human and domestic animals. | currently, information on species-specific hookworm infection is unavailable in malaysia and is restricted worldwide due to limited application of molecular diagnostic tools. given the importance of accurate identification of hookworms, this study was conducted as part of an ongoing molecular epidemiological investigation aimed at providing the first documented data on species-specific hookworm infection, associated risk factors and the role of domestic animals as reservoirs for hookworm infecti ... | 2012 | 22347515 |
| quantitative detection of viable helminth ova from raw wastewater, human feces, and environmental soil samples using novel pma-qpcr methods. | in this study, we have evaluated the efficacy of propidium monoazide quantitative polymerase chain reaction (pma-qpcr) to differentiate between viable and non-viable ancylostoma caninum ova. the newly developed method was validated using raw wastewater seeded with known numbers of a. caninum ova. results of this study confirmed that pma-qpcr has resulted in average of 88 % reduction (p < 0.05) in gene copy numbers for 50 % viable +50 % non-viable when compared with 100 % viable ova. a reduction ... | 2016 | 27306209 |
| comparison of concentration methods for rapid detection of hookworm ova in wastewater matrices using quantitative pcr. | hookworm infection contributes around 700 million infections worldwide especially in developing nations due to increased use of wastewater for crop production. the effective recovery of hookworm ova from wastewater matrices is difficult due to their low concentrations and heterogeneous distribution. in this study, we compared the recovery rates of (i) four rapid hookworm ova concentration methods from municipal wastewater, and (ii) two concentration methods from sludge samples. ancylostoma canin ... | 2015 | 26358269 |
| rapid concentration and sensitive detection of hookworm ova from wastewater matrices using a real-time pcr method. | the risk of human hookworm infections from land application of wastewater matrices could be high in regions with high hookworm prevalence. a rapid, sensitive and specific hookworm detection method from wastewater matrices is required in order to assess human health risks. currently available methods used to identify hookworm ova to the species level are time consuming and lack accuracy. in this study, a real-time pcr method was developed for the rapid, sensitive and specific detection of canine ... | 2015 | 26297680 |
| new tools for ntd vaccines: a case study of quality control assays for product development of the human hookworm vaccine na-apr-1m74. | na-apr-1(m74) is an aspartic protease that is rendered enzymatically inactive by site-directed mutagenesis and is a candidate antigen component in the human hookworm vaccine. the mutant protease exerts vaccine efficacy by inducing antibodies that neutralize the enzymatic activity of wild type enzyme (na-apr-1wt) in the gut of the hookworm, thereby depriving the worm of its ability to digest its blood meal. previously, canines immunized with na-apr-1(m74) and challenged with ancylostoma caninum w ... | 2015 | 26018444 |
| molecular detection of ancylostoma duodenale, ancylostoma ceylanicum, and necator americanus in humans in northeastern and southern thailand. | the 2 principal species of hookworms infecting humans are necator americanus and ancylostoma duodenale. case studies on zoonotic hookworm infections with ancylostoma ceylanicum and/or ancylostoma caninum are known mainly from asian countries. of these 2 zoonotic species, only a. ceylanicum can develop to adulthood in humans. in the present study, we report a molecular-based survey of human hookworm infections present in southern and northeastern thailand. thirty larval hookworm samples were obta ... | 2013 | 24516284 |
| molecular and biological diagnostic tests for monitoring benzimidazole resistance in human soil-transmitted helminths. | in endemic countries with soil-transmitted helminths mass drug administration with albendazole or mebendazole are being implemented as a control strategy. however, it is well known in veterinary helminths that the use of the same benzimidazole drugs can place selection on the β-tubulin gene, leading to resistance. given the concern that resistance could arise in human soil-transmitted helminths, there is an urgent need to develop accurate diagnostic tools for monitoring resistance. in this study ... | 2013 | 23458960 |
| ancylostoma ceylanicum hookworm in the solomon islands. | although hookworm is highly prevalent in the solomon islands, the species involved are unknown. we initiated this study in response to finding ancylostoma ceylanicum hookworm in a peacekeeper in australia who had returned from the solomon islands. kato-katz fecal surveys performed in 2013 and 2014 in 2 village groups in east malaita, solomon islands, identified hookworm-positive samples. these specimens were tested by cytochrome oxidase 1 (cox-1) gene multiplex pcr and sequenced. of 66 positive ... | 2017 | 28098526 |
