Publications

rate of expulsion of necator americanus and the false hookworm ternidens deminutus railliet and henry 1909 (nematoda) from humans following albendazole treatment.		1990	2278080
epidemiology and immunology of necator americanus infection in a community in papua new guinea: humoral responses to excretory-secretory and cuticular collagen antigens.	baseline data from an immuno-epidemiological study of hookworm infection in a rural village in madang province, papua new guinea are reported. necator americanus was found to be the commonest helminth infection, with a prevalence of near 100% and intensity of 40 worms per host in adults. enterobius vermicularis, ascaris lumbricoides and trichuris trichiura were also present, at prevalences of 53, 10 and 3% respectively; ancylostoma duodenale was absent. the frequency distribution of n. americanu ...	1990	2345664
efficacy of agar-plate culture in detection of strongyloides stercoralis infection.	agar-plate culture of feces using a modified petri dish proved to be highly efficient in the detection of strongyloides stercoralis infection. furrows left by s. stercoralis on the agar plate were distinguished readily in size from those left by necator americanus.	1990	2352073
necator americanus in the mouse: histopathological changes associated with the passage of larvae through the lungs of mice exposed to primary and secondary infection.	the mouse/necator americanus model was studied to assess the histopathological changes that occur in the lungs following primary and secondary exposure to infective larvae. groups of balb/c mice were infected percutaneously and killed on various days post infection. parasite numbers were counted, the bronchoalveolar leukocyte response was quantified and histological sections of lung material were examined for evidence of host protective inflammatory reactions. an increase in the inflammatory inf ...	1990	2352915
parasite detection efficiencies of five stool concentration systems.	fresh fecal material that was free of ova and parasites was pooled with 10% formalin in a 1:4 ratio to prepare a standard specimen. portions of 100 ml of this specimen were individually seeded with cryptosporidium oocysts, entamoeba coli, entamoeba histolytica, and giardia lamblia cysts; ova of necator americanus; and strongyloides larvae. appropriate volumes of each parasite suspension were used to evaluate the fecal concentrator kit (remel, lenexa, kans.), fecal parasite concentrator (evergree ...	1990	2380347
the epidemiological significance of the immune response to the cuticular collagen of necator americanus: a preliminary study in a hookworm-endemic area in papua new guinea.		1990	1978540
necator americanus in the dsn hamster: density-dependent expulsion of adult worms during primary infection.	neonatal hamsters were exposed to varying doses of necator americanus larvae and changes in the stability of the resulting worm burdens were monitored over a period of 25 weeks. no change in worm burdens was evident for the first 5 weeks of infection, irrespective of the infection intensity, but the more heavily infected groups subsequently lost worms in a density-dependent manner. male and female hamsters lost comparable proportions of their established parasite burdens indicating that there wa ...	1990	2362772
[clinical observations on the treatment of hookworm, ascaris and trichuris infection with oxibendazole].	340 cases of hookworm infection, 196 cases of ascariasis and 178 cases of trichuriasis were treated with an anthelmintic, oxibendazole, 15mg/kg.d x 3d; 102, 70 and 66 cases of respective infections were treated with pyrantel 10mg/kg.d x 3d and 108, 74 and 63 cases took placebo for comparison and as control under double-blind observations. re-examinations of the stool were performed after the treatment. among the cases treated with oxibendazole, the egg negative conversion rates of hookworm, asca ...	1990	2208619
[levamisole, mebendazole, thiabendazole. their effectiveness as helminthicides in african patients recently arrived in cuba. from 1987 to 1988].	ninety one passengers coming from africa, carriers of geohelminthes, were selected and treated with helminthicides of large use in our country (levamisole, mebendazole, thiabendazole). an excellent effective response was obtained for ascaris lumbricoides (96.5%), and a good effective response was obtained for the rest of the parasites: trichuri trichiura (88.5%), strongyloides stercoralis (87.5%), and necator americanus (78.9), according to data of therapeutical response efficiency of the who.	1990	2089506
the identification of a species-specific antigen from necator americanus.	a 17 kd protein of necator americanus was isolated by sds-page and used to raise monospecific antisera in rabbits. elisa and western blotting against a range of parasite extracts demonstrated the species specificity of this protein. it is expressed at all stages of the life-cycle, appears to be accumulated through the larval stages to adulthood, and can be localized in the oesophageal glands and cuticle of the adult parasite. the possible nature and diagnostic potential of this protein is discus ...	1990	1696710
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
mass treatment of intestinal parasites among ethiopian immigrants.	intestinal parasites are common among the ethiopian immigrants to israel and mass treatment is necessary to prevent local transmission. for this purpose, stool samples obtained from the immigrants in absorption centers were examined. of 5,412 samples obtained, 4,399 (81.3%) were positive: 2,644 (54.2%) for necator americanus, 2,273 (46.6%) for schistosoma mansoni, 990 (20.3%) for ascaris lumbricoides, 1,040 (21.3%) for hymenolepsis nana, 940 (19.2%) for trichuris trichiura, 219 (4.5%) for strong ...	1991	2050509
identification of human hookworm in failed-treatment cases using chinese hamsters (cricetulus griseus) and scanning electron microscopy.	an attempt was made to identify the human hookworm involved in failed-treatment cases using abnormal hosts and scanning electron microscopy. thirty-seven, 2 to 6 month old chinese hamsters (cricetulus griseus) from a closed, outbred, conventional colony, were each given between 20 and 120 filariform larvae per os. the larvae were cultured from faeces from mebendazole (vermox) 500 mg single-dose, failed-treatment cases living in the lowveld farming area of the transvaal province, south africa. ab ...	1991	2050988
necator americanus secretory acetylcholinesterase and its purification from excretory-secretory products by affinity chromatography.	acetylcholinesterase (ache) secretion by adult n. americanus was enhanced in vitro by incorporating insoluble collagen rafts into culture dishes. enzyme produced in this way had preferential substrate specificity for acetylthiocholine iodide (atc), and its activity was inhibited by eserine (1.1 x 10(-8) m). ancylostoma ceylanicum, another hookworm species, failed to produce comparable amounts of ache in culture. ache was efficiently purified from culture medium by affinity chromatography on edro ...	1991	2052405
