Parasitic Infections and Host Tissue Response in Histopathology: A Rare Retrospective Research Study from Rural India.

OBJECTIVE: Parasite are living organisms which survive on another living being for their nourishment and survival. When these parasites resides on human body, they bring about inflammatory response. This inflammatory response leads to tissue reaction. Tissue response on microscopy appear as an eosinophilia, abscess and granulomas. This study was planned with the objective to know the frequency of parasite infection, tissue response in parasite infection and its comparison in terms of variables like age, sex and the type of parasite. METHODS: This is a retrospective study, conducted in the department of pathology. A total of 26 cases of parasitic infections in human specimens reported in our department from January 2008 to December 2019 were included in this study. On all archived cases hematoxylin and eosin and where ever required periodic acid schiff was applied. These slides were thoroughly examined and clinicopathological correlation was studied. RESULTS: Age range of patients was 5 years to 70 years. Maximum number of patients were belonging to 11-20 year age group. Male to female ratio was 1:2. Among the 26 cases, there were 9 cases (34.62%) of hydatid cyst, six cases of Entamoeba histolytica (23.07%), four cases of Enterobious vermicularis (15.38%), and two cases (7.69%) each of Ascaris lumbricoides, filaria and cysticercosis respectively. A specific tissue response seen in cysticercosis having chronic inflammatory cells, palisaded epithelioid cells granuloma and giant cell reaction while other showed inflammatory cells infiltration. CONCLUSION: Clinically diagnosis of parasitic infection in each and every case is not possible, similarly radiological investigation is also suggestive only. Histopathology examination is the benchmark investigation to diagnose parasite infection and tissue reaction to the host. Histopathology examination must be implicated in every case to identify parasite and tissue reaction so that the patients can be managed accordingly before the complications rises.

A parasite that should not be neglected in geriatric individuals: Entamoeba histolytica.

OBJECTIVES: To highlight the importance of neglected Entamoeba histolytica (E. histolytica) infections in the geriatric age group, which is an increasing proportion of the world's population. METHODS: This study was carried out between January 2022 and December 2023 at Van Yüzüncü Yil University, Faculty of Medicine, Parasitology Laboratory, Van, Turkey. The study included 96 geriatric patients with diarrhea (geriatric group). Two different control groups (CGs) were also included in the study, comprising 92 patients aged 18-64 years with diarrhea as CG1 and 50 geriatric individuals without diarrhea and other gastrointestinal complaints as CG2. Samples were analysed macroscopically and then evaluated by microscopic, enzyme-linked immunoassay, and polymerase chain reaction. RESULTS: This study detected E. histolytica in 31.3% of the geriatric group and 14.1% of the patients in CG1 (p=0.004). Entamoeba histolytica positivity was not detected in CG2. According to the multiple correspondence analysis, there was a close association between E. histolytica positivity and bloody diarrhea and mucous diarrhea in the geriatric patients. It was also determined that E. histolytica can cause abdominal pain, abdominal distension, and epigastric tenderness in geriatric patients. CONCLUSION: Both the risk of E. histolytica infection and the pathogenicity of the infection increase in geriatric individuals. Therefore, it was concluded that amoebiasis is a serious health problem in the geriatric population and should not be neglected.

Molecular characterization of Giardia duodenalis, Cryptosporidium spp., and Entamoeba spp. infecting domestic and feral/stray cats in Jordan.

