Search Results (80)

Limited molecular data exist on zoonotic parasites Cryptosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi in Angus calves from Guizhou, China. This study constitutes the first molecular epidemiological survey of these pathogens in this region. 817 fecal samples from Angus calves across 7 intensive beef farms (Bijie City). Nested PCR methods targeting SSU rRNA (Cryptosporidium spp.), gp60 (Cryptosporidium bovis subtyping), bg/gdh/tpi (G. duodenalis), and ITS (E. bieneusi) coupled with DNA sequencing were employed. DNA sequences were analyzed against the NCBI. database. Statistical differences were assessed via a generalized linear mixed-effects model. Cryptosporidium spp. prevalence 23.5% (192/817; 95% CI 28.1–34.6%), with C. bovis predominating 89.6% (172/192; 95% CI 84.4–93.5%) and six subtypes (XXVIa-XXVIf). Highest infection in 4–8-week-olds 29.9% (143/479; 95% CI 25.8–34.1%) (p < 0.01). G. duodenalis: 31.3% (256/817; 95% CI 28.1–34.6%) positive, overwhelmingly assemblage E 97.6% (6/256; 95% CI 0.9–5.0%), zoonotic assemblage A was marginal 0.7% (6/817; 95% CI 0.3–1.6%). Farm-level variation exceeded 10-fold (e.g., Gantang: 55.0% (55/100; 95% CI 44.7–65.0%) vs. Tieshi: 4.9% (5/102; 95% CI 1.6–11.1%). E. bieneusi: prevalence 19.7% (161/817; 95% CI 17.0–22.6%), exclusively zoonotic genotypes BEB4: 49.7% (80/161; 95% CI 41.7–57.7%); I: 40.4% (65/161; 95% CI 32.7–48.4%). Strong diarrhea association (p < 0.01) and site-specific patterns (e.g., Guanyindong: 39.2%). While Giardia exhibited the highest prevalence (31.3%) with minimal zoonotic risk, Enterocytozoon—despite lower prevalence (19.7%)—posed the greatest public health threat due to exclusive circulation of human-pathogenic genotypes (BEB4/I) and significant diarrhea association, highlighting divergent control priorities for these enteric parasites in Guizhou calves. Management/Public health impact: Dominant zoonotic E. bieneusi genotypes (BEB4/I) necessitate: 1. Targeted treatment of 4–8-week-old Angus calves. 2. Manure biofermentation (≥55 °C, 3 days), and 3. UV-disinfection (≥1 mJ/cm²) for karst water to disrupt transmission in this high-humidity region. Full article

Zoonotic opportunistic enteric protozoa represent a significant global health threat to immunocompromised populations, especially individuals with human immunodeficiency virus (HIV). Despite China’s severe HIV burden, molecular epidemiological data on enteric protozoa remain limited in this population. In this study, we investigated the occurrence and molecular characteristics of Cryptosporidium species, Giardia duodenalis, and Enterocytozoon bieneusi among 150 AIDS patients with severe immunodeficiency in Wuhan city, Hubei Province, China. The overall test-positive rate was 5.33% (8/150), comprising Cryptosporidium species (including C. hominis, C. parvum, and C. meleagridis) in 2.00% (3/150) and G. duodenalis (including assemblage A, B, and E) in 3.33% (5/150); E. bieneusi was not detected. Notably, this study reports the first identification of the C. parvum subtype IIcA5G3 in humans in China, certainly indicating possible cross-border transmission. Furthermore, the detection of C. meleagridis IIIbA22G1R1c provided additional molecular evidence for chicken-to-human transmission. The finding of G. duodenalis assemblage E highlights the underrecognized zoonotic spillover risks to immunocompromised populations. These findings emphasize the diversity of infectious reservoirs, and the need for enhanced national molecular surveillance of these neglected zoonotic enteric protozoa, alongside targeted interventions for vulnerable populations. Full article

