Blastocystis hominis is a common intestinal eukaryotic organism that infects both humans and animals. Although its pathogenicity remains debated, it has been associated with diarrhoea and gastroenteritis. This study aimed to determine its prevalence and characterize its genetic subtypes (STs) in symptomatic patients presenting with gastrointestinal complaints. DNA was extracted from 279 stool samples collected from patients in northern and central regions of Jordan. Nested polymerase chain reaction targeting the 18S rRNA gene locus and Sanger sequencing of positive samples were used for B. hominis detection and subtype identification. Phylogenetic relationships were analysed using Unipro UGENE and MEGA software. Statistical analyses, prevalence, Pearson's χ2 test (p<0.05) were conducted using SPSS. The present study found a B. hominis prevalence of 7.2% (20/279). Three subtypes were identified: ST1 35% (7/20), ST2 10% (2/20) and ST3 55% (11/20). No mixed-subtype infections were detected. A statistically significant association was observed between B. hominis infection and patient age (p<0.05), with infection rates influenced by age and not by gender. The highest prevalence, based on sequencing, was observed in the 6- to <12-y age group. The association between B. hominis infection and gender was not statistically significant. The relatively low prevalence of B. hominis among patients suggests it may function more as an indicator of gut health rather than as a primary pathogen. However, confirmation of this hypothesis requires additional microbiome and longitudinal studies. The frequent detection of ST1 and ST3 aligns with previous findings that link these subtypes to clinical symptoms. Broader epidemiological studies are needed to clarify the distribution patterns and clinical significance of B. hominis in human populations.

The Belén District in Loreto Region, Peru, is known for its extensive riverfront areas, where many houses are built on stilts and float during the rainy season. We conducted fecal examinations on 997 schoolchildren (ages 4-14 years; 488 boys, 497 girls) across 4 schools in Belén using the Kato-Katz thick smear and formalin-ethyl acetate sedimentation techniques. The results revealed high rates of soilborne helminths and waterborne protozoan infections, with an overall parasite-positive rate of 79.7%. The primary helminth species were Ascaris lumbricoides (39.2%), Trichuris trichiura (33.2%), Hymenolepis nana (3.4%), hookworms (2.1%), and Enterobius vermicularis (1.5%). The main pathogenic protozoans were Giardia lamblia (20.9%) and Entamoeba histolytica/E. dispar (14.2%), along with Cryptosporidium-like coccidian (4.6%). Non-pathogenic protozoans included Entamoeba coli (31.5%), Endolimax nana (15.1%), and Blastocystis hominis (3.7%). The intensity of soilborne helminth infections was very high for A. lumbricoides (average eggs per gram of feces per child: 18,589), followed by T. trichiura (1,501) and hookworms (160). The prevalence of anemia, often associated with malnutrition, was moderate at 33.1% (298 anemic children among 901 examined). Mass deworming was initiated with albendazole 400 mg, 3 times a year, in conjunction with health education and environmental sanitation. Metronidazole was administered once at a dose of 200 mg 3 times daily for 10 days. A notable finding in this study was that soilborne and waterborne parasites are both highly prevalent among schoolchildren in the floating villages of the Belén District, Loreto Region. Sustained mass deworming is urgently needed and the WASH program is crucial.

Despite the importance of wastewater environmental monitoring in disease prevention and response strategies, its use remains poorly documented in Senegal. In addition, there is more onsite sanitation than sewer networks in Dakar, and open drains channel for rainwater are also used as clandestine wastewater discharge into the sea. This study aimed to assess the presence of specific pathogens in wastewater, faecal sludge, and bathing water (the sea). Samples were taken at treatment plants, an open drain, and in the receiving environment (the sea) from June to December 2023. Total nucleic acid was subjected to multiplex qualitative qPCR using SeeGene Allplex™ kits targeting 34 gastrointestinal pathogens. Descriptive statistics, multiple correspondence analysis (MCA) and logistic regression were performed. Considering all matrices, across 51 analysed samples, the results revealed strong bacterial (96.08%, n = 49), parasitic (84.31%, n = 43), and viral (68.63%, n = 35) presence. These results showed high levels of Aeromonas spp. (96.08%), Blastocystis hominis (80.39%), Enterocytozoon (58.82%), and Norovirus GII (74.51%) among bacteria, protozoa, helminths, and viruses, respectively. Moreover, faecal sludge and pumping station samples show more identified pathogen than wastewater treatment plant and seawater samples. The MCA revealed that the dry season is spatially associated with a greater number of pathogens than the rainy season, but the latter showed a greater species diversity. Logistic regression showed that certain physicochemical parameters, including BOD5, turbidity, pH, and suspended solids, influence pathogen detection. However, qualitative detection and sampling period may constitute limitations. These results reveal that wastewater and bathing water can serve as sources of information on the circulation of pathogens of interest with epidemic potential. Therefore, this valuable epidemiological tool could serve as an adjunct to clinical surveillance in order to prevent future epidemics.