This study aimed to carry out a molecular screening for the presence of Giardia, Cryptosporidium, and/or Entamoeba in the feces of pet and stray/feral cats in Jordan. G. duodenalis was found in 27.9% (95% CI, 23.2-32.9) of the 348 sampled cats overall; E. histolytica was found in only 0.6% (95% CI, 0.1-2.1) of the cats, while none of the sampled cats had Cryptosporidium infections. The infection rate of G. duodenalis among indoor cats (32.3%) did not differ significantly from that among outdoor cats (24.1%). There were significantly more infections (p = 0.0004) geographically in the cold semiarid areas (67%) than in the cold desert areas (24%). Multilocus sequence typing analysis of amplicons based on the bg, tpi, and gdh genes revealed that the majority of G. duodenalis infections were zoonotic assemblage B (65.9%; 64 of 97 positive samples); followed by feline-specific assemblage F (18.5%, 18/97); cattle-specific assemblage E (5.2%, 5/97); and then assemblage C that was shared with canids (1.0%; 1/97). Within Giardia isolates, a substitution mutation (A/G) was found at position 297 of the complete protein coding sequence (cds) of tpi-assemblage B, which may represent a new spreading mutation within this gene among the cat population in Jordan. The results of the present study suggest that close human-cat interactions could play a role in zoonotic transmission of Giardia, but further research is needed to determine the possible contribution of cats to the transmission of other protozoa to humans.

Detection and molecular identification of Entamoebaspecies in faecal samples from Duhok province, Kurdistan Region, Iraq.

The study involved the estimation of the prevalence of Entamoeba spp. using microscopy and molecular techniques among symptomatic outpatients during April 2021 to March, 2022. Stool samples were collected from 2592 outpatients with amoebiasis symptoms of both sexes and different ages (≤ l to 60). Also, 107 stool samples were taken randomly from asymptomatic individuals and examined microscopically to detect infection with Entamoeba spp. the positive specimens were used for molecular analysis with positive symptomatic samples targeting the 18S rRNA gene by nested PCR. Microscopically 21.68% (562/2592) were positive, for Entamoeba spp. Males showed highest infection rate than females (67.43% vs 32.56%). Ages from 1-10 years showed the highest rate (54.09%), and urban inhabitant had somewhat a higher rate than rural one (58.54% vs 41.45%) which was statistically non-significant(P>0.05). Among asymptomatic individuals, 57% (61/107) were positive for Entamoeba spp. Nested PCR analysis yielded 73% positive samples for Entamoeba spp. with a fragment size of 897 bp. Three fragment sizes were produced, for E. histolytica, E. dispar and E. moshkovskii which were 439, 174 and 553 bps, respectively. Single infection occurred with, E. histolytica in 46%, of symptomatic and 6% of asymptomatic cases, E. dispar in 38% of asymptomatic and 10% of symptomatic cases, E. moshkovskii, reported at very low rate among both groups.

Entamoeba histolytica in Different Water Sources of Nigde Province of Turkey.

PURPOSE: This study was carried out to determine the presence of Entamoeba histolytica in water sources of Nigde province in Turkey, between June and November 2021. METHODS: A total of 90 water samples were taken from 15 different water sources (drinking water, well water, spring water, wastewater and dam water) every month and the presence of E. histolytica antigens in the samples was examined by ELISA. RESULTS: The positivity for E. histolytica was determined in 7 (7.7%) of 90 samples. While no antigens were found in any of the samples in June and September, E. histolytica was positive for three samples (20%) in July, one sample (6.6%) in August and October and two samples in November (13.3%). One of 24 dam samples (4.1%), 1 of 12 wastewater samples (8.3%), 1 of 12 well samples (8.3%), and 4 of 24 fountain samples (16.6%) that examined by ELISA were found positive. On the other hand, none of the examined 18 spring samples were positive. In addition, 4 (8.8%) of 45 samples that examined in summer and 3 (6.6%) of 45 samples that examined in autumn were detected positive by using ELISA. Entamoeba histolytica positivity in samples was statistically insignificant in terms of months, water resources and seasons (P > 0.05). CONCLUSION: As a result, the presence of E. histolytica, which is an important public health problem in water sources, was determined for the first time in Nigde province of Türkiye with this study.

Survey of Entamoeba infections in schoolchildren and macaques in Kathmandu, Nepal, and analysis of genetic polymorphisms of Entamoeba nuttalli and Entamoeba dispar isolates.

