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Acta Parasitologica Sep 2021The present systematic review and meta-analysis was aimed to assess the weighted molecular prevalence of Blastocystis sp. in humans along with the comparative molecular... (Meta-Analysis)
Meta-Analysis Review
Comparative molecular prevalence and subtypes distribution of Blastocystis sp. a potentially zoonotic infection isolated from symptomatic and asymptomatic patients in Iran: A systematic review and meta-analysis.
PURPOSE
The present systematic review and meta-analysis was aimed to assess the weighted molecular prevalence of Blastocystis sp. in humans along with the comparative molecular prevalence and subtypes distribution of Blastocystis isolated from symptomatic and asymptomatic patients in Iran.
METHODS
International electronic databases including Medline/PubMed, ProQuest, Scopus, Embase, and Google Scholar were explored until 4th October 2020. Heterogeneity index was evaluated among studies using Cochran's Q test and I index. Finally, 23 eligible studies were qualified to be included in this review.
RESULTS
The pooled molecular prevalence of Blastocystis sp. in Iran was reported 15.2% (95% CI 11.5-19.7). In addition, the molecular prevalence based on PCR-sequencing and STS primers was reported 12.5% (95% CI 8.6-17.7) and 19.8% (95% CI 13.1-28.8), respectively. Interestingly, there was a considerably higher prevalence among asymptomatic patients [25.1% (95% CI 20.8-30.0)] in comparison to symptomatic ones [21.0% (95% CI 15.9-27.2)]. In addition, the frequency of Blastocystis ST1, ST2, and ST3 from positive samples in symptomatic patients was 19.7%, 35.1%, and 47.4%, respectively. In addition, the prevalence of Blastocystis ST1, ST2, and ST3 from positive samples in asymptomatic patients was 27.1%, 26.8%, and 37.8%, respectively. The results obtained in Iran showed that Blastocystis is more common in asymptomatic patients compared to patients having clinical symptoms. Of note, ST3, as the most common subtype causing clinical symptoms, was the most prevalent reported subtype among both symptomatic and asymptomatic patients in the country.
CONCLUSIONS
Hence, the pathogenicity of the Blastocystis parasite is not subtype-specific and appears to be related to a variety of risk factors. Still the Blastocystis epidemiology is open to question and more large-scale studies should be performed on this aspect.
Topics: Animals; Blastocystis; Blastocystis Infections; DNA, Protozoan; Feces; Genetic Variation; Humans; Iran; Phylogeny; Prevalence; Zoonoses
PubMed: 33686524
DOI: 10.1007/s11686-021-00360-0 -
Acta Parasitologica Dec 2021Entamoeba gingivalis (E. gingivalis) is one of the members of the wide range of oral resident pathogens in humans, particularly found in dental plaques, surfaces of... (Meta-Analysis)
Meta-Analysis Review
PURPOSE
Entamoeba gingivalis (E. gingivalis) is one of the members of the wide range of oral resident pathogens in humans, particularly found in dental plaques, surfaces of gingiva or teeth, interdental spaces and carious lesions. The purpose of the current review and meta-analysis was to determine the global prevalence of E. gingivalis infection and its association with oral diseases based on published literatures.
MATERIALS AND METHODS
Multiple English databases (PubMed, Scopus, Science Direct, Web of Science and Google Scholar) were explored for papers published until August 2020. A total of 52 studies (including 7596 participants) met the inclusion criteria.
RESULTS
The overall prevalence of E. gingivalis was estimated to be 37% (95% CI 29-46%). With regard to different countries, the highest and lowest pooled prevalence of E. gingivalis infection were related to Jordan with 87% (95% CI 81-92%) and Portugal with 3% (95% CI 0-10%), respectively. Based on WHO regions, the highest prevalence was related to the region of the Americas with 56% (95% CI 31-79%). The infection was most prevalent in 46-55 mean age groups [61% (95% CI 21-94%)]. Among different diagnostic methods, the highest rate of the pooled prevalence was related to the molecular [53% (95% CI 24-81%)] and the direct methods [36% (95% CI 25-47%)], respectively. Our analyses revealed that E. gingivalis infection was associated with 4.34-fold increased risk of oral diseases (P < 0.05).
