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egg production of oesophagostomum bifurcum, a locally common parasite of humans in togo.in northern togo and northeastern ghana, oesophagostomum bifurcum is a common parasite in humans. diagnosis is based on coproculture because the eggs of hookworm and oesophagostomum are indistinguishable. to determine the level of egg production, 12 subjects were treated with 2 x 10 mg/kg of pyrantel pamoate and the worms they evacuated were then counted. pretreatment and post-treatment species-specific egg counts were calculated on the basis of larval and total egg counts. the median worm burde ...19921575294
the helminth fauna of the digestive tracts of chacma baboons, papio ursinus, from different localities in the transvaal.all of the 111 baboons examined from the loskop dam, suikerbosrand and scrutton nature reserves and the sabie-tweefontein forest reserve were infested with helminths of the digestive tract. the helminths recovered were bertiella studeri, enterobius vermicularis, oesophagostomum bifurcum, physaloptera caucasica, streptopharagus pigmentatus, strongyloides fülleborni, trichostrongylus falculatus, trichuris trichiura and females of trichuris which possibly belong to a new species. most baboons harbo ...19846533507
treatment of mixed oesophagostomum and hookworm infection: effect of albendazole, pyrantel pamoate, levamisole and thiabendazole.oesophagostomum bifurcum has recently been recognized as a common parasite of man in northern togo and in ghana. in a preliminary trial several anthelmintics were evaluated in the treatment of mixed oesophagostomum and hookworm infections. diagnosis was based on faecal culture, since the eggs of oesophagostomum and hookworm cannot be distinguished morphologically. of the anthelmintics tested, albendazole was most effective against both parasites. pyrantel pamoate, 2 x 10 mg/kg, was effective aga ...19938465409
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 ...19979379311
systematic relationships of some members of the genera oesophagostomum and chabertia (nematoda: chabertiidae) based on ribosomal dna sequence data.the present study characterised seven species of the chabertiidae (nematoda: strongyloidea) belonging to either the subfamily oesophagostominae (oesophagostomum radiatum, oesophagostomum venulosum, oesophagostomum dentatum, oesophagostomum quadrispinulatum, oesophagostomum columbianum, oesophagostomum bifurcum) or to the subfamily chabertiinae (chabertia ovina) by their second internal transcribed spacer rdna sequence, assessed the extent of intraspecific variation and interspecific differences ...19989846616
diagnosis of oesophagostomum bifurcum and hookworm infection in humans: day-to-day and within-specimen variation of larval counts.oesophagostomum bifurcum, as well as hookworm infections are hyperendemic among humans in northern togo and ghana. for parasite-specific diagnosis a coproculture is obligatory, because only the infective larvae, and not the eggs, can be distinguished morphologically. the sensitivity of duplicate coprocultures from a single stool sample was found to be above 90% in comparison to a gold standard of 10 coprocultures made from a single stool specimen. prevalence of infection with o. bifurcum and hoo ...199910205804
molecular separation of oesophagostomum stephanostomum and oesophagostomum bifurcum (nematoda: strongyloidea) from non-human primates.the its-2 sequences for adult specimens of oesophagostomum stephanostomum from the common chimpanzee and oesophagostomum bifurcum from the mona monkey were determined. for both species, the length and gc content of the its-2 sequences were 216 bp and 43%, respectively. while there was no unequivocal sequence difference among individual worms representing each of the two species, five (2.3%) interspecific nucleotide differences were detected. these differences were associated with the presence of ...199910501618
geographic distribution and epidemiology of oesophagostomum bifurcum and hookworm infections in humans in togo.in contrast to the rest of the world, infections with oesophagostomum bifurcum are commonly found in humans in northern togo and ghana. in addition, infections with hookworm are endemic in this region. in the present study, a detailed map of the geographic distribution of o. bifurcum and hookworm infections in northern togo was made. there were a number of foci with high prevalence of infection with o. bifurcum. all the villages examined were infected with hookworm, and the distribution was quit ...199910674676
pcr assay for the specific amplification of oesophagostomum bifurcum dna from human faeces.oesophagostomiasis in humans due to infection with oesophagostomum bifurcum (nodule worm) is of major human health significance in northern togo and ghana where the human hookworm, necator americanus, also exists at high prevalence. accurate diagnosis of o. bifurcum infection in humans is central to studying the epidemiology and controlling the parasite. to overcome limitations of current copro-diagnostic methods, we have developed an alternative, molecular approach. utilising genetic markers in ...200010704596
