Eggs In Faecal Samples Research Articles

An In-Depth Analysis of a Piece of Shit: Distribution of Schistosoma mansoni and Hookworm Eggs in Human Stool

BackgroundAn accurate diagnosis of helminth infection is important to improve patient management. However, there is considerable intra- and inter-specimen variation of helminth egg counts in human feces. Homogenization of stool samples has been suggested to improve diagnostic accuracy, but there are no detailed investigations. Rapid disintegration of hookworm eggs constitutes another problem in epidemiological surveys. We studied the spatial distribution of Schistosoma mansoni and hookworm eggs in stool samples, the effect of homogenization, and determined egg counts over time in stool samples stored under different conditions.MethodologyWhole-stool samples were collected from 222 individuals in a rural part of south Côte d'Ivoire. Samples were cut into four pieces and helminth egg locations from the front to the back and from the center to the surface were analyzed. Some samples were homogenized and fecal egg counts (FECs) compared before and after homogenization. The effect of stool storing methods on FECs was investigated over time, comparing stool storage on ice, covering stool samples with a water-soaked tissue, or keeping stool samples in the shade.Principal FindingsWe found no clear spatial pattern of S. mansoni and hookworm eggs in fecal samples. Homogenization decreased S. mansoni FECs (p = 0.026), while no effect was observed for hookworm and other soil-transmitted helminths. Hookworm FECs decreased over time. Storing stool samples on ice or covered with a moist tissue slowed down hookworm egg decay (p<0.005).Conclusions/SignificanceOur findings have important implications for helminth diagnosis at the individual patient level and for epidemiological surveys, anthelmintic drug efficacy studies and monitoring of control programs. Specifically, homogenization of fecal samples is recommended for an accurate detection of S. mansoni eggs, while keeping collected stool samples cool and moist delayed the disintegration of hookworm eggs.

Duplex quantitative real-time PCR assay for the detection and discrimination of the eggs of Toxocara canis and Toxocara cati (Nematoda, Ascaridoidea) in soil and fecal samples

BackgroundToxocarosis is a zoonotic disease caused by Toxocara canis (T. canis) and/or Toxocara cati (T. cati), two worldwide distributed roundworms which are parasites of canids and felids, respectively. Infections of humans occur through ingestion of embryonated eggs of T. canis or T. cati, when playing with soils contaminated with dogs or cats feces. Accordingly, the assessment of potential contamination of these areas with these roundworms eggs is paramount.MethodsA duplex quantitative real-time PCR (2qPCR) targeting the ribosomal RNA gene internal transcribed spacer (ITS2) has been developed and used for rapid and specific identification of T. canis and T. cati eggs in fecal and soil samples. The assay was set up on DNA samples extracted from 53 adult worms including T. canis, T. cati, T. leonina, Ascaris suum (A. suum) and Parascaris equorum (P. equorum). The assay was used to assess the presence of T. cati eggs in several samples, including 12 clean soil samples spiked with eggs of either T. cati or A. suum, 10 actual soil samples randomly collected from playgrounds in Brussels, and fecal samples from cats, dogs, and other animals. 2qPCR results on dogs and cats fecal samples were compared with results from microscopic examination.Results2qPCR assay allowed specific detection of T. canis and T. cati, whether adult worms, eggs spiked in soil or fecal samples. The 2qPCR limit of detection (LOD) in spiked soil samples was 2 eggs per g of soil for a turnaround time of 3 hours. A perfect concordance was observed between 2qPCR assay and microscopic examination on dogs and cats feces.ConclusionThe newly developed 2qPCR assay can be useful for high throughput prospective or retrospective detection of T.canis and/or T. cati eggs in fecal samples as well as in soil samples from playgrounds, parks and sandpits.