Entamoeba species infect humans and non-human primates, raising concerns associated with potential zoonotic transmission. Therefore, the prevalence of human Entamoeba infections is crucial for its management in areas, where macaques exhibit high infection rates. Previously, we demonstrated prevalent E. nuttalli infections in rhesus macaques in Kathmandu, Nepal. In this study, we surveyed Entamoeba infection among 185 schoolchildren from two schools visited by wild rhesus macaques to assess the risk of transmission. PCR-based screening for Entamoeba species identified E. coli in 13 % and E. dispar in 0.5 % of the human stool samples. However, E. nuttalli and E. chattoni infections, prevalent in macaques, were not detected in human samples. This suggests that Entamoeba spp. are not transmitted through macaques in the school environment. We surveyed the rhesus macaques living in the temple near schools as well as the rhesus and Assam macaques inhabiting Shivapri Nagarjun National Park, Kathmandu. Among the 49 macaque stool samples, E. chattoni, E. coli, E. nuttalli, and E. dispar were detected in 92 %, 86 %, 41 %, and 18 % of the samples, respectively. Notably, E. dispar infections in macaques were mostly prevalent in the temple. A sample isolated from Nagarujun showed an identical genotype at two tRNA-linked short tandem repeat loci to that of E. dispar isolated from humans, suggesting potential transmission from humans to macaques. Genotypic analysis of cultured E. nuttalli strains obtained from the macaques colonizing three locations demonstrated that the geographical distance rather than differences in macaque species played a crucial role in the genetic diversity of the parasites. The phylogenetic tree of E. nuttalli strains, including the previously isolated strains, reflected the geographical distribution of the isolation sites. This study sheds light on the intricate dynamics of Entamoeba transmission and genetic diversity in macaques and humans.

Molecular characterization and zoonotic potential of Entamoeba spp., Enterocytozoon bieneusi and Blastocystis from captive wild animals in northwest China.

BACKGROUND: Parasites Entamoeba spp., Enterocytozoon bieneusi and Blastocystis are prevalent pathogens causing gastrointestinal illnesses in animals and humans. Consequently, researches on their occurrence, distribution and hosts are crucial for the well-being of both animals and humans. Due to the confined spaces and frequent interaction between animals and humans, animal sanctuaries have emerged as potential reservoirs for these parasites. In this study, the wildlife sanctuary near the Huang Gorge of the Qinling Mountains in northwest China is chosen as an ideal site for parasite distribution research, considering its expansive stocking area and high biodiversity. RESULTS: We collected 191 fecal specimens from 37 distinct wildlife species and extracted genomic DNA. We identified these three parasites by amplifying specific gene regions and analyzed their characteristics and evolutionary relationships. All the parasites exhibited a high overall infection rate, reaching 90.05%. Among them, seven Entamoeba species were identified, accounting for a prevalence of 54.97%, with the highest infection observed in Entamoeba bovis. In total, 11 Enterocytozoon bieneusi genotypes were discovered, representing a prevalence of 35.08%, including three genotypes of human-pathogenic Group 1 and two novel genotypes (SXWZ and SXLG). Additionally, 13 Blastocystis subtypes were detected, showing a prevalence of 74.87% and encompassing eight zoonotic subtypes. All of the above suggests significant possibilities of parasite transmission between animals and humans. CONCLUSIONS: This study investigated the occurrence and prevalence of three intestinal parasites, enhancing our understanding of their genetic diversity and host ranges in northwest China. Furthermore, the distribution of these parasites implies significant potential of zoonotic transmission, underscoring the imperative for ongoing surveillance and implementation of control measures. These efforts are essential to mitigate the risk of zoonotic disease outbreaks originating from wildlife sanctuary.

Prevalence, socio-economic, and associated risk factors of oral cavity parasites in children with intellectual disability from Lorestan province, Iran.

