| [iron-deficiency anemia related to ancylostoma duodenale infection among ethiopian immigrants to israel]. | among the diseases imported by the ethiopian immigrants to israel are many parasite infections. hookworm infections, caused by the nematodes necator americanus and ancylostoma duodenale, involve the gastrointestinal tract, causing iron-deficiency anemia. | 2003 | 14518163 |
| [transmission of schistosomiasis in an urban population and prevalence of intestinal helminthiasis in bamako, mali ]. | parasitological, malacological and anthropological studies were performed to assess the prevalence of schistosoma haematobium and s. mansoni in schoolchildren living in the suburban area of bamako. a total of 1017 schoolchildren aged 6-14 years were selected in two different areas between september 1997 and december 1999. in djikoroni, the prevalence of s. haematobium and s. mansoni was 80.7% (339/420) and 22.8% (85/372) respectively. there was no significant difference of prevalence and intensi ... | 2003 | 14582293 |
| [polymorphism analysis of cytochrome c oxidase 1 (coi) gene in necator americanus collected from 5 provinces in china]. | to detect and compare the coi gene sequences of necator americanus collected from the provinces of sichuan, hainan, yunnan, hubei and jiangsu, and to analyze the genetic diversity of the geographic isolates. | 2003 | 14628369 |
| a survey for helminth parasites in feral new world non-human primate populations and its comparison with parasitological data from man in the region. | a survey for helminth parasites in feral new world non-human primates was conducted and compared with parasitological data from man in the region. a total of 835 fecal samples were collected from feral aotus nancymae, a. vociferans, saguinus labiatus, s. mystax, saimiri boliviensis peruviensis, s. sciureus macrodon, lagothrix lagotricha and cacajao calvus rubicundus. in addition, adult parasites were collected from necropsies performed on monkeys that died during quarantine and in captivity. hel ... | 2003 | 14641789 |
| an epidemiological study of pleuropulmonary paragonimiasis among pupils in the peri-urban zone of kumba town, meme division, cameroon. | paragonimiasis have previously been reported in two zones of the southwest province of cameroon including the kupe mountain and mundani foci. the aim of this study was to investigate the presence and epidemiology of paragonimiasis in the peri-urban zone of kumba, meme division, located about 50 km away from the kupe mountain focus. | 2003 | 14678562 |
| [intestinal parasitosis in the asymptomatic subsaharian immigrant population. gran canaria 2000]. | a prospective study has been conducted in order to known the prevalence and the type of intestinal parasitoses in a cohort of healthy subsaharian immigrants that reached gran canaria along the year 2000. | 2004 | 14746755 |
| the innate allergenicity of helminth parasites. | helminth parasites are well known to induce an immune response in their hosts characterised by elevated ige, peripheral blood or local tissue eosinophilia, and in some cases, intestinal mastocytosis. this immunological response has a strong t-helper 2 (th2) cytokine bias and is reminiscent of the immunological constellation found in allergic diseases. however, the molecular forces driving the th2 response to helminth parasites are still not understood. by using the human hookworm parasite necato ... | 2004 | 14755076 |
| [eosinophilic pleurisy and pericarditis during necator americanus infestation]. | | 1951 | 14824457 |
| necator americanus: maintenance through one hundred generations in golden hamsters (mesocricetus auratus). ii. morphological development of the adult and its comparison with humans. | through 100 passages, the human hookworm necator americanus was adapted to the golden hamster, mesocricetus auratus, without either the requirement for exogenous steroids or other immunosuppressive agents, nor the requirement to infect hamsters as pups. adult n. americanus recovered from infected hamsters were morphologically similar to those from infected humans in sichuan province, china, although they were smaller and the females produced fewer eggs. the natural history and kinetics of n. ame ... | 2003 | 14990312 |
| molecular analysis of the beta-tubulin gene of human hookworms as a basis for possible benzimidazole resistance on pemba island. | | 2004 | 15003848 |
| common intestinal parasites. | intestinal parasites cause significant morbidity and mortality. diseases caused by enterobius vermicularis, giardia lamblia, ancylostoma duodenale, necator americanus, and entamoeba histolytica occur in the united states. e. vermicularis, or pinworm, causes irritation and sleep disturbances. diagnosis can be made using the "cellophane tape test." treatment includes mebendazole and household sanitation. giardia causes nausea, vomiting, malabsorption, diarrhea, and weight loss. stool ova and paras ... | 2004 | 15023017 |
| intestinal helminthic infestation in children. | in this study of fecal samples from 1000 children below 6 years of age, 680 (68.0%) detected to have intestinal helminthic infection. the incidence of intestinal helminthiasis in urban group of children was 56.8% (284 out of 500 tested) while in rural group of children was 79.2% (396 out of 500 tested). both in rural and urban population ascaris lumbricoides was the single predominant species, whereas a combination of a. lumbricoides and trichuris trichiura was common multiple infection. all cul ... | 2003 | 15025321 |
| hookworm (necator americanus) transmission in inland areas of sandy soils in kwazulu-natal, south africa. | this study extended the association between hookworm transmission in kwazulu-natal and the sandy coastal plain by investigating the parasite's occurrence in isolated areas of sandy soils further inland. a school-based prevalence survey was carried out in selected inland sandy areas and in surrounding areas dominated by clay soils within a narrow altitudinal range of between 500 and 700 m to reduce the effect of altitude on climate-related factors (rainfall and temperature). sandy areas situated ... | 2004 | 15078265 |
| cellular responses and cytokine production in post-treatment hookworm patients from an endemic area in brazil. | human hookworm infections are distributed widely in tropical areas and have a significant impact on host morbidity and human health. in the present study, we investigated the cellular responsiveness and cytokine production in peripheral blood mononuclear cells (pbmc) from necator americanus-infected schoolchildren who had recently received chemotherapy, and compared them with non-infected endemic controls. hookworm patients and treated, egg-negative individuals showed a lower cellular reactivity ... | 2004 | 15086399 |
| resistance to helminth infection: the case for interleukin-5-dependent mechanisms. | | 2004 | 15243913 |