prenatal immune priming with helminth infections: parasite-specific cellular reactivity and th1 and th2 cytokine responses in neonates.the present investigation aimed to determine to what extent maternal helminth infection primes parasite-specific cellular responsiveness in neonates. umbilical cord mononuclear blood cells (ucbc) and peripheral blood mononuclear cells (pbmc) from mothers proliferated in response to mitogenic stimulation with concanavalin a, as well as to bacterial streptococcus pyogenes-derived (streptolysin o) and helminth-specific antigens of necator americanus and onchocerca volvulus. cellular responses to ec ...200010955699
ultrasound appearance of preclinical oesophagostomum bifurcum induced colonic pathology. 200111247903
experimental oesophagostomum bifurcum in monkeys.oesophagostomum bifurcum: larvae, cultured from human stools collected in northern ghana, were used to establish experimental infections in monkeys. a patent infection was established in a rhesus monkey (macaca mulatta) and this infection was used to generate larvae to inoculate additional monkeys. in all, 17 animals were inoculated. thirteen of 15 animals developed antibodies to the infection between 19 and 62 days post inoculation (pi); two animals had a positive response before inoculation. f ...200111316472
natural progression of oesophagostomum bifurcum pathology and infection in a rural community of northern ghana.an estimated 250,000 people in northern ghana and togo are infected with the intestinal helminth parasite oesophagostomum bifurcum, as detected by stool cultures. clinical disease caused by o. bifurcum is responsible for about 50 cases per year at the region's central hospital, and presents as painful abdominal masses: inflammatory colonic nodules containing live juvenile stages of the helminth. in individuals living in villages highly endemic with o. bifurcum infection, colonic pathology visibl ...200111491001
determining the prevalence of oesophagostomum bifurcum and necator americanus infections using specific pcr amplification of dna from faecal samples.until recently infection of humans with oesophagostomum bifurcum was regarded as a rare zoonosis. but in northern togo and ghana its prevalence is 50% or more in certain villages. diagnosis is hampered by the fact that the eggs of o. bifurcum are morphologically identical to those of the hookworm necator americanus. stools have to be cultured for 7 days to allow eggs to hatch to the characteristic third-stage (l3) larvae. we evaluated the applicability of specific polymerase chain reactions (pcr ...200111555440
parasite-specific antibody and cellular immune responses in human infected with necator americanus and oesophagostomum bifurcum.in this study parasite-specific antibody, cellular reactivity and thl-type or th2-type cytokine responses were investigated in humans concurrently infected with necator americanus and oesophagostomum bifurcum. the prospects for o. bifurcum-specific serodiagnosis based on igg4 and ige were evaluated. igg4 showed low specificity for o. bifurcum due to antigen cross-reactivity with n. americanus, while ige specifically distinguished between hookworm and o. bifurcum, and, in doubly infected patients ...200111570557
screening for haplotypic variability within oesophagostomum bifurcum (nematoda) employing a single-strand conformation polymorphism approach.genetic markers in the mitochondrial genome have proven useful for population genetic studies because of their maternal inheritance and relatively high evolutionary rates. in this study, we exploited the high resolution capacity of pcr-coupled single-strand conformation polymorphism (sscp) to screen for sequence variation in part of the cytochrome c oxidase subunit 1 gene (p cox 1) among individuals of the parasitic nematode, oesophagostomum bifurcum from human or mona monkey hosts from africa. ...200212144769
the short-term impact of albendazole treatment on oesophagostomum bifurcum and hookworm infections in northern ghana.in november-december 2002, stool samples from a random sample of the human population (n = 190) in the garu area of northern ghana were checked for intestinal helminths, using a single kato smear and duplicate coprocultures for each subject. all 190 subjects were subsequently treated with a single, 400-mg dose of albendazole and 146 of them were successfully re-examined 21-28 days post-treatment. prior to treatment, 75.5% of the kato smears were found to contain 'hookworm-like' eggs (with a geom ...200415228719
definition of genetic markers in nuclear ribosomal dna for a neglected parasite of primates, ternidens deminutus (nematoda: strongylida)--diagnostic and epidemiological implications.ternidens deminutus (strongylida) is a parasitic nematode infecting non-human and human primates in parts of africa, asia and the pacific islands. the present study genetically characterized t. deminutus and defined genetic markers in nuclear ribosomal dna (rdna) as a basis for developing molecular-diagnostic tools. the sequences of the second internal transcribed spacer (its-2) of rdna were determined for adult specimens of t. deminutus (nematoda: strongylida: oesophagostominae) from the olive ...200516174419
