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Parasitology Research Dec 2023To investigate the prevalence of Blastocystis and Dientamoeba fragilis in diarrhea patients and healthy individuals in Corum, Türkiye, fecal samples from 92 diarrhea...
To investigate the prevalence of Blastocystis and Dientamoeba fragilis in diarrhea patients and healthy individuals in Corum, Türkiye, fecal samples from 92 diarrhea patients and 50 healthy individuals were collected and evaluated using direct microscopy and molecular methods to screen for bacteria, protozoa, and viruses. The prevalence of Blastocystis was 24.6% in total and more frequent in the healthy group (30.0%). The commonly detected STs (subtypes) were ST3 (40.0%) and ST2 (34.2%). The distribution of Blastocystis STs in the healthy and diarrheal groups did not show any difference in sex and age, but ST3 was detected more frequently in patients aged from 40 to 59 years (p < 0.05). Alleles 4 (8/12) and 2 (4/12) were present in ST1; 9 (3/5) and 12 (2/5) in ST2; 34 (9/14), 36 (3/14), and 38 (2/14) in ST3; and only allele 42 (2/2) in ST4. D. fragilis was present in 8.4% of the population. However, there was no statistically significant difference between the healthy and diarrheic groups (12.0% and 6.5%, respectively), neither with respect to age nor sex. Co-infection was 58.3% and was more frequent in healthy individuals (33.3%) than in diarrhea patients (25.0%). Blastocystis ST3 was the most common subtype detected, with D. fragilis at 33.3%. Salmonella, Shigella, or helminth eggs were not observed in all groups, but Entamoeba histolytica, Giardia intestinalis, Cryptosporidium, Rotavirus, Adenovirus, and Clostridium difficile toxin were found only in diarrhea patients. These findings support the hypothesis that Blastocystis and D. fragilis may be part of the healthy human gut microbiome.
Topics: Humans; Adult; Middle Aged; Blastocystis; Dientamoeba; Blastocystis Infections; Cryptosporidiosis; Prevalence; Interleukin-1 Receptor-Like 1 Protein; Cryptosporidium; Diarrhea; Feces
PubMed: 37779160
DOI: 10.1007/s00436-023-07987-0 -
Clinical Microbiology and Infection :... Jan 2024The aim of this study was to assess the clinical significance of Dientamoeba fragilis (DF) and Blastocystis species (Bs) in human stool. (Observational Study)
Observational Study
OBJECTIVES
The aim of this study was to assess the clinical significance of Dientamoeba fragilis (DF) and Blastocystis species (Bs) in human stool.
METHODS
Observational study of patients ≥18 years, who were tested by stool multiplex PCR for bacteria and parasites between April 2019 and March 2022. Although DF and Bs are part of the PCR kit, these results are not routinely reported to the patient or the ordering physician. The main outcomes were the incidence of symptoms during 14 days before the referral to stool PCR test, and the incidence of several clinical outcomes during 60 days after the PCR test (symptoms, referrals to further evaluation, prescription of symptomatic, or antibiotic treatment).
RESULTS
A total of 27 918 patients were tested by stool PCR during the 3 study years. A total of 6215 (22.3%) and 5337 (19.2%) were positive for DF and Bs, respectively. The incidence of symptoms before the test was similar in those positive for Bs or DF and those with all-negative PCR (adjusted OR and 95% CI of 0.87 [0.80-0.95] and 0.82 [0.76-0.88] for Bs and DF, respectively), whereas significantly higher (2.47 [2.23-2.73]) in those positive for the other multiplex PCR assay components. During the 60 days after the test, the prevalence of any of the outcomes was similar in those positive for Bs or DF and those with negative PCR (adjusted OR and 95% CI of 0.92 [0.83-1.02] and 0.89 [0.81-0.97] for symptoms, 0.84 [0.75-0.94] and 0.93 [0.85-1.01] for referrals, 0.88 [0.75-1.03] and 0.82 [0.71-0.94] for symptomatic treatment, and 0.88 [0.75-1.02] and 0.86 [0.75-0.98] for antibiotic treatment in the Bs and DF positive individuals, respectively). The PCR cycle threshold was not associated with any of the outcomes.
DISCUSSION
Positive stool PCR for DF or Bs was not associated with any of the measured clinical outcomes.
Topics: Humans; Blastocystis; Dientamoeba; Clinical Relevance; Retrospective Studies; Multiplex Polymerase Chain Reaction; Feces; Anti-Bacterial Agents
PubMed: 37689266
DOI: 10.1016/j.cmi.2023.09.003 -
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 -
Zoonoses and Public Health Dec 2022Dientamoeba fragilis is a flagellated protozoan with amoeba-like morphology that inhabits the human gastrointestinal tract. It is endemic in a vast geography around the...