A Novel Procedure for Precise Quantification of Schistosoma japonicum Eggs in Bovine Feces

Schistosomiasis japonica is a zoonosis with a number of mammalian species acting as reservoir hosts, including water buffaloes which can contribute up to 75% to human transmission in the People's Republic of China. Determining prevalence and intensity of Schistosoma japonicum in mammalian hosts is important for calculating transmission rates and determining environmental contamination. A new procedure, the formalin–ethyl acetate sedimentation-digestion (FEA–SD) technique, for increased visualization of S. japonicum eggs in bovine feces, is described that is an effective technique for identifying and quantifying S. japonicum eggs in fecal samples from naturally infected Chinese water buffaloes and from carabao (water buffalo) in the Philippines. The procedure involves filtration, sedimentation, potassium hydroxide digestion and centrifugation steps prior to microscopy. Bulk debris, including the dense cellulosic material present in bovine feces, often obscures schistosome eggs with the result that prevalence and infection intensity based on direct visualization cannot be made accurately. This technique removes nearly 70% of debris from the fecal samples and renders the remaining debris translucent. It allows improved microscopic visualization of S. japonicum eggs and provides an accurate quantitative method for the estimation of infection in bovines and other ruminant reservoir hosts. We show that the FEA-SD technique could be of considerable value if applied as a surveillance tool for animal reservoirs of S. japonicum, particularly in areas with low to high infection intensity, or where, following control efforts, there is suspected elimination of schistosomiasis japonica.

Prevalence of intestinal parasites among captive Asian Elephants Elephas maximus: effect of season, host demography, and management systems in Tamil Nadu, India

Maintenance of wild animals in captivity is fraught with numerous challenges, including the control of disease. This study evaluates the effect of season, host demography (age-sex), and differing management systems on the prevalence of intestinal parasites among elephants managed in three captive systems: temple, private, and forest department, in Tamil Nadu. In addition, the study also assessed the availability of veterinary care for elephants in these systems. The parasitic prevalence was evaluated by direct microscopic identification of helminth eggs in faecal samples (n = 115) collected from different age/sex classes of elephants. Of the 115 elephants examined, 37% showed positive results, being infected only with Strongyles sp. The prevalence rate varied significantly across seasons, with the highest rate during summer (49%) followed by monsoon (41%) and the lowest rate during winter (15%). While males had a significantly lower parasite prevalence compared to females (29% vs. 40%), age classes showed no significant difference. Despite the fact that the proportion of animals receiving veterinary care was higher under the forest department system (100%) compared to the private system (26%), parasite prevalence was significantly higher under the former (48%) than the latter (31%) system. The difference in the proportion of animals with parasitic prevalence among the three systems could be due to differing management practices (i.e. in solitary versus groups) and the details are discussed.

Evaluation and application of a molecular method to assess the composition of strongylid nematode populations in sheep with naturally acquired infections

We evaluated the performance of a PCR method for the diagnosis of naturally acquired strongylid nematode infections in sheep ( n = 470; in a temperate climatic zone of south-eastern Australia), using a panel of 100 ‘negative control’ samples from sheep known not to harbour parasitic helminths. We compared the diagnostic sensitivity (98%) and specificity (100%) of this assay against a conventional faecal flotation method and also established a system to rank the contribution of particular strongylid nematodes to the faecal egg counts (FECs) from ‘mixed infections’ in individual sheep. The testing of faecal samples herein revealed that Teladorsagia circumcincta (80%) and Trichostrongylus spp. (66%) were most prevalent, followed by Chabertia ovina (33%), Oesophagostomum venulosum (28%) and Haemonchus contortus (1%). For the majority of sheep in this study, T. circumcincta and Trichostrongylus spp. represented the largest proportion of strongylid eggs in faecal samples from individual sheep. This is the first large-scale prevalence survey of gastrointestinal nematodes in live sheep using a molecular tool. The ability to rapidly rank strongylid nematodes according to their contribution to mixed infections represents a major advantage over routine coprological methods. This PCR tool has the potential to replace the conventional technique of larval culture. Future efforts will focus on enhancing and adapting this molecular method for high throughput application in routine, diagnostic settings.