| immune responses in human necatoriasis: association between interleukin-5 responses and resistance to reinfection. | cytokine and proliferative responses to necator americanus infection were measured in a treatment-reinfection study of infected subjects from an area of papua new guinea where n. americanus is highly endemic. before treatment, most subjects produced detectable interleukin (il)-4 (97%), il-5 (86%), and interferon (ifn)- gamma (64%) in response to adult n. americanus antigen. pretreatment ifn- gamma responses were negatively associated with hookworm burden, decreasing by 18 pg/ml for each increase ... | 2004 | 15243914 |
| a secreted protein from the human hookworm necator americanus binds selectively to nk cells and induces ifn-gamma production. | parasitic helminths induce chronic infections in their hosts although, with most human helminthiases, protective immunity gradually develops with age or exposure of the host. one exception is infection with the human hookworm, necator americanus, where virtually no protection ensues over time. such observations suggest these parasites have developed unique mechanisms to evade host immunity, leading us to investigate the role of the excretory/secretory (es) products of adult n. americanus in mani ... | 2004 | 15294988 |
| comparison of mitochondrial cytochrome oxidase 1 dna sequences from necator americanus hookworms maintained for 100 generations in golden hamsters (mesocricetus auratus) and hookworms from natural human infections. | the human hookworm necator americanus was maintained through one hundred generations in the golden hamsters. the strain is now routinely maintained in laboratory hamsters through serial passage, and is the laboratory strain of choice for vaccine studies. comparison of the mitochondrial cytochrome oxidase 1 (cox-1) sequences was shown previously to be useful for comparing the genetic structure of populations of n. americanus in china. cytochrome oxidase 1 genes were amplified by the polymerase ch ... | 2004 | 15301977 |
| ac-saa-1, an immunodominant 16 kda surface-associated antigen of infective larvae and adults of ancylostoma caninum. | a cdna encoding a surface-associated antigen was cloned from an ancylostoma caninum infective larvae (l(3)) cdna library by immunoscreening with pooled human immune sera. the sera were obtained from individuals living in an ancylostoma duodenale hookworm-endemic region of china, who had light intensity infections and high antibody titers against a. caninum l(3). ancylostoma caninum surface-associated antigen-1 is encoded by an 843 bp mrna with a predicted open reading frame of 162 amino acids. r ... | 2004 | 15313130 |
| hookworm infection: new developments and prospects for control. | hookworm infection remains a major health burden in developing countries. successful control will likely be achieved through continued advances in our understanding of the epidemiology, molecular biology and immunopathogenesis of hookworm infection. this review summarizes recent advances in each of these fields, and discusses ongoing efforts to develop vaccines against hookworm anemia and growth delay. | 2004 | 15353961 |
| do hookworms elicit protective immunity in man? | the two main species of human hookworm, ancylostoma duodenale and necator americanus (table 1), are together believed to infect about 900 million people - mainly in tropical countries where adequate sanitary facilities may be lacking. but interactions between the two species, and their relative contributions to observed age-related infection patterns and seasonal cycles of transmission, continue to engender controversy. people tend to remain susceptible to infection through-out life, even with c ... | 1987 | 15462956 |
| hookworm antigens: the potential for vaccination. | hookworms rank with ascaris as the most prevalent soil-transmitted helminths of man. up to 1000 million people may be infected. not all suffer the life-threatening anaemia that reflects heavy burdens of hookworms, but even mild iron-deficiency anaemia due to hookworms can lead to intellectual and growth retardation - especially among infected children. health education, mass chemotherapy and the sanitary disposal of faeces have been the traditional mainstays of hookworm control, but more recentl ... | 1987 | 15462967 |
| an immunological and biochemical comparison of hookworm species. | the successful development of diagnostic tests capable of distinguishing human hookworm species will ultimately depend on an increase in our knowledge of their comparative biochemistry. here, david pritchard, paul mckean and gerry schad describe some aspects of the comparative biochemistry of necator americanus and ancylostoma duodenale, and emphasize differences between the species that could form the basis of discriminatory diagnostic tests. | 1990 | 15463327 |
| [intestinal helminthiasis among school children: preliminary results of a prospective study in agboville in southern côte d'ivoire]. | intestinal helminthiasis affects the health and academic performance of children in developing countries. to highlight a few socio-economic factors that impact the presence and upholding of intestinal helminthiasis, a cohort study was performed from february to june 2001. this study took place in agboville in southern côte d'ivoire on 363 children, under the age of 15, regularly enrolled in school and selected by two-step clustered sampling. after the survey was completed, their stools were exam ... | 2004 | 15563408 |
| an in vitro larval motility assay to determine anthelmintic sensitivity for human hookworm and strongyloides species. | with the implementation of programs to control lymphatic filariasis and soil-transmitted helminths using broad spectrum anthelmintics, including albendazole and ivermectin, there is a need to develop an in vitro assay for detection of drug resistance. this report describes an in vitro assay for measuring the effects of ivermectin and benzimidazoles on the motility of larvae of the hookworm species ancylostoma ceylanicum, a. caninum, and necator americanus, and strongyloides species including str ... | 2004 | 15569793 |
| infective larvae of the human hookworms necator americanus and ancylostoma duodenale differ in their orientation behaviour when crawling on surfaces. | the infective third stage larvae of hookworms infect their hosts by active skin invasion, and they find and recognize their hosts by the behavioural phases of activation, directed crawling, and penetration. here we analyse the orientation of the infective larvae of the human hookworms necator americanus and ancylostoma duodenale when crawling on surfaces. their behaviour differed from that of the larvae of the dog hookworm ancylostoma caninum, but the two species also differed from each other. n ... | 2004 | 15614586 |
| behavioural strategies used by the hookworms necator americanus and ancylostoma duodenale to find, recognize and invade the human host. | the infective third-stage larvae of the hookworms necator americanus and ancylostoma duodenale infect their human hosts by active skin invasion, but a. duodenale is in addition capable of oral infection. the behaviour of the larvae when crawling on surfaces has already been described. here we analyse in various in vitro systems the other behavioural invasion phases: activation, penetration, and orientation within the host. the larvae normally remained in a motionless, energy-saving, resting post ... | 2004 | 15614587 |