CONCLUSION
Our findings revealed a high prevalence rate of the infection among periodontal disease patients with 37% (95% CI 20-57%). To conclude, it must be considered that E. gingivalis can be a risk factor associated with oral diseases and a wide range of research is needed to specify its role in the pathogenesis of these disorders.
Topics: Entamoeba; Humans; Portugal; Prevalence; Risk Factors
PubMed: 34050504
DOI: 10.1007/s11686-021-00423-2 -
Microbial Pathogenesis Nov 2021The intestinal parasite Blastocystis sp. is a widely distributed protist among humans and various animal hosts, with significant prevalence in developing countries. Due... (Meta-Analysis)
Meta-Analysis Review
Global prevalence, subtypes distribution, zoonotic potential, and associated risk factors of Blastocystis sp. in domestic pigs (Sus domesticus) and wild boars (Sus scrofa): A systematic review and meta-analysis.
The intestinal parasite Blastocystis sp. is a widely distributed protist among humans and various animal hosts, with significant prevalence in developing countries. Due to the zoonotic nature of its subtypes (STs), we aimed at global estimation of the prevalence, STs distribution, zoonotic potential, and associated risk factors of Blastocystis sp. infection in domestic pigs (Sus domesticus) and wild pigs/wild boars (Sus scrofa). The study was designed and conducted in 2021 via searching articles in PubMed, Scopus, Google Scholar, and Web of Science databases, based on the PRISMA checklist, and meta-analysis was done using a random-effects model to calculate the weighted estimates and 95% confidence intervals (95% CIs). Totally, 43 papers (47 datasets) reported data on 7977 examined pigs in 24 countries with a total prevalence of 50.9% (95% CI: 42.8-59%). In details, prevalence was higher among domestic pigs [52.4% (95% CI: 43.9-60.7%)] than wild boars [31.2% (95% CI: 11.2-62%)], but is poorly statistically supported as far as the CIs largely overlap. Out of 28 reported STs, nine (ST1-ST7, ST10, and ST15) were reported from domestic pigs, while six (ST1, ST3-ST5, ST8, and ST15) had been isolated from wild boars. Among nine zoonotic STs (ST1-ST8, and ST12), all were identified in examined swine populations, except for ST12. As well, ST1 and ST5 were probably the most frequently circulating STs among these animals. In addition, male and older pigs showed higher Blastocystis sp. infection. Altogether, Blastocystis epidemiology and the distribution of its related STs in pigs is still open to question and requires more extensive studies, especially in the neglected regions of the world.
Topics: Animals; Blastocystis; Blastocystis Infections; Feces; Male; Phylogeny; Prevalence; Risk Factors; Sus scrofa; Swine
PubMed: 34517066
DOI: 10.1016/j.micpath.2021.105183 -
Parasitology Research Sep 2017Irritable bowel syndrome (IBS) is globally one of the most prevalent gastrointestinal disorders with a negative impact on quality of life and socio-economic status of... (Meta-Analysis)
Meta-Analysis Review
Irritable bowel syndrome (IBS) is globally one of the most prevalent gastrointestinal disorders with a negative impact on quality of life and socio-economic status of patients. Recently, controversial evidences suggest that Blastocystis sp. and Dientamoeba fragilis infections may be implicated in the development of IBS. We performed a systematic review and meta-analysis to examine the possible association regarding this issue. PubMed, ScienceDirect, Scopus, Web of Science, and Cochrane electronic databases were searched (up to February 2017) to identify the relevant studies. Pooled odds ratio (OR) and 95% confidence intervals were estimated using a random effects meta-analysis model on data from included studies. A total of 17 studies including 5882 participants (2527 patients and 3310 controls) met the eligibility criteria. Individuals with Blastocystis infection were found to have a positive association with IBS (OR, 2.19; 95% CI, 1.54-3.13), while this association was not observed for D. fragilis infection (OR, 1.13; 95% CI, 0.22-5.72). In subgroup analysis for Blastocystis infection, the pooled ORs were OR 2.29, 95% CI 1.55-3.41; OR 1.70, 95% CI 0.83-3.44; and OR 3.83, 95% CI 2.34-6.27 for hospital-based, healthy volunteers, and combined controls, respectively. Considering the subtypes, meta-analysis result demonstrated significant positive ORs for ST1 (OR, 4.40; 95% CI, 2.81-6.90) and ST3 (OR, 1.94; 95% CI, 1.36-2.77) to be potential risk factors for IBS. Our results support the existence of a positive association between Blastocystis sp. and IBS. Further studies with more sample size should be performed to better investigate the real impact of these parasites on the occurrence of IBS.