oesophagostomum bifurcum in non-human primates is not a potential reservoir for human infection in ghana.in northern togo and ghana, human infection with the parasitic nematode oesophagostomum bifurcum is of major health importance. elsewhere, oesophagostomiasis is considered a zoonotic infection, non-human primates being the natural host. we examined 349 faecal samples of the olive baboon, mona monkey and black and white colobus monkey from two geographically distinct areas in ghana, outside the region endemic for o. bifurcum in humans. using both microscopy and species-specific pcr, we found a hi ...200516359413
morphological variability within oesophagostomum bifurcum among different primate species from ghana.adult oesophagostomum bifurcum (nematoda: strongylida) from human and non-human primates from ghana were compared in order to investigate the extent of morphological variability within the species. using analysis of variance and principal component analysis, significant differences in morphological characters (such as parasite length, width, length of the oesophagus and length of spicules) were demonstrated between o. bifurcum worms from humans, the mona, patas or green monkey and/or olive baboo ...200617125544
simultaneous detection and quantification of ancylostoma duodenale, necator americanus, and oesophagostomum bifurcum in fecal samples using multiplex real-time pcr.a multiplex real-time pcr was developed and evaluated for the simultaneous detection of ancylostoma duodenale, necator americanus, and oesophagostomum bifurcum in fecal samples. using well-defined control samples (n = 150), known positive fecal samples (n = 50), and fecal samples from an area in ghana where human infections with all 3 nematode species are endemic (n = 339), the method proved to be highly specific and sensitive. cycle threshold (ct) values, reflecting parasite-specific dna load, ...200717978072
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 ...19938509618
[dapaong "tumor". helminthiasis caused by oesophagostomum].28 cases of pseudotumors of the bowel, ileum and appendix by an infestation with oesophagostomum bifurcum, a rare human parasite, are studied.19883214503
the capacity of the third-stage larvae of oesophagostomum bifurcum to survive adverse conditions.human infections with the intestinal nematode oesophagostomum bifurcum are commonly found in the sudan savannah of northern togo and ghana. apparently, the long and hot dry season in this region does not prevent transmission, which is believed to take place through ingestion of the infective, third-stage larvae (l3). oesophagostomum l3 cultured from human stools, unlike the larvae of necator americanus, were shown to survive desiccation. in addition, 93% of the o. bifurcum l3 frozen for 24 h at ...200010827871
pathogenic eukaryotes in gut microbiota of western lowland gorillas as revealed by molecular survey.although gorillas regarded as the largest extant species of primates and have a close phylogenetic relationship with humans, eukaryotic communities have not been previously studied in these populations. herein, 35 eukaryotic primer sets targeting the 18s rrna gene, internal transcribed spacer gene and other specific genes were used firstly to explore the eukaryotes in a fecal sample from a wild western lowland gorilla (gorilla gorilla gorilla). then specific real-time pcrs were achieved in addit ...201425231746
insights into the epidemiology and genetic make-up of oesophagostomum bifurcum from human and non-human primates using molecular tools.the nodule worm oesophagostomum bifurcum (nematoda: strongylida) is a parasite of major human health importance predominantly in northern togo and ghana. currently, it is estimated that 0.25 million people are infected with this nematode, and at least 1 million people are at risk of infection. infection with this parasite causes significant disease as a consequence of encysted larvae in the wall of the large intestine. in spite of the health problems caused by o. bifurcum, there have been signif ...200616332292
oesophagostomum bifurcum-induced nodular pathology in a highly endemic area of northern ghana.human infection with oesophagostomum bifurcum is rare globally, but focally endemic and common in ghana and togo. two clinical presentations are identified: uni-nodular disease, which may be recognized as a 'dapaong tumour', and multi-nodular disease. here, we describe the prevalence of o. bifurcum infection and the association with nodular pathology in northern ghana. the study was performed in october 2002. out of a well-defined population of approximately 18000, 928 subjects of all ages were ...200515837353
distribution of human oesophagostomum bifurcum, hookworm and strongyloides stercoralis infections in northern ghana.a cross-sectional study was carried out in 216 randomly selected, representative rural villages in the northeastern part of ghana from march 1995 to may 1998. inhabitants of randomly selected households, stratified by age and gender, were included. the geographical position of villages was recorded with a global positioning system (gps). the prevalence of oesophagostomum, hookworm and strongyloides stercoralis infections in a study population of 20250 people was determined by microscopic examina ...200515550259