parasitic infections in young jamaicans in different ecological zones of the island.	data are presented for the first country wide prospective study on gastrointestinal tract parasitic infections done in jamaica. samples from 2,947 young jamaicans drawn from all ecological zones and from all parochial divisions of the island were analyzed. pica was practised by 8.6%. generally, prevalence of organisms was as follows: trichuris trichiura (12.3%), ascaris lumbricoides (9.5%), hookworm (2.2%), strongyloides stercoralis (0.3%), giardia lamblia (6.3%) and entamoeba coli (7.7%). sever ...	1991	1750103
antigenic cross-reactivity between necator americanus and ascaris lumbricoides in a community in papua new guinea infected predominantly with hookworm.	sero-epidemiological data are presented in which antigenic cross-reactivity between necator americanus and ascaris lumbricoides has been investigated in a community in papua new guinea infected predominantly with n. americanus. it is our contention that the antigenic cross-reactivity which undoubtedly exists between these species accounted for (i) a peak in antibody levels against n. americanus in 10-13 years old children (driven by infection with a. lumbricoides), and (ii) the maintenance of ap ...	1991	1755061
comparative efficacy of single dose anthelmintics in relation to intensity of geohelminth infections.	the efficacy of a single dose of albendazole 400 mg, levamisole 2.5 mg/kg, mebendazole 500 mg, mebendazole 200 mg and pyrantel pamoate 10 mg/kg was evaluated in relation to the intensity of infection of ascaris lumbricoides, necator americanus and trichuris trichiura. the study group comprised 667 3 to 12 year old children from poorer segments of the community. all 5 treatments produced high egg reduction rates ranging from 95.9% to 99.7% and substantial cure rates for ascaris infection; the dif ...	1991	1807845
[comparison of several coproparasitological techniques for the diagnosis of soil-transmitted intestinal helminthiasis].	five hundred and eleven samples of feces were examined by several coproparasitological techniques: kato-katz, willis, ritchie and direct wet mount. it was found that kato-katz was the most reliable technique for the diagnosis of trichuris trichiura, necator americanus, and ascaris lumbricoides, demonstrating the largest number of cases. willis, ritchie and direct wet mount were effective in that order. taking into account that kato-katz is a quantitative method, it should be recommended in the d ...	1991	1844969
hookworm (necator americanus) infection and storage iron depletion.	the relationship between iron status and the intensity of infection with hookworm was investigated in a rural population on karkar island, mandang province, papua new guinea. there was a significant negative correlation between plasma ferritin level and hookworm burden, which was strongest in males. in contrast, there was no correlation between plasma ferritin and hookworm egg count, and no consistent correlation between haemoglobin level or haematocrit and either measure of hookworm intensity. ...	1991	1887481
detection of wuchereria bancrofti specific antigens in the serum of endemic residents.	a sandwich enzyme-linked immunosorbent assay (s-elisa) is developed for detecting circulatory antigens in individuals infected with wuchereria bancrofti in an endemic area using antibody (ig) against excretory-secretory-metabolic antigens of the microfilariae raised in rabbit (anti-mf-esm) and labelled with alkaline phosphatase (esm-ig-conjugate). an optical density reading of a sample greater than 0.075 (after subtracting the background) was taken as positive in the s-elisa. when homologous (wb ...	1991	1896764
reinfection and infection rates of soil-transmitted-helminths in kemiri sewu, yogyakarta, indonesia.	a study on the reinfection and infection rates of soil-transmitted helminths was conducted in kemiri sewu, godean district, sleman regency, yogyakarta special province, indonesia, from august 1988 to june 1990. a total 61 individuals rendered ascaris lumbricoides egg-negative by drug treatment were used in the reinfection study and 412 individuals found negative for ascaris eggs in the pretreatment stool examination were used for the infection rate study. in both groups, children had higher and ...	1991	1948282
[eosinophilia in a patient from cape verde].		1992	1292605
prevalence of hookworm species in pondicherry, india.	a study was carried out to find out the hookworm species prevalent in pondicherry, india, based on the identification of filariform larvae recovered from coproculture of hookworm positive stools. a total of 184 hookworm positive stools were cultured using the harada-mori coproculture method. the results of the study for the first time showed both hookworm species, ancylostoma duodenale (60 cases) and necator americanus (49 cases) to be present in pondicherry. the former species was relatively mo ...	1992	1295152
[clinical observation on efficacy of ivermectin in the treatment of intestinal nematode infections].	a total of 166 cases were divided into 3 groups: group a comprised 55, group b 54 and group c 57 cases. group a received ivermectin 0.1 mg/kg orally at a single dose, the cure rates were 100%, 3.8% and 50% for ascaris, hookworm and trichuris, infections respectively: group b received ivermectin 0.2 mg/kg orally at a single dose, the corresponding cure rates were 95.5%, 11.8% and 76.5% respectively; group c received pyrantel pamoate 10 mg/kg orally at a single dose, the corresponding cure rates w ...	1992	1303336
studies in intestinal parasitic disease agents in stools of people in a rural area of nigeria.	a summary of 300 villagers who reported at the parasitology laboratory of the school of medical laboratory technology (s.m.l.t) vom, plateau state, nigeria was carried out for the presence of parasites' cysts, eggs, or larva. of the 300 faecal samples examined using the light microscope after formal-ether centrifugation, 127 (42.3%) harboured one or more parasites. the parasites identified and their prevalent rates were: entamoeba coli (19.0%) necator americanus (17.0%); entamoeba histolytica (4 ...	1992	1390369