| immunobiology of hookworm infection. | hookworms infect almost one billion people and are a major cause of iron-deficiency anaemia in developing countries of the tropics. despite their prevalence and the morbidity they cause, little is known about the immune response to this complex eukaryotic parasite. recent publications have shed light on the human cellular immune responses to hookworms, as well as mechanisms that hookworms utilize to skew the immune response in its favour. unlike most other human helminth infections, neither age- ... | 2005 | 15681140 |
| x-ray structure of na-asp-2, a pathogenesis-related-1 protein from the nematode parasite, necator americanus, and a vaccine antigen for human hookworm infection. | human hookworm infection is a major cause of anemia and malnutrition of adults and children in the developing world. as part of on-going efforts to control hookworm infection, the human hookworm vaccine initiative has identified candidate vaccine antigens from the infective l3 larval stages of the parasite, including a family of pathogenesis-related (pr) proteins known as the ancylostoma-secreted proteins (asps). a novel crystal structure of na-asp-2, a pr-1 protein secreted by infective larvae ... | 2005 | 15713464 |
| the immunoepidemiology of human hookworm infection. | advances in hookworm immunoepidemiology are reviewed. recent studies demonstrate a mixed th1/th2 response in human hookworm infection, with immunosuppression of specific and nonspecific ifn-gamma responses. there is increasing evidence for protective immunity in human hookworm infection, including anti-larval il-5- and ige-dependent mechanisms, and for immunological interactions between hookworm infection and other diseases. | 2004 | 15771680 |
| tribendimidine: a promising, safe and broad-spectrum anthelmintic agent from china. | we review, for the first time, a 20-year chinese story of research and development pertaining to tribendimidine, a promising anthelmintic agent that is safe and exhibits a broad spectrum of activity. tribendimidine was first synthesized at the national institute of parasitic diseases in shanghai in the mid 1980s. in laboratory studies, tribendimidine showed high efficacy against nippostrongylus braziliensis in rats, necator americanus in hamsters, ancylostoma caninum and toxocara canis in dogs, ... | 2005 | 15777691 |
| field evaluation of anthelmintic drug sensitivity using in vitro egg hatch and larval motility assays with necator americanus recovered from human clinical isolates. | a field-applicable assay for testing anthelmintic sensitivity is required to monitor for anthelmintic resistance. we undertook a study to evaluate the ability of three in vitro assay systems to define drug sensitivity of clinical isolates of the human hookworm parasite necator americanus recovered from children resident in a village in madang province, papua new guinea. the assays entailed observation of drug effects on egg hatch (eha), larval development (lda), and motility of infective stage l ... | 2005 | 15777920 |
| parasite role reversal: worms on trial. | asthma has reached epidemic proportions globally. this has been attributed by many to improved hygiene. the frequent failure of conventional pharmaceuticals to manage the disease has led to the introduction of parasites as a potential alternative therapy for asthma and other immunological diseases. in this article, we briefly review the immunological rationale underpinning therapeutic parasitic infection, describe recently initiated trials, and highlight potential risks and benefits of introduci ... | 2005 | 15780835 |
| helminth infection and cognitive impairment among filipino children. | the objective of this study was to examine the independent effect of infection with each of four helminths (ascaris lumbricoides, schistosoma japonicum, necator americanus, and trichuris trichiura) on cognitive function after adjusting for the potential confounders nutritional status, socioeconomic status (ses), hemoglobin, sex, and the presence of other helminthes. this cross-sectional study was carried out in a rural village in leyte, the philippines in 319 children 7-18 years old. three stool ... | 2005 | 15891127 |
| the assessment of hookworm calreticulin as a potential vaccine for necatoriasis. | a vaccine against the human hookworm necator americanus is urgently required to reduce hookworm-induced morbidity in endemic areas. in the present study, recombinant hookworm calreticulin, a nominated vaccine candidate, has been tested in mice. mice given calreticulin had 43-49% fewer worms in their lungs, compared to non-vaccinated controls, following challenge infection with infective hookworm larvae. these levels of protection were achieved in the absence of adjuvant following intraperitoneal ... | 2005 | 15910422 |
| polymerase chain reaction-based differential diagnosis of ancylostoma duodenale and necator americanus infections in humans in northern ghana. | we evaluated a two-step semi-nested polymerase chain reaction (pcr)-based approach for the specific detection of ancylostoma duodenale dna in human faeces. the test was used to determine to what extent this species of hookworm is present in the regions of bolgatanga and garu of northern ghana. initially, the sensitivity and specificity of the pcr were tested using a range of well-defined control samples. subsequently, a total of 378 human faecal dna samples from bolgatanga and garu were subjecte ... | 2005 | 15941421 |
| antibodies against a secreted protein from hookworm larvae reduce the intensity of hookworm infection in humans and vaccinated laboratory animals. | the development of a vaccine would provide an important new tool for the control of human hookworm infection. on the basis of successful vaccination of laboratory animals with living irradiated, third-stage hookworm larvae (l3), we examined the antibody responses of individuals from hookworm endemic areas of brazil and china against the most abundant l3 secreted antigens, the ancylostoma secreted proteins, asp-1 and asp-2. logistic regression was used to investigate the effects of antibody isoty ... | 2005 | 16037096 |
| [intestinal helminthiasis in school children in haiti in 2002]. | a survey on intestinal helminths in school children was conducted in haiti in 2002. this first nationwide study involving the entire country was stratified by department according to urban and rural zones using the cluster method. focusing on elementary school children (n=5792; age range 3 to 20 years), it involved 26 urban and 49 rural schools randomly selected. stools were preserved in formalin and examined by the ritchie technique. thirty-four per cent of stools (1981/5792) tested positive fo ... | 2005 | 16050381 |