Identification of villin-interacting virulence factors of Blastocystis hominis using yeast two-hybrid screening.

Background and AimsIntestinal parasitic infections (IPIs) remain a significant public health challenge, particularly among school-aged children in low- and middle-income countries (LMICs). This systematic review and meta-analysis aimed to estimate the pooled prevalence of IPIs and identify associated risk factors in Africa and Asia.MethodA systematic search of Medline/PubMed, Embase, Scopus, ScienceDirect, Epistemonikos, and additional searches such as Google and Google Scholar was conducted between January 2019 and April 2024. The review followed the PRISMA guidelines. Data extraction was performed using Microsoft Excel, and meta-analyses were conducted using STATA. Methodological quality was assessed using the Newcastle–Ottawa Scale. A random-effects model was used to estimate the pooled prevalence, while heterogeneity was assessed using the I2 statistic. Publication bias was evaluated through funnel plots and Egger’s regression test. The study protocol was registered in PROSPERO (CRD42024536604).Results47 studies comprising 20,334 school-aged children were included. The pooled prevalence of at least one intestinal parasitic infection was 39% (95% CI: 33%–45%). Regional analysis showed a higher prevalence in Africa (41%) compared to Asia (35%). Protozoan infections (29%) exceeded those of helminths (19%) and mixed infections (2%). The most common parasites were Blastocystis hominis (16%), Endolimax nana (16%), Entamoeba histolytica (15%), Entamoeba coli (12%), and Ascaris lumbricoides (11%). Infections were primarily single (37%), followed by double (10%), triple (3%), and quadruple (1%). Significant risk factors included school type, socioeconomic status, larger family size, presence of domestic animals, and finger-sucking habits.ConclusionIntestinal parasitic infections remain a significant public health challenge among school-aged children in Africa and Asia. The findings underscore the need for sustained, school-based health programs that integrate regular deworming, hygiene education, and targeted sanitation improvements. Strengthening surveillance and addressing behavioral and environmental risk factors are essential to reducing infection burden and promoting child health.Supplementary InformationThe online version contains supplementary material available at 10.1186/s13643-025-03063-z.

Blastocystis hominis infection in patients with Parkinson's disease may exacerbate gut microbiota dysbiosis, potentially worsening neurological symptoms; however, such associations remain speculative without microbiome data. Targeted interventions to restore gut microbial balance could mitigate disease progression and improve patient outcomes. An 86-year-old Caucasian male presented to the emergency department with severe watery diarrhea, up to six episodes per day, of 1month duration. The patient's diarrhea was nonbloody and nonmucoid. He denied fever, nausea, vomiting, abdominal pain, bloating, loss of appetite, or anal itching. There was no history of weight loss, fatigue, or systemic symptoms. A stool sample was examined microscopically using normal saline, revealing Blastocystis hominis cysts (the burden was not quantified) and a rare white blood cell count. The sample was concentrated using acetylacetate and ether. Additional tests, including Clostridioides difficile and other common infectious pathogens, were ruled out in our patient to address alternative infectious etiologies.The patient was started on intravenous ciprofloxacin and metronidazole, resulting in an improvement in diarrhea consistency and frequency until the resolution of symptoms within 4days of initiating intravenous therapy. The patient also reported mild improvement in his Parkinson's disease symptoms by the end of hospitalization, though objective neurologic post-treatment scoring (eg. Unified Parkinson's Disease Rating Scale) was not performed. This case highlights the need to consider parasitic infections in patients with Parkinson's disease presenting with chronic diarrhea. While we hypothesize that B. hominis infection may transiently worsen Parkinson's disease symptoms through inflammatory or microbiota-mediated pathways, this remains speculative in the absence of microbiome sequencing or objective neurologic evaluation. Further studies integrating clinical, microbiological, and microbiome analyses are warranted.