skin penetration by ensheathed third-stage infective larvae of necator americanus, and the host's immune response to larval antigens.	in vitro experiments were conducted to assess skin penetration by ensheathed third-stage infective larvae (l3) of necator americanus. the fact that only a small proportion of larval sheaths was recoverable from the outer skin surface suggested that some larvae penetrate mouse skin without undergoing exsheathment. penetration by ensheathed larvae was confirmed visually using a novel fluorescein isothiocyanate (fitc)-labelling technique in which viable ensheathed larvae were fluoresceinated, appli ...	1992	1399240
secretion of metalloproteases by living infective larvae of necator americanus.	fresh living third-stage larvae of necator americanus released a significant amount of label within 2 hr of their incubation on 125i-labeled gelatin-coated polystyrene plastic plates. this protease activity was primarily susceptible to o-phenanthroline, which identifies the activity as predominantly metalloprotease.	1992	1403440
cultivation of the third-stage larvae of necator americanus in vitro.	when filariform larvae of necator americanus, enclosed within the second sheath, were cultured in various semi-defined media, the best larval development was achieved in waymouth's mb 752/1 with 20% foetal calf serum (fcs). in this medium, most of the filariform larvae cast off the second sheath and developed into third-stage larvae with provisional buccal capsules and some larvae developed further; 26% were fourth stage after 49 days of culture. of several supplements tested, only fcs supported ...	1992	1417207
metabolism of lipid peroxidation products by the gastro-intestinal nematodes necator americanus, ancylostoma ceylanicum and heligmosomoides polygyrus.	somatic extracts of the three parasitic nematodes necator americanus, ancylostoma ceylanicum and heligmosomoides polygyrus were able to detoxify a model hydroperoxide and a putative natural peroxide by glutathione-dependent peroxidase activity while cytotoxic carbonyls could be metabolized by nadph-linked reduction activities. unlike cestodes and digeneans, the nematodes in this study could not enzymatically conjugate carbonyls with glutathione. the results indicate that the three nematodes can ...	1992	1459777
isotypic variation in antibody responses in a community in papua new guinea to larval and adult antigens during infection, and following reinfection, with the hookworm necator americanus.	the natural infection of a community with the hookworm necator americanus induces a vigorous humoral response to both larval and adult parasite antigens. this response occurs in all five human antibody isotypes, and data are presented to show that, at the population level, isotypes respond differently, following chemotherapy and during reinfection, to changes in antigen stimulation. the differential response probably reflects the fact that the parasite, during the course of its life cycle, prese ...	1992	1470481
resumption of feeding in vitro by hookworm third-stage larvae: a comparative study.	third-stage infective larvae of the canine hookworm ancylostoma caninum resume feeding in vitro in response to several stimuli. experiments were conducted to characterize the in vitro feeding behavior of several hookworm species. reduced glutathione and, to a lesser extent, canine and human serum stimulated third-stage larvae of ancylostoma duodenale to resume feeding. glutathione-induced feeding reached a maximum by 16 hr and was concentration-dependent between 0- and 15-mm glutathione. oxidize ...	1992	1491295
influence of intestinal parasitism on lactose absorption in well-nourished african children.	hydrogen breath tests were performed in gabon (central africa) after a loading dose of lactose in 67 well-nourished african children (50 with intestinal parasites and 17 unparasitized) and in 18 unparasitized young adults. all had normal nutritional status, and none had diarrhea or digestive symptoms. parasites that were found included ascaris lumbricoides in 76% of the parasitized children, trichuris trichiura in 58%, giardia in 24%, entamoeba histolytica in 20%, schistosoma intercalatum in 16% ...	1992	1539747
the epidemiology and population biology of necator americanus infection in a rural community in zimbabwe.	baseline data from an epidemiological study of hookworm infection in a rural community in zimbabwe are presented. the infection status of an age-stratified sample of the community was assessed using anthelmintic expulsion techniques. necator americanus was the only helminth parasite found to be present. the age-prevalence and intensity profiles rose asymptotically to an adult prevalence of about 80% and adult mean burden of 7.7 worms per host. the overall mean burden was 4.8 worms per host. the ...	1992	1566314
distinction of human hookworm larvae based on lectin-binding characteristics.	a comparative study of lectin binding to ensheathed (enl3) and exsheathed (exl3) l3 larvae of necator americanus, ancylostoma duodenale and ancylostoma ceylanicum revealed a number of differences between these hookworm species. these differences could provide a novel approach to distinguish infective l3 larvae in field conditions. for example, binding of ulex europaeus agglutinin (uea) and ricinus communis agglutinin (rca120) to n. americanus enl3 distinguished them from those of a. duodenale an ...	1992	1570175
a novel method for the isolation of nematode larvae using pluronic f-68-treated cellulose strips.	a new method is described for the isolation of cultured nematode larvae. this allows effective separation of larvae from fecal contamination, exsheathed larvae from cast sheaths, and viable larvae from nonviable larvae. the method involves the use of cellulose strips and has been assessed using larvae from 2 hookworm species, necator americanus and ancylostoma ceylanicum. pretreatment of the cellulose strips with 1.0% (w/v) of the nonionic surfactant, pluronic f-68, significantly increased larva ...	1992	1597809
the human environment, occupation, and possible water-borne transmission of the human hookworm, necator americanus, in endemic coastal communities of the niger delta, nigeria.	a 15-month longitudinal study was carried out in four riverine communities of the niger delta to ascertain the impact of the environment and occupation on the transmission and infection pattern of the human hookworm necator americanus. a total of 925 (50.10%) individuals were found to be infected. male and female infection rates were 54.26% and 47.96% respectively. the difference was statistically significant (p less than 0.05). the prevalence of infection, the egg counts, and the seasonal incid ...	1992	1603919
cross-reactivity between necator americanus and schistosoma mansoni in mice.	poly-parasitism is common in endemic communities and reactivity of sera from hookworm-infected patients against schistosomular antigens has been reported. protective cross-immunity between n. americanus and s. mansoni was investigated in nih and balb/c mice. protective resistance to homologous challenge with both parasites was confirmed in this model, however, functional immunity to heterologous challenge was not demonstrated. sera from animals which had received homologous challenge with n. ame ...	1992	1487373