| first molecular identifications of necator americanus and ancylostoma ceylanicum infecting rural communities in lower myanmar. | hookworms are enteric parasitic roundworms infecting an estimated 400 million persons worldwide. herein, we provide the first molecular identifications of human hookworms from certain parts of rural lower myanmar. dna was extracted from hookworm-positive stool samples, as determined by microscopy. dna sequences of the partial internal transcribed spacer 1, full length 5.8s gene, and partial internal transcribed spacer 2 were determined and compared with available hookworm sequences from public d ... | 2017 | 28077747 |
| the hookworm ancylostoma ceylanicum intestinal transcriptome provides a platform for selecting drug and vaccine candidates. | the intestine of hookworms contains enzymes and proteins involved in the blood-feeding process of the parasite and is therefore a promising source of possible vaccine antigens. one such antigen, the hemoglobin-digesting intestinal aspartic protease known as na-apr-1 from the human hookworm necator americanus, is currently a lead candidate antigen in clinical trials, as is na-gst-1 a heme-detoxifying glutathione s-transferase. | 2016 | 27677574 |
| evaluation of an fda approved library against laboratory models of human intestinal nematode infections. | treatment options for infections with soil-transmitted helminths (sth) - ascaris lumbricoides, trichuris trichiura and the two hookworm species, ancylostoma duodenale and necator americanus - are limited despite their considerable global health burden. the aim of the present study was to test the activity of an openly available fda library against laboratory models of human intestinal nematode infections. | 2016 | 27363703 |
| a novel isothermal microcalorimetry tool to assess drug effects on ancylostoma ceylanicum and necator americanus. | soil-transmitted helminths, which affect the poorest communities, worldwide cause a range of symptoms and morbidity, yet few treatment options are available and drug resistance is a concern. to improve and accelerate anthelminthic drug discovery, novel drug screening tools such as isothermal microcalorimetry (imc) have been tested with great potential. in this study, we used a novel microcalorimeter, the calscreener™, to study the viability on the hookworms necator americanus and ancylostoma cey ... | 2016 | 26519051 |
| identification of ancylostoma ceylanicum in children from a tribal community in tamil nadu, india using a semi-nested pcr-rflp tool. | it is generally assumed that hookworm infections in humans are caused by necator americanus and ancylostoma duodenale. however, previous studies have also reported the presence of the animal hookworm a. ceylanicum in human stools. | 2015 | 25618132 |
| an extensive comparison of the effect of anthelmintic classes on diverse nematodes. | soil-transmitted helminths are parasitic nematodes that inhabit the human intestine. these parasites, which include two hookworm species, ancylostomaduodenale and necator americanus, the whipworm trichuristrichiura, and the large roundworm ascarislumbricoides, infect upwards of two billion people and are a major cause of disease burden in children and pregnant women. the challenge with treating these diseases is that poverty, safety, and inefficient public health policy have marginalized drug de ... | 2013 | 23869246 |
| genetic characterization of selected parasites from people with histories of gastrointestinal disorders using a mutation scanning-coupled approach. | a sscp analysis and targeted sequencing approach was used for the genetic characterization of some major pathogens from a cohort of 227 people with histories of gastrointestinal disorders. genomic dnas from fecal samples were subjected to pcr-amplification of regions in the glycoprotein (gp60) or triose phosphate isomerase (tpi) gene, or the second internal transcribed spacer of nuclear ribosomal dna (its-2). cryptosporidium, giardia, and strongylid nematodes were detected in 94, 132 and 12 samp ... | 2013 | 23592267 |
| activity of oxantel pamoate monotherapy and combination chemotherapy against trichuris muris and hookworms: revival of an old drug. | it is widely recognized that only a handful of drugs are available against soil-transmitted helminthiasis, all of which are characterized by a low efficacy against trichuris trichiura, when administered as single doses. the re-evaluation of old, forgotten drugs is a promising strategy to identify alternative anthelminthic drug candidates or drug combinations. | 2013 | 23556013 |
