| studies on necator americanus, thai-strain. the prevalence, distribution and faecal egg count of necator americanus in the human intestine. | | 1981 | 7229568 |
| intestinal parasites of man in oriental mindoro, philippines, with emphasis on schistosomiasis. | an intestinal parasite survey was conducted in the town of victoria, oriental mindoro, philippines in 1978 in order to estimate the current schistosomiasis situation in this area of the philippines and schistosoma japonicum eggs were detected in 20% of 1058 fecal specimens examined. the prevalence was more than twice as high as had been previously estimated. infection rates were higher in males than in females, 26 versus 15% and age-wise were infrequent in young children (8%) and moderately comm ... | 1981 | 7256349 |
| intestinal parasites of man in bukidnon, philippines, with emphasis on schistosomiasis. | a total of 831 fecal specimens from malay-balay, mindanao, philippines were examined for schistosomiasis and common intestinal parasites. schistosoma japonicum eggs were found in 16% of the samples. infections were more common in males (20%) than in females (12%). age-wise, infections were infrequently diagnosed in children less than 10 years and infections in older age groups varied from 12-27%. hookworm, chiefly necator americanus, was the most common parasite found (44%) followed by ascaris l ... | 1981 | 7256354 |
| [necator americanus uncinariasis in an infant born and residing in mexico city]. | a six-month-old infant is reported with the unquestionable diagnosis diagnosis of necator americanus uncinariasis. the mother was also infected with the same hookworm. the patient was born and has always dwelt in mexico city, where helminthiasis is considered extremely rare. the epidemiologic studies determined that the dwelling conditions were inadequate for the transmittal of the agent through the soil. the authors emphasize the importance of the presumptive diagnosis in those cases suggesting ... | 1981 | 7259852 |
| human neonatal infections with hookworms in an endemic area of southern nigeria. a possible transmammary route. | examination of faecal smears of 316 neonates (4-5 weeks old) in a human hookworm endemic area of southern nigeria showed that 33 (10%) of them were hookworm infected. the majority of the neonatal infections (88%) were due to ancylostoma duodenale although necator americanus was the more prevalent hookworm species in the area. the incidence of neonatal infections was pronounced (64%) for mothers who were a. duodenale-positive 5-6 weeks postpartum. a thorough screening of 12.4 litres of colostral ... | 1981 | 7281208 |
| anthelmintic efficacy of amoscanate (c 9333-go/cgp 4540) against various infections in rodents, dogs and monkeys. | the anthelmintic activity of amoscanate (c 9333-go/cgp 4540) has been studied in experimental infections with the human hookworm, necator americanus, in hamsters; nematospiroides dubius, hymenolepsis nana and natural infections with syphacia obvelata in mice; ancylostoma caninum, a. ceylanicum in mongrel dogs; oesophagostomum apiostumum and strongyloides fuelleborni in rhesus monkeys. single oral doses of 30-60 mg/kg eliminated 94 to 99% of the total necator parasites in 37-day-old non-patent in ... | 1981 | 7283017 |
| wormy persons: contributions to the nature and patterns of overdispersion with ascaris lumbricoides, ancylosotma duodenale, necator americanus and trichuris trichiura. | the dominant intestinal helminths in the iranian villages of kargar malleh (hookworms), bandar abbas (hookworms) and jazin (ascaris lumbricoides and trichuris trichiura), were recorded with their frequency distributions, in 80, 40 and 111 villagers, respectively in 1977-78. anthelminthics were then used to remove all intestinal stages which were identified and counted. analyses showed clumped or over-dispersed patterns in all cases. each community contained 'wormy persons', 1 to 3% of the indivi ... | 1981 | 7314236 |
| transient hypereosinophilia in necator americanus and schistosoma mansoni infections. | | 1981 | 7330957 |
| necator americanus in infant rabbits: complete development, humoral antibody, leukocyte response and serum protein changes following infection. | necator americanus, originally isolated from man, developed completely in infant rabbits (rsg-1). this infection was serially passed in infant rabbits up to the 6th generation without using any immunosuppressant. two day old infant rabbits demonstrated a high degree of susceptibility to n. americanus. studies revealed the retention of worms in the intestine for more than 150 days during which egg production was high. in this experimental model the leukocyte, antibody and serum protein responses ... | 1980 | 7410812 |
| glucose uptake & glycogen synthesis in adult necator americanus. | | 1980 | 7429594 |
| necator americanus: population structure, distribution, and fluctuations in population densities of infective larvae in contaminated farmlands. | observations have been made over a 15-month period on the frequency distribution of human faecal deposits and infective larvae of necator americanus in a hookworm endemic area. the agestructure of infective larvae in a field population and their vertical distribution in soils were determined. these studies were undertaken to examine the hypothesis that hookworm transmission in the tropics is discontinuous and limited mainly to the rainy season. the distribution of larvae was found to be overdisp ... | 1980 | 7434873 |