Topics: Blastocystis; Blastocystis Infections; Dientamoeba; Dientamoebiasis; Feces; Humans; Irritable Bowel Syndrome; Middle Aged; Prevalence; Quality of Life; Risk Factors
PubMed: 28668983
DOI: 10.1007/s00436-017-5535-6 -
Acta Tropica Sep 2018Blastocystis is a prevalent eukaryotic microorganism that has been frequently reported from the stool samples of human and animals, all over the world. The prevalence of... (Meta-Analysis)
Meta-Analysis Review
Blastocystis is a prevalent eukaryotic microorganism that has been frequently reported from the stool samples of human and animals, all over the world. The prevalence of this parasite has close correlation with the climate and hygiene situation of studied populations. For the current study, English and Persian databases were searched for the following terms: "Blastocystis hominis", "Blastocystis sp.", "Intestinal Parasites", "Prevalence" and "Iran". In order to data analysis and assess the possibility of publication bias, STATA v11 and Begg's Funnel plot were employed respectively. From 605 searched cases, 86 publications met our criteria for the analysis. The pooled prevalence of Blastocystis was 9.1% (95%CI: 8.2%, 10.1%). The results represented that the prevalence of the parasite using molecular techniques or cultivation followed by molecular techniques (20.89%) was higher than only microscopical examination (8.96%). The prevalence rate of Blastocystis according to human development index was 7.6%, 7.2%, 11.9%, 13.4%, and 3.3% for ranks 1 to 5, respectively. This is the first study signifying the prevalence of Blastocystis regarding the human development index and climate conditions. The findings represented that although human development index, low levels of socioeconomic situations together with appropriate climate such as sufficient humidity and high temperature increase the chance of transmission of Blastocystis in a society.
Topics: Animals; Blastocystis Infections; Blastocystis hominis; Climate; Feces; Human Development; Humans; Iran; Prevalence
PubMed: 29802845
DOI: 10.1016/j.actatropica.2018.05.014 -
Epidemiology and Infection Nov 2018A comprehensive meta-analysis study was performed to estimate the reliable national prevalence and molecular epidemiology of amoebiasis in Iran. Nine English and Persian... (Meta-Analysis)
Meta-Analysis
A comprehensive meta-analysis study was performed to estimate the reliable national prevalence and molecular epidemiology of amoebiasis in Iran. Nine English and Persian databases were searched to achieve the relevant studies. Pooled estimates were generated and meta-regression was performed. We identified 71 eligible articles involving 330 930 subjects from 25 provinces to be included in the final analysis. Moreover, 17 studies compromising 462 polymerase chain reaction (PCR)-positive isolates performed molecular analysis to inter-species differentiation. The pooled prevalence of Entamoeba infection among Iranian population was about 1% (95% CI 0.8-2.0%). Moreover, regarding Human Development Index (HDI), a higher prevalence was observed in undeveloped provinces. Out of 462 PCR-positive isolates, 83% (95% CI 69-94%) and 12% (95% CI 3-24%) were Entamoeba dispar, Entamoeba histolytica, respectively. In subgroup analysis based on molecular results, in general, population prevalence of Entamoeba dispar and E. histolytica were 91% (95% CI 80-99%) and 7%, (95% CI 0-19%), respectively, while prevalence of these species in patients with gastrointestinal disorders were 75% (95% CI 45-96%) and 18% (95% CI 1-43%), respectively. Our findings indicate the low burden of amoebiasis in Iran. E. dispar, that is mostly non-pathogenic, was identified as most prevalent species. Nevertheless, we suggest more public health interventions in areas with lower HDI.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Child; Child, Preschool; Entamoeba histolytica; Entamoebiasis; Female; Humans; Infant; Infant, Newborn; Iran; Male; Middle Aged; Molecular Epidemiology; Polymerase Chain Reaction; Prevalence; Sequence Analysis, DNA; Young Adult