Introduction: Children with intellectual disability (ID) often face challenges in maintaining proper oral hygiene due to their motor, sensory, and intellectual impairments, which can lead to compromised oral health; therefore, there is a need to enhance the oral health status of these populations and establish an effective system for administering preventive interventions. Here, we aimed to evaluate the prevalence of Entamoeba gingivalis and Trichomonas tenax among children with ID in Lorestan province, in Western Iran through parasitological and molecular methods. Methods: The current descriptive investigation involved 215 in children with ID and 215 healthy children (non-ID) who were referred to health facilities in Lorestan province, Iran between October 2022 and March 2024. The prevalence of protozoa in the oral cavity was found through the utilization of both microscopic analysis and conventional polymerase chain reaction (PCR) techniques. Results: The total prevalence of the E. gingivalis and T. tenax in children with ID was found to be 87 (40.5%) and 92 (42.8%) through microscopic and PCR methods, respectively. Among the positive samples, 57 (61.9%) and 35 (38.1%) children tested positive for E. gingivalis and T. tenax, respectively. In contrast, among the 215 non-ID children in the control group, 39 (18.1%) and 42 (19.5%) tested positive by microscopic and PCR methods, respectively. Among positive samples in non-ID children, 23 (54.7%) and 19 (45.3%) children were positive for E. gingivalis and T. tenax, respectively. Multiple logistic regression analysis indicated that residing in urban areas, parental education, monthly family income, and tooth brushing p<0.001) were identified as independent risk factors for oral cavity parasites. Conclusion: This study identified a notable prevalence of oral cavity parasites in children with ID in Lorestan province, Western Iran. It is imperative to recognize the primary risk factors associated with these parasites, particularly inadequate teeth brushing, in order to enhance public and oral health strategies for children with ID. Therefore, pediatric dental professionals should remain vigilant regarding these risk factors to effectively recognize and address oral health issues in this population, thereby mitigating the occurrence of oral diseases and infections.

Association of Entamoeba gingivalis with Periodontal Disease-Systematic Review and Meta-Analysis.

The oral cavity is a habitat to a diverse range of organisms that make up an essential element of the human microbiota. There are up to 1000 species of micro-organisms capable of colonizing the mouth. Thirty percent of them are uncultivable. The genus Entamoeba includes several species, out of which at least seven of them are able to inhabit the human body (Entamoeba histolytica, Entamoeba dispar, Entamoeba moshkovskii, Entamoeba coli, Entamoeba polecki, Entamoeba hartmann, Entamoeba gingivalis). It was shown that only E. gingivalis is able to colonize the oral cavity. The aim of this study was to evaluate the association and prevalence of E. gingivalis in periodontal disease using two electronic database search engines. In order to have a broader view of the subject, a comprehensive manual search was conducted between 15th February 2023 and 1 April 2023 on these content aggregators and the initial search resulted in 277 articles using the keywords "E. gingivalis", "periodontitis", "E. gingivalis", "periodontal disease", "prevalence", and "incidence", in different combinations. The results showed that 755 patients were infected with E. gingivalis out of a total number of 1729 patients diagnosed with periodontal disease, indicating a global prevalence of 43% in the set of patients analyzed. E. gingivalis was prevalent in 58% of the patients that had gingivitis and in 44% of the patients with periodontitis. Prevalence of E. gingivalis based on gender was 43% in female patients and 47% in male patients. The results indicate that the higher incidence of E. gingivalis in people with periodontal disease compared to healthy people is more than just a sign of the disease; it could also be linked to the severity of the condition and the disease propensity to progress.

Epidemiological investigation of Entamoeba in wild rhesus macaques in China: A novel ribosomal lineage and genetic differentiation of Entamoeba nuttalli.

Wild rhesus macaques are a potential source of zoonotic parasites for humans, and Entamoeba spp. are common intestinal parasites. To investigate the prevalence of Entamoeba in wild rhesus macaques in China and explore the genetic differentiation of the potentially pathogenic species Entamoeba nuttalli, a total of 276 fecal samples from five populations at high altitudes (HAG, 2,800-4,100 m above sea level) and four populations at low altitudes (LAG, 5-1,000 m above sea level) were collected. PCR methods based on the ssrRNA gene were used to detect Entamoeba infection. Genotyping of E. nuttalli was performed based on six tRNA-linked short tandem repeat (STR) loci for further genetic analyses. The results revealed that Entamoeba infection (69.2%) was common in wild rhesus macaques in China, especially in LAG which had a significantly higher prevalence rate than that in HAG (P < 0.001). Three zoonotic species were identified: Entamoeba chattoni (60.9%) was the most prevalent species and distributed in all the populations, followed by Entamoeba coli (33.3%) and Entamoeba nuttalli (17.4%). In addition, a novel Entamoeba ribosomal lineage named RL13 (22.8%) was identified, and phylogenetic analysis revealed a close genetic relationship between RL13 and Entamoeba. hartmanni. Genotyping of E. nuttalli obtained 24 genotypes from five populations and further analysis showed E. nuttalli had a high degree of genetic differentiation (FST > 0.25, Nm < 1) between the host populations. The result of analysis of molecular variance (AMOVA) revealed that observed genetic differences mainly originate from differences among populations (FST = 0.91). Meanwhile, the phylogenetic tree showed that these genotypes of E. nuttalli were clustered according to geographical populations, indicating a significant phylogeographic distribution pattern. Considering the potential pathogenicity of E. nuttalli, attention should be paid to its risk of zoonotic transmission.

