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Tropical Parasitology 2022() diagnosis is an intestinal protozoan parasite globally found in rural and urban areas and is attracting a growing interest. Its prevalence in stool varies from 0.2%...
INTRODUCTION
() diagnosis is an intestinal protozoan parasite globally found in rural and urban areas and is attracting a growing interest. Its prevalence in stool varies from 0.2% to more than 19% depending upon the population studied.
MATERIALS AND METHODS
This study was based on the examination of 100 stool samples of randomly referred cases in a rural area in Motobus district, Kafr El-Sheikh governorate, Egypt. Our aim was to investigate the presence of in stool of the examined individuals using conventional polymerase chain reaction (PCR) compared to wet mount and trichrome stain with confirmation of infection by transmission electron microscopy.
RESULTS
was detected in 13/100 of the stool samples examined using wet mount smears, while trichrome stain detected 17/100. Conventional PCR diagnosed 41 cases of in the studied group. A very good agreement was found between wet mount and trichrome stain for diagnosing , while there was fair agreement between conventional PCR and both microscopy methods. Transmission electron microscope was performed on pooled positive samples that revealed the internal structures of trophozoite with its characteristic nucleus.
CONCLUSIONS
PCR technique was superior to microscopy for the detection of . Trichrome stain remains vital for microscopic diagnosis.
PubMed: 36643979
DOI: 10.4103/tp.tp_93_21 -
Revista Do Instituto de Medicina... 2021In order to provide additional data on the prevalence and genetic diversity of Dientamoeba fragilis in human populations, we conducted a study in children from...
In order to provide additional data on the prevalence and genetic diversity of Dientamoeba fragilis in human populations, we conducted a study in children from low-income communities in Sao Paulo State, Brazil. Fecal samples from daycare center attendees up to 6 years old (n=156) and staff members (n=18) were submitted to PCR and sequencing of D. fragilis as well as to microscopic examination for the presence of other intestinal parasites. All children assessed were asymptomatic and 10.3% (16/156) were positive for D. fragilis. No worker was found to be positive. An association between Dientamoeba and coinfection with other intestinal parasites was observed. Concerning the genetic diversity, 14 and only two isolates were genotype 1 and genotype 2, respectively. Our findings outline interesting aspects: (1) asymptomatic children as carriers of Dientamoeba in communities in which environmental conditions ensure parasite transmission and, (2) association between Dientamoeba infection in young children and coinfection with other enteric parasites, reinforcing its transmission via the fecal-oral route.
Topics: Brazil; Child; Child, Preschool; Dientamoeba; Dientamoebiasis; Feces; Humans; Intestinal Diseases, Parasitic; Prevalence
PubMed: 33978095
DOI: 10.1590/S1678-9946202163039 -
Journal of Clinical Microbiology Sep 2016Dientamoeba fragilis is a single-celled protozoan, closely related to the trichomonads. Reported worldwide as causing human gastrointestinal symptoms, D. fragilis is... (Review)
Review
Dientamoeba fragilis is a single-celled protozoan, closely related to the trichomonads. Reported worldwide as causing human gastrointestinal symptoms, D. fragilis is very common and is second only to Blastocystis spp. Dientamoebiasis equals or exceeds the incidence of giardiasis. This minireview includes diagnostic options, clinical relevance, therapy, an animal model, the confirmed cyst stage, and sequencing data. The development of a rodent model, fulfilling Koch's postulates, and the confirmation of a cyst stage have clarified transmission routes, including fecal-oral transmission. The prevalence of D. fragilis varies between 0% to over 82%; results depend on the geographic location, group studied, and diagnostic methods used.
Topics: Animals; Antiprotozoal Agents; Dientamoeba; Dientamoebiasis; Disease Models, Animal; Humans; Incidence; Intestinal Diseases, Parasitic; Neglected Diseases; Prevalence
PubMed: 27053676
DOI: 10.1128/JCM.00400-16 -
Clinical Microbiology Reviews Jul 2016Dientamoeba fragilis is a protozoan parasite of the human bowel, commonly reported throughout the world in association with gastrointestinal symptoms. Despite its... (Review)
Review
Dientamoeba fragilis is a protozoan parasite of the human bowel, commonly reported throughout the world in association with gastrointestinal symptoms. Despite its initial discovery over 100 years ago, arguably, we know less about this peculiar organism than any other pathogenic or potentially pathogenic protozoan that infects humans. The details of its life cycle and mode of transmission are not completely known, and its potential as a human pathogen is debated within the scientific community. Recently, several major advances have been made with respect to this organism's life cycle and molecular biology. While many questions remain unanswered, these and other recent advances have given rise to some intriguing new leads, which will pave the way for future research. This review encompasses a large body of knowledge generated on various aspects of D. fragilis over the last century, together with an update on the most recent developments. This includes an update on the latest diagnostic techniques and treatments, the clinical aspects of dientamoebiasis, the development of an animal model, the description of a D. fragilis cyst stage, and the sequencing of the first D. fragilis transcriptome.