| expression of the necator americanus hookworm larval antigen na-asp-2 in pichia pastoris and purification of the recombinant protein for use in human clinical trials. | the asp-2 protein secreted by infective larvae of the human hookworm, necator americanus, is under development as a recombinant vaccine. recombinant na-asp-2 was expressed in pichia pastoris, and the purified protein was characterized. at the 60 l scale, the 21.3 kda recombinant protein was produced at a yield of 0.4 g/l. when formulated with alhydrogel and injected into rats to determine immunological potency, three 50 microg doses of the formulated recombinant protein elicited geometric mean a ... | 2005 | 16054275 |
| effects of climatic, socio-economic and behavioural factors on the transmission of hookworm (necator americanus) on two low-country plantations in sri lanka. | the climatic, socio-economic and behavioural factors influencing hookworm (necator americanus) infection in sri lanka were explored between february 2000 and june 2001. in february 2000, a single stool sample was collected from each of the 477 subjects investigated, who were aged 2-74 years (median = 13 years) and lived on the 'lowcountry' maliboda and ayr plantations. the 'baseline' prevalence (28.5%) and intensity of hookworm infection (0- 4828.5 eggs/g faeces, with a mean of 128.4 eggs/g) wer ... | 2005 | 16156974 |
| biochemical characterization and vaccine potential of a heme-binding glutathione transferase from the adult hookworm ancylostoma caninum. | we report the cloning and expression of ac-gst-1, a novel glutathione s-transferase from the adult hookworm ancylostoma caninum, and its possible role in parasite blood feeding and as a vaccine target. the predicted ac-gst-1 open reading frame contains 207 amino acids (mass, 24 kda) and exhibited up to 65% amino acid identity with other nematode gsts. mrna encoding ac-gst-1 was detected in adults, eggs, and larval stages, but the protein was detected only in adult hookworm somatic extracts and e ... | 2005 | 16177370 |
| the end of the line for hookworm? an update on vaccine development. | | 2005 | 16187734 |
| necator americanus: optimization of the golden hamster model for testing anthelmintic drugs. | laboratory golden hamsters (mesocricetus auratus) were infected with necator americanus under several different parasite and host conditions to optimize the model for testing anthelminthic drugs. the results confirmed that male hamsters were more susceptible to infection than females. host age in the range of 5-15 weeks was not a factor that impacted on adult worm burden, and similar worm burdens were achieved using doses of 150, 250 or 500 n. americanus l3 (nal3). the largest numbers of adult h ... | 2005 | 16198341 |
| immune responses following experimental human hookworm infection. | to characterize the immune response following primary human hookworm infection, an adult volunteer was infected with 50 l3 larvae of necator americanus, reinfected 27 months later and followed for a further 6 months. clinical signs, blood picture, ex-vivo peripheral blood cytokine production (ifn-gamma, il-5, il-13, il-10 to mitogen and hookworm antigen), acute phase proteins (app) (c-reactive protein, crp and alpha1-antitrypsin, alpha1-at) and antibody levels were determined. dermatitis, oedema ... | 2005 | 16232230 |
| cytokine and chemokine responses in patients co-infected with entamoeba histolytica/dispar, necator americanus and mansonella perstans and changes after anti-parasite treatment. | this study examined the impact of concurrent parasite infections (amoebiasis, filariasis, necatoriasis) and the effect of anti-parasite treatment on cytokine and chemokine responses in singly and poly-parasitized patients. cellular reactivity and parasite-specific th1- and th2-type cytokine and chemokine profiles were investigated before and six weeks after treatment. in those patients infected with three parasite species, cellular secretion of interleukin 5 (il-5) and il-12p40 by pbmc was stron ... | 2006 | 16239120 |
| enhancement of protein secretion in pichia pastoris by overexpression of protein disulfide isomerase. | a potential vaccine candidate, necator americanus secretory protein (na-asp1), against hookworm infections, has been expressed in pichia pastoris. na-asp1, a 45 kda protein containing 20 cysteines, was directed outside the cell by fusing the protein to the preprosequence of the alpha-mating factor of saccharomyces cerevisiae. most of the protein produced by single copy clones was secreted outside the cell. however, increasing gene copy number of na-asp1 protein in p. pastoris saturated secretory ... | 2006 | 16255058 |
| arsenic-contaminated water and extent of acute childhood malnutrition (wasting) in rural bangladesh. | to investigate whether children's nutritional status, especially the extent of wasting [acute malnutrition as measured by weight-for-height z (whz) score] is associated with arsenic contamination of drinking water, a survey was carried out in two discrete rural areas located less than 30 km southeast and northeast of dhaka, the capital of bangladesh. 761 children between 7 and 14 years of age were randomly selected, one child per household. the arsenic concentration in the tube well water used b ... | 2005 | 16308561 |
| a proof of concept study establishing necator americanus in crohn's patients and reservoir donors. | | 2006 | 16344586 |
| crystallization and preliminary x-ray analysis of na-asp-1, a multi-domain pathogenesis-related-1 protein from the human hookworm parasite necator americanus. | human hookworm infection is a major cause of anemia and malnutrition in the developing world. in an effort to control hookworm infection, the human hookworm vaccine initiative has identified candidate vaccine antigens from the infective larval stage (l3) of the parasite, including a family of pathogenesis-related-1 (pr-1) proteins known as the ancylostoma-secreted proteins (asps). the functions of the asps are unknown. in addition, it is unclear why some asps have one while others have multiple ... | 2005 | 16511050 |
| a survey of the intestinal transcriptomes of the hookworms, necator americanus and ancylostoma caninum, using tissues isolated by laser microdissection microscopy. | the gastrointestinal tracts of multi-cellular blood-feeding parasites are targets for vaccines and drugs. recently, recombinant vaccines that interrupt the digestion of blood in the hookworm gut have shown efficacy, so we explored the intestinal transcriptomes of the human and canine hookworms, necator americanus and ancylostoma caninum, respectively. we used laser microdissection microscopy to dissect gut tissue from the parasites, extracted the rna and generated cdna libraries. a total of 480 ... | 2006 | 16545815 |
| intestinal parasitic infections among school children of the dhahira region of oman. | to determine the prevalence of intestinal parasitic infections among primary school children in dhahira region of oman. | 2006 | 16680250 |
| aflp fingerprinting for the analysis of genetic diversity within necator americanus. | in the present study, we utilised the method of aflp to screen for genetic variation within and among individuals of the blood-feeding human hookworm necator americanus (nematoda) from africa, asia and south america. a total of 45 adult worms (i.e. 20 from ghana, 16 from colombia and 9 from nepal) were subjected to analysis using the restriction enzyme/primer combination hindiii+ag/bglii+ac. cluster analysis divided n. americanus into multiple, genetically distinct groups, consistent with previo ... | 2006 | 16716566 |