Development of PCR/dot blot assay for specific detection and differentiation of taeniid cestode eggs in canids

We report the development of a colourimetric PCR/dot blot assay targeting the mitochondrial gene NADH dehydrogenase subunit 1 (nad1) for differential diagnosis of taeniid eggs. Partial sequences of the cestode nad1 gene were aligned and new primers were designed based on conserved regions. Species-specific oligonucleotide probes (S-SONP) for canine taeniid cestodes were then designed manually based on the variable region between the conserved primers. Specifically, S-SONP were designed for the Taenia crassiceps, T. hydatigena, T. multiceps, T. ovis, T. taeniaeformis, Echinococcus granulosus (genotype 1), E. multilocularis and E. vogeli. Each probe showed high specificity as no cross-hybridisation with any amplified nad1 fragment was observed. We evaluated the assay using 49 taeniid egg-positive samples collected from dogs in Zambia. DNA from 5 to 10 eggs was extracted in each sample. Using the PCR/dot blot assay, the probes successfully detected PCR products from T. hydatigena in 42 samples, T. multiceps in 3 samples, and both species (mixed infection) in the remaining 4 samples. The results indicate that the PCR/dot blot assay is a reliable alternative for differential diagnosis of taeniid eggs in faecal samples.

Copro-molecular identification of infections with hookworm eggs in rural Lao PDR

The prevalence of hookworm eggs in fecal samples, by modified cellophane thick-smear technique, was found to be 30.0% (61/203 samples) in Lahanam Village, Savannakhet Province, Lao PDR. The hookworm eggs were morphologically heterogeneous, so that identification was confirmed by copro-PCR with specific primers for hookworms and Trichostrongylus spp.; 12 samples were positive for Necator americanus, 19 for Ancylostoma spp., with one mixed infection of both. Sequencing of the Ancylostoma spp. copro-PCR products found A. duodenale, and also the animal hookworms, A. caninum and A. ceylanicum. Moreover, Trichostrongylus spp.-specific copro-PCR revealed a significant rate of infection (43/203; 21.2%). Sequencing confirmed the zoonotic species, T. colubriformis. PCR/sequencing is useful for differentiating parasite species. The positives by the Kato-Katz method, and by the combined hookworm/Trichostrongylus specific-PCR, were comparable, although the agreement between the two methodologies was only 50%.

Fasciola hepatica: Comparison of the sedimentation and FLOTAC techniques for the detection and quantification of faecal egg counts in rats

We compared the sedimentation and FLOTAC techniques for the detection and quantification of Fasciola hepatica eggs in faecal samples obtained from 120 experimentally-infected rats before intervention, and in 42 rats after drug administration. Additionally, the average time for a single test was determined. A single FLOTAC showed a higher sensitivity (92.6%) than 2, 4 and 8 sedimentation readings (63.0–85.2%) for detecting F. hepatica eggs in rat faeces post-treatment. On average, it took 21 min to prepare and examine a single FLOTAC, whereas 114 min were needed for the sedimentation method including the reading of 8 slides. In both treated and untreated rats, the sedimentation method resulted in higher mean faecal egg counts (FECs) than FLOTAC ( P < 0.05). In view of the high sensitivity and efficiency, the FLOTAC technique holds promise for experimental work in the F. hepatica-rat model. Additional research is needed to determine the reasons for the observed differences in FECs.