Genetic characterization of the Entamoeba moshkovskii population based on different potential genetic markers.

Entamoeba moshkovskii, according to recent studies, appears to exert a more significant impact on diarrhoeal infections than previously believed. The efficient identification and genetic characterization of E. moshkovskii isolates from endemic areas worldwide are crucial for understanding the impact of parasite genomes on amoebic infections. In this study, we employed a multilocus sequence typing system to characterize E. moshkovskii isolates, with the aim of assessing the role of genetic variation in the pathogenic potential of E. moshkovskii. We incorporated 3 potential genetic markers: KERP1, a protein rich in lysine and glutamic acid; amoebapore C (apc) and chitinase. Sequencing was attempted for all target loci in 68 positive E. moshkovskii samples, and successfully sequenced a total of 33 samples for all 3 loci. The analysis revealed 17 distinct genotypes, labelled M1­M17, across the tested samples when combining all loci. Notably, genotype M1 demonstrated a statistically significant association with diarrhoeal incidence within E. moshkovskii infection (P = 0.0394). This suggests that M1 may represent a pathogenic strain with the highest potential for causing diarrhoeal symptoms. Additionally, we have identified a few single-nucleotide polymorphisms in the studied loci that can be utilized as genetic markers for recognizing the most potentially pathogenic E. moshkovskii isolates. In our genetic diversity study, the apc locus demonstrated the highest Hd value and π value, indicating its pivotal role in reflecting the evolutionary history and adaptation of the E. moshkovskii population. Furthermore, analyses of linkage disequilibrium and recombination within the E. moshkovskii population suggested that the apc locus could play a crucial role in determining the virulence of E. moshkovskii.

Molecular Detection of a Pathogenic Entamoeba among Symptomatic Children in Eastern Kurdistan of Iraq.

Entamoeba histolytica infects the large intestine of humans, causing a spectrum of clinical appearances ranging from asymptomatic colonization to severe intestinal and extra-intestinal disease. The parasite is identical microscopically to commensal nonpathogenic amoeba. To detect the pathogenic Entamoeba and estimate the precise prevalence of the parasite among the symptomatic pediatric population using molecular techniques. 323 fecal samples were collected from symptomatic children admitted to Sulaimani Pediatric Teaching Hospital, Sulaimaniyah Province, Iraq, from June to October 2021. A structured, validated questionnaire was prepared and used to report participants' gender, residency, and drinking water source. Then, stool samples were microscopically examined, and the positive samples were submitted to molecular analysis by amplifying the 18s rRNA gene using nested PCR to differentiate E. histolytica from other nonpathogenic Entamoeba. Finally, gene sequences were done to confirm the species. Microscopically, 58 positive samples represented Entamoeba species infection rate of 18% among symptomatic patients. However, only 18 samples were positive for E. histolytica based on molecular methods, which accounts for 31% of the positive by microscopy and 5.6% among the 323 symptomatic populations. NCBI, available in their database, gives the gene sequence and accession number. Patients' sociodemographic data and water sources were directly related to the infection rate. Classical microscopic examination provides a misleading profile about the prevalence of E. histolytica in an endemic region that might lead to unnecessary treatments and a lack of appropriate management for patients.