Objective:Celiac disease (CD) is a chronic, immune-mediated enteropathy of the small intestine and may be associated with parasitic infections. This study investigated the prevalence of intestinal protozoan parasites in patients with CD and evaluated genetic variation using phylogenetic analysis.Materials and Methods:We screened stool samples from patients with CD for Entamoeba histolytica, Entamoeba moshkovskii, Dientamoeba fragilis, Blastocystis hominis, Giardia intestinalis, Cryptosporidium parvum, Cystoisospora belli, and Cyclospora cayetanensis using microscopy, serology, quantitative polymerase chain reaction, and DNA sequencing. We performed phylogenetic analyses in Geneious (v9.1.3) and conducted statistical analyses in IBM SPSS Statistics (v20).Results:Among 74 patients, positivity for D. fragilis and B. hominis was significantly associated with CD (P = 0.005). Positivity rates for these parasites differed by sex and were higher in female patients. Sequence analysis identified three subtypes. Our isolates showed high similarity to previously reported isolates (mean pairwise identity ≈ 99%) but also contained nucleotide-level variation.Conclusion:Intestinal protozoan parasites may contribute to CD through immune-mediated mechanisms, and the altered intestinal environment in CD may also increase susceptibility to colonization. These findings support a possible association between CD and selected intestinal protozoan parasites.

Water-borne parasitism has been an issue of concern in the recent past because of the pollution of different water sources. Objectives: To evaluate the prevalence and diversity of waterborne parasites in water samples of Lahore and Faisalabad. Methods: A total of 420 samples were collected from different sources (river, canal, borehole, and filter). A descriptive cross sectional study was conducted from April 2024 to July 2024. Different developmental stages of both protozoan and helminth have been isolated and examined from all the sampled water sources by filtration and centrifugation then the parasites were observed under a microscope. Results: Helminths isolated from water samples include Ancylostoma duodenale (1.19%), Ascaris lumbricoides (2.38%), Clonorchis sinensis (0.48%), Dracunculus medinensis (0.24%), Enterobius vermicularis (1.43%), Hymenolepsis nana (0.95%), and Schistosoma spp. (0.48%), Strongyloides stercoralis (3.33%), Taenia saginata (2.14%) and Trichostrongylus spp. (0.24%). Protozoans isolated include Balantidium coli (1.67%), Blastocystis hominis (1.19%), Cryptosporidium parvum (2.86%), Cystoisospora belli (1.9%), Entamoeba histolytica (2.38%), Entamoeba coli (1.43%), Giardia duodenale (0.48%), Giardia lamblia (1.67%), and Iodoameoba butschii (0.95%). Recreational water has the highest prevalence of 45.71%, followed by borehole 30% and filtered water 6.42%. Statistically significant difference (P&lt;0.05) has been observed between borehole and recreational water. The highest prevalence of waterborne parasites has been observed in the month of April, 47.9%, followed by May, 37%, June, 14.7%, and July, 1.2%. Conclusions: Parasitic prevalence in water sources shows that water should be treated before use. High parasitic contamination in recreational water shows that it should not be used for human and animal activities.