Congenital Asplenia and Severe Visceral Toxocariasis

To the Editors: Infection of humans with the larvae of Toxocara canis leads to toxocariasis, one of the most common ascariases. The prevalence in humans ranges between 1 and 4% of the adult population in Western Europe and 60% of children in developing countries.1 Playground sandboxes and domestic canines represent major sources of infection. Geophagia is an important risk factor in children, documented to be etiologic in 10–30% of cases. Visceral larva migrans is the clinical term for Toxocara infection associated with major organs. Generally, it is considered a self-limited disease. Previous reports have demonstrated varied presentations, including chronic hypereosinophilia, pyogenic liver abscesses, hepatic granulomas, abdominal lymph node enlargement, pulmonary involvement, myocarditis, and thrombocytosis. Central nervous system involvement in toxocariasis is extremely rare2,3 and takes several distinct forms, including encephalopathy, meningoencephalitis, meningitis, seizures, motor dysfunction, and neuropsychiatric disturbances.3–5 Magnetic resonance imaging alterations have been described in a few patients with central nervous system toxocariasis that include vasculitic areas identified by angiography, focal lesions, and nonspecific T2-weighted areas of increased signals.2,3,6,7 The case of a male child diagnosed with congenital asplenia at 5 years of age in the context of pneumococcal septic shock is presented. Relevant facts in the patient's history include exposure to various domestic canines (the patient's father was a hunter), psychomotor development impairment with onset at 1 year of age, autistic-like behavior, and ataxia. The medical evaluation has been inconclusive. At 6 years of age, the patient was admitted to this hospital with fever and an associated leukemoid reaction. Laboratory studies showed a WBC count of 65,200/μL (65% eosinophils); normal renal and hepatic studies, and a negative C-reactive protein. Bone marrow morphology was not compatible with eosinophilic leukemia. Additional studies demonstrated a marked hypergammaglobulinemia (26.4 g/L) with markedly increased IgG (2800 mg/dL), IgE (8415 U/mL), and titers of isohemagglutinins (anti-A1, 1/8192; anti-A2, 1/4096; and anti-B, 1/256), the presence of Ascaris lumbricoides eggs in fecal samples, and a positive serologic test for Toxocara canis (passive hemagglutination test: 1/160 and ELISA: 0.662), confirmed by Western blot analysis. Ophthalmologic examination, chest radiograph, an echocardiogram, and an EEG were normal. An abdominal CT scan revealed hepatomegaly with nodules dispersed throughout the liver parenchyma; a biopsy confirmed the presence of a granulomatous hepatitis with intense eosinophilia and fibrosis consistent with parasitic infestation. Cerebral magnetic resonance imaging revealed a moderate bilateral peritrigonal hypersignal. Treatment began with mebendazole, but because of persistent eosinophilia it was changed to albendazole and prednisolone, that resulted in hematologic, radiographic and behavior/neurologic improvement. Serum values of eosinophils, immunoglobulins, and isohemagglutinins returned to normal, hepatic nodules disappeared and Toxocara antibody titers were reduced. Despite implementation of measures aimed at preventing reinfection, the patient died at 9 years of age from pneumococcal meningitis. No association has been reported between toxocariasis and asplenia. It has been suggested that bacterial or viral meningitis may be enhanced by helminthic larvae that migrate to the central nervous system.8 Additionally, it has been speculated that splenectomizated patients may be predisposed to a more rapid or severe infection by free-living parasites, as noted for Trypanosoma brucei rhodesiense.9 The diagnosis of toxocariasis requires a high level of suspicion and delayed treatment may result in pulmonary, hepatic, and neurologic lesions and sequelae. Ana Rita Araújo, JD Idalina Maciel, MD Department of Pediatrics Centro Hospitalar do Alto Minho Viana do Castelo, Portugal Licínia Lima, MD Isabel Chacim, MD Department of Pediatrics Barcelos Hospital, Portugal José Barbot, MD Department of Hematology Children's Hospital Maria Pia Porto, Portugal

Detection and semi-quantification of Strongylus vulgaris DNA in equine faeces by real-time quantitative PCR

Strongylus vulgaris is an important strongyle nematode with high pathogenic potential infecting horses world-wide. Several decades of intensive anthelmintic use has virtually eliminated clinical disease caused by S. vulgaris, but has also caused high levels of anthelmintic resistance in equine small strongyle (cyathostomin) nematodes. Recommendations aimed at limiting the development of anthelmintic resistance by reducing treatment intensity raises a simultaneous demand for reliable and accurate diagnostic tools for detecting important parasitic pathogens. Presently, the only means available to differentiate among strongyle species in a faecal sample is by identifying individual L3 larvae following a two week coproculture procedure. The aim of the present study is to overcome this diagnostic obstacle by developing a fluorescence-based quantitative PCR assay capable of identifying S. vulgaris eggs in faecal samples from horses. Species-specific primers and a TaqMan® probe were designed by alignment of published ribosomal DNA sequences of the second internal transcribed spacer of cyathostomin and Strongylus spp. nematodes. The assay was tested for specificity and optimized using genomic DNA extracted from identified male worms of Strongylus and cyathostomin species. In addition, eggs were collected from adult female worms and used to evaluate the quantitative potential of the assay. Statistically significant linear relationships were found between egg numbers and cycle of threshold (Ct) values. PCR results were unaffected by the presence of cyathostomin DNA in the sample and there was no indication of PCR inhibition by faecal sources. A field evaluation on faecal samples obtained from four Danish horse farms revealed a good agreement with the traditional larval culture (κ-value=0.78), but with a significantly higher performance of the PCR assay. An association between Ct values and S. vulgaris larval counts was statistically significant. The present assay can reliably and semi-quantitatively detect minute quantities of S. vulgaris eggs in faecal samples.