| homology between roundworm (ascaris) and hookworm (n. americanus) antigens detected by human ige antibodies. | utilizing the techniques of radioallergosorbent test (rast), inhibition of rast and isoelectric focusing on polyacrylamide gels, antigenic cross-reactivity has been shown between extracts of ascaris lumbricoides. ascaris suum and necator americanus (hookworm). antigenic homology is extensive between the two ascaris preparations. the antigens common to hookworm and ascaris, while representing a minor component of ascaris body fluid, are nonetheless potent stimulators of ige antibody production in ... | 1980 | 7458774 |
| 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 |
| 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 |
| 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 |
| 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 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 |
| the anti-haemostatic strategies of the human hookworm necator americanus. | | 1995 | 7667839 |
| [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 |
| 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 |
| 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 |
| 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 |
| the changing epidemiology of human hookworm infection in australia. | to document the distribution of human hookworm infection in australia. | 1995 | 7854229 |
| 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 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| [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 |
| [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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| wrong hookworm. | | 1996 | 8638147 |
| 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 |
| detection of gastrointestinal nematodes by a coproantigen capture elisa. | an assay is described for the quantitative detection of excretory/secretory antigens liberated by the intestinal nematode heligmosomoides polygyrus and voided in the host's faeces. a rabbit polyclonal antiserum to the antigens detected them in a dose-dependent manner and was sufficiently sensitive to recognise infection in mice carrying a mean worm burden of nine worms. the assay was specific, giving higher optical density readings with the faeces of mice infected with h polygyrus than with faec ... | 1996 | 8745247 |
| 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 |
| 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 |
| characterization of monoclonal antibodies reactive with schistosoma haematobium-soluble egg and infected human urinary antigens. | six murine monoclonal antibodies (mabs) [sh1/71.7 (igm), sh2/15.f (igg1), sh3/15.28 (igg1), sh3/38.2 (igm), sh4/14.3 (igg1), and sh5/32.30 (igm)] produced against s. haematobium were extensively characterized. all the mabs stained the surface membranes of miracidia as determined by the indirect fluorescent antibody test, yet three of them (sh1/71.7, sh3/15.28, and sh3/38.2) also stained internal cytoplasmic antigens. proteinase-k digestion and periodate oxidation studies showed that these three ... | 1996 | 8823620 |
| igg4 responses to antigens of adult necator americanus: potential for use in large-scale epidemiological studies. | described is an epidemiological investigation of hookworm infections in a rural community in zimbabwe, where necator americanus is the only human helminth species present. among a cohort of 120 individuals the overall prevalence of infection was 78%. intensity of infection was quantified both as egg counts (range: 0-2563 eggs per g of stool) and worm burden (range: 0-100 worms). although both these measures provide useful quantitative data, they are tedious to determine in large-scale epidemiolo ... | 1996 | 8823959 |
| [recent features of parasites detected from clinical specimens]. | it is generally considered that we have already been through with problems caused by various kinds of parasites which had once raged throughout the country. on the contrary to our common concept, we occasionally encounter some kinds of parasites in a laboratory as well as in clinical fields, which have become unfamiliar to us in these days. parasitic diseases are in the first place, proper and limited to certain local regions, but the present situation has been greatly changed. nowadays, specifi ... | 1996 | 8847822 |
| analysis of the prevalence of infection and associations between human gastrointestinal nematodes among different age classes living in the urban and suburban communities of port harcourt, nigeria. | fresh stool samples from 300 subjects presenting at out-patient clinics in two major hospitals in port harcourt were analysed for the prevalence and intensity of gastrointestinal (gi) nematode infections and 85.3% were found to carry at least one of the four species of gi nematodes recognized during the study. the most common species was ascaris lumbricoides (54%), followed by trichuris trichiura (43.7%) and necator americanus (42.7%) and lastly strongyloides stercoralis (33%). peak prevalence f ... | 1996 | 8960202 |