Waterborne gastrointestinal infections remain a global health concern, with approximately 1.7 billion diarrhea-related illnesses annually attributable to protozoan parasites. These pathogens are transmitted through contaminated water and exhibit high resistance to chlorination, posing substantial challenges to effective water treatment. This study focused on the most prevalent intestinal parasites in the Los Ríos Region of Chile: Blastocystis sp., Giardia duodenalis, and Entamoeba coli. The objectives were to assess the prevalence of eukaryotic parasites in water samples—covering both drinking and recreational sources—to describe the circulating subtypes of Blastocystis sp. and to identify ecological factors associated with parasite presence. Water samples were analyzed using conventional PCR, next-generation sequencing (NGS) was employed for Blastocystis sp. subtype identification, and the environmental predictors were evaluated using a multivariable logistic regression model. A total of 132 water samples were analyzed, of which 15.2% were positive for Blastocystis sp. and 1.5% for E. coli, while no samples tested positive for G. duodenalis. We identified subtypes ST1–ST4 of Blastocystis sp., along with ST7, ST10, ST14, ST21, and ST23–ST26, the latter being reported for the first time in Chile. Ecological factors significantly associated with Blastocystis sp. presence included higher water temperature and greater rainfall at positive sites. Potable water was associated with significantly lower odds of Blastocystis sp. infection (aOR = 0.04, 95% CI: 0.00–0.87; p = 0.041), while precipitation increased infection odds by 3% per additional millimeter (aOR = 1.03, 95% CI: 1.00–1.06; p = 0.036). Greater distance to the nearest farmhouse was also significantly associated with reduced infection risk, suggesting that proximity to livestock environments may influence Blastocystis sp. transmission. These findings help explain the high prevalence of Blastocystis sp. observed in humans in the Los Ríos Region and highlight the pivotal role of ecological conditions in driving waterborne transmission. To our knowledge, this is the first environmental study in Chile to clearly demonstrate the association between human infection, environmental factors, and the transmission dynamics of Blastocystis sp. Full article

Enterocytozoon bieneusi and Giardia duodenalis are major zoonotic pathogens that often cause diarrhea in immunocompromised humans or animals. Beef cattle are important reservoirs for these two pathogens. Yunnan Province is a major region for beef cattle farming, and its suitable climatic conditions facilitate the transmission of the pathogens. However, research on the prevalence and distribution of E. bieneusi and G. duodenalis in beef cattle in Yunnan remains understudied. This study collected 529 fecal samples from seven beef cattle breeds in four regions in Yunnan Province for an epidemiological survey. Nested PCR combined with sequencing was used to detect E. bieneusi and G. duodenalis, and the sequencing results were analyzed to determine genotypes or assemblage types. Our results demonstrate that the prevalence rates of E. bieneusi and G. duodenalis were 3.0% (16/529) and 3.6% (19/529), respectively. The study identified four genotypes of E. bieneusi, including I (n = 8), J (n = 4), BEB8 (n = 3), and BEB4 (n = 1). Both assemblages E (n = 18) and A (n = 1) were identified among G. duodenalis-positive animals. Phylogenetic analysis revealed that the E. bieneusi genotypes detected in this study belong to Group 2. In conclusion, these findings indicate that although the overall prevalence is relatively low compared to other regions, the presence of zoonotic Group 2 genotypes and assemblage A highlights the potential risk of cross-species transmission. Moreover, the results provide foundational data to support the development of region-specific surveillance and control strategies for bovine giardiasis and microsporidiosis, and emphasize the importance of the One Health approach in managing parasitic infections in livestock populations. Full article

Flagellates of the genus Giardia are intestinal parasites with a broad host range. Several Giardia duodenalis variants (assemblages) recently elevated to species rank—G. duodenalis (assemblage A1), G. intestinalis (A2) and Giardia enterica (B) are human pathogens. Giardia enterica has been reported in some hystricomorph rodents such as wild crested porcupines (Hystrix cristata), but no data were previously available from Brazilian porcupines (Coendou prehensilis) and naked mole rats (Heterocephalus glaber). The aim of this study is to genetically identify the Giardia isolates from these three rodent species, all housed in a zoological institution. Fecal samples were processed using the Bailenger concentration method, and DNA was extracted from the sediments using commercial kits. Partial PCR amplification and sequencing of the glutamate dehydrogenase, beta-giardin, and triose-phosphate isomerase genes revealed that all isolates belonged to G. enterica, showing 99–100% identity with sequences available in GenBank. Prevalences could not be reliably estimated due to small group sizes and the resulting proportions may be biased. To our knowledge, this is the first report identifying Giardia (G. enterica) in C. prehensilis and H. glaber, thus expanding the known host range of this parasite species and reinforcing the importance of surveillance in captive wild hosts. Full article

Giardia duodenalis is a flagellated protozoan pathogen causing parasitic enteric disease outbreaks worldwide. Among detection methods, loop-mediated isothermal amplification (LAMP) has high selectivity and sensitivity, and the detection time is lower than that of conventional molecular methods. In this study, three published Giardia LAMP primer sets were tested and adapted to touchdown LAMP conditions. The measurement time, the volume of reagents, the effect of the denaturation step, different kinds of polymerases, and the presence or absence of betaine on the reaction were tested and evaluated. Based on the results of this study, the 66–60 °C range touchdown LAMP with the use of betaine, 90 °C denaturation step, Bst 2.0 WarmStart^® DNA Polymerase, and the primer set of Momoda et al. were the optimal conditions. We increased the analytical sensitivity of the LAMP reaction to 7.8- and 8-fold higher than the previously published methods for G. duodenalis assemblages A and B, with detection limits of 20 and 19.5 fg/assay, respectively, instead of 156 fg/assay. The detection time was less than 49 min for G. duodenalis assemblage A and less than 35 min for assemblage B, compared to the previously published 60 min. Our optimized LAMP protocol can be directly applied to improve Giardia LAMP tests in routine testing laboratories, could be implemented in standard diagnostic or environmental monitoring workflows, and can be used for the development of Giardia LAMP point-of-care devices or high-throughput systems. Full article