[differential diagnostic value of occult blood in stool in hookworm infection in the third world. study from papua new guinea].	in 633 persons of the madang province in papua-new guinea hookworm-infection, blood hemoglobin and the presence of blood in stools were studied. 60% of the subjects were infected with hookworm (necator americanus). there was a significant linear correlation between the intensity of hookworm infection and blood haemoglobin level. the colo-rectal test gave positive results in 17% of the cases without worm-infection. in infected persons, the colo-rectal test gave an increasing rate of positive resu ...	1992	1471386
intestinal parasitic infections in likupang, north sulawesi, indonesia.	a parasitological survey was conducted on the inhabitants of 6 villages of likupang, minahasa peninsula, north sulawesi, indonesia, in august 1991. a total of 419 fecal samples were examined by using direct smear, flotation, formalin ether concentration, harada-mori culture and agar-plate culture techniques. five nematode and 7 protozoan parasites were detected, while trematode and cestode infection was not observed. soil-transmitted nematode infections were predominant. among the younger inhabi ...	1992	1439973
the partial characterization of proteases present in the excretory/secretory products and exsheathing fluid of the infective (l3) larva of necator americanus.	following the observation that live third-stage larvae (l3) could digest gelatin in vitro, gelatinolytic protease activity has been demonstrated at ph 8.5, in both exsheathing fluid (ef) and excretory/secretory (es) products of infective l3 of necator americanus. ef resolved as a single band of proteolytic activity, with a mol. wt of 116 kda, while l3 es products exhibited multiple bands of proteolysis, at 219, 200, 195, 166, 137, 92, 72 and 62 kda; weak bands were detectable at 92 and 72 kda. t ...	1992	1399239
[prevalence of strongyloides stercoralis infection in childhood. orán, salta, argentina].	an enteroparasitological, clinical and epidemiological study was carried out in 36 infants who attended the hospital san vicente de paul from orán for medical assistance. the age of the children varied between 0 and 4 years with an average of 28 months. the main clinical causes for consultation were bronchitis (52.8%), inappetence (52.8%) and paleness (27.8%). the general characteristics of the stool samples were: formed 44.4% and diarrheic 55.6%. the frequency of intestinal helminthic and proto ...	1993	7993534
sensitivity to ivermectin and pyrantel of ancylostoma ceylanicum and necator americanus.	experiments were carried out in the hamster to compare the relative susceptibility of necator americanus and ancylostoma ceylanicum to treatment with ivermectin. a. ceylanicum was found to be 300 times more sensitive to the anthelmintic with a 50% effective dose (ed50) of the order of 10-15 micrograms kg-1 body weight whilst that for n. americanus approximated to 3-5 mg kg-1. furthermore, whereas complete clearance of a. ceylanicum was observed with a dose of 100 micrograms kg-1, n. americanus w ...	1993	8106187
intestinal parasitic infections in campalagian district, south sulawesi, indonesia.	intestinal parasitic infections were surveyed in the inhabitants of 3 coastal and 2 inland villages of campalagian district, south sulawesi, indonesia, in july 1992. a total of 398 fecal samples were examined by using kato-katz thick smear, harada-mori culture and agar-plate culture techniques. protozoan cysts were examined by formalin ether concentration technique on 380 fecal samples. soil-transmitted helminth infections were highly prevalent with the overall positive rates as follows: ascaris ...	1993	8266235
necator americanus in inbred mice: a re-evaluation of primary infection kinetics.	the course of a primary necator americanus infection was studied in the lungs and small intestines of syngeneic mice. following percutaneous infection no difference in initial larval establishment in the lungs was found between male balb/c, nih or b10.g mice. however, significant differences in the subsequent kinetics of infection were demonstrated between the balb/c and nih strains. lung worm burdens declined more slowly in nih mice than in balb/c strain. surprisingly, however, a greater propor ...	1993	8278222
[existence in tunisia of necator americanus (nematoda, ankylostomidae)].		1993	8292917
density-dependent effects on establishment of necator americanus and ancylostoma ceylanicum.	the relationships between the number of infective larvae (l3s) to which animals were exposed and the establishment of a. ceylanicum and n. americanus in hamsters were examined. there was no evidence of density-dependent constraints on the establishment of a. ceylanicum in the range 10-1000 larvae, but an experiment in which the range was extended to 1500 l3s gave a significant negative correlation between the magnitude of the infecting dose and percentage establishment. even so the percentage re ...	1993	8354861
serum igg reactivity with 41-, 31-, and 28-kda larval proteins of strongyloides stercoralis in individuals with strongyloidiasis.	proteins from a deoxycholate-soluble extract of strongyloides stercoralis infective larvae were separated by sds-page, blotted onto nitrocellulose paper, and reacted with sera from individuals with confirmed s. stercoralis infections (n = 100), suspected s. stercoralis infections in whom no larvae could be detected (n = 27), and other nematode infections (40 with wuchereria bancrofti, 20 with onchocerca volvulus, 20 with necator americanus, and 20 with mixed ascaris lumbricoides and trichuris tr ...	1993	8354924
the detection of autoantibodies to ige in plasma of individuals infected with hookworm (necator americanus) and the demonstration of a predominant igg1 anti-ige autoantibody response.	in this study we have demonstrated significantly elevated levels of circulating igg autoanti-ige antibody in hookworm infected individuals from kebasob village on karkar island, papua new guinea. although anti-ige activity was demonstrable in igg1, igg3 and igg4, igg1 was by far the most important subclass of igg anti-ige in terms of frequency of detection (34/39; 87.2%) and magnitude of increase (p = 0.0000); with igg3 (16/39; 41.0%) and igg4 (15/39; 38.5%) antibodies being considerably less pr ...	1993	8433852