| limited field evaluation of a rapid monoclonal antibody-based dipstick assay for urinary schistosomiasis. | a rapid, visually read monoclonal antibody (moab)-based dipstick assay for specific diagnosis of urinary schistosomiasis was field tested with microscopy and the use of hematuria and proteinuria in a schistosomiasis hematobia endemic area in southern ghana. the study group consisted of 229 individuals (114 males and 115 females) aged 1 to 86 years; 145/229 (63.3%) of the subjects submitted stool samples from which no s. mansoni eggs were detected. however, infections with necator americanus (hoo ... | 1996 | 8985756 |
| necator americanus in inbred mice: evidence in support of genetically determined differences in the cellular immune response to a primary infection. | the blood and broncho-alveolar leucocyte (bal) responses, to a primary necator americanus infection, were studied in male balb/c and nih mice. following percutaneous infection, a significant blood leucocytosis occurred in both the balb/c and nih strains. the peak response occurred, in both strains, on day 10 p.i. and this was reflected in the eosinophil response which peaked at the same time-point. the change in blood eosinophil numbers, as a result of infection, was found to be the greatest rec ... | 1997 | 9011074 |
| intestinal geohelminthiasis in the developing world. | intestinal parasitic helminths such as roundworms (ascaris lumbricoides), hookworms (ancylostoma doudenale and necator americanus) and whipworm (trichuris trichiura) are common in the developing world. strongyloides stercoralis, though not so common, also contributes to health problems. the prevalence of intestinal worm infestation in india varies from 5% to 76%, which is similar to that in other developing countries. these parasitic infestations are acquired by ingestion, inhalation or penetrat ... | 1997 | 9153983 |
| ascariasis and hookworm. | ascariasis and hookworm (ancylostomiasis) remain the most common intestinal nematodes in the world with significant economic, social, and medical impact. an understanding of the transmission and pathogenesis of ascariasis and hookworm are necessary to recognize their clinical manifestations and to manage the pulmonary sequelae of infection. transmission occurs predominantly in the tropics and rural areas where there is suboptimal sanitation, personal hygiene, and education regarding these parasi ... | 1997 | 9195678 |
| the distribution of necator americanus and ancylostoma duodenale among schoolchildren in lagos, nigeria. | | 1997 | 9231191 |
| differentiation of oesophagostomum bifurcum from necator americanus by pcr using genetic markers in spacer ribosomal dna. | oesophagostomiasis in humans due to infection with oesophagostomum bifurcum (nodular worm) is of major human health significance in northern togo and ghana where necator americanus (human hookworm) also exists at high prevalence. however, very little is known about the transmission patterns of o. bifurcum, partly due to the difficulty in differentiating o. bifurcum from n. americanus at some life-cycle stages using morphological features. to overcome this limitation, a molecular approach utilizi ... | 1997 | 9232615 |
| failure of mebendazole in treatment of human hookworm infections in the southern region of mali. | preliminary studies indicated that single-dose (500 mg) mebendazole gave disappointing results in the treatment of hookworm infections (necator americanus) in mali. a placebo-controlled, randomized trial conducted with the participation of 103 infected subjects (background hookworm prevalence > 50%) confirmed that mebendazole (vermox) did not reduce parasite burdens significantly, as assessed through fecal egg counts. in contrast, a group of subjects treated with pyrantel (combantrin) experience ... | 1997 | 9242313 |
| [profile of intestinal helminthiases in school aged children in the city of abidjan]. | feces of 1001 school children aged from 4 to 15 years were examined as an epidemiological investigation. direct analyses were completed by kato and ritchie methods. the outcome was the global prevalence of intestinal helminthiasis in school age children in the abidjan area is 36.5%. male subjects are more infected than females. the most infected group is aged from 12 to 13 years and the less infected from 4 to 5 years. the frequent parasite species are trichuris trichiura (23.4%), ascaris lumbri ... | 1997 | 9264753 |
| cutaneous larva migrans: the case for routine oral treatment. | | 1997 | 9274651 |
| hookworm control as a strategy to prevent iron deficiency. | the hookworms necator americanus and ancylostoma duodenale infect approximately 1 billion people worldwide. the prevalence of hookworm infection increases with age in children, typically reaching a plateau in late adolescence, whereas the intensity of infection may continue to increase throughout adulthood. hookworms cause intestinal blood loss in amounts proportional to the number of adult worms in the gut. the relationship between hookworm infection intensity and hemoglobin concentration is ev ... | 1997 | 9279058 |
| characterization of oesophagostomum bifurcum and necator americanus by pcr-rflp of rdna. | esophagostomiasis in humans due to infection with oesophagostomum bifurcum (nodular worm) is of major human health significance in northern togo and ghana, where necator americanus (human hookworm) also exists at high prevalence. yet, very little is known about the transmission patterns of o. bifurcum, which is in part due to the difficulties in diagnosis and in differentiating some life-cycle stages of o. bifurcum from n. americanus using morphological features. as a first step toward developin ... | 1997 | 9379311 |