PubMed: 29991366
DOI: 10.1017/S0950268818001863 -
Transboundary and Emerging Diseases Nov 2020Naegleria species (spp.) is a free-living amoeba whose pathogenic species such as N. fowleri pose a significant health risk to young people, and the most important... (Meta-Analysis)
Meta-Analysis
Naegleria species (spp.) is a free-living amoeba whose pathogenic species such as N. fowleri pose a significant health risk to young people, and the most important source of infection is water source. This study aims to perform a systematic review and meta-analysis of the data on the prevalence of Naegleria spp. in water sources in the available literature. Included articles on the prevalence of Naegleria spp. in water sources in PubMed, Google Scholar, ProQuest, ScienceDirect, EMBASE, Scopus and Web of Science were systematically searched between January 1977 and September 2019. Regarding meta-analysis, the random-effect model was employed by forest plot with 95% of confidence interval (CI). The meta-analysis considered 103 articles surveying the prevalence of Naegleria spp. in various water sources. The pooled worldwide prevalence of Naegleria spp. across 35 countries was 26.42% (95% CI = 21.52-31.63). The subgroup analysis reported that the pooled worldwide prevalence of N. fowleri is 23.27%, N. australiensis 9.12%, N. lovaniensis 7.68%, N. pagei 5.95, N. polaris 5.17%, N. gruberi 3.95%, N. clarki 3.54%, N. americana 3.19%, N. philippinensis 1.99% and N. dobsoni 1.73%. This is the first systematic review on the prevalence of Naegleria spp. in water sources. Our findings suggest a wide distribution of Naegleria spp., including potential pathogenic species such as N. fowleri, in water sources all over the world. Therefore, it is of paramount importance to provide comprehensive data and systematic analysis regarding the prevalence of Naegleria spp. in water sources. Accordingly, further studies are highly recommended to investigate the presence of pathogenic N. fowleri in other countries.
Topics: Animals; Naegleria; Phylogeny; Rivers; Sports and Recreational Facilities; Swimming Pools; Water; Water Supply
PubMed: 32443167
DOI: 10.1111/tbed.13635 -
International Journal of Environmental... Feb 2023Primary amoebic meningoencephalitis (PAM) is a rare but lethal infection of the brain caused by a eukaryote called (). The aim of this review is to consolidate the... (Review)
Review
INTRODUCTION
Primary amoebic meningoencephalitis (PAM) is a rare but lethal infection of the brain caused by a eukaryote called (). The aim of this review is to consolidate the recently published case reports of infection by describing its epidemiology and clinical features with the goal of ultimately disseminating this information to healthcare personnel.
METHODS
A comprehensive literature search was carried out using PubMed, Web of Science, Scopus, and OVID databases until 31 December 2022 by two independent reviewers. All studies from the year 2013 were extracted, and quality assessments were carried out meticulously prior to their inclusion in the final analysis.
RESULTS
A total of 21 studies were selected for qualitative analyses out of the 461 studies extracted. The cases were distributed globally, and 72.7% of the cases succumbed to mortality. The youngest case was an 11-day-old boy, while the eldest was a 75-year-old. Significant exposure to freshwater either from recreational activities or from a habit of irrigating the nostrils preceded onset. The symptoms at early presentation included fever, headache, and vomiting, while late sequalae showed neurological manifestation. An accurate diagnosis remains a challenge, as the symptoms mimic bacterial meningitis. Confirmatory tests include the direct visualisation of the amoeba or the use of the polymerase chain reaction method.