reinfection with hookworm after chemotherapy in papua new guinea.	reinfection with hookworm (necator americanus) following chemotherapy was studied over 2 years in a rural village in madang province, papua new guinea. the prevalence of hookworm infection had returned to pre-treatment levels after 2 years, and the geometric mean hookworm burden had returned to 58% of the pre-treatment value. the rate of acquisition of adult worms was independent of host age, and was estimated as a geometric mean of 2.9-3.3 worms/host/year (arithmetic mean 7.9-8.9 worms/host/yea ...	1993	8316435
the ecology of animal parasitic nematodes in endemic areas of jos, nigeria.	a survey involving 3418 faecal samples collected from three areas of heavy human and animal activities in jos, nigeria showed that 2354 (68.9%) of the samples harboured various parasitic nematodes of man and animals. altogether, twelve species of parasitic nematodes were encountered. five of these, namely: ascaris lumbricoides, ancylostoma duodenale, necator americanus, trichuris trichiura and strongyloides stercoralis infect man while five others: trichostrongylus probolurus, t. colubriformis, ...	1993	8334456
the immunogenicity of hookworm (necator americanus) acetylcholinesterase (ache) in man.	a number of different but complementary approaches have been used to demonstrate the immunogenicity of necator americanus acetylcholinesterase to infected individuals. western blotting of parasite somatic extracts with human post-infection sera and a specific rabbit antiserum to ache resulted in the development of almost identical antigen-recognition profiles. ache-containing fractions produced by preparative iso-electric focusing were subsequently shown to be antigenic in elisa using post-infec ...	1993	8506114
soluble (s)cd23 levels in a parasitized population from papua new guinea.	levels of scd23, total and specific ige were found to be considerably elevated in the plasma of a helminth infected population from papua new guinea. using age-corrected data, a significant negative correlation was seen between scd23 and total ige in the young, at a time when hookworms are being rapidly acquired, and total ige levels are rising most dramatically. it is suggested on the basis of this data that this inverse correlation is due to the stabilizing effect of ige on the fc epsilon rii ...	1993	8506115
observations on the morphology of adults and larval stages of oesophagostomum sp. isolated from man in northern togo and ghana.	infection with oesophagostomum sp. appears to be extremely common in man in northern togo and ghana. adult specimens were recovered from the intestinal lumen by treatment with pyrantel pamoate and the morphological characteristics of oesophagostomes of man could for the first time be compared with information available on the morphology of oesophagostomes of monkeys. the observations and measurements demonstrated that the species involved is oesophagostomum bifurcum and that the eggs of this spe ...	1993	8509618
immunodiagnosis of strongyloides stercoralis infection: a method for increasing the specificity of the indirect elisa.	indirect enzyme-linked immunosorbent assay (elisa) allows sensitive detection of serum immunoglobulin (ig) g against a soluble extract of strongyloides stercoralis infective larvae. in this study, 40/40 (100%) human strongyloidiasis sera had high levels of anti-s. stercoralis igg, but 30/40 (75%) filariasis sera, and 12/40 (30%) necatoriasis sera also had higher levels than control sera from uk residents. in attempts to increase the assay specificity by absorption of cross-reactive igg, the effe ...	1993	8337720
assessment of the effectiveness of primary health care interventions in the control of three intestinal nematode infections in rural communities.	in a 30 months' longitudinal study, primary health care intervention was effective in reducing the prevalence of three common intestinal nematode infections (ascaris lumbricoides, trichuris trichiura and necator americanus) in three communities. this was achieved by training school leavers and auxiliary aides as microscopists, health inspectors and field assistants and deploying them to provide screening, surveillance, environmental sanitation, and mass-expulsion chemotherapy (mec). post-control ...	1993	8475245
hookworm infections and human iron metabolism.	ancylostoma duodenale and necator americanus are extremely common species of soil-transmitted helminth which flourish where poverty and malnutrition prevail. hookworms contribute significantly to iron-deficiency anaemia, which remains one of the world's major nutritional problems, through the feeding activities of intestinal stages leading to chronic blood loss into the gut. in this article, a mathematical model is proposed to explain how human iron metabolism may respond to hookworm infection o ...	1993	8115178
new observations on proteases of the human hookworm necator americanus.	two protease populations have been identified in the somatic products of adult necator americanus. one population (158, 138, 34 and 31 kda) loses, whereas the other population (107, 74, 51 and 20 kda) retains, its proteolytic activity after elution from substrate gels. the present study warns that hookworm proteases may oligomerise and/or lose their activity under the conditions necessary for their purification. we suggest that following assessment of protease activity on substrate gels, the pro ...	1993	8358325
[scanning electron microscopic observations on the copulatory spicules of the male necator americanus and ancylostoma duodenale].	scanning electron microscopic observations were made on the morphological structures of the two copulatory spicules of the male necator americanus and ancylostoma duodenale. in both species, one of the two copulatory spicules was in the shape of a concave groove and the other, in the shape of an oblate tube. owing to the difference in the concavity of the groove shaped copulatory spicule between the two species as shown by the cross sections, necator americanus usually appear to have only one co ...	1993	8168247
[field studies on different control schemes for hookworm infection].	three different control schemes including selective chemotherapy, a combination of selective chemotherapy and management of fecal disposal and mass treatment with mebendazole-medicated salt were implemented for the control of hookworm infection in luwo town and taiping village, wuming county, guangxi zhuang autonomous region during 1971-1990. through ten years of selective chemotherapy, the results showed that the hookworm infection rate dropped from 42.6% to 3.9% and the infection intensity fro ...	1993	8168249
observations on the feeding behaviour of parasitic third-stage hookworm larvae.	the feeding behaviour of parasitic 3rd-stage larvae (l3) of the hookworms ancylostoma caninum, a. ceylanicum and necator americanus was examined. less than 11% of a. caninum l3 recovered from the small intestines of dogs infected orally were feeding at 4-48 h post-infection (p.i.), and none of the a. ceylanicum l3 recovered from the intestines of orally infected hamsters had resumed feeding. all l4 of both species recovered at 36 and 48 h p.i. had resumed feeding. on the other hand, approximatel ...	1993	8446471