| contrasting patterns in the small-scale heterogeneity of human helminth infections in urban and rural environments in brazil. | marked heterogeneity exists in the patterns of parasitic infection between individuals, households and communities. analysis of parasite distributions within populations is complicated by the fact that parasite distributions are highly aggregated and few studies have explicitly incorporated this distribution when investigating small-scale spatial heterogeneities. this study aimed to quantify the small-scale (within- and between-household) heterogeneity of helminth infection in an area of minas g ... | 2006 | 16814294 |
| comparative immunology of human and animal models of hookworm infection. | hookworm infection is a major cause of disease burden for animals and humans. over the past years, the use of animal models in hookworm infections has been driven by the search of new anthelminthic therapies and, especially, vaccine development. these studies also contributed to the advance of knowledge on immunity to hookworms, offering new insights to understand the nature of this parasitic infection. in this article, we will summarize the essential features of the immune response in the two m ... | 2006 | 16842265 |
| strongyloides fuelleborni kellyi and other intestinal helminths in children from papua new guinea: associations with nutritional status and socioeconomic factors. | this survey examined the prevalence and intensity of strongyloides fuelleborni kellyi and other intestinal helminths in children 5 years of age or under living near kanabea, papua new guinea. of 179 samples, 27% of the children tested positive for strongyloides, with 81% of these children being a year or less in age. overall, 68% of the children had one or more infections including ascaris lumbricoides and hookworm (necator americanus) as well as strongyloides. egg counts in the stools ranged fr ... | 2004 | 16862942 |
| [effect of a novel drug--enteric coated tribendimidine in the treatment of intestinal nematode infections]. | to study the therapeutic effect and possible adverse effects of tribendimidine enteric coated tablets in the treatment of infections due to hookworms, ascaris lumbricoides, trichuris trichiura, enterobius vermicularis. | 2006 | 16866136 |
| allergy controls the population density of necator americanus in the small intestine. | nearly 700 million people remain infected with hookworms. although allergy is intuitively linked to immunity against helminths, few positive examples have been characterized. larval migration through the lungs has been considered the likely interface at which hookworm attrition occurs. as part of a study evaluating a potential role for hookworms in the modulation of human autoimmunity, we examined parasite migration and intestinal colonization. | 2006 | 16890593 |
| hookworm infections in human and laboratory animals--differences and similarities in immune responses. | hookworm infection is one of the most important parasitic infections of humans. about 740 million people are infected with ancylostoma duodenale and necator americanus in the tropics and subtropics. unlike most other human helminth infections, neither age nor exposure-related immunity develops in the majority of infected people. this review presents the contemporary knowledge concerning the immune response to this complex eukaryotic parasite, recent findings on the human cellular immune response ... | 2005 | 16913526 |
| immunogenicity of the hookworm na-asp-2 vaccine candidate: characterization of humoral and cellular responses after vaccination in the sprague dawley rat. | the recombinant larval protein na-asp-2 from the human helminth parasite necator americanus is a lead candidate for a human hookworm vaccine. we have characterized the humoral and cellular immune responses elicited by the na-asp-2 formulated with the aluminum-based adjuvant alhydrogel in the sprague dawley rat. we demonstrated that na-asp-2 vaccine induced a strong antibody response at all doses tested, as evidenced by high specific igg1, igg2a and igm titers. high igg antibody titers were maint ... | 2005 | 17012856 |
| age-related changes in hookworm infection, anaemia and iron deficiency in an area of high necator americanus hookworm transmission in south-eastern brazil. | surprisingly few detailed age-stratified data exist on the epidemiology of hookworm and iron status, especially in latin america. we present data from a cross-sectional survey examining 1332 individuals aged 0-86 years from a community in south-east brazil for hookworm, anaemia and iron deficiency. sixty-eight percent of individuals were infected with the human hookworm necator americanus. the force of infection (lambda=0.354) was similar to estimates from other areas of high hookworm transmissi ... | 2007 | 17027054 |
| intestinal allergy expels hookworms: seeing is believing. | it is unclear how immunity limits hookworm infection. australian researchers, using capsule and conventional gastrointestinal endoscopy in volunteers inoculated with necator americanus, have reported that virtually all larvae reach the intestine within six weeks. unlike the neutral response surrounding resident hookworms, newly arrived adults provoke an eosinophilic enteropathy. this allergic reaction curtails the attachment of hookworms and accompanies the passage of additional worms as they ar ... | 2006 | 17035088 |
| some epidemiological aspects of intestinal parasites in women workers before going abroad. | a study was conducted in jakarta on 903 women workers before going abroad through stool examination by ritchie's technical method. of the women workers studied, 640 subjects (70.87%) were found to be infected with intestinal parasites either helminthes, protozoa or combination. out of those infected, 451 (70.47%) subjects were infected with intestinal helminthes, namely ascaris lumbricoides (38.13%), trichuris trichiura (28.13%), a combination of necator americanus and ancylostoma duodenale (13. ... | 2006 | 17041558 |
| the finding of echinostoma (trematoda: digenea) and hookworm eggs in coprolites collected from a brazilian mummified body dated 600-1,200 years before present. | the identification of parasites from ancient cultures expands our list of parasites infective to extant humans. a partially mummified human body from the archeological site of lapa do boquete, minas gerais state, brazil, was recently discovered. it was interred between 600 and 1,200 yr ago. dietary analysis showed that the mummified body was from a society that had a mixed subsistence of agriculture and gathering of wild foods. coprolites from the body contained numerous helminth eggs. the eggs ... | 2005 | 17089781 |
