Search Results (162)

Acute diarrheal disease (ADD) caused by parasites and Tuberculosis (TB) remain major public health concerns in vulnerable indigenous communities with limited access to sanitation, safe water, and healthcare, and where humans, animals and the environment interact closely. Using a One Health framework, this study investigated TB and Intestinal parasites in human, animal and environmental samples from 15 Wayuu indigenous communities in Manaure, La Guajira. A total of 190 samples, including human sputum and feces, animal milk and feces, soil and drinking water, were analyzed according to sample type, preservation suitability, and availability using parasitological concentration techniques, qPCR for helminth detection, metatranscriptomic sequencing, Xpert ^® MTB/RIF assay, and mycobacterial culture. Mycobacterium tuberculosis was detected in 8.3% of human sputum samples, with no evidence of rifampicin resistance, whereas Mycobacterium bovis was not detected in animal milk. Human fecal samples analyzed by microscopy showed Blastocystis sp. and the Entamoeba histolytica/Entamoeba dispar complex (38.8% each), followed by Giardia (19.4%), Hymenolepis nana and Trichuris trichiura (5.1% each) and Hymenolepis diminuta (1%). Commensal parasites were also identified, with Entamoeba coli (46.9%) being the most frequent species, indicating inadequate sanitary conditions and poor hygiene practices. Co-infections were common in humans (60.2%). In animal fecal samples, strongylids (66.7%), amoebas (16.7%) and Giardia (8.3%) were observed. Giardia sp. was detected in 2.38% of soil samples by microscopy, supporting environmental circulation, whereas no parasites were detected in water sediments. Multiplex qPCR detected Trichuris trichiura DNA in human feces and Trichuris spp. DNA in soil and sheep fecal samples. Metatranscriptomic analysis of 22 human fecal samples revealed a high diversity and frequency of parasitic protozoa (90.9%), with Blastocystis spp. being the most frequent (81.8%). Additionally, reads of free-living amoebae, including Acanthamoeba spp. (10%) and Naegleria spp. (5%) were detected in community drinking water sources. These findings suggest active transmission of TB and parasitic-associated ADD in Wayuu communities and highlight the need for integrated surveillance and culturally appropriate interventions focused on sanitation, hygiene, veterinary services and community health education to improve the living and health conditions of these vulnerable populations. Full article

Giardia duodenalis (synonyms G. lamblia and G. intestinalis) and Blastocystis sp. are prevalent zoonotic intestinal protozoans with significant public health and economic importance. Both parasites infect various hosts, including humans and most livestock. G. duodenalis can cause infections ranging from asymptomatic carriage to clinical manifestations such as acute diarrheal disease, growth stunting and malabsorption, whereas Blastocystsi sp. infection is often asymptomatic and its pathogenicity remains debated. Following the rapid expansion of modern equine industries (horse racing, equestrian sports, production, and tourism), concern about the spread of parasitic diseases caused by human–horse contact has gradually increased. In this study, 631 horse fecal specimens were collected from three geographical localities in Shanxi Province, North China. The prevalence and genetic characteristics of the two parasites were determined by amplification of multiple genetic loci (tpi, triosephosphate isomerase; gdh, glutamate dehydrogenase; bg, beta-giardin) for G. duodenalis and the small subunit ribosomal RNA (SSU rRNA) gene for Blastocystis sp. Overall, the prevalence of G. duodenalis and Blastocystis sp. in horses in Shanxi Province was 7.9% and 0.8%, respectively. Sequence analysis identified three assemblages (A, B, and E) of G. duodenalis and two subtypes (ST1 and ST5) of Blastocystis sp. in horses; assemblage B and subtype ST1 were detected more frequently than the other types (subtypes) in this data set. This study is the first to report G. duodenalis and Blastocystis sp. infections in horses in Shanxi Province, and these findings provide baseline molecular epidemiological data for horses in Shanxi Province and support continued hygiene management to reduce potential zoonotic transmission. Full article