the distribution of intestinal helminth infections in a rural village in guatemala.	fecal egg count scores were used to investigate the distribution and abundance of intestinal helminths in the population of a rural village. prevalences of the major helminths were 41% with ascaris lumbricoides, 60% with trichuris trichiura and 50% with necator americanus. all three parasites showed a highly aggregated distribution among hosts. age/prevalence and age/intensity profiles were typical for both a. lumbricoides and t. trichiura with the highest worm burdens in the 5-10 year old child ...	1993	8246757
[blind treatment or treatment oriented to intestinal parasitoses in a parisian health center for refugees].	the comede health care center for political refugees received 4,414 first arrivals from 70 african, asian and south american countries in 1989. many arrived from areas where intestinal parasitic infections are endemic, and where infections by nematodes (ancyclostoma duodenale, necator americanus, ascaris lumbricoides, trichuris trichiura, strongyloides stercoralis), trematodes (schistosoma hematobium, schistosoma stercoralis) and protozoa (entamoeba coli) cause significant morbidity. the questio ...	1994	8162360
effect of ivermectin on infection with gastro-intestinal nematodes in sierra leone.	levels of intestinal nematode infections were assessed six months after a two year trial of ivermectin for efficacy against onchocerciasis had ended. in the trial the inhabitants of six villages in sierra leone were offered treatment with ivermectin or placebo at six monthly intervals for four rounds in total. quantitative faecal egg counts were carried out on stool samples provided by 202 subjects, all of whom had received all four rounds of treatment, in two of the villages (dodo and mogibisi) ...	1994	7829838
coproantigen detection in rats experimentally infected with strongyloides ratti.	the possibility of coproantigen detection in the diagnosis of strongyloidiasis was investigated in rats experimentally infected with strongyloides ratti. a capture elisa was developed using affinity-purified polyclonal antibodies raised in rabbits against adult and filariform larval somatic antigens. the first detection of coproantigen coincided with patency and the coproantigen level remained elevated even when the parasite count was low. following challenge infection, when examination of stool ...	1994	8022659
cryopreservation of human hookworms.	first-stage larvae (l1) of the human hookworms ancylostoma duodenale and necator americanus were frozen over liquid nitrogen after a 1-hr incubation in a cryoprotectant (10% dmso and 10% dextran). thawed larvae developed to the infective third stage (l3) on agar plates. in the case of a. duodenale, the larvae were infective to dogs. the infectivity of n. americanus l3 was not tested.	1994	8064535
the molecular forms of acetylcholinesterase from necator americanus (nematoda), a hookworm parasite of the human intestine.	necator americanus (nematoda: strongyloidea), a human hookworm parasite, is known to release considerable amounts of acetylcholinesterase (ache) [pritchard, d. i., leggett k. v., rogan, m. t., mckean, p. g. & brown, a. (1991) necator americanus secretory acetylcholinesterase and its purification from excretory/secretory products by affinity chromatography, parasite immunol. 13, 187-199]. the present study deals with ache activity recovered in sequential somatic extracts, and excretory/secretory ...	1994	8306998
density-dependent regulation of the growth of the hookworms necator americanus and ancylostoma ceylanicum.	laboratory bred dsn hamsters were exposed to varying doses of infective larvae of ancylostoma ceylanicum (orally) or necator americanus (percutaneously) and were autopsied at times which corresponded to a period immediately before cessation of growth of worms or soon afterwards. a total of 829 (404 male and 425 female) a. ceylanicum and 1582 (781 male and 801 female) n. americanus were measured. at worm burdens of fewer than 100, the length of a. ceylanicum appeared to increase with infection in ...	1994	8058362
apparent feeding behaviour of ensheathed third-stage infective larvae of human hookworms.	the third-stage ensheathed infective larvae (l3) of hookworms are reputed to be non-feeding stages, and the l2-derived sheath is considered to be a barrier to macromolecular uptake and secretion. during a study of the lectin-binding characteristics of en- and exsheathed l3 larvae of ancylostoma duodenale, fluorescein isothiocyanate conjugated lectins (con a and ulex europaeus agglutinin) were repeatedly seen in the oesophageal lumen, as well as on the surface of l3 larvae encased in the l2 sheat ...	1994	8021101
resistance of the hookworms ancylostoma ceylanicum and necator americanus to intestinal inflammatory responses induced by heterologous infection.	experiments were carried out to ascertain whether the acute inflammatory phase of the intestinal response of hamsters to infection with trichinella spiralis would adversely affect hookworms in concurrently infected animals. the survival and growth of hookworms were unaffected. however, the presence of hookworms reduced the establishment of t. spiralis, the initial growth of female worms and their fecundity. the expulsion of t. spiralis was also significantly slower in concurrently infected anima ...	1994	8021111
effect of albendazole on the larvae and eggs of necator americanus in golden hamster.	when golden hamsters infected with adult necator americanus were treated ig with albendazole(alb) 75 or 150 mg/kg, the efficacy rates were 83.8% and 100%, respectively. three days before treatment, the mean numbers of larvae recorded from the incubation of feces from 2 treated groups were 29,716 +/- 3,299 and 28,256 +/- 118 per gram of feces, while in the control group, it was 8,828 +/- 2,659. within 3 days after treatment, no larva was detected in the 2 treated groups, but in the control group ...	1994	7867156
the population biology and control of necator americanus in a village community in south-eastern china.	the population dynamic parameters of necator americanus infections were estimated from longitudinal intensity and prevalence data from a village in south-eastern china. the theoretical predictions of a deterministic model incorporating these parameters were then compared with observed, horizontal, age-prevalence data from an infected population (n = 565), and an estimate of the basic reproduction rate (r0 = 3.7) of n. americanus was obtained. the findings indicate that populations of n. american ...	1994	7893178