Multi-locus sequence analysis reveals phylogenetically segregated Entamoeba histolytica population.

Amoebiasis, caused by the enteric parasite, Entamoeba histolytica, is one of the major food- and water-borne parasitic diseases in developing countries with improper sanitation and poor hygiene. Infection with E. histolytica has diverse disease outcomes, which are determined by the genetic diversity of the infecting strains. Comparative genetic analysis of infecting E. histolytica strains associated with differential disease outcomes from different geographical regions of the world is important to identify the specific genetic patterns of the pathogen that trigger certain disease outcomes of Amoebiasis. The strategy is able to elucidate the genealogical relation and population structure of infecting E. histolytica strains from different geographical regions. In the present study, we have performed a comparative genetic analysis of circulating E. histolytica strains identified from different parts of the world, including our study region, based on five tRNA-linked short tandem repeat (STR) loci (i.e., D-A, NK2, R-R, STGA-D and A-L) and evaluated their potential associations with differential disease outcomes of Amoebiasis. A number of regional-specific, emerging haplotypes of E. histolytica, significantly associated with specific disease outcomes have been identified. Haplotypes, which have a significant positive association with asymptomatic and amoebic liver abscess outcomes, showed a significant negative association with diarrheal outcome, or vice versa. Comparative multi-locus analysis revealed that E. histolytica isolates from our study region are phylogenetically segregated from the isolates of other geographical regions. This study provides a crucial overview of the population structure and emerging pattern of the enteric parasite, E. histolytica.

Differential diagnosis of human Entamoeba infections: Morphological and molecular characterization of new isolates in Argentina.

Entamoeba infections occur worldwide, with higher frequency in countries of low socioeconomic status and poor public health. Since Entamoeba histolytica has long been recognized as the only pathogenic species, making a differential diagnosis of other morphologically identical Entamoeba is important. This study aimed to determine the prevalence of Entamoeba species in two populations from Argentina, make a differential diagnosis by PCR and characterize Entamoeba isolates at the SSU rRNA gene. A total of 493 serial fecal samples were obtained from individuals in the provinces of Buenos Aires (n=210) and Misiones (n=283). Samples were examined by conventional methods (formalin-ethyl acetate and Willis flotation) and specific PCRs to differentiate Entamoeba species. Entamoeba isolates were characterized by sequencing a fragment of the SSU rRNA gene. The overall prevalence of Entamoeba infection was 12.4%, being more prevalent in Buenos Aires than in Misiones (14.8% vs. 10.6%). A case of E. histolytica confirmed by PCR and sequence analysis was reported for the first time in Buenos Aires. Moreover, new genetic data on Entamoeba coli and Entamoeba dispar were recorded. The phylogenetic analysis revealed a congruence between morphological characteristics and SSU rRNA gene sequences. This study increases the amount of information on the distribution of these species in Argentina and the region of the Americas.

Short tandem repeat (STR) based sequence typing of Entamoeba histolytica identifies STGA-D locus as a genetic marker, associated with disease outcomes.

Amoebiasis, caused by the enteric parasite Entamoeba histolytica has differential disease outcomes. The association of parasite genotypes with outcomes of amoebic infection is still a paradox and requires to be explored. The genetic information of infecting strains from endemic settings of different geographical regions is essential to evaluate the relation. Comparative genetics of E. histolytica clinical isolates from different disease outcomes have been explored based on two tRNA-linked STR loci (STGA-D and A-L). All of the repeat patterns in the A-L locus were newly identified and unique to Indian isolates. The majority of newly identified repeat patterns in STGA-D locus have outcome-specific distributions, predicting the emergence of disease-specific mutations in this target locus. Statistical analysis further reinforces this observation, as identified repeat patterns only from STGA-D but not A-L locus were significantly associated with disease outcomes. Phylogenetic analysis indicates independent segregation and divergence of tRNA-linked STR arrays for each STR locus.

Evaluation of a rapid immunochromatographic test for the diagnosis of intestinal protozoan infections among patients attending a rural outreach outpatient department in Northern India.