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. Full article

Children living in resource-limited regions with inadequate environmental sanitation, such as the Bolivian highlands, are affected by parasitic infections that may compromise nutritional status. Objective: This study aimed to assess the prevalence of intestinal parasitic infections and their associations with nutritional status, micronutrient deficiencies, and anemia in school-aged children from La Paz, Bolivia. Methods: A cross-sectional study was conducted among 212 schoolchildren aged 5–13 years in the municipality of La Paz, in highland areas characterized by high poverty levels. Parasitological examination, anthropometric measurements, and biochemical assessment of micronutrients (vitamins A and D, zinc, iron) were performed to evaluate children’s health status. Results: Mild malnutrition was more prevalent than moderate-to-severe forms. Micronutrient analysis revealed substantial deficiencies in vitamin A (39%), zinc (25%), and vitamin D (18%). Zinc deficiency was significantly more common in children aged 11–13 years compared to younger age groups (p = 0.034). Intestinal protozoan infections showed significant associations with micronutrient deficiencies. Giardia lamblia infection was associated with both vitamin A (30.9%, p = 0.042) and vitamin D (78.9%, p = 0.001) deficiencies. Blastocystis spp. infection was similarly linked to higher prevalence of vitamin A (35.8%, p = 0.025) and vitamin D (69.7%, p = 0.004) deficiencies. Entamoeba coli infection was significantly associated with vitamin D deficiency (p = 0.021), while Iodamoeba bütschlii infection showed a significant association with zinc status (p = 0.027), with notably lower zinc deficiency prevalence in infected children (7.7%) compared to non-infected children. Among helminth infections, Ascaris lumbricoides was significantly associated with vitamin D deficiency (37%, p = 0.018). Moderate-to-severe anemia was highly prevalent, affecting over half of the children regardless of sex. Wasting (BAZ) was significantly associated with age (p = 0.030), with moderate-to-severe cases most prevalent in children aged 5–7 years and absent in older groups, while mild wasting increased with age. In univariate logistic regression analysis, zinc deficiency emerged as a significant risk factor for anemia (OR = 2.51, 95% CI: 1.19–5.29, p = 0.016). No significant associations were observed between anemia and sex, age group, vitamin A or D status, or anthropometric indicators including underweight, stunting, or wasting. Conclusions: These findings highlight the substantial burden of micronutrient deficiencies, parasitic infections, and anemia among children in this impoverished region, underscoring the urgent need for targeted public health interventions addressing nutritional supplementation, parasite control, and improved sanitation. Full article

The intestine is considered a habitat for both bacteria and parasites. In this study, many fecal bacterial isolates and the protozoan Blastocystis sp. were recovered from stool samples of individuals with gastrointestinal conditions. Isolated bacteria were tested for extracellular protease production, and the most potent producer was identified by 16SrDNA gene sequencing as P. aeruginosa FZM498. The enzyme was extracted and purified to electrophoretic homogeneity by the DEAE-Sepharose ion-exchanger and SDS-PAGE revealed a major band at 42.15 KDa. It exhibited maximal activity at 35 °C with thermostability at 60 °C (T_1/2 = 200.04 min). It was most active at pH 8.0 and stable at 5.0–9.5. Enzymatic activity was greatly stimulated in the presence of Fe²⁺ ions, but was repressed by Zn²⁺ and Hg²⁺ ions. Inhibition by PMSF, TLCK, aprotinin, benzamidine, and SBTI protease reagents suggests a serine protease family. The V_max and K_m dynamic constants against azocasein were 36.232 U/mL and 0.0072 mM, respectively. It exhibited the lowest K_m value against the synthetic substrate D-Val-Leu-Lys-pNA among all substrates, indicating a plasmin-like activity. Interestingly, when tested against Blastocystis sp., cysts appeared progressively shrunken, ruptured, and mycelial-like, indicating complete structural collapse with leakage of intracellular contents. The importance of this research is that it is the first study to test the anti-Blastocystis activity of an extracted bacterial serine protease from the gut. This could be a promising, eco-friendly, natural alternative as an anti-Blastocystis agent. The objective of this study was to isolate, purify, and biochemically characterize an extracellular serine protease produced by gut-associated bacteria, as well as to assess its in vitro anti-Blastocystis efficacy as a potential natural and ecologically friendly antiparasitic therapy. Full article

Thalassogenic diseases are human infections associated with exposure to marine environments. This review explores the occurrence of Cryptosporidium spp., Giardia duodenalis, and Blastocystis sp. in seawater and shellfish and their implications for public health. Between 2015 and 2026, multiple studies reported the presence of these parasites in shellfish and seawater. Cryptosporidium spp. was found at average concentrations of 5.5 × 10¹ oocysts/g in shellfish and up to 3.7 × 10¹ oocysts/L in seawater. Giardia duodenalis reached 9.1 × 10¹ cysts/g in shellfish, close to the infectious dose, and 3.5 × 10¹ cysts/L in seawater. Blastocystis sp. showed prevalence rates of 33.82% in shellfish and 17.3% in seawater. These findings highlight a potential infection risk for bathers and seafood consumers, emphasizing the need to determine the specific species (or subtypes) involved and assess their viability to accurately evaluate public health implications. The persistence of these parasites in the environment needs improved monitoring. Future strategies should integrate next-generation sequencing (NGS) or use of various fecal indicators to enhance environmental surveillance and reduce health risks in coastal regions. Full article