detection of hookworm and hookworm-like larvae in human fecocultures in suriname.	estimation of the prevalence of hookworm infection is usually based on finding eggs of the parasite in the stool. eggs of the different hookworm species are difficult to distinguish and can be confused with those of hookworm-like species. proper identification can be made after hatching the eggs and cultivating larvae to the infective stage. we have used the harada-mori method to study the stools of bushnegroes in suriname and have identified the emerged larvae. of the 804 individuals examined, ...	1994	7943579
a case of tropical pulmonary eosinophilia.		1994	7948545
prevalence of intestinal helminthic infections in kao district, north halmahera, indonesia.	a parasitological survey was conducted on the inhabitants of six villages of kao district, halmahera island, north maluku, indonesia, in july 1993. a total of 422 fecal samples were examined by using kato-katz thick smear, modified harada-mori culture and formalin ether concentration techniques. seven nematode species, ie ascaris lumbricoides, trichuris trichiura, necator americanus, ancylostoma duodenale, strongyloides stercoralis, enterobius vermicularis and unidentified rhabditoids of free-li ...	1994	7667724
[epidemiology and control of hookworm infection in fujian province].	fujian province has been known to be endemic for mixed hookworm infection with ancylostoma duodenale as the predominant species. the infection rate was 50% before 1980. as a result of mass treatment starting from 1980, the infection rate was decreased in most areas. and, infection foci were changed from sweet potato fields to the banana, sweatcane and asparagus fields where the infection rate tended to increase. it is stressed that the current endemic characteristics of hookworm infection should ...	1994	7720205
[immunity in hookworm infection].		1994	7720209
survey of the prevalence of intestinal parasites in children of primary school age.	a survey of the prevalence of intestinal parasites in primary school children was carried out in nimo in njikoka local government area of anambra state, nigeria. stool samples were taken from children belonging to eight (8) primary schools in the area. of the 1,536 stool samples examined using light microscopy after formalether centrifugation, 922 (60%) harboured one or more parasites. the prevalence of the parasites was as follows: ascaris lumbricoides (20.8%); trichuris trichiura, (15.3%); nec ...	1994	7756189
immunosuppression in nigerians with hookworm infection.	t rosette cells results in patients with (necator americanus and ancylostoma duodenale) hookworm infection, divided into groups on the basis of the degree of anaemia (group i had marked anaemia hb 1-7, hypochromia ), group ii had moderate anaemia (hb 8-11, hypochromia ++) and group iii had no signs of anaemia despite the underlying hookworm infection), were compared with results in 28 healthy controls who had no signs of other infection and excreting no ova of hookworm or other parasites. the le ...	1994	7604745
health status of pediatric refugees in buffalo, ny.	to characterize the health status of recent pediatric refugees.	1995	7633543
[gastrointestinal and urinary parasitic infection in children at a regional hospital center in togo: some epidemiological aspects].	to determine the impact of parasitic infection of the digestive and urinary tract in children living in a rural area of togo, a retrospective study was conducted in a pediatric department of kara, togo. results revealed that 35% of the 1610 children between the ages of 0 and 16 years had positive tests for parasites in stools or urine and that 117 had more than one parasite. trichomonas intestinalis, entamoeba histolytica, schistosoma mansoni and necator americanus accounted for 86.5% of the par ...	1995	7637613
prevalence of intestinal parasitic infection in five farms in holambra, são paulo, brazil.	a parasitological survey was carried out on 222 inhabitants of five farms in holambra, located 30 km north of campinas, são paulo, brazil, on october 1992. approximately 70% of the inhabitants were found to be infected with at least one species of intestinal parasite. the positive rates of 6 helminths and 7 protozoan species detected are as follows: 5.4% ascaris lumbricoides; 8.6% trichuris trichiura; 19.8% necator americanus; 10.4% strongyloides stercoralis; 1.4% enterobius vermicularis; 0.9% h ...	1995	7569635
glutathione s-transferase (gst) expression in the human hookworm necator americanus: potential roles for excretory-secretory forms of gst.	the difficulty in demonstrating protective immunity to human gastro-intestinal nematodes is thought to be a consequence of the expression of defences by the parasites directed against the toxic metabolites of leukocytes produced during inflammation (brophy and pritchard, 1992a). parasite glutathione s-transferases (gsts) may provide part of this defence by detoxifying the secondary products of lipid peroxidation produced via immune initiated free-radical attack on host or parasite membranes (bro ...	1995	7572433
epidemiology of human hookworm and ascaris lumbricoides infestations in rural gambia.	in a cross-sectional study of helminth infections in a rural village in the gambia, west africa, hookworm, probably necator americanus and ascaris lumbricoides were found to be the most prevalent helminths present at prevalence levels of 30% and 25% respectively. other parasites present were trichuris trichiura (2.4%) and schistosoma mansoni (1.5%). the mean egg counts of n. americanus and a. lumbricoides in all age groups and in the total population were low. egg counts between age and sex grou ...	1995	7588150
immunity in humans to necator americanus: ige, parasite weight and fecundity.	the effect of the humoral immune response on the weight and fecundity of the hookworm necator americanus was examined in an endemically-infected human population. there was a highly significant negative correlation between total ige levels and parasite weight and fecundity, after controlling for any effects of host age and hookworm burden. this correlation was present both at initial treatment and after 2 years' reinfection. there was a similar negative correlation between the number of eosinoph ...	1995	7761110
the anti-haemostatic strategies of the human hookworm necator americanus.		1995	7667839
the changing epidemiology of human hookworm infection in australia.	to document the distribution of human hookworm infection in australia.	1995	7854229