Despite great efforts, intestinal protozoan infections remain a significant healthcare concern worldwide. Although many point-of-care (POC) tests are increasingly being used, microscopic examination of stool specimens remains the mainstay for their diagnosis, especially in resource-limited settings. We assessed the utility of rapid POC tests based on immunochromatography among patients from rural Northern India. A total of 78 patients were enrolled in the study. Out of nine specimens that tested positive for Giardia duodenalis on microscopy, an immunochromatographic test (ICT) could detect only five (55.55%). Entamoeba histolytica/dispar was demonstrated in two specimens on microscopy, both of which were missed by ICT. Its overall sensitivity, specificity, and positive and negative predictive value were 50%, 98.5%, 83.3%, and 93%, respectively. Its performance was considered unsatisfactory. Although ICT-based tests provide a relatively rapid and less labor-intensive alternative, they should be used to supplement and not replace stool microscopy.

Prevalence and risk factors for infection with Entamoeba histolytica/dispar/ moshkovskii complex in people living in the slightest and outermost islands of Indonesia.

Entamoeba histolytica (E. histolytica), the causative agent of amoebiasis, is still a global public health problem that cannot be controlled, especially in tropical and subtropical countries. This study was conducted to obtain information about the incidence of Entamoeba histolytica/dispar/ moshkovskii complex infection and the factors that influence it. The prevalence of infection with the Entamoeba histolytica/dispar/moshkovskii complex and the factors that influence it in people living on the smallest and outermost island of Indonesia, Sabang Island, Aceh Province. This study involved 335 respondents aged >= 10 years. Respondents were selected by non-probability sampling technique. Interviews and observations were conducted to identify risk factors. The Entamoeba histolytica/dispar/ moshkovskii complex was identified by direct examination, concentration, and Whitley's trichrome staining techniques. A Chi-Square test was performed to analyze the correlation of risk factors with the incidence of infection. The prevalence of infection with the Entamoeba histolytica/dispar/ moshkovskii complex in the people of Sabang Island was 26.6% (89/335). Source and adequacy of clean water correlated with the incidence of Entamoeba histolytica/dispar/moshkovskii complex infection. Demographic variables are not correlated with the incidence of infection. However, the group of women aged > 61 years, unemployed, unmarried, and earning less than the regional minimum wage tend to be more likely to be found with Entamoeba histolytica/dispar/moshkovskii complex infections. Thus it can be concluded that the prevalence of infection with the Entamoeba histolytica/dispar/moshkovskii complex on Sabang Island is in the high category. The prevalence of E. histolytica as the causative agent of amoebiasis cannot be explained with certainty because the two identical non-pathogenic Entamoeba species cannot be distinguished by microscopic identification. Sources and adequacy of clean water correlate with the incidence of Entamoeba histolytica/dispar/moshkovskii complex infection in the people of Sabang Island.

Prevalence and molecular characterization of Entamoeba moshkovskii in diarrheal patients from Eastern India.