Background: Recent studies have shown that digital microscopy (DM) combined with a convolutional neural network (CNN) model is a valid approach for detecting intestinal protozoa and helminth ova or larvae in both trichrome-stained and wet-mount stool preparations. This study evaluated the diagnostic performance of a DM/CNN workflow for routine detection of intestinal parasites in a clinical microbiology laboratory. Methods: A clinical validation was conducted using the Grundium Ocus 40 scanner combined with the Techcyte Human Fecal Wet Mount (HFW) algorithm. The system was evaluated on (a) 135 reference samples and (b) 208 routine clinical samples submitted for intestinal parasite testing. Analytical sensitivity, precision, and limit of detection (LOD) were assessed. Results: For reference samples, the DM/CNN workflow achieved a positive slide-level agreement of 97.6% (95% CI: 94.4–100%), following a confidence threshold adjustment for Schistosoma mansoni, and a negative agreement of 96.0% (95% CI: 86.6–98.9%) compared with light microscopy (LM). Dilution series with reference samples revealed slightly lower analytical sensitivity of the DM/CNN at higher dilutions. Both intra- and inter-run precision studies demonstrated high reproducibility and stability. In prospective testing on 208 routine samples, overall agreement between DM/CNN and LM was 98.1% (95% CI: 95.2–99.2%) with a Cohen’s Kappa coefficient of κ = 0.915. Minor discrepancies involved Blastocystis spp., with DM/CNN showing slightly higher sensitivity. Conclusions: For the first time, we show that the combination of the Grundium Ocus 40 scanner and the Techcyte HFW algorithm provides a reliable, low-throughput screening solution that can effectively assist diagnostic technicians by pre-classifying putative parasitic structures for targeted expert review. Despite its lower throughput, the system substantially reduces the manual review process and simplifies the parasitological workflow. Implementation in a clinical microbiology laboratory requires extensive site-specific validation to account for differences in sample processing and imaging conditions. Moreover, optimization of confidence thresholds for specific classifiers is essential to ensure consistent analytical performance across different laboratory settings. Full article

Intestinal protozoa are a common cause of morbidity in people living with HIV (PWH), particularly in tropical regions with poor sanitation. We conducted a cross-sectional study in 315 PWH from Iquitos, Peru, between October 2023 and May 2024, to assess their prevalence and risk factors. Stool samples were examined using Lugol’s iodine, modified Ziehl–Neelsen (MZN) staining, and immunochromatography (ICT). The mean age was 41 years, with a median CD4+ count of 431 cells/µL; 12.4% were in the AIDS stage, and 21.5% had a detectable viral load. 51.4% of the participants tested positive for any intestinal protozoa. The overall Cryptosporidium spp. prevalence (by combining MZN and ICT results) was 25.7%. The overall Giardia spp. and Entamoeba spp. prevalences (by combining Lugol’s iodine and ICT results) were 2.9% and 1.9%, respectively. Blastocystis spp. was frequently isolated, though its pathogenicity remains uncertain. Diagnostic agreement was almost perfect between Lugol and ICT for Giardia and Entamoeba (κ = 0.87; p < 0.001 and κ = 0.91; p < 0.001, respectively), but only slight between MZN and ICT. Homosexual practices were identified as a significant risk factor for pathogenic protozoa infection (AOR 2.52; 95% CI: 1.04–6.12). In conclusion, the high prevalence of protozoa infection reflects ongoing fecal–oral exposure, underscoring the need for public health education, routine diagnosis, and treatment in similar settings. Full article

Urticaria is a skin disorder characterized by erythematous, edematous, and pruritic lesions. Intestinal microorganisms can trigger various immunological responses, and Blastocystis has been suggested to affect gut-associated lymphoid tissue homeostasis and induce allergic reactions. This study aimed to evaluate the effect of Blastocystis on the intestinal microbiota in patients with urticaria. A total of 33 patients diagnosed with urticaria and 34 healthy controls were included. Independent sample t-tests, Welch’s t-tests, or Mann–Whitney U tests were applied to assess differences in the Shannon, Simpson, and Chao-1 indices between groups. Significant differences were observed in Proteobacteria (p = 0.015), Bacteroidetes (p = 0.008), Escherichia (p = 0.005), Phocaelcola (p = 0.043), and Prevotella (p = 0.047) between the urticaria and control groups. Bacteroidetes (p = 0.003) and Phocaelcola (p = 0.032) also differed significantly between samples with and without Blastocystis. Overall microbiota composition showed a significant difference between Blastocystis-positive and -negative samples (p = 0.009). The Firmicutes/Bacteroidetes ratio was 4.1 in healthy controls and 6.4 in urticaria patients. In conclusion, both urticaria and Blastocystis infection significantly influence intestinal microbiota composition, suggesting a potential interaction between Blastocystis colonization and host immune regulation in urticaria. Full article