| ["the demon that turned into worms": the translation of public health in the british caribbean, 1914-1920]. | the earliest programs of the rockefeller foundation's international health commission - ihc were pilot projects for the treatment of hookworm disease in the british colonies of british guiana and trinidad. these pioneering ventures into international health have often been portrayed as governed by rigid biomedical principles. in contrast to this view, the article emphasizes the degree to which the exigencies of a public health project that sought to make biomedicine intelligible within the medic ... | 2006 | 17115527 |
| dose-ranging study for trials of therapeutic infection with necator americanus in humans. | epidemiological studies suggest that a hookworm infection producing 50 eggs/gram of feces may protect against asthma. we conducted a dose-ranging study to identify the dose of hookworm larvae necessary to achieve 50 eggs/gram of feces for therapeutic trials of asthma. ten healthy subjects without asthma or airway hyperresponsiveness to inhaled methacholine received 10, 25, 50, or 100 necator americanus larvae administered double blind to an area of skin on the arm. subjects were seen weekly for ... | 2006 | 17123987 |
| development and characterization of microsatellite markers for the canine hookworm, ancylostoma caninum. | microsatellites are repetitive genomic elements that show high levels of variation and therefore provide excellent tools to study the genetics of eukaryotic organisms. hookworms are extremely common and important nematode parasites of humans and animals, causing potentially serious disease morbidity. control of hookworms in dogs is achieved by frequent treatment with anthelmintics, and in humans, anthelmintics are frequently administered in a mass-treatment community-wide approach. understanding ... | 2007 | 17136387 |
| [asymptomatic eosinophilia in an african immigrant]. | | 2007 | 17261246 |
| onchocerca volvulus-specific antibody and cytokine responses in onchocerciasis patients after 16 years of repeated ivermectin therapy. | the recommended control option against onchocerciasis is repeated ivermectin treatment, which will need to be implemented for decades, and it remains unknown how repeated ivermectin therapy might affect immunity against onchocerca volvulus in the long term. o. volvulus-specific antibody reactivity and cellular cytokine production were investigated in onchocerciasis patients receiving ivermectin (150 microg/kg) annually for 16 years. in treated patients, the t helper type 2 (th2) cytokine interle ... | 2007 | 17302900 |
| protective immunity elicited by ultraviolet-irradiated third-stage infective hookworm (necator americanus and ancylostoma caninum) larvae in mice and hamsters. | the protective immunity elicited by ultraviolet-irradiated third-stage infective larvae of necator americanus (uv-nal3) and ancylostoma caninum (uv-acl3) was evaluated in laboratory mice (a non-permissive model) and hamsters (a permissive model). after optimizing the time of exposure to uv-irradiation, both oral and subcutaneous vaccination routes with uv-acl3 in mice were explored. oral vaccination was more effective at reducing the number of challenge acl3 entering the lungs, whereas subcutane ... | 2006 | 17333729 |
| characterization of a toxocara canis species-specific excretory-secretory antigen (tces-57) and development of a double sandwich elisa for diagnosis of visceral larva migrans. | this study describes the isolation of a toxocara canis species-specific excretory-secretory (es) antigen and the development of an enzyme-linked immunosorbent assay (elisa) based on this antigen. analysis of the es antigens of t. canis, toxocara vitulorum, ascaris lumbricoides and necator americanus larval antigen was performed by sds-page followed by western blotting. a 57 kda t. canis-specific antibody fraction (tces-57) was identified by western blotting and labelling with anti-toxocara antib ... | 2007 | 17374974 |
| differential diagnosis of trichostrongylus and hookworm eggs via pcr using its-1 sequence. | trichostrongylus eggs observed in cellophane-thick smears are difficult, in practice, to distinguish from hookworm eggs. in order to overcome these limitations, a molecular approach was conducted. a trichostrongylus colubriformis adult worm was obtained from a human in laos, which was identified morphologically. its-1 sequence of this worm was determined, and found to be most similar with that of t. colubriformis among the trichostrongylus spp. reported so far. then, this sequence was compared w ... | 2007 | 17374982 |
| effectiveness of dried carica papaya seeds against human intestinal parasitosis: a pilot study. | the tropical fruit carica papaya and its seeds have proven antihelminthic and anti-amoebic activities. to determine the effectiveness of air-dried c. papaya seeds on human intestinal parasitosis, 60 asymptomatic nigerian children with stool microscopic evidence of intestinal parasites received immediate doses (20 ml) of either an elixir composed with air-dried c. papaya seeds and honey (cph) or honey alone (placebo) in two randomized treatment groups. repeat stool microscopic examinations were c ... | 2007 | 17472487 |
| the exsheathment of necator americanus infective larvae. | infective 3rd-stage larvae of necator americanus were treated with human sweat under various conditions, and compared with human serum, 1.5% saline solution, and distilled water. the infective larvae were observed under inverted microscopy. the highest percentage (14.0%) of the exsheathed larvae was found in human sweat after 2 hours' incubation at 37 degrees c. the proportion of exsheathed larvae in human sweat was significantly different from human serum (p<0.001), 1.5% saline solution (p<0.00 ... | 2006 | 17547047 |
| drug efficacy of praziquantel and albendazole in school children in mwea division, central province, kenya. | the objective of this research was to assess drug efficacy in school children after mass chemotherapy with praziquantel and albendazole conducted in mwea division, kirinyaga district, central kenya in 2004. in total 2300 children aged between 4 and 18 years in five primary schools were selected for the study. before mass chemotherapy, prevalence of infection was 47.4% for schistosoma mansoni, 16.7% for necator americanus, 1.6% for ascaris lumbricoides, and 0.8% for trichuris trichiura. post-trea ... | 2007 | 17572368 |
| stage-specific immune responses in human necator americanus infection. | we describe how hookworms interact with their human hosts by comparing lymphocyte phenotyping, proliferative responses, and cytokine and chemokine secretion patterns in adults who are either mono-infected with necator americanus or egg-negative controls resident in an area of high transmission in brazil. cellular immune responses against crude hookworm antigen extracts from different developmental stages were evaluated simultaneously. principal component analysis (pca) was used to reduce the sta ... | 2007 | 17576364 |
| x-ray structures of na-gst-1 and na-gst-2 two glutathione s-transferase from the human hookworm necator americanus. | human hookworm infection is a major cause of anemia and malnutrition of adults and children in the developing world. as part of on-going efforts to control hookworm infection, the human hookworm vaccine initiative has identified candidate vaccine antigens from the infective l3 larval stages and adult stages of the parasite. adult stage antigens include the cytosolic glutathione-s-transferases (gsts). nematode gsts facilitate the inactivation and degradation of a variety of electrophilic substrat ... | 2007 | 17594497 |