the specificity of the human ige response to necator americanus.	human ige responses to helminth infections have been described as both problematic and beneficial, in that type 1 hypersensitivity to parasite infections can reputedly cause pathology and/or parasite expulsion, (pritchard, quinnell & walsh 1995). in the present communication, we can report that the ige response to helminth infections may be beneficial in a diagnostic sense, in that antibodies of this isotype showed minimal cross-reactivity against antigens from the parasites tested. this informa ...	1995	8817608
targeted chemotherapy for parasite infestations in rural black preschool children.	to investigate whether targeted chemotherapy can reduce parasite prevalence rates in rural black preschool children.	1995	8545746
in vitro studies on the relative sensitivity to ivermectin of necator americanus and ancylostoma ceylanicum.	experiments were carried out to compare the sensitivity of ancylostoma ceylanicum and necator americanus to ivermectin (ivm) and pyrantel in vitro. loss of motility and inhibition of ingestion by ivm were compared and a. ceylanicum was found to be approximately 40-50 times more sensitive to ivm than n. americanus. both species showed a similar sensitivity to pyrantel. uptake of [3h]ivm across the cuticle was compared and shown to be unlikely to account for the differences in sensitivity to ivm b ...	1995	8557465
an initial characterization of the proteolytic enzymes secreted by the adult stage of the human hookworm necator americanus.	the proteolytic activities present in adult necator americanus excretory-secretory products have been assessed using biologically relevant, naturally occurring substrates (haemoglobin and fibrinogen) and a number of synthetic fluorogenic and chromogenic substrates. one broad peak of activity was observed against haemoglobin in the ph range 5 to 7, with maximum activity at ph 6.6, while fibrinogenolytic activity was shown to be greater at ph 3.5. inhibition studies against haemoglobin, fibrinogen ...	1995	7596639
[digestive parasitic diseases. a continuous current problem].		1995	9506123
common intestinal helminths.	groups at risk for intestinal helminth infestation include international students and travelers, migrant laborers, refugees, children of foreign adoptions and the homeless. symptoms are often minimal or vague, yet many such infections carry significant long-term morbidity. enterobius vermicularis, the common pinworm, is usually manifested in children as anal itching and is best diagnosed by using the cellophane-tape test to recover eggs from the perianal skin. treatment with mebendazole is indic ...	1995	7484705
immunoepidemiology of human necatoriasis: correlations between antibody responses and parasite burdens.	in this paper we describe the relationship between antibodies to necator americanus stage-specific antigens and parasite burden in an endemically-infected population in papua new guinea. using an age-structured analysis, we show that the correlation coefficient between levels of igg against adult worm excretory-secretory (es) antigen and parasite burden declined significantly with host age from positive in younger hosts to significantly negative in older hosts. a trend towards similar patterns w ...	1995	7494644
hookworm infection.	it retards growth and intellectual development in millions of children yet is largely ignored by researchers. new findings suggest excellent possibilities for a vaccine.	1995	7761817
infantile hookworm disease in china. a review.	hundreds of cases of infantile hookworm disease which shows bloody stools, melena, anorexia, listlessness and oedema, have been reported in china since the 1960s. hookworm eggs were detected in due course in the faeces of the reported cases. with the exception of a single worm identified as necator americanus, all the adult worms expelled following chemotherapy or examined at autopsy were ancylostoma duodenale. many children showed clinical manifestations and eggs in their faeces on day 1-26 aft ...	1995	8533661
gastrointestinal nematodes: the karkar experience.	this paper reviews our research on the hookworm necator americanus over several years. our field site for the research was on karkar island, papua new guinea, where we found a prevalence of n. americanus infection among adults of nearly 100%. the intensity of infection was related to host age and to the development of iron deficiency anaemia, which occurred at a much lower infection intensity than had been previously reported. we studied the immune response to infection and our results initially ...	1995	9522871
the anti-haemostatic strategies of the human hookworm necator americanus.	the human hookworm necator americanus appears to have evolved a number of complementary strategies to overcome the host's haemostatic processes. these include the inhibition of blood coagulation, platelet aggregation and mediator release, and the secretion of fibrinogenolytic enzymes. these strategies presumably allow the parasite to establish the chronic infections so often documented in human populations.	1996	8587805
differentiation between the human hookworms ancylostoma duodenale and necator americanus using pcr-rflp.	there are 2 major species of hookworms that infect humans. ancylostoma duodenale and necator americanus. although traditionally considered to be identical for treatment purposes, there are significant life history differences between the species that must be considered for the rational design of chemotherapeutic and immunoprophylactic control strategies. however, identification of the species infecting a particular population has been problematic, as the eggs of the 2 species cannot be reliably ...	1996	8691377
schistosomiasis mansoni in kenya: relationship between infection and anaemia in schoolchildren at the community level.	haematological surveys were carried out in 3 schools in 2 areas where schistosoma mansoni is endemic in machakos district, kenya, before and after a treatment campaign using praziquantel. earlier clinical impressions of differences in the levels of anaemia between the 2 areas were not confirmed. although individual haemoglobin levels and haematocrits often fell below international norms, significant anaemia with abnormal red blood cell morphology was rare (< 5%), but varied between schools. alti ...	1996	8730312
the distribution of common intestinal nematodes along an altitudinal transect in kwazulu-natal, south africa.	in order to study the effect of climate and topography on the distribution of common, intestinal nematodes in schoolchildren, changes in prevalence were investigated along an altitudinal transect from approximately 50 m above sea level (asl), near the coast, to approximately 1700 m asl, in the foothills of the drakensberg mountains, kwazulu-natal, south africa. these changes were related to several permutations of temperature, rainfall and evaporation, using univariate and multiple regression an ...	1996	8762408