Dientamoeba fragilis is a flagellated protozoan with amoeba-like morphology that inhabits the human gastrointestinal tract. It is endemic in a vast geography around the world, including developed countries. There are limited studies on non-human hosts of the parasite, and suitable hosts have not been clarified. The parasite has been detected in non-human primates, pigs, cats, dogs and rats. There is no study in the literature investigating and detecting the presence of this parasite in cattle. In this study, stool samples taken from 163 different cattle and calves from 11 different farms between March 2017 and May 2022 were examined for the detection of D. fragilis via PCR. Trichrome staining was performed on all PCR-positive samples. The isolates with the expected amplicon size were sequenced using the 18S ribosomal RNA region, and their genotypes were determined by BLAST analysis. Sequences were analysed with the most similar and reference sequences in the literature, forming a phylogenetic tree. We detected D. fragilis in 31 (19.01%) of the 163 stool samples. D. fragilis cysts/trophozoites were detected by trichrome staining method in six of 31 samples. All PCR products selected for molecular analysis from positive samples had the same nucleotide sequence. As a result of BLAST analysis, all sequences were determined to belong to D. fragilis genotype 1. This study determined for the first time that cattle are suitable hosts for D. fragilis. Furthermore, the parasite subtype we detected belongs to genotype 1, which is the most common type in humans, suggesting that the parasite may have a zoonotic character. Our result is important in terms of the epidemiology of the parasite, as the mode of transmission is controversial, and available data on its suitable hosts are limited.
Topics: Cattle; Animals; Dogs; Rats; Swine; Dientamoeba; Dientamoebiasis; Phylogeny; Feces; Polymerase Chain Reaction; Cattle Diseases; Dog Diseases; Swine Diseases
PubMed: 35796090
DOI: 10.1111/zph.12986 -
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 -
New Microbes and New Infections Sep 2023(), the most common intestinal protozoal pathogen in affluent countries, causes asymptomatic or symptomatic infections with severity ranging from mild to disabling....
BACKGROUND
(), the most common intestinal protozoal pathogen in affluent countries, causes asymptomatic or symptomatic infections with severity ranging from mild to disabling. Currently, many studies of treatment options only have small sample sizes and report results that are partly contradictory.
METHODS
Investigating data retrieved from Helsinki University Hospital and Helsinki City patient records, we searched for the most effective antiprotozoal in treating infections. To study microbiological clearance of , we collected laboratory results of control samples from patients given one of four commonly used antiprotozoals: doxycycline, metronidazole, paromomycin, or secnidazole. For patients symptomatic prior to antiprotozoal treatment, we also retrieved data on clinical outcomes. Furthermore, we explored factors associated with faecal clearance and clinical cure.
RESULTS
A total of 369 patients (median age 38) and 492 treatment episodes were included. Paromomycin (n = 297) proved effective (clearance rate 83%), showing strong association with faecal clearance (aOR 18.08 [7.24-45.16], p < 0.001). For metronidazole the rate was 42% (n = 84), for secnidazole 37% (n = 79), and doxycycline 22% (n = 32). In pairwise comparisons, paromomycin outdid the three other regimens (p < 0.001, test). Faecal clearance was associated with clinical cure (aOR 5.85 [3.02-11.32], p < 0.001).
CONCLUSIONS
Faecal clearance, strongly associated with clinical cure, is most effectively achieved with a course of paromomycin, followed by metronidazole, secnidazole and doxycycline. Our findings will be useful in devising treatment guidelines for adults with symptomatic infection.
PubMed: 37786407
DOI: 10.1016/j.nmni.2023.101179 -
European Journal of Clinical... Jan 2020The actual role of Dientamoeba fragilis and Blastocystis in patients with gastrointestinal symptoms is still under debate. A multicenter case-control study was performed...
The actual role of Dientamoeba fragilis and Blastocystis in patients with gastrointestinal symptoms is still under debate. A multicenter case-control study was performed in The Netherlands to elucidate the clinical relevance of molecular diagnostics results in gastroenteritis (GE). Samples from this case-control study were used to perform a detailed analysis on the presence of D. fragilis and Blastocystis in relation to gastrointestinal symptoms. In the present study, a real-time PCR for Blastocystis was performed on 1374 case samples and 1026 control samples from the multicenter gastroenteritis case-control study previously tested for D. fragilis. Prevalence of both micro-organisms was highest in children under 20 years of age and lowest in the oldest age group. A significantly lower overall detection of D. fragilis and Blastocystis was found in cases (both 25.8%) as compared to controls (37.6% and 40.0%, respectively). The difference for D. fragilis was statistically significant for subjects above 20 years of age. For Blastocystis, the difference was statistically significant in all age groups, except in children less than 5 years of age. A negative relation between D. fragilis-positive cases and diarrhea was found in this study population. More GE symptoms were reported in cases without D. fragilis or Blastocystis. In the present study, prevalence of both D. fragilis and Blastocystis is lower in cases with gastroenteritic symptoms than in controls. Besides, in cases with D. fragilis or Blastocystis, no association is shown between any of the GE symptoms. Interestingly, this suggests that the presence of these protozoans may be considered characteristic of a healthy intestinal microbiome.
Topics: Adolescent; Adult; Blastocystis; Blastocystis Infections; Case-Control Studies; Child; Child, Preschool; Diarrhea; Dientamoeba; Dientamoebiasis; Feces; Female; Gastroenteritis; Humans; Male; Middle Aged; Netherlands; Prevalence; Young Adult
PubMed: 31659566
DOI: 10.1007/s10096-019-03710-z -
Parasitology International Feb 2021Dientamoeba fragilis is an intestinal protozoan, an inhabitant of the human gastrointestinal tract, with a worldwide distribution. The reported prevalence of D. fragilis...