Topics: Animals; Dientamoeba; Dientamoebiasis; Disease Models, Animal; Humans; Intestines; Life Cycle Stages; Phylogeny
PubMed: 27170141
DOI: 10.1128/CMR.00076-15 -
Archives of Disease in Childhood Jul 2019To study the association between colonisation and faecal calprotectin to see whether the parasite is a harmless commensal or a gut pathogen.
OBJECTIVE
To study the association between colonisation and faecal calprotectin to see whether the parasite is a harmless commensal or a gut pathogen.
DESIGN
Cross-sectional study of previously collected stool samples.
SETTING AND PATIENTS
Two hundred stool samples originated from children aged 5-19 years with chronic abdominal pain and diarrhoea, who were seen in paediatric clinics in the Netherlands and Belgium and in whom somatic gastrointestinal disorders were excluded. Another 122 samples came from a healthy community-based reference population of the same age. All stool samples were analysed with real-time PCR for the detection of and with an ELISA for calprotectin-a biomarker of gastrointestinal inflammation.
MAIN OUTCOME MEASURES
Prevalence of colonisation and results of stool calprotectin testing.
RESULTS
was detected in 45% (95% CI 38% to 51%) of patients and in 71% (95% CI 63% to 79%) of healthy children. Median (IQR) concentrations of calprotectin in patients and healthy children with a positive PCR result were not different from those with a negative PCR result (40 (40-55) μg/g vs 40 (40-75) μg/g, respectively).
CONCLUSION
Since colonisation is most prevalent in healthy children and is not associated with an increase in faecal calprotectin concentration, our data do not support the inference that is a pathogenic parasite. Routinely testing for in children with chronic abdominal pain should therefore be discouraged.
Topics: Abdominal Pain; Adolescent; Belgium; Child; Child, Preschool; Cohort Studies; Cross-Sectional Studies; Dientamoeba; Dientamoebiasis; Feces; Female; Humans; Male; Netherlands; Prevalence; Prospective Studies; Real-Time Polymerase Chain Reaction; Retrospective Studies; Young Adult
PubMed: 30798256
DOI: 10.1136/archdischild-2018-316383 -
Trends in Parasitology Jul 2014Trichomonads are common parasites of many vertebrate and invertebrate species, with four species classically recognized as human parasites: Dientamoeba fragilis,... (Review)
Review
Trichomonads are common parasites of many vertebrate and invertebrate species, with four species classically recognized as human parasites: Dientamoeba fragilis, Pentatrichomonas hominis, Trichomonas vaginalis, and Trichomonas tenax. The latter two species are considered human-specific; by contrast, D. fragilis and P. hominis have been isolated from domestic and farm mammals, demonstrating a wide host range and potential zoonotic origin. Several new studies have highlighted the zoonotic dimension of trichomonads. First, species typically known to infect birds and domestic mammals have been identified in human clinical samples. Second, several phylogenetic analyses have identified animal-derived trichomonads as close sister taxa of the two human-specific species. It is our opinion, therefore, that these observations prompt further investigation into the importance of zoonotic trichomonads for human health.
Topics: Animals; Bird Diseases; Birds; Humans; Phylogeny; Trichomonas Infections; Trichomonas vaginalis; Zoonoses
PubMed: 24951156
DOI: 10.1016/j.pt.2014.05.005 -
The American Journal of Tropical... Nov 2018is an intestinal protozoan, usually considered nonpathogenic. However, in the last years, there has been an attempt to clarify its possible pathogenic role. We aim to... (Observational Study)
Observational Study
is an intestinal protozoan, usually considered nonpathogenic. However, in the last years, there has been an attempt to clarify its possible pathogenic role. We aim to evaluate the clinical and epidemiological characteristics of -infected patients. Adults with detection in feces who attended the Vall d'Hebron University Hospital (Barcelona, Spain) were evaluated retrospectively from April 2009 to March 2014. We classified the patients in asymptomatic, symptomatic without other causes except infection of , and symptomatic with another cause. Among symptomatic patients, treatment response was evaluated. One hundred eight patients were included. Sixty-three percent of the patients were immigrants, 29.6% were autochthonous, and 7.4% were travelers. Forty-nine (45.3%) patients presented symptoms, and eosinophilia was observed in 26 (24.1%) patients. Overall, 59 (54.7%) patients were asymptomatic, 15 (13.8%) presented symptoms which were attributable to other causes, and 34 (31.5%) patients presented symptoms with no other causes. In this last group, 29 patients received specific treatment and 65.5% of them presented a complete resolution of the symptoms. The group of symptomatic patients with no other cause had more proportion of women, more proportion of autochthonous people, and were older compared with the group of asymptomatic patients. infection should be considered as pathogenic when other causes are ruled out.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Asymptomatic Infections; Dientamoeba; Dientamoebiasis; Eosinophilia; Feces; Female; Humans; Male; Middle Aged; Retrospective Studies; Risk Factors; Spain; Tertiary Care Centers; Young Adult
PubMed: 30328410
DOI: 10.4269/ajtmh.18-0433 -
Journal of Clinical Microbiology May 2019is a gastrointestinal trichomonad parasite whose pathogenicity is yet to be determined. The difficulty involved in microscopically diagnosing in feces led to the... (Comparative Study)
Comparative Study
is a gastrointestinal trichomonad parasite whose pathogenicity is yet to be determined. The difficulty involved in microscopically diagnosing in feces led to the development of real-time PCR methodologies for the detection of in stool samples. Prevalence studies in Europe show much higher levels of infection where a laboratory-developed real-time assay is the predominant assay for the detection of than in regions that use the EasyScreen assay for detection of gastrointestinal pathogens. The aim of this study was to compare a commercially available assay (Genetic Signatures EasyScreen assay) to a widely used laboratory-developed real-time PCR method. Two hundred fifty fecal samples were screened using the laboratory-developed real-time assay on four real-time PCR platforms producing a number of discrepant results. Limit-of-detection studies were undertaken to attempt to resolve sensitivity for each platform tested. The presence or absence of DNA in discrepant samples was shown using PCR amplicon next-generation sequencing. Eukaryotic 18S diversity profiling was conducted on discrepant samples to identify the presence or absence of additional protozoan species in samples that may be responsible for cross-reactivity seen in these samples. The results revealed the potential for multiple false-positive results when using the laboratory-developed real-time assay across multiple real-time platforms using manufacturer default settings. This report provides recommendations to resolve these issues where possible and suggestions for future prevalence studies, and it emphasizes the EasyScreen assay as the molecular method of choice as well as the need for standardization of detection assays across all nations screening for .