Here, 18S-rDNA sequences of Blastocystis sp., previously documented from symptomatic (cases) and asymptomatic (controls) carriers, were analyzed to determine their population structure, predict their secondary structure, and examine their interactions with ribosomal proteins (Bud23, RPS5, and RPS18). Phylogenetic and population differentiation analyses were performed using STRUCTURE software V2.3.4. Moreover, an analysis of the rRNA secondary structure and folding of each sequence was performed, and their probability of interaction with ribosomal proteins was determined. Phylogenetic and haplotype analyses sorted the sequences into genetic subtypes ST1, ST2, and ST3, while the population structure showed each cluster as a differentiated subpopulation, suggesting incipient speciation or cryptic species differentiation. Furthermore, the analysis of the secondary structure of rRNA exhibited specific arrangements for each subtype. In addition, the probability of interaction between 18S-rRNA sequences of Blastocystis from cases and controls with RPS5 and RPS18 was significant, matching the biological plausibility of the previously documented finding that control isolates had a lower generation time than isolates obtained from cases. These findings reinforce the hypothesis that ribosomal subtypes ST1–ST3 of Blastocystis represent evolutionarily distinct lineages with the potential to be recognized as future species. Furthermore, they underscore the functional relevance of 18S-rRNA sequences from clinical isolates of Blastocystis. Full article

Background/Objectives: The effects of geographical origin, alongside age, diet, and drug treatments, on the gut microbiota have not been thoroughly analyzed in African countries. Furthermore, eukaryotic components, including Blastocystis, the most common intestinal protozoan worldwide, require further investigation. This study compares the gut microbiota of Italian subjects with that of two African groups to examine the influence of dietary patterns and the effects of Blastocystis presence and subtypes. Methods: Three cohorts of healthy subjects (Italians residing in Rome, Africans residing in the Côte d’Ivoire, and Africans living in Italy) were compared by sequencing the V3-V4 hypervariable regions of the 16S rDNA gene. Taxa abundance and associations with typical West African and Italian foods were determined using DESeq2. Co-abundant genera were identified with a weighted correlation network analysis (WGCNA). Blastocystis subtypes were determined and correlated with the microbial composition in the three groups. Results: Distinct microbial taxa were associated with specific foods, including palm oil, Cube Maggi, sunflower oil, and olive oil. A Mediterranean diet consumed for over two years did not alter the abundance of Faecalibacterium and Dorea in the Africans living in Italy compared with Africans living in Côte d’Ivoire, whereas differences were observed in the abundance of some Prevotella-9, Bacteroides, and Lachnospiraceae OTUs. Significant associations were identified between palm oil and Subdoligranulum, Cube Maggi and Dorea, sunflower oil and the Ruminococcus torques group, and olive oil and Faecalibacterium. Concerning Blastocystis, alpha and beta diversity analysis showed a significant separation between carriers and non-carriers. Conclusions: This study provides the first comparative analysis of gut microbiota composition between individuals from Côte d’Ivoire and Italians focusing on the influence of distinct dietary patterns. Full article

Coastal fecal contamination is a global public health concern, particularly due to waterborne protozoan parasites such as Giardia duodenalis and Blastocystis sp. Concepcion Bay (Chile) is an important recreational and productive area in Chile. Nevertheless, it is impacted by two submarine outfalls and a rural sewage treatment plant, which may contribute to fecal pollution. This study evaluated the presence of waterborne parasites in Aulacomya atra mussels intended for human consumption. The mussels were collected from three sectors of the bay: northern, central, and southern. A total of 600 mussels were analyzed as accumulators using PCR targeting SSU-rDNA and β-giardin genes for the detection of Blastocystis sp. and G. duodenalis, respectively. Additionally, thermotolerant coliforms were quantified using the most probable number (MPN) method. Both parasites and coliforms were detected in all sectors, with the southern zone showing the highest number of positive samples, indicating a localized public health concern. This is the first report of these protozoa in mussels from Concepción Bay. The findings highlight the need for regulatory frameworks to control protozoan discharge and reduce pathogen transmission risks in coastal ecosystems, especially in areas with high recreational and economic activity, both in Chile and worldwide. Full article