Dientamoeba fragilis is an intestinal protozoan, an inhabitant of the human gastrointestinal tract, with a worldwide distribution. The reported prevalence of D. fragilis varies worldwide in different populations between 0.3% and 82.9%, and its role as a pathogen is still unclear. The parasite has been identified in the faeces of asymptomatic patients and with different acute and chronic symptoms, like abdominal pain, diarrhoea, flatulence, nausea and vomiting. The aims of this study were to evaluate the prevalence of D. fragilis in the North-East of Italy, and the clinical improvement of symptoms after recommended treatment with paromomycin or metronidazole. Furthermore, a literature review of D. fragilis prevalence studies in Italy was carried out to show the Italian situation. Of 575 enrolled people, 85 (14.8%) were positive for D. fragilis. The most prevalent symptoms were abdominal pain 28.2%, anal itching 27.1%, watery diarrhoea 18.8%, meteorism 16.5% and nausea/lack of appetite 14.1%. The high rate of anal itching was unexpected, because it wasn't a common symptom. 32 patients were co-infected with B. hominis (37.7%) and three with G. lamblia (3.5%). Our study showed paromomycin had a high efficacy for treatment of D. fragilis infections 100.0% (45/45), while caution must be used when using metronidazole 53.3% (24/40). We recommend paromomycin for empirical treatment, given its great effectiveness in our population.
Topics: Adolescent; Adult; Aged; Antiprotozoal Agents; Child; Child, Preschool; Cross-Sectional Studies; Dientamoeba; Dientamoebiasis; Female; Humans; Infant; Italy; Male; Metronidazole; Middle Aged; Paromomycin; Prevalence; Young Adult
PubMed: 33137500
DOI: 10.1016/j.parint.2020.102227 -
Parasitology Aug 2019Dientamoeba fragilis (D. fragilis) is an intestinal parasite frequently detected in humans with abdominal pain and diarrhoea, but it is also commonly found in... (Review)
Review
Dientamoeba fragilis (D. fragilis) is an intestinal parasite frequently detected in humans with abdominal pain and diarrhoea, but it is also commonly found in asymptomatic subjects. Hence its clinical relevance is often disputed. The introduction of polymerase chain reaction (PCR) is a versatile and sensitive diagnostic technique for the detection of intestinal parasites, and in some Western world countries PCR has almost completely replaced microscopic diagnostics. PCR has however resulted in an increase in the number of D. fragilis-positive patients. The disputed pathogenic nature of this intestinal parasite and an apparent increase in the incidence of patients with positive PCR results have renewed the discussions between clinicians and microbiologists on how to deal with an infected patient. Moreover, treatment guidelines differ throughout the world which makes it difficult for clinicians to choose an optimal therapeutic regimen.AimTo summarize and discuss the current knowledge on the pathogenicity, best diagnostic approach, treatment and follow-up of children and adults infected with D. fragilis.
Topics: Adult; Animals; Antiprotozoal Agents; Child; Diarrhea; Dientamoeba; Dientamoebiasis; Feces; Humans; Practice Guidelines as Topic
PubMed: 30165915
DOI: 10.1017/S0031182018001385 -
Journal of Water and Health Oct 2023The current study presents a comprehensive review of worldwide waterborne parasitic protozoan outbreaks reported between 2017 and 2022. In total, 416 outbreaks were... (Review)
Review
The current study presents a comprehensive review of worldwide waterborne parasitic protozoan outbreaks reported between 2017 and 2022. In total, 416 outbreaks were attributed to the waterborne transmission of parasitic protozoa. Cryptosporidium accounted for 77.4% (322) of outbreaks, while Giardia was identified as the etiological agent in 17.1% (71). Toxoplasma gondii and Naegleria fowleri were the primary causes in 1.4% (6) and 1% (4) of outbreaks, respectively. Blastocystis hominis, Cyclospora cayetanensis, and Dientamoeba fragilis were independently identified in 0.72% (3) of outbreaks. Moreover, Acanthamoeba spp., Entamoeba histolytica, Vittaforma corneae, and Enterocytozoon bieneusi were independently the causal agents in 0.24% (1) of the total outbreaks. The majority of the outbreaks (195, 47%) were reported in North America. The suspected sources for 313 (75.2%) waterborne parasitic outbreaks were recreational water and/or swimming pools, accounting for 92% of the total Cryptosporidium outbreaks. Furthermore, 25.3% of the outbreaks caused by Giardia were associated with recreational water and/or swimming pools. Developing countries are most likely to be impacted by such outbreaks due to the lack of reliable monitoring strategies and water treatment processes. There is still a need for international surveillance and reporting systems concerning both waterborne diseases and water contamination with parasitic protozoa.
Topics: Animals; Humans; Parasites; Cryptosporidiosis; Cryptosporidium; Disease Outbreaks; Giardiasis; Giardia
PubMed: 37902200
DOI: 10.2166/wh.2023.094