| the evaluation of recombinant hookworm antigens as vaccines in hamsters (mesocricetus auratus) challenged with human hookworm, necator americanus. | we have previously reported the successful adaptation of human hookworm necator americanus in the golden hamster, mesocricetus auratus. this animal model was used to test a battery of hookworm (n. americanus and ancylostoma caninum) recombinant antigens as potential vaccine antigens. hamsters immunized a leading vaccine candidate n. americanus-ancylostoma secreted protein 2 (na-asp-2) and challenged with n. americanus infective larvae (l3), resulted in 30-46.2% worm reduction over the course of ... | 2008 | 17645877 |
| characterization of beta-tubulin genes in hookworms and investigation of resistance-associated mutations using real-time pcr. | human hookworms (ancylostoma duodenale, necator americanus) are a major cause of malnutrition and anemia, particularly in children, and high worm burdens can lead to stunted growth and mental retardation. mass drug administration (mda) with benzimidazole (bz) anthelmintics has the potential to greatly reduce morbidity and infection prevalence. however, such treatment strategies may apply significant selection pressure on resistance alleles. in several strongylid parasites of livestock, resistanc ... | 2007 | 17850900 |
| a study on the prevalence of hookworm infection in four districts of west bengal and its linkage with anaemia. | stool samples collected from the districts of darjeeling, jalpaiguri, hooghly and calcutta in west bengal were examined for hookworm and associated parasites. it was found that maximum prevalence of hookworm was in hooghly district (24.8%). n. americanus appeared to be more prevalent species in all the districts studied. the load ofhookworm infection appeared to be mostly in the mild range. ascaris lumbricoides appeared to the most common accompanying infection. in the affected population, the d ... | 2007 | 17883107 |
| public health programs in early twentieth-century louisiana. | | 2000 | 17896453 |
| saturation of the secretory pathway by overexpression of a hookworm (necator americanus) protein (na-asp1). | human hookworm infection is one of the most significant parasitic infections, and a leading global cause of anemia and malnutrition of adults and children in rural areas of the tropics and subtropics. necator americanus secretory protein (na-asp1), which is a potential vaccine candidate against hookworm infections, has been expressed in pichia pastoris. na-asp1 protein was expressed extracellulary by employing the leader sequence of the alpha-mating factor of saccharomyces cerevisiae. most of th ... | 2007 | 17951635 |
| simultaneous detection and quantification of ancylostoma duodenale, necator americanus, and oesophagostomum bifurcum in fecal samples using multiplex real-time pcr. | a multiplex real-time pcr was developed and evaluated for the simultaneous detection of ancylostoma duodenale, necator americanus, and oesophagostomum bifurcum in fecal samples. using well-defined control samples (n = 150), known positive fecal samples (n = 50), and fecal samples from an area in ghana where human infections with all 3 nematode species are endemic (n = 339), the method proved to be highly specific and sensitive. cycle threshold (ct) values, reflecting parasite-specific dna load, ... | 2007 | 17978072 |
| basophil competence during hookworm (necator americanus) infection. | a popular hypothesis to explain parasite survival in the presence of a pronounced t helper 2 phenotype in helminth-parasitized populations has been fc epsilonri blockade by parasite-induced polyclonal ige. to begin to test the hypothesis that fc epsilonri-bearing cells would be refractory to activation in parasitized populations, we investigated basophil function in 43 individuals from a hookworm endemic area. study individuals had high levels of total ige and eosinophilia and a mean hookworm bu ... | 2007 | 17984343 |
| mitochondrial dna variation of the dog hookworm ancylostoma caninum in brazilian populations. | the mitochondrial cytochrome oxidase i gene was partially sequenced for 164 ancylostoma caninum individuals, originating from five different localities in brazil, with the aim of describing the genetic diversity and genetic structure of brazilian hookworm populations. allelic and nucleotide diversity were moderate (overall h=0.88 and pi=0.016) and were similar among cities. there was moderate genetic differentiation among the populations sampled (approximately phi(st)=0.12) and a weak but nonsig ... | 2008 | 17997042 |
| use of the air pouch model to investigate immune responses to a hookworm vaccine containing the na-asp-2 protein in rats. | hookworms are gastrointestinal nematodes that affect approximately 600 million people in developing countries. using the air pouch model, we have examined the effects of vaccination with the recombinant hookworm larval antigen na-asp-2 and the adjuvant alhydrogel on the skin immune response to hookworms in sprague dawley rats. following vaccination, rats were inoculated 100 necator americanus l3 into the air pouch, and the exudates and cell infiltrates were collected from the pouch 24 h later. l ... | 2008 | 18086017 |
| hookworm vaccines. | hookworm infection caused by the soil-transmitted nematodes necator americanus and ancylostoma duodenale is one of the most common parasitic infections worldwide. although not directly responsible for substantial mortality, it causes significant morbidity in the form of chronic anemia and protein malnutrition. current global control efforts based on periodic mass anthelmintic administration are unsustainable, and new control strategies must be developed. this review describes progress in the dev ... | 2008 | 18171264 |
| necator americanus: the na-asp-2 protein secreted by the infective larvae induces neutrophil recruitment in vivo and in vitro. | the l3-secreted ancylostoma secreted protein-2 from the human hookworm necator americanus (na-asp-2) has been selected as a candidate vaccine antigen in anticipation of clinical trials. its crystal structure revealed that na-asp-2 has structural and charge similarities to cc-chemokines, suggesting that it might act as a chemokine mimic when released by the infective larvae during tissue migration. using the air pouch model of acute inflammation, we found that na-asp-2 induced a significant leuko ... | 2008 | 18199436 |
| application of in vitro anthelmintic sensitivity assays to canine parasitology: detecting resistance to pyrantel in ancylostoma caninum. | resistance of the canine hookworm ancylostoma caninum to anthelmintic therapy with pyrantel is an emerging problem in canine veterinary practice. detecting anthelmintic resistance in parasites of pets is problematic because traditional resistance-monitoring techniques used with livestock parasites, such as the faecal egg count reduction test, are often impractical for use in small animals. we used two field-collected isolates of a. caninum in an abbreviated critical trial to test their pyrantel ... | 2008 | 18242867 |