Diet and gut microbiota are significant determinants of host health, but how dietary quality modulates gut microbiota in Blastocystis-colonised individuals remains underexplored. We studied two contrasting cohorts: university students (FACSA, n = 46) and institutionalised children with their caregivers (PAVILA, n = 37), representing distinct dietary and sociodemographic contexts. Eight participants from each cohort tested positive for Blastocystis; however, two PAVILA samples could not be sequenced, resulting in a final microbiota subcohort of 14 individuals (FACSA n = 8, PAVILA n = 6). Dietary quality was assessed using the Healthy Eating Index-2020 (HEI-2020), and faecal microbiota was characterised through 16S rRNA sequencing. Alpha and beta diversity were analysed, and genus-level transformed data were further evaluated using permutational multivariate analysis of variance (PERMANOVA), principal coordinates analysis (PCoA), and distance-based redundancy analysis (db-RDA). The FACSA cohort exhibited higher microbial richness and diversity (Shannon and Simpson indexes, p < 0.01) compared to PAVILA, with marked differences in microbial composition (PERMANOVA R² = 0.39, p = 0.002). Total diet quality correlated with microbial structure (R² = 0.26, p = 0.016), with protein (R² = 0.23, p = 0.017) and vegetable components (R² = 0.17, p = 0.044) as primary contributors. Multivariate analysis showed that higher protein and vegetable intakes were associated with genera such as Sellimonas, Murimonas, Alistipes, and Desulfovibrio (FACSA group). In contrast, Hydrogenoanaerobacterium, V9D2013_group, and Haemophilus were linked to lower-quality diets (PAVILA group). Our results indicate that diet quality significantly influences gut microbiota composition in individuals colonised by Blastocystis, underscoring its potential as a target for nutritional interventions in vulnerable populations. Full article

Blastocystis spp. is an enteric protist that is present worldwide. Despite being discovered a century ago, there is still much to be learned about its pathogenicity and transmission. Different subtypes (ST) of Blastocystis spp. have been identified in various hosts, including humans, birds, and insects, and there is potential for zoonotic transmission through contact between humans and animals. The prevalence of Blastocystis spp. in humans and macaques in Singapore was understudied, and the findings revealed a significant prevalence of the parasite, with rates of 90% and 100% observed in each respective Macaca fascicularis population 1 and 2, with main subtypes (ST1, ST2, ST3, and ST5). Using metagenomics, the different subtypes of Blastocystis spp. (comprising ST2, ST3, and ST17) were identified in a healthy Singaporean cohort. Additionally, seven incidental findings of Blastocystis spp. were discovered in human patients with other gut parasites, including two ST1, two ST2, two ST3, and one ST8. Several factors such as diet or reverse zoonotic transmission are suggested to play a role in Blastocystis sp. subtype distribution. Full article

Gastrointestinal (GI) parasitic infections in non-human primates are of growing concern due to their implications for both veterinary and public health. Long-tailed macaques (Macaca fascicularis), commonly found in peri-urban and temple environments in Southeast Asia, may act as reservoirs for zoonotic parasites, posing risks to humans and domestic animals. This study investigated the prevalence and species diversity of GI parasites in free-ranging macaques from four provinces in Northeast Thailand (Loei, Khon Kaen, Bueng Kan, and Sisaket). A cross-sectional study was conducted between April and May 2025. A total of 445 fecal samples were examined using two parasitological techniques: agar plate culture (APC) and the formalin–ethyl acetate concentration technique (FECT). The overall prevalence of parasitic infection was 86.5%, with Strongyloides sp. (65.2%) as the most prevalent helminth and Balantioides coli-like (29.5%) and Entamoeba histolytica-like (28.8%) as the predominant protozoa. Other parasites identified included helminths (Trichuris sp., Ascaris sp.) and protozoa (Blastocystis sp., Iodamoeba bütschlii, Entamoeba coli, and Chilomastix mesnili). Mixed infections were frequently observed, with both helminths and protozoa co-occurring in 37.3% of cases. The high infection rates and parasite diversity reflect substantial environmental contamination and sustained transmission cycles. These findings underscore the importance of integrated surveillance in wildlife populations and the need for One Health-based approaches to minimize zoonotic transmission risks at the human–animal–environment interface. Full article