| molecular identification of human hookworm infections in economically disadvantaged communities in peninsular malaysia. | species identification of human hookworm infections among eight communities in rural areas of peninsular malaysia was determined during 2009-2011. fecal samples were examined by microscopy and subsequently, the internal transcribed spacer 2 and 28s ribosomal rna region of necator americanus and ancylostoma spp. were sequenced. overall, 9.1% (58 of 634) were identified positive by microscopy for hookworm infection, and 47 (81.0%) of 58 were successfully amplified and sequenced. sequence compariso ... | 2012 | 22556084 |
| soil-transmitted helminthiasis in laos: a community-wide cross-sectional study of humans and dogs in a mass drug administration environment. | we conducted a community cross-sectional survey of soil-transmitted helminthiasis in humans and dogs in four provinces in northern laos. we collected and tested human and dog fecal samples and analyzed results against sociodemographic data. the prevalence of ascaris lumbricoides, trichuris trichiura, hookworm, and strongyloides stercoralis was 26.1% (95% confidence interval [ci] = 23.7-28.4%), 41.5% (95% ci = 38.8-44.1%), 46.3% (95% ci = 43.3-49.0%), and 8.9% (95% ci = 7.4-10.4%), respectively. ... | 2012 | 22492147 |
| blastocystis subtyping and its association with intestinal parasites in children from different geographical regions of colombia. | blastocystis is a common enteric protist colonizing probably more than 1 billion people with a large variety of non-human hosts. remarkable genetic diversity has been observed, leading to the subdivision of the genus into multiple subtypes (st), some of which are exclusively found in non-human hosts. the aim of this study was to determine the distribution of blastocystis sts/18s alleles in symptomatic (abdominal pain, anal pruritus, diarrhea, headache, nauseas and/or vomit) and asymptomatic chil ... | 2017 | 28222192 |
| detection and quantification of soil-transmitted helminths in environmental samples: a review of current state-of-the-art and future perspectives. | it is estimated that over a billion people are infected with soil-transmitted helminths (sths) globally with majority occurring in tropical and subtropical regions of the world. the roundworm (ascaris lumbricoides), whipworm (trichuris trichiura), and hookworms (ancylostoma duodenale and necator americanus) are the main species infecting people. these infections are mostly gained through exposure to faecally contaminated water, soil or contaminated food and with an increase in the risk of infect ... | 2017 | 28214519 |
| association of community sanitation usage with soil-transmitted helminth infections among school-aged children in amhara region, ethiopia. | globally, in 2010, approximately 1.5 billion people were infected with at least one species of soil-transmitted helminth (sth), ascaris lumbricoides, trichuris trichiura, hookworm (ancylostoma duodenale and necator americanus). infection occurs through ingestion or contact (hookworm) with eggs or larvae in the environment from fecal contamination. to control these infections, the world health organization recommends periodic mass treatment of at-risk populations with deworming drugs. prevention ... | 2017 | 28212668 |
| the molecular speciation of soil-transmitted helminth eggs collected from school children across six endemic countries. | the diagnosis of soil-transmitted helminths (sths; ascaris, trichuris and hookworms) is traditionally based on the demonstration of eggs in stool using microscopic techniques. while molecular techniques are more appropriate to speciate sth species they are seldom applied. in this study we speciated sth eggs from stool using molecular techniques to gain insights into the distribution of both human and animal sth species in the human host. | 2017 | 28100811 |
| diagnosis of intestinal parasites in a rural community of venezuela: advantages and disadvantages of using microscopy or rt-pcr. | a cross-sectional study was carried out to determine the prevalence and diagnostic performance of microscopy and real time pcr (rt-pcr) for 14 intestinal parasites in a venezuelan rural community with a long history of persistent intestinal parasitic infections despite the implementation of regular anthelminthic treatments. a total of 228 participants were included in this study. a multiplex rt-pcr was used for the detection of dientamoeba fragilis, giardia intestinalis, cryptosporidium sp. and ... | 2017 | 28007484 |