| endoscopic diagnosis of chronic severe upper gi bleeding due to helminthic infection. | | 2008 | 18243186 |
| controlling soil-transmitted helminthiasis in pre-school-age children through preventive chemotherapy. | pre-school age children account for 10%-20% of the 2 billion people worldwide who are infected with soil-transmitted helminths (sths): ascaris lumbricoides (roundworm), trichuris trichiura (whipworm), and ancylostoma duodenale/necator americanus (hookworms). through a systematic review of the published literature and using information collated at world health organization headquarters, this paper summarizes the available evidence to support the recommendation that pre-school children should be i ... | 2008 | 18365031 |
| randomized, placebo-controlled, double-blind trial of the na-asp-2 hookworm vaccine in unexposed adults. | necator americanus ancylostoma secreted protein-2 (na-asp-2) is a leading larval-stage hookworm vaccine candidate. recombinant na-asp-2 was expressed in pichia pastoris and formulated with alhydrogel. in a phase 1 trial, 36 healthy adults without history of hookworm infection were enrolled into 1 of 3 dose cohorts (n=12 per cohort) and randomized to receive intramuscular injections of either na-asp-2 or saline placebo. nine participants in the first, second and third cohorts were assigned to rec ... | 2008 | 18396361 |
| the complete mitochondrial genomes for three toxocara species of human and animal health significance. | studying mitochondrial (mt) genomics has important implications for various fundamental areas, including mt biochemistry, physiology and molecular biology. in addition, mt genome sequences have provided useful markers for investigating population genetic structures, systematics and phylogenetics of organisms. toxocara canis, toxocara cati and toxocara malaysiensis cause significant health problems in animals and humans. although they are of importance in human and animal health, no information o ... | 2008 | 18482460 |
| a family of cathepsin b cysteine proteases expressed in the gut of the human hookworm, necator americanus. | mrnas encoding cathepsin b-like cysteine proteases (catbs) are abundantly expressed in the genomes of blood-feeding nematodes. recombinant catbs have been partially efficacious in vaccine trials in animal models of hookworm infection, supporting further investigation of these enzymes as new control tools. we recently described a family of four distinct catbs (na-cp-2, -3, -4, -5) from the human hookworm, necator americanus. here we show that these n. americanus catbs form a robust clade with oth ... | 2008 | 18501979 |
| extensive and complex sequence diversity in mitochondrial cytochrome c oxidase subunit 1 within necator americanus from colombia revealed by sscp-coupled sequencing. | in spite of the human health importance of hookworms, there has been only a small number of studies of genetic variability within necator americanus, and none in south america. in the present study, we investigated sequence variability in a 395-bp region of the mitochondrial cytochrome c oxidase subunit 1 gene among n. americanus individuals (n=100) from humans of six villages in colombia, employing a mutation scanning-coupled sequencing approach. haplotypic diversity within n. americanus varied ... | 2008 | 18513922 |
| development of a model of hookworm infection exhibiting salient characteristics of human infection. | patent and pathologic infections of the human hookworm necator americanus were established in the common marmoset (callithrix jacchus). in a pilot study, a laboratory strain of n. americanus was compared with a fresh field isolate. pathology was more severe in animals infected with a fresh isolate. in all animals, infection was associated with increased total plasma ige and production of igg specific to adult worm excretory/secretory (es) products. histamine was released by basophils in response ... | 2008 | 18541773 |
| pcr-based coprodiagnostic tools reveal dogs as reservoirs of zoonotic ancylostomiasis caused by ancylostoma ceylanicum in temple communities in bangkok. | a survey of gastrointestinal parasites of dogs and humans from temple communities in bangkok revealed that 58% of dogs and 3.4% of humans, among those sampled, were infected with hookworms utilising faecal flotation techniques and microscopy. a previously established polymerase chain reaction (pcr)-rflp approach was utilised to determine the species of hookworms infecting dogs found positive for hookworm eggs. single infections with ancylostoma ceylanicum and ancylostoma caninum were recorded in ... | 2008 | 18556131 |
| hookworm, ascaris lumbricoides infection and polyparasitism associated with poor cognitive performance in brazilian schoolchildren. | to investigate the relationship between hookworm and ascaris lumbricoides infection and performance on three subsets of the wechsler intelligence scale for children - third edition (wisc-iii) (digit span, arithmetic and coding) and raven colored progressive matrices. | 2008 | 18627581 |
| binding of excreted and/or secreted products of adult hookworms to human nk cells in necator americanus-infected individuals from brazil. | the impact of the interaction between excreted and/or secreted (es) necator americanus products and nk cells from necator-infected individuals was analyzed. we investigated the binding of es products to nk cells, the expression of nk cell receptors (cd56, cd159a/nkg2a, cd314/nkg2d, cd335/nkp46, and klrf1/nkp80), the frequency of gamma interferon (ifn-gamma)-producing nk cells after whole-blood in vitro stimulation, and the capacity of n. americanus es products to induce nk cell chemotaxis. in co ... | 2008 | 18838519 |
| early stage-specific immune responses in primary experimental human hookworm infection. | to determine the cellular immune response during different stages of hookworm infection, we infected two human volunteers with necator americanus and followed their immune responses against stage-specific, crude antigen extracts through larval migration, pre-patency, and early patency. after chemotherapy, the volunteers were followed for an additional 6 months. low-dose n. americanus infection resulted in mild clinical signs and peripheral blood eosinophilia occurred during the estimated time of ... | 2008 | 18848637 |
| a new modified technique for concentrating intestinal parasites. | the present study evaluated the diagnostic performance of a modification of the formol ethyl acetate concentration technique, with the addition of 25% acetic acid as compared with formol ethyl acetate concentration technique (fea) and fecal parasite concentrator kit fresh fecal material, free of ova and parasites, was pooled in a ratio of 1:4 with 10% buffered formalin to prepare a standardized specimen. sufficient volumes of formalin-fixed suspension of giardia lamblia cysts, entamoeba histolyt ... | 2008 | 18853623 |