intraobserver and interobserver variation of ultrasound diagnosis of oesophagostomum bifurcum colon lesions.infection by the nematode oesophagostomum bifurcum is focally distributed in africa and causes a syndrome of abdominal pain, obstruction, or abdominal mass because of its predilection for invasion of colonic mucosa. to determine the reliability of ultrasound for the detection of colon pathology induced by this parasite, three studies to assess the intraobserver and interobserver variation of the technique were performed. in an area of northern ghana endemic for o. bifurcum, 181 people from a low ...200212518861
the role of pigs as transport hosts of the human helminths oesophagostomum bifurcum and necator americanus.we conducted a study in an endemic area of both oesophagostomum bifurcum and necator americanus in northern ghana to examine the possibility of pigs acting as transport hosts for these two human helminth species, due to the commonly observed coprophagic habits of pigs. under controlled conditions four parasite-free pigs consumed fresh faeces from people heavily infected with both helminths, and faeces were subsequently collected from the rectum of the pigs from 5 to 50 h post-feeding. four to fi ...200010936571
clinical epidemiology and classification of human oesophagostomiasis.the intestinal helminth oesophagostomum bifurcum is highly and focally endemic in northern ghana and togo, and its juveniles produce a nodular inflammatory response as they develop in the intestinal wall. this pathology can produce clinical symptoms. we report on 156 cases of oesophagostomiasis presenting in 1996-98 to nalerigu hospital in northern ghana. the disease accounted for 0.2% of the out-patient department new presentations (about 1 patient per week), and 1% (16) of the major acute surg ...200010897362
screening for nucleotide variations in ribosomal dna arrays of oesophagostomum bifurcum by polymerase chain reaction-coupled single-strand conformation polymorphism.we exploited the high resolution capacity of polymerase chain reaction (pcr)-coupled single-strand conformation polymorphism (sscp) to screen for sequence variation in the second internal transcribed spacer (its-2) of ribosomal dna (rdna) among 77 individuals representing oesophagostumum bifurcum from human or mona monkey hosts from africa. sscp analysis revealed distinct profiles among some of the individuals, and sequence analysis of representative samples defined different its-2 sequence type ...199910424472
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 ...19979232615
reinfection patterns of oesophagostomum bifurcum after anthelmintic treatment.subjects infected with the adult worms of oesophagostomum bifurcum, diagnosed through semiquantitative detection of characteristic third stage larvae, were treated in the middle of the dry or in the middle of the rainy season with two different dosages of albendazole. a third group was not treated. the pattern of reinfection after treatment was analysed. transmission of oesophagostomum infection appeared to be limited to the rainy season and the rate of reinfection was independent of the dose of ...19958560587
quantitative interpretation of coprocultures in a population infected with oesophagostomum bifurcum.coproculture is used in northern togo and ghana in the research on oesophagostomum bifurcum, a common parasite of man in these regions. prior to a follow-up study to investigate patterns of reinfection in oesophagostomum and hookworm, it was attempted to evaluate the relevance of counting larvae for the assessment of the intensity of infection at the population level. of 102 samples, one egg count (kato-smear) and three coprocultures were carried out. frequency distributions of counts of larvae ...19958560586
serological diagnosis of oesophagostomum infections.a sensitive and specific enzyme-linked immunosorbent assay (elisa) is described to diagnose human infection with oesophagostomum bifurcum. in an elisa using crude soluble antigen, prepared from adult o. bifurcum, many cross reactions occurred when measuring igg titres in patients with other helminth infections. an elisa based on the detection of specific igg4, however, had a specificity of over 95%. the sensitivity of the igg4 elisa was difficult to assess because a reliable parasitological diag ...19938249074
human oesophagostomum infection in northern togo and ghana: epidemiological aspects.recently, it has been established that human infection with oesophagostomum bifurcum is common in northern togo and northeastern ghana. two surveys were conducted in this area. in a regional survey, o. bifurcum infection appeared to occur in 38 of 43 villages. the highest prevalences (up to 59%) occurred mostly in small isolated villages and were usually associated with high hookworm infection rates. the infection was relatively rare in children under five years of age (7% infected). in older in ...19921449277
impact of repeated mass treatment on human oesophagostomum and hookworm infections in northern ghana.oesophagostomum bifurcum is a common parasite of humans causing disease in parts of northern ghana and northern togo. the impact of repeated mass treatment with albendazole on infection with o. bifurcum and hookworm is analysed and the results compared with those in a control area where no treatment was given. at baseline, o. bifurcum and hookworm prevalences were 53.0% and 86.9%, respectively (n=1011). after 12 months, following two rounds of albendazole treatment, prevalences decreased signifi ...200617054758