| molecular modeling and structural analysis of arylesterase of ancylostoma duodenale. | parasitic worm infection of humans is one of the most commonly prevalent helminth infection that has imposed great impact on society and public health in the developing world. the two species of hookworm, namely ancylostoma duodenale and necator americanus may be primarily responsible for causing parasitic infections in human beings. the highly prevalent areas for ancylostoma duodenale infections are mainly india, middle east, australia, northern africa and other parts of the world. the serum ar ... | 2017 | 27642240 |
| molecular identification of hookworm isolates in humans, dogs and soil in a tribal area in tamil nadu, india. | hookworms (necator americanus and ancylostoma duodenale) remain a major public health problem worldwide. infections with hookworms (e.g., a. caninum, a. ceylanicum and a. braziliense) are also prevalent in dogs, but the role of dogs as a reservoir for zoonotic hookworm infections in humans needs to be further explored. | 2016 | 27486798 |
| molecular diagnostics for soil-transmitted helminths. | historically, the diagnosis of soil-transmitted helminths (sths) (e.g., strongyloides stercoralis, trichuris trichiura, ancylostoma duodenale, necator americanus, and ascaris lumbricoides) has relied on often-insensitive microscopy techniques. over the past several years, there has been an effort to use molecular diagnostics, particularly quantitative polymerase chain reaction (qpcr), to detect intestinal pathogens. while some platforms have been approved by regulatory bodies (e.g., food and dru ... | 2016 | 27481053 |
| improved pcr-based detection of soil transmitted helminth infections using a next-generation sequencing approach to assay design. | the soil transmitted helminths are a group of parasitic worms responsible for extensive morbidity in many of the world's most economically depressed locations. with growing emphasis on disease mapping and eradication, the availability of accurate and cost-effective diagnostic measures is of paramount importance to global control and elimination efforts. while real-time pcr-based molecular detection assays have shown great promise, to date, these assays have utilized sub-optimal targets. by perfo ... | 2016 | 27027771 |
| [geohelminths]. | millions of people in in rural areas and deprived tropical and subtropical regions are infected by soil-transmitted helminths: ascaris lumbricoides, trichuris trichiura, hookworms (ancylostoma duodenale and necator americanus), and strongyloides stercoralis. large migratory flows have made their worldwide distribution easier. besides being debilitating and producing a significant mortality, they cause high morbidity, leading to physical and intellectual impairment in millions of children who liv ... | 2017 | 26980233 |
| immune polarization by hookworms: taking cues from t helper type 2, type 2 innate lymphoid cells and alternatively activated macrophages. | cellular and molecular investigation of parasitic helminth infections has greatly accelerated the understanding of type 2 immune responses. however, there remains considerable debate regarding the specific leucocytes that kill parasites and whether these mechanisms are distinct from those responsible for tissue repair. herein, we chronicle discoveries over the past decade highlighting current paradigms in type 2 immunity with a particular emphasis upon how cd4(+) t helper type 2 cells, type 2 in ... | 2016 | 26928141 |
| multi-parallel qpcr provides increased sensitivity and diagnostic breadth for gastrointestinal parasites of humans: field-based inferences on the impact of mass deworming. | although chronic morbidity in humans from soil transmitted helminth (sth) infections can be reduced by anthelmintic treatment, inconsistent diagnostic tools make it difficult to reliably measure the impact of deworming programs and often miss light helminth infections. | 2016 | 26813411 |
| epidemiological surveys of, and research on, soil-transmitted helminths in southeast asia: a systematic review. | soil-transmitted helminth (sth) infections of humans fall within the world health organization's (who) grouping termed the neglected tropical diseases (ntds). it is estimated that they affect approximately 1.4 billion people worldwide. a significant proportion of these infections are in the population of southeast asia. this review analyses published data on sth prevalence and intensity in southeast asia over the time period of 1900 to the present to describe age related patterns in these epidem ... | 2016 | 26813007 |
| detection of intestinal parasites by use of the cuvette-based automated microscopy analyser sedimax(®). | microscopy is the reference method for intestinal parasite identification. the cuvette-based automated microscopy analyser, sedimax 1, provides 15 digital images of each sediment sample. in this study, we have evaluated this fully automated instrument for detection of enteric parasites, helminths and protozoa. a total of 700 consecutively preserved samples consisting of 60 positive samples (50 protozoa, ten helminths) and 640 negative samples were analysed. operators were blinded to each others' ... | 2016 | 26679923 |