PCR-based Species-Specific Amplification of ITS of Mecistocirrus digitatus and Its Application in Identification of GI Nematode Eggs in Bovine Faeces

Differential diagnosis of Mecistocirrus digitatus infection relies on morphological examination of either eggs in faecal samples or L3 larvae developed in vitro. Technical limitations hinder the practicability of these approaches. Hence, in order to develop a specific diagnostic measure for M. digitatus infection, we determined the sequence of the internal transcribed spacer (ITS) of its ribosomal DNA (rDNA) and designed primers for PCR-based species-specific amplification of the ITS to differentiate between M. digitatus and other common gastrointestinal (GI) nematode species. The newly designed primers amplified a single specific 520 base pair (bp) fragment from the M. digitatus ITS, and its detection limit was as low as 0.001 ng. Further, this sensitivity suggested that the specific fragment could be amplified even from a unicellular egg that collected directly from uteri of an adult M. digitatus female. In fact, we designed a method that employs a small piece of a cover slip and a filter paper by which we could differentially amplify a PCR fragment from a unicellular egg. The reliability of the specific PCR assay was also demonstrated with 10 oval samples that collected from bovine faeces by using sugar flotation method. These data suggested that the specific PCR assay of the ITS region of M. digitatus rDNA could be useful for the identification of GI nematodes.

Surveillance and control of post-transmission schistosomiasis in Jiaxing prefecture, Zhejiang province, China

A surveillance system has been put in place in the Zhejiang province since achieving there the criteria for transmission interruption of schistosomiasis japonica. Suspected patients and special high-risk groups (e.g. the so called ‘floating population’ and children under 14 years of age) are screened for Schistosoma japonicum using serological tests. Those with positive serological result are subjected to faecal examination and if S. japonicum eggs are found they are treated with praziquantel and followed by regular re-examination until complete cure, i.e. absence of S. japonicum eggs in faecal samples. Patients with advanced schistosomiasis japonica are continuously followed-up. Implementation of the surveillance system from 1995 to 2002 detected two S. japonicum-infected persons; one came from Anhui province and the other from Jiangsu province, but no new infection occurred among local residents. The number of patients with advanced schistosomiasis japonica decreased from 1524 in 1995 to 906 by the end of 2002; a reduction of 40.6%. However, post-transmission schistosomiasis still continues to weigh on the medial resources. We conclude that the surveillance system in Zhejiang province is effective and a useful means for monitoring the endemic situation of schistosomiasis. Hence, it is recommended to be pursued in the years to come.

Copro-PCR based detection of Schistosoma eggs using mitochondrial DNA markers

We report on a sensitive, specific and easy to interpret PCR based diagnostic tool for the detection of Schistosoma japonicum eggs in the faeces of infected mammalian hosts. Primer pairs were designed to amplify regions of the mitochondrial DNA of the parasite. The specificity of the PCR primers was tested using either faecal samples from non-infected hosts or hosts infected with the related schistosome species S. mansoni. Sensitivity was investigated in a study, which differentiated the presence or absence of eggs in faecal samples. PCR results were correlated with analysis of the samples by microscopy. PCR analysis provided a level of sensitivity of 87.7%, while specificity was 100%. The PCR-based assay could detect mitochondrial DNA from as little as 0.3 of a single egg. The overall detection threshold of the PCR test was >or=60 eggs per gram of faeces. Advantages of this technique include the ability to scale-up screening and the reproducibility and simplicity of interpretation of results compared with standard microscopic methods.

A note on endoparasites of wild ostriches (Struthio camelus) in the Mokolodi Nature Reserve, Gaborone, Botswana.

A study was undertaken to investigate the prevalence of endoparasites of wild ostriches at Mokolodi Nature Reserve, Gaborone, over a 7-month period. Large numbers of strongyle eggs were recovered from faecal material in April and September and a decline in the strongyle egg counts was evident during June and July. Noteworthy was the absence of helminth eggs in faecal samples collected from chicks and coccidia oocysts from any of the ostriches.