distribution and clustering of oesophagostomum bifurcum and hookworm infections in northern ghana.human oesophagostomum infections are locally common in northern ghana. the present study describes the results of a cross-sectional survey involving 1011 subjects, selected by a compound-based random sampling method from 1227 compounds in 24 villages. selected persons were examined by both kato and coproculture methods. hookworm-like eggs, representing ova of oesophagostomum bifurcum and hookworm were detected in 87.5% of the kato smears. the geometric mean egg count of the infected subjects was ...200616388688
high resolution dna fingerprinting by aflp to study the genetic variation among oesophagostomum bifurcum (nematoda) from human and non-human primates from ghana.an aflp approach was established to investigate genetic diversity within oesophagostomum bifurcum (order strongylida) from human and non-human primates. evaluation of different combinations of restriction enzymes (n = 8) and primers (n = 29) demonstrated that the use of hindiii/bglii digested templates and primers with the selective nucleotides + ag/ +ac, respectively, was the most effective for the analysis of o. bifurcum dna. a total of 63 o. bifurcum adults from human, patas monkey, mona monk ...200515727072
human oesophagostomiasis: a histomorphometric study of 13 new cases in northern ghana.oesophagostomiasis is an infrequently described and recognised parasitic infection in humans, caused by oesophagostomum bifurcum. although the disease is most often found in the northern part of togo and the neighbouring part of ghana, sporadic cases have been described in other parts of africa and in asia and south america: uganda, ivory coast, sudan, kenya, ethiopia, indonesia, malaysia and brazil. infection probably occurs by way of the ingestion of l3 larvae. these larvae penetrate the intes ...200111499836
ultrasonographic detection and assessment of preclinical oesophagostomum bifurcum-induced colonic pathology.in northern ghana and togo, oesophagostomum bifurcum infects an estimated 250,000 people, as determined by cultures of stool samples. the juvenile stages of the helminth develop within colonic wall nodules, causing dapaong tumor or multinodular disease, at the rate of 1 case per week at nalerigu hospital in ghana. our aim was to discover whether suspected colonic-wall pathology is ultrasonographically visible in asymptomatic individuals living in the area where o. bifurcum is endemic. a total of ...200111418875
the effect of albendazole on oesophagostomum bifurcum infection and pathology in children from rural northern ghana.ultrasonography has already revealed that up to 50% of individuals in some villages in northern ghana have colonic pathology induced by oesophagostomum bifurcum. approximately 2% of those affected progress to clinical oesophagostomiasis if left untreated. in the present study, ultrasound-positive children living in a heavily infected community were each given 5 days of treatment with albendazole (10 mg/kg.day), early in the dry season. treatment reduced the prevalence, number, size and half-life ...200111235558
ultrasound diagnosis of oesophagostomiasis.human infection with oesophagostomum bifurcum, a parasitic intestinal helminth, is endemic in parts of west africa. oesophagostomum bifurcum juveniles develop in the colonic wall, causing pus-filled granulomas. the pathology has two distinct forms. multinodular oesophagostomiasis comprises hundreds of small nodules within a thickened, oedematous wall of the large intestine. uninodular oesophagostomiasis, called the dapaong tumour, presents as a painful 30-60 mm granulomatous mass in the abdomina ...200010817053
mass treatment with albendazole reduces the prevalence and severity of oesophagostomum-induced nodular pathology in northern ghana.previous surveys conducted in northern ghana where oesophagostomum bifurcum is endemic showed that o. bifurcum-induced nodular pathology could be detected in up to 50% of the inhabitants. the impact of albendazole-based mass treatment to control both infection and morbidity is assessed and compared with the situation in a control area where no mass treatment has taken place. a significant reduction in the prevalence of infection based on stool cultures was achieved following two rounds of mass t ...200616730763
genetic substructuring within oesophagostomum bifurcum (nematoda) from human and non-human primates from ghana based on random amplified polymorphic dna analysis.random amplified polymorphic dna (rapd) was used to study genetic variation within oesophagostomum bifurcum in ghana. four different decamer primers were used for the amplification of dna from individual o. bifurcum adults (n = 41) from humans and non-human primates (including the mona monkey, patas monkey and olive baboon) from different geographic regions. analysis of the amplicons from all 41 nematodes by high resolution, denaturing polyacrylamide gel electrophoresis defined a total of 326 in ...200415306716
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