Blastocystis is a common intestinal parasite, previously known as Blastocystis hominis, that is found worldwide in both humans and animals. Its role as a pathogen is debated because most infected individuals are asymptomatic, though it is linked to gastrointestinal issues like diarrhea, abdominal pain, and vomiting in some cases. Diagnosis requires finding the organism in a stool sample and correlating it with symptoms. While some infections may resolve on their own, treatment with antibiotics like metronidazole or other antiprotozoal medications may be considered if symptoms are severe. Blastocystis hominis infection, also called blastocystosis, is an infection with a single-celled parasite that is often asymptomatic, but can cause gastrointestinal symptoms like diarrhea, abdominal pain, and gas. Infection is spread through the fecal-oral route, which includes ingesting contaminated food or water and poor hygiene. A microscopic parasite that can be found in the intestines and is being studied for its link to Irritable Bowel Syndrome (IBS), a functional gastrointestinal disorder. Research is ongoing to understand Blastocystis' role, with some studies finding it in individuals with IBS symptoms like diarrhea, bloating, and abdominal pain, while others find it in asymptomatic individuals, indicating the pathogenic potential is still controversial. Treatment for symptomatic cases may involve antibiotics, but diagnosis and treatment can be challenging as many infections are mild and resolve on their own. The prevalence of Blastocystis hominis varies globally, being significantly higher in developing countries (often exceeding 50%) compared to developed countries (typically around 10% or less). Transmission can occur through contaminated food and water, and via animal-to-human and human-to-human contact. Factors like sanitation, socioeconomic conditions, and personal hygiene play a major role in the parasite's prevalence. Blastocystis hominis infection in females is similar to in males, though some studies show slight prevalence differences. Many individuals are asymptomatic, but when symptoms occur, they can include diarrhea, abdominal pain, bloating, gas, and anal itching. Females, particularly pregnant women, can also be at risk for iron deficiency anemia from this infection

BackgroundDiarrhea remains a major health concern in children under five years, with enteric pathogens being key contributors. However, the interactions among these pathogens and their combined effects on disease severity are not well understood. The study investigates the interactions among co-infecting enteric pathogens on diarrhea pathogenesis within an epidemiological framework.MethodsThis large-scale, multicenter case-control study was conducted from January 1, 2024 to December 31, 2024, across four tertiary hospitals in Guangzhou, Guangdong Province, China. Stool samples were collected from children under five years with diarrhea (cases) and those without (non-diarrheal children). 21 enteric pathogens in each specimen were identified. Potential interactions between co-infecting pathogens were assessed using both additive and multiplicative models.ResultsEnteric pathogens were more frequently detected in children with diarrhea than in non-diarrheal children (53.6% vs. 27.8%, P < 0.001), with significantly higher detection of both viral (23.3% vs. 13.3%) and bacterial pathogens (34.2% vs. 12.5%). Pathogens independently associated with diarrhea included diarrheagenic Escherichia coli (DEC), Vibrio parahaemolyticus, Clostridioides difficile (CD), group A rotavirus (RVA), and Norovirus GII (NoVs GII). The proportion of children with any form of co-infection was also significantly higher in the diarrhea group compared with non-diarrheal children (16.1% vs. 4.5%, χ2 = 32.594, P < 0.001). Several specific dual-pathogen combinations—namely RVA + DEC (χ2 = 4.956, P = 0.026), RVA + CD (χ2 = 10.313, P < 0.001), RVA + NoVs GII (χ2 = 15.503, P < 0.001), and DEC + Blastocystis hominis (Bh)—were significantly more common among diarrhea cases (χ2 = 4.207, P = 0.041). Multiplicative interaction analysis further identified significant synergistic effects for RVA + DEC [odds ratio (OR) = 2.304, 95% confidence interval (CI): 1.194–5.089], RVA + CD (OR = 6.199, 95% CI: 1.701–10.601), RVA + NoVs GII (OR = 6.296, 95% CI: 2.061–10.723), and DEC + Bh (OR = 4.602, 95% CI: 2.213–9.878).ConclusionThis study demonstrates the frequent occurrence of co-infections in diarrheal children, and enteric pathogens may interact synergistically or antagonistically. It highlights the central role of RVA in exacerbating the severity of these co-infections. The findings emphasize the critical role of RVA vaccination in alleviating the burden and severity of diarrhea.Trial Registration The study was registered in the Chinese Clinical Trial Registry (ChiCTR-ROC-17013620).Graphical Supplementary InformationThe online version contains supplementary material available at 10.1186/s40249-025-01392-8.