| [parasitosis in an adult population with chronic gastrointestinal disorders]. | we worked with 185 middle-class patients above 18 years of age, both sexes, who presented diarrhea and/or chronic gastrointestinal disorders. the faeces were collected serially in formol 10% and processed in the following way: direct microscopy, with and without wet staining, concentration by ritchie's method, 1% safranine technique for a specific investigation of cryptosporidium sp., and faecal sieving macroparasites. twenty eight point six of the studied patients showed at least one enteropara ... | 1997 | 9412130 |
| effect of albendazole and mebendazole on soil-transmitted helminth eggs. | primary school children from nakhon si thammarat province, thailand, on endemic area of soil-transmitted helminths, were selected for study. the infected children were divided into two groups and pair-matched according to intensity of infections: group i were given albendazole (400mg) single dose and group ii were given mebendazole (100mg) twice daily for 3 days. on the day following treatment, the number of trichuris eggs in the stool markedly increased and the egg shape was also altered. these ... | 1997 | 9444013 |
| minimum effective doses of mebendazole in treatment of soil-transmitted helminths. | three hundred and fifteen primary school children infected with soil-transmitted helminths were divided into 5 groups. three groups were treated with 25, 50 and 75 mg mebendazole (mbz) single dose. one group was given mbz conventional dose of 100 mg twice daily for 3 days and another group was given albendazole (abz) standard dose of 400 mg single dose. every trial lower mbz dose 75 mg, 50 mg and 25 mg regimen were highly effective against ascaris lumbricoides but only moderately effective again ... | 1997 | 9444014 |
| [digestive parasitic diseases. a continuous current problem]. | | 1995 | 9506123 |
| 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 |
| necator americanus (nematoda: ancylostomatidae) from africa and malaysia have different its-2 rdna sequences. | the nucleotide sequences of the second internal transcribed spacer of rdna were determined for adult worms of necator americanus originating from togo (africa) and sarawak (malaysia). the length of the sequences of specimens from togo (325 bp) were shorter than those from sarawak (327 bp). there were six fixed genetic differences in the aligned sequences of n. americanus from sarawak and togo, excluding one or two polymorphic sites within the sequence of n. americanus from each geographical regi ... | 1998 | 9602384 |
| parasitic infections in villagers from three districts of the brazilian amazon. | a survey of intestinal parasites among 827 rural villagers in the brazilian amazon revealed that the prevalences of infection with necator americanus, trichuris trichiura and/or ascaris lumbricoides were high. however, the intensities of infection with the two parasites for which there were enough data on intensity for further analysis, n. americanus and t. trichiura, were only low or moderate in each of the three districts studied. possible reasons for the unusual (but not unique) absence of hi ... | 1998 | 9614457 |
| specific amplification of necator americanus or ancylostoma duodenale dna by pcr using markers in its-1 rdna, and its implications. | necator americanus and ancylostoma duodenale are the two most important species of human hookworm, and occur in sympatry over much of their distribution. the specific diagnosis of hookworm infections is central to control. diagnosis currently relies on the detection of hookworm eggs in human faeces and/or the specific identification of larvae by 'copro-culture' combined with microscopic examination. however, the eggs of the two species are morphologically indistinguishable, and the procedure of ... | 1998 | 9633041 |
| epidemiological evidence for a differential effect of hookworm species, ancylostoma duodenale or necator americanus, on iron status of children. | the hookworms, ancylostoma duodenale and necator americanus, cause significant gastrointestinal blood loss. in clinical studies, greater blood losses have been reported with a. duodenale. however, there has been no evidence that endemic a. duodenale infection has greater impact than n. americanus infection on the iron status of populations. | 1998 | 9698148 |
| th1 and th2 cells and immunity to intestinal helminths. | | 1998 | 9761955 |
| ancylostoma secreted protein 1 (asp-1) homologues in human hookworms. | | 1999 | 10029316 |
| [wakana disease]. | | 1999 | 10201249 |
| necator americanus (human hookworm) aspartyl proteinases and digestion of skin macromolecules during skin penetration. | the infective larvae of necator americanus were shown to secrete all mechanistic classes of proteolytic enzymes with two overall ph optima of 6.5 and 8.5 using fluorescein isothiocyanate-labeled casein as the substrate. since infective larvae are obligate skin penetrators, the effect of each of these enzyme classes against macromolecules derived from human skin was examined. larval secretions were shown to degrade collagen types i, iii, iv, and v, fibronectin, laminin, and elastin. all the skin ... | 1999 | 10344662 |