Topics: Cross-Sectional Studies; DNA, Protozoan; Dientamoeba; Dientamoebiasis; Europe; False Positive Reactions; Feces; High-Throughput Nucleotide Sequencing; Humans; Reagent Kits, Diagnostic; Real-Time Polymerase Chain Reaction; Sensitivity and Specificity
PubMed: 30814263
DOI: 10.1128/JCM.01466-18 -
The Korean Journal of Parasitology Apr 2020In most developing countries, Dientamoeba fragilis infection is an obscure protozoan infection. We aimed to determine a frequency and clinical importance of D. fragilis...
In most developing countries, Dientamoeba fragilis infection is an obscure protozoan infection. We aimed to determine a frequency and clinical importance of D. fragilis infection in Taif, Saudi Arabia. A 1-year case control study included patients with gastrointestinal (cases, n=114) or non-gastrointestinal symptoms (controls, n=90). The fecal samples were examined with the classical parasitological methods for intestinal protozoa, and by real time PCR for D. fragilis. The infection by D. fragilis was detected in 5.8% by PCR and in 4.4% patients by microscopy. The infection was identified more in control group (n=9) than in cases (n=3); a sole infection in 11 patients and mixed with Giardia in 1 patient. The other enteric parasites detected were Blastocystis sp. (8.3%), Giardia sp. (5.3%), Cryptosporidium sp. (2.9%), Entamoeba histolytica (1.4%), Entamoeba coli (0.9%) and Hymenolepis nana (0.4%). Our results tend to reinforce the need to increase awareness of D. fragilis infection in Saudi Arabia.
Topics: Asymptomatic Diseases; Case-Control Studies; Dientamoeba; Dientamoebiasis; Digestive System Diseases; Humans; Polymerase Chain Reaction; Saudi Arabia
PubMed: 32418381
DOI: 10.3347/kjp.2020.58.2.129 -
Journal of Infection in Developing... Jan 2018Dientamoeba fragilis, an intestinal trichomonad, occurs in humans with and without gastrointestinal symptoms. Its presence was investigated in individuals referred to...
INTRODUCTION
Dientamoeba fragilis, an intestinal trichomonad, occurs in humans with and without gastrointestinal symptoms. Its presence was investigated in individuals referred to Milad Hospital, Tehran.
METHODOLOGY
In a cross-sectional study, three time-separated fecal samples were collected from 200 participants from March through June 2011. Specimens were examined using traditional techniques for detecting D. fragilis and other gastrointestinal parasites: direct smear, culture, formalin-ether concentration, and iron-hematoxylin staining. The presence of D. fragilis was determined using PCR assays targeting 5.8S rRNA or small subunit ribosomal RNA.
RESULTS
Dientamoeba fragilis, Blastocystis sp., Giardia lamblia, Entamoeba coli, and Iodamoeba butschlii were detected by one or more traditional and molecular methods, with an overall prevalence of 56.5%. Dientamoeba was not detected by direct smear or formalin-ether concentration but was identified in 1% and 5% of cases by culture and iron-hematoxylin staining, respectively. PCR amplification of SSU rRNA and 5.8S rRNA genes diagnosed D. fragilis in 6% and 13.5%, respectively. Prevalence of D. fragilis was unrelated to participant gender, age, or gastrointestinal symptoms.
CONCLUSIONS
This is the first report of molecular assays to screen for D. fragilis in Iran. The frequent finding of D. fragilis via fecal analysis indicated the need to include this parasite in routine stool examination in diagnostic laboratories. As the length of amplification target correlates to the sensitivity of PCR, this assay targeting the D. fragilis 5.8S rRNA gene seems optimal for parasite detection and is recommended in combination with conventional microscopy for diagnosing intestinal parasites.
PubMed: 31628834
DOI: 10.3855/jidc.9643