A novel therapeutic potential of the anti-hiv ritonavir against Blastocystis hominis: a dual approach in vitro and in vivo

Background and ObjectivesMunicipal solid waste workers (MSWWs) are important in the city’s waste management. With these vital contributions, they face unique occupational hazards and health risks. This study aims to determine the prevalence of occupational infections, such as soil-transmitted helminth infections (STHI) and hepatitis A virus (HAV), as well as the occurrence of Helicobacter pylori infection among the MSWWs of Baguio City.MethodsThis cross-sectional analytic study collected data from volunteer MSWWs using a questionnaire to gather information on age, duration of employment, use of gloves in the workplace, and hand hygiene practices. Stool samples were obtained from participants and were analyzed for STHI using the Formalin Ether Concentration Technique (FECT). H. pylori infection was detected using the SD Bioline rapid antigen test kit on stool samples while blood samples were collected and tested for HAV antibodies using the Aria IgG/IgM rapid test kit.ResultsOf the 44 volunteer MSWWs tested, 25 were infected with hazardous pathogens. Specifically, six workers (13.6%) were infected with STHI, four (9.1%) were infected with HAV and 15 (34.1%) were infected with H. pylori. Among those infected with STHI, Ascaris lumbricoides and Endolimax nana were the predominant species, each with a prevalence rate of 33.3%. In contrast, Blastocystis hominis and hookworm infections each had a prevalence rate of 16.7%. A significant association was found between STHI prevalence and the preference for alcohol hand rubs over hand washing, with a p-value of 0.008.ConclusionThe analysis revealed a significant association between the prevalence of STHI and the preference for alcohol hand rubs over hand washing, suggesting that MSWWs may have a false sense of security regarding their hygiene practices. The findings revealed the critical importance of proper hand washing in preventing STHI. Future research should expand data collection to encompass a broader range of socio-demographic, environmental, and lifestyle factors that may influence infection rates. Additionally, including a control group of individuals not exposed to waste management could help differentiate between factors specific to waste handling and those related to other occupations. This study emphasizes the need for collaborative efforts among researchers, public health authorities, and waste management agencies to enhance the health and safety of MSWWs while addressing broader public health concerns related to waste management practices.

Street foods offer affordable, nutritious, and accessible food options for many urban residents in developing countries. Most university students in Bangladesh rely on street foods due to their appealing appearance. However, these foods are often prepared and served under poor hygienic conditions, making them potential sources of parasitic contamination and faeco-oral disease transmission. Considering the increasing demand for these food items among students, a study was carried out on 50 food samples comprising three types of foods: tamarind water of snacks (27 samples), fruit juices (16 samples), and sliced fruits (7 samples), and 50 corresponding fecal samples from vendors of Dhaka University Campus to assess the parasitic contamination in street foods. Food vendors were also asked to fill a questionnaire on their socio-economic and demographic profile and hygienic practices. It was found that 46 (92%) food samples were contaminated with 6 different types of parasites (Blastocystis hominis, Cystoisospora belli, Hymenolepis diminuta, Hymenolepis nana, Ascaris lumbricoides, and Trichuris trichiura); their prevalence ranged between 4% and 48%. Besides, 92% of vendors were infected with 7 different parasites; the highest prevalence was observed for B. hominis (66%). Out of 4 identified parasites in food and corresponding stool samples, B. hominis (40%) was the most prevalent parasite, followed by C. belli (32%), A. lumbricoides (26%), and H. nana (2%). Fisher’s exact tests revealed that there was a significant association between the presence of B. hominis (p=0.002) and C. belli (p=0.001) in stool and its presence in food. We also found a significant association (at 5% significant level) between the presence of C. belli in food and the water sterilization practice of the food vendors (p-value=0.03). The study shows the serious health risks resulting from poor hygiene practices. So, we need to take immediate action to mitigate the significant public health risks, particularly those who consume street food in the area. Bangladesh J. Zool. 53(2): 201-208, 2025

Prevalence of Blastocystis hominis, Cryptosporidium, and Strongyloidesstercoralis among patients with colorectal carcinoma in Egypt.

Assessing healthcare workers as potential stool donors for faecal microbiota transplantation: a cross-sectional study of antimicrobial-resistant gut bacteria and enteropathogenic micro-organisms.

Anti-inflammatory effect of probiotics in patients with Blastocystis spp. infection.