CONCLUSIONS
infection is rare but leads to PAM. Its occurrence is worldwide with a significant risk of fatality. The suggested probable case definition based on the findings is the acute onset of fever, headache, and vomiting with meningeal symptoms following exposure to freshwater within the previous 14 days. Continuous health promotion and health education activities for the public can help to improve knowledge and awareness prior to engagement in freshwater activities.
Topics: Aged; Humans; Male; Amoeba; Brain; Central Nervous System Protozoal Infections; Fever; Headache; Naegleria fowleri
PubMed: 36833715
DOI: 10.3390/ijerph20043021 -
Annals of Parasitology 2018Acanthamoeba, an opportunistic protozoan parasite, is distributed in the environment globally, causes serious human infections, including a fatal encephalitis and... (Meta-Analysis)
Meta-Analysis
Acanthamoeba, an opportunistic protozoan parasite, is distributed in the environment globally, causes serious human infections, including a fatal encephalitis and keratitis. The purpose of this study was to evaluate the prevalence and genotyping of Acanthamoeba spp. from different water and soil sources in Iran. Six English language and four Persian language databases were searched to identify studies published from March 2005 to October 2016. Random effect model and Stats Direct statistical software was used for the meta-analysis. This review resulted in a total 34 articles meeting the including criteria. The overall prevalence rate of Acanthamoeba spp. among the 1850 water and soil samples in Iran with using random-effect model was estimated 42.7%. The genotyping results of the Acanthamoeba isolates showed that T4 (81.2%) was a predominant strain in Iran. In addition, other genotypes, T2, T3, T4, T5, T6, T11, T13, T15, mixed T3/T4 and mixed T2/T6, were obtained in the environmental samples of Iran. This study may be the first systematic review and meta-analysis of Acanthamoeba prevalence and genotyping in different environmental sources of Iran. Knowledge about wide distribution of Acanthamoeba T4 in the environmental sources may help physicians to manage the patients and susceptible persons in Iran.
Topics: Acanthamoeba; Acanthamoeba Keratitis; Genotype; Humans; Iran; Soil; Water
PubMed: 30710471
DOI: 10.17420/ap6404.163 -
Gastroenterologia Y Hepatologia 2017Blastocystis hominis (B. hominis) is a protozoan commonly found in the gastrointestinal tract. There are doubts about its clinical significance. Metronidazole (MTZ) is... (Review)
Review
INTRODUCTION
Blastocystis hominis (B. hominis) is a protozoan commonly found in the gastrointestinal tract. There are doubts about its clinical significance. Metronidazole (MTZ) is the recommended first-line treatment.
MATERIALS AND METHODS
A retrospective review was carried out between 2011 and 2012. A total of 151 samples were randomly selected from 383 samples positive for B. hominis. Inclusion criteria were: suggestive symptoms, treatment indication and microbiological follow-up. A systematic review was performed of all studies that evaluated the effect of MTZ on B. hominis infection.
RESULTS
Forty-six patients met the inclusion criteria (64% women; age, 44.2±2 years). MTZ was used in 39 patients, 31 of whom obtained a clinical response (79.5%) but only 15 a microbiological response (48.4%). No dose-effect relationship was observed. Twenty patients with no initial microbiological response received a second round of treatment (MTZ, cotrimoxazole, paramomycin, others), with a microbiological response in 70%. Overall, B. hominis was cured in 72% (95% CI: 57%-83%). Of 54 treatments associated with a clinical response, a microbiological response occurred in 31 (57%), while in the remaining 12 with no clinical response, microbiological cure was observed in only 2 (17%) (P=.022). The eradication rate in the systematic review varied between 0% and 100%.
CONCLUSIONS
There seems to be a relationship between the clinical and microbiological response to B. hominis treatment. The microbiological response to MTZ treatment is insufficient in our geographical setting. The systematic review shows that the response to MTZ is very variable.
Topics: Aged; Antiprotozoal Agents; Blastocystis Infections; Blastocystis hominis; Diarrhea; Drug Resistance; Drug Substitution; Dyspepsia; Feces; Female; Humans; Male; Metronidazole; Middle Aged; Retrospective Studies; Sampling Studies; Treatment Outcome
PubMed: 28279442
DOI: 10.1016/j.gastrohep.2016.11.003