BACKGROUND: Importance of the amphizoic amoeba Entamoeba moshkovskii is increasing in the study of amoebiasis as a common human pathogen in some settings. Limited studies are found on the genetic and phylogenetic characterization of E. moshkovskii from India; hence remain largely unknown. In this study, we determined the prevalence and characterized the E. moshkovskii isolates in eastern India. METHODS: A three-year systemic surveillance study among a total of 6051 diarrhoeal patients from ID Hospital and BC Roy Hospital, Kolkata was conducted for E. moshkovskii detection via a nested PCR system targeting 18S rRNA locus. The outer primer set detected the genus Entamoeba and the inner primer pair identified the E. moshkovskii species. The 18S rRNA locus of the positive samples was sequenced. Genetic and phylogenetic structures were determined using DnaSP.v5 and MEGA-X. GraphPad Prism (v.8.4.2), CA, USA was used to analyze the statistical data. RESULT: 4.84% (95%CI = 0.0433-0.0541) samples were positive for Entamoeba spp and 3.12% (95%CI = 0.027-0.036) were infected with E. moshkovskii. E. moshkovskii infection was significantly associated with age groups (X2 = 26.01, P<0.0001) but not with gender (Fisher's exact test = 0.2548, P<0.05). A unique seasonal pattern was found for E. moshkovskii infection. Additionally, 46.56% (95%CI = 0.396-0.537) were sole E. moshkovskii infections and significantly associated with diarrheal incidence (X2 = 335.5,df = 9; P<0.0001). Sequencing revealed that the local E. moshkovskii strains were 99.59%-100% identical to the prototype (GenBank: KP722605.1). The study found certain SNPs that showed a correlation with clinical features, but it is not necessarily indicative of direct control over pathogenicity. However, SNPs in the 18S rRNA gene could impact the biology of the amoeba and serve as a useful phylogenetic marker for identifying pathogenic E. moshkovskii isolates. Neutrality tests of different coinfected subgroups indicated deviations from neutrality and implied population expansion after a bottleneck event or a selective sweep and/or purifying selection in co-infected subgroups. The majority of FST values of different coinfected subgroups were <0.25, indicating low to moderate genetic differentiation within the subgroups of this geographical area. CONCLUSION: The findings reveal the epidemiological significance of E. moshkovskii infection in Eastern India as the first report in this geographical area and expose this species as a possible emerging enteric pathogen in India. Our findings provide useful knowledge for further research and the development of future control strategies against E. moshkovskii.

Entamoeba histolytica induced NETosis and the dual role of NETs in amoebiasis.

Entamoeba histolytica (Eh), a microaerophilic parasite, causes deadly enteric infections that result in Amoebiasis. Every year, the count of invasive infections reaches 50 million approximately and 40,000 to 1,00,000 deaths occurring due to amoebiasis are reported globally. Profound inflammation is the hallmark of severe amoebiasis which is facilitated by immune first defenders, neutrophils. Due to size incompatibility, neutrophils are unable to phagocytose Eh and thus, came up with the miraculous antiparasitic mechanism of neutrophil extracellular traps (NETs). This review provides an in-depth analysis of NETosis induced by Eh including the antigens involved in the recognition of Eh and the biochemistry of NET formation. Additionally, it underscores its novelty by describing the dual role of NETs in amoebiasis where it acts as a double-edged sword in terms of both clearing and exacerbating amoebiasis. It also provides a comprehensive account of the virulence factors discovered to date that are implicated directly and indirectly in the pathophysiology of Eh infections through the lens of NETs and can be interesting drug targets.

Intestinal parasitic infections and risk factors for infection in Kenyan children with and without HIV infection.

It has been reported that HIV infection is not a risk factor for Entamoeba species infection but is for Giardia intestinalis assemblage B in children living in Western Kenya. This study aimed to investigate the prevalence of and the risk factors for Entamoeba spp. and G. intestinalis infection in children living in Nairobi, Kenya. This cross-sectional study included 87 children with HIV [HIV(+)] and 85 without HIV [HIV(-)]. Stool and blood samples were collected for the detection of the parasites by PCR and immunological analyses using flow cytometry. Sociobehavioral and hygienic data were collected using questionnaires and analyzed statistically. The prevalence of Entamoeba spp. infection was significantly lower in the HIV(+) than in the HIV(-) children (63.2% vs. 78.8%, P = 0.024), whereas the prevalence of G. intestinalis infection was not (27.6% vs. 32.9%, P = 0.445). "Not boiling drinking water" (adjusted odds ratio [aOR]: 3.8, P = 0.044) and "helping in nursery care" (aOR: 2.8, P = 0.009) were related to G. intestinalis assemblage B infection, and "CD4/CD8 ratio ≥1" was related to Entamoeba spp. infection (aOR: 3.3, P = 0.005). In stratified regression analyses, HIV infection was negatively associated with G. intestinalis assemblage B infection in females (aOR: 0.3, P = 0.022), but positively associated in males (aOR 3.8, P = 0.04). These results suggest that G. intestinalis assemblage B infection is related to hygienic conditions, while Entamoeba spp. infection is an indicator of better immunological status, and that the role of HIV infection in Giardia infection may differ between Kenyan boys and girls.