| development and evaluation of a loop mediated isothermal amplification (lamp) technique for the detection of hookworm (necator americanus) infection in fecal samples. | hookworm infection is a major concern in sub-saharan africa, particularly in children and pregnant women. necator americanus and ancylostoma duodenale are responsible for this condition. hookworm disease is one of the neglected tropical diseases (ntds) that are targeted for elimination through global mass chemotherapy. to support this there is a need for reliable diagnostic tools. the conventional diagnostic test, kato-katz that is based on microscopic detection of parasite ova in faecal samples ... | 2015 | 26546069 |
| identification of human intestinal parasites affecting an asymptomatic peri-urban argentinian population using multi-parallel quantitative real-time polymerase chain reaction. | in resource-limited countries, stool microscopy is the diagnostic test of choice for intestinal parasites (soil-transmitted helminths and/or intestinal protozoa). however, sensitivity and specificity is low. improved diagnosis of intestinal parasites is especially important for accurate measurements of prevalence and intensity of infections in endemic areas. | 2015 | 26183074 |
| soil-transmitted helminths in southwestern china: a cross-sectional study of links to cognitive ability, nutrition, and school performance among children. | empirical evidence suggests that the prevalence of soil-transmitted helminth (sth) infections in remote and poor rural areas is still high among children, the most vulnerable to infection. there is concern that sth infections may detrimentally affect children's healthy development, including their cognitive ability, nutritional status, and school performance. medical studies have not yet identified the exact nature of the impact sth infections have on children. the objective of this study is to ... | 2015 | 26110518 |
| infection with soil-transmitted helminths is associated with increased insulin sensitivity. | given that helminth infections have been shown to improve insulin sensitivity in animal studies, which may be explained by beneficial effects on energy balance or by a shift in the immune system to an anti-inflammatory profile, we investigated whether soil-transmitted helminth (sth)-infected subjects are more insulin sensitive than sth-uninfected subjects. | 2015 | 26061042 |
| heavy metals and parasitic geohelminths toxicity among geophagous pregnant women: a case study of nakuru municipality, kenya. | geophagia is defined as deliberate consumption of earths' materials, e.g. soil, clay and soft stones. the practice is widespread among pregnant women, and there are conflicting views as to whether it is beneficial to health or not. geophagic materials may be a source of micronutrients though the materials may bind the micronutrients thus reducing or hindering their bioavailability in the body. geophagia is closely associated with geohelminthic infections among pregnant women and heavy metal pois ... | 2016 | 25750054 |
| water, sanitation, hygiene, and soil-transmitted helminth infection: a systematic review and meta-analysis. | preventive chemotherapy represents a powerful but short-term control strategy for soil-transmitted helminthiasis. since humans are often re-infected rapidly, long-term solutions require improvements in water, sanitation, and hygiene (wash). the purpose of this study was to quantitatively summarize the relationship between wash access or practices and soil-transmitted helminth (sth) infection. | 2014 | 24667810 |
| current status of human hookworm infections, ascariasis, trichuriasis, schistosomiasis mekongi and other trematodiases in lao people's democratic republic. | soil-transmitted helminth (sth) infections, and schistosomiasis and other trematodiases often have a high prevalence in developing countries. here, we present updated information on the prevalence of these parasites in the lao people's democratic republic (lao pdr) in 2012, arising from the annual national helminthiasis survey. fecal specimens were collected from 8,610 inhabitants of 12 provinces and one municipality (bokeo, houaphan, luang namtha, luang prabang, oudomxay, and phongsaly province ... | 2014 | 24515942 |
| prevalence and risk factors of soil-transmitted helminth infection in nepal. | the purpose of this study is to evaluate the prevalence and intensity and examine the risk factors of soil transmitted helminth (sth; i.e., roundworm [ascaris lumbricoides], hookworms [ancylostoma duodenale and necator americanus], and whipworm [trichuris trichiura]) infections in nepal. | 2014 | 24488979 |