Coprotest® quantitativo: quantificação de ovos de helmintos em amostras fecais utilizando-se sistema de diagnóstico comercial

A técnica coproparasitológica de concentração em formol acetato de etila foi empregada para a quantificação de ovos de helmintos. O método quantitativo proposto foi padronizado utilizando-se o sistema comercial Coprotest® e amostras fecais contendo diferentes cargas de ovos de Ascaris lumbricoides. Para a comparação do Coprotest® quantitativo com outros métodos de quantificação de ovos, foi preparada em laboratório uma série de amostras fecais, com carga decrescente de ovos de A. lumbricoides, Trichuris trichiura e Schistosoma mansoni. Discutem-se as vantagens de se empregar um método capaz de detectar maior número de espécies de helmintos, além de protozoários, e que permita, concomitantemente, estimar a intensidade das infecções por geo-helmintos e S. mansoni nas populações. O Coprotest® quantitativo mostrou ser de aplicação viável, fornecendo resultados comparáveis a outros métodos quantitativos já descritos na literatura.

Gambaran Nilai Darah Pada Sapi Yang Terinfeksi Fascioliasis Yang Dipotong di Rumah Potong Hewan Kota Banda Aceh

ABSTRACT.The main purpose of the research was to determain the blood value of fascioliasis on blood of the cattle slaughtered in abattoir. It has been examined fifty samples of fecal, bile fluids and blood of the cattle slaughtered at the Banda Aceh abattoir. The samples were examined for the values of hematocrit, erythrocyte and leucocyte differentiation and the presence of helminth eggs respectively. It was found that the egg count variet from 7.168 ± 0.225 trematode eggs in fecal samples and 14.554 ± 2.154 trematode eggs in bile duct repectively. The result of this study showed that, the prevalence rate of fascioliasis in cattle categorical a mild infestation was 44 %. Both in the length and width of body size of the flukes are affected by the life stage. The size of adult fluke was about 34.649 ± 8.992 mm x 12.030 ± 3.494 mm, while that of young fluke was 1.650 ± 0.240 mm x 1.487 ± 0.227 mm. the blood indices of affected cattle indicated significant (P 0.05) decrease in hematocrit and erythrocyte count compared with those not affected by the disease. The mean count of hematocrit and erythrocyte 29.773% ± 3.366% and 547.337 x 104 ± 13.599 in cattle infected and in cattle non infected was 32.357 ± 2.818 and 566.457 x 104 ± 12.886 respectively. The result of this study, also significant (P 0.05) in increasing of the eosinophilia 16.22% ± 4.03% compared with that non-affected ones (10.54 ± 4.56).

Hematological values and parasite fauna in free-rangingMacaca hecki and theM. hecki/M. tonkeana hybrid group of Sulawesi Island, Indonesia

Hematological values and parasitological fauna of free-rangingMacaca hecki and the hybrid group betweenM. hecki/M. tonkeana of Sulawesi Island, Indonesia, were investigated. The hematological values, especially the red cell number (RBC), were lower than those of other macaque species, indicating that Sulawesi macaques are slightly anemic. Several parasites including Plasmodium sp., trombiculid mites, andTrichuris trichiura were identified. Although infection by Plasmodium was observed with considerable frequency, no clear relationship between its infection and the occurrence of anemia was found. Trombiculid mites and eggs ofAnatrichosoma sp. were detected in foci of the ears of most monkeys. The infection with a trombiculid mite is the first recorded occurrence in free-ranging wild Sulawesi macaques. Gastrointestinal parasites were identified from their eggs in fecal samples, where five species of nematoda and one trematoda species were found.

Screening for schistosome eggs by digital image processing

Schistosomiasis is an epidemic disease that seriously endangers the health of people in China. Therefore, it is advantageous to screen for scFwistosome eggs automatically. This paper describes a screening method implemented on the Leitz TAS+ image analysis instrument for the presence of schistosome eggs in fecal samples.

Occurrence of avian Schistosomatidae (Trematoda) in South African birds as determined by a faecal survey

The abundance, prevalence and distribution of avian Schistosomatidae in South African birds has been estimated by means of a survey for parasite eggs in faecal samples. Eight types of eggs were recovered, mostly from members of the Anatidae and Laridae and these have been assigned to the following schistosome genera: Austrobilharzia (1), Gigantobilharzia (1), Trichobilharzia (5) and Ornithobilharzia (1).