Giardiasis is the most common enteric protozoan infection notifiable in New South Wales (NSW), Australia. Surveillance by NSW Health had shown a steady increase (prior to the COVID-19 pandemic) in the number of cases reported since 2012 and the reasons for this currently remain unknown. This study aimed to investigate the occurrence of Giardia intestinalis assemblages causing human infection in NSW. Individual faecal specimens were collected from participating hospitals and private laboratories, and the presence of Giardia and co-infections was confirmed by real-time multiplex-polymerase chain reaction (PCR). Samples were genotyped by sequence analysis of the triose phosphate isomerase (tpi) gene and the small subunit rDNA. Combined genotyping showed that most samples belong to assemblage B, and only a small percentage were infected with only assemblage A. Mixtures of assemblages A and B in individuals were relatively common. Co-infections were observed in ∼ half of the cases, with the most common co-infection being Blastocystis hominis and Dientamoeba fragilis. Although giardiasis was more prevalent in males, the assemblage distribution between the sexes appeared uniform. The age distribution was bimodal, with peaks in 0–15-year-olds and in adults in their 30s. The overall largest number of cases was collected from patients aged 30–49 years. Interestingly, females aged 5 years old and under had a greater risk of assemblage B infection than their male counterparts. No significant correlation was found between assemblage and clinical symptoms. This study provides new insights into the molecular diversity of giardiasis in NSW and helps inform enhanced surveillance and prevention strategies in Sydney.

Identifying actionable genetic mutations and microsatellite instability in liquid biopsy of colorectal cancer

Background: Intestinal protozoan infection is a global health problem caused by several protozoans including Blastocystis hominis. Southeast Asia is a region with diverse demographic conditions, both in lifestyle and socio-economic conditions. Therefore, studying the prevalence and risk factors of Blastocystis sp. in this region is very interesting in order to gather precise data on this protozoan. The purpose of this study is to determine the prevalence and risk factors of Blastocystis sp. infections in Southeast Asian countries. Methods: This systematic review synthesized findings from 28 studies published between 2014 and 2024 to assess the prevalence and risk factors of these infections across Southeast Asia. Relevant articles were selected using PRISMA guidelines from databases including PubMed, Scopus, and Web of Science, focusing on observational studies that reported on human infections. Results: The analysis revealed high variability in Blastocystis sp. infection rates, ranging from 3.35% to 83.7%. Identified risk factors included sanitation, water source, personal hygiene, animal contact, demographic, health condition, and transmission. Conclusion: This study found that Blastocystis sp. prevalence in Southeast Asia varies widely and is driven by poor sanitation, unsafe water, inadequate hygiene, demographic and socioeconomic factors, and possible zoonotic transmission. These findings highlight the need for a one health approach integrating human, environmental, and pathogen factors.

Background: Emerging evidence suggests that chronic intestinal colonization by Blastocystis hominis may influence host inflammation and epithelial homeostasis, potentially contributing to colorectal carcinogenesis. However, the molecular mechanisms linking parasitic infection and tumorigenesis remain poorly understood. Objective: This study aimed to investigate the shared molecular pathways and potential biomarker candidates connecting B. hominis infection and colorectal cancer (CRC) using an integrative bioinformatics approach. Materials and Methods: Transcriptomic datasets of B. hominis–infected intestinal tissues and CRC samples were obtained from the GEO and TCGA databases. Differentially expressed genes (DEGs) were identified using limma and DESeq2, followed by overlap analysis, functional enrichment, and protein–protein interaction (PPI) network construction. Hub genes were ranked via MCODE and cytoHubba algorithms. Diagnostic performance was validated using ROC analysis. Results: A total of 114 shared DEGs (73 upregulated, 41 downregulated) were identified, mainly enriched in NF-κB, IL-17, JAK/STAT, and tight junction pathways. PPI analysis revealed five hub genes, IL6, CXCL8, STAT3, MMP9, and TNF, as central regulators of inflammation and epithelial remodeling. ROC analysis demonstrated strong diagnostic accuracy for IL6 (AUC = 0.89) and CXCL8 (AUC = 0.86), indicating their potential as dual-purpose biomarkers in infection-associated CRC. Conclusions: This integrative in silico study highlights convergent inflammatory and immune-regulatory mechanisms between B. hominis infection and colorectal cancer. The shared molecular signatures identified may serve as valuable leads for biomarker development and future mechanistic studies exploring infection-driven carcinogenesis.