Parasitic infections pose a significant global health burden, affecting millions of people worldwide. Despite their importance, studies integrating human and animal parasitology to understand transmission pathways are scarce. This study, conducted between August 2022 and April 2023, aimed to investigate the prevalence of parasites in humans and domestic dogs in the Los Rios Region, southern Chile, and explore the risk factors associated with parasitism. A total of 291 human participants provided fecal and blood samples for parasitological and serological analyses, while 92 fecal samples from owned dogs were analyzed. The detection of intestinal parasites employed microscopy and molecular techniques, including next-generation sequencing (NGS). Anti-Toxocara canis and anti-Echinococcus granulosus antibodies in humans were assessed using ELISA. Socioeconomic surveys explored the risk factors associated with parasitism. The results showed a parasite prevalence of 39% in humans and 40% in dogs. Anti-Toxocara canis IgG antibodies were detected in 28.2% of humans. Zoonotic subtypes of Giardia duodenalis and Blastocystis sp. were identified. Thus, the results of our study indicate a high prevalence of intestinal and extraintestinal parasites in the human population of our region. Furthermore, our findings underscore the significant risk of zoonotic transmission of parasites from companion animals. This study contributes to the understanding of parasite transmission dynamics in southern Chile and has implications for public health policy and practice. The results emphasize the importance of considering the connection between human, animal, and environmental health to develop effective control strategies and mitigate the impact of parasitic infections. Full article

Cryptosporidium spp. and Giardia duodenalis are important diarrheal agents in children in developing countries. Little is known about their molecular epidemiology; as such, the objective of this study was to determine the risk factors and genetic diversity of both parasites in diarrheal samples in Mozambique. In this study, two nested PCRs targeting ssurRNA and gp60 genes were used for genetic diversity of Cryptosporidium spp. and b-giardin for G. duodenalis. Sociodemographic and clinical characteristics were obtained through questionnaires. The location (odds ratio [OR] 3.499), mother’s education level (OR 2.150) and age were significant factors for acquiring infection by Cryptosporidium spp. (p < 0.05). Cryptosporidium hominis was the predominant (77.8%) species. Four families (three C. hominis and one C. parvum) were identified, with the highest for Ib (73.9%), followed by Id (13%), Ia (8.7%) and IIc (4.3%). The location (p-value < 0.001), drinking untreated water (p-value = 0.04) and living in masonry houses (p-value = 0.002) were identified as risks associated with G. duodenalis infection. Assemblage A was the dominant type (65.2%). Among the subassemblages of assemblage A, AII was the most frequent (86.6%), followed by AIII (6.6%). For assemblage B, subassemblages BIII (87.5%) and BIV (12.5%) were identified. The dominance of the subtype IbA9G3 of C. hominis, as well as the AII subassemblage of G. duodenalis, seems to indicate that the transmission of both protozoa occurs mainly through the anthroponotic route. Full article

Giardia duodenalis is a zoonotic parasite that causes gastrointestinal diseases in both humans and animals. To evaluate the prevalence and genetic diversity of G. duodenalis in black goats, we collected 539 fecal samples from nine districts in Fujian Province, China. The presence of G. duodenalis was confirmed through nested PCR targeting the SSU rRNA gene, and genotyping was performed at the beta-giardin, glutamate dehydrogenase, and triosephosphate isomerase loci. Among the samples, 115 tested positive, yielding an overall infection rate of 21.34%. Assemblages A and E were identified, with assemblage E being predominant. Statistical analysis revealed significant regional differences in infection rates (p < 0.01), with Zhangzhou exhibiting the highest infection rate (39%) and Fuzhou the lowest (3.13%). No significant differences in infection rates were observed based on age: 24.56% (56/228) for goats <1 year, 14.92% (27/181) for goats 1–2 years, 26.8% (26/97) for goats 2–3 years, and 18.18% (6/33) for goats ≥ 3 years. Similarly, no significant differences were found between sexes: 24.84% (40/161) for males and 19.84% (75/378) for females. Notably, assemblage A, a zoonotic genotype, was detected, indicating a potential risk of cross-species transmission. This study contributes to a deeper understanding of G. duodenalis in black goats and provides critical data for the development of targeted control strategies in Fujian Province. Full article

Cryptosporidium spp. and Giardia duodenalis are zoonotic food- and water-borne protozoa of veterinary importance. They are one of the main causes of diarrhea in domestic dogs (Canis familiaris). Wild canids, such as red foxes (Vulpes vulpes) and raccoon dogs (Nyctereutes procyonoides), can act as natural reservoirs for these parasites. The aim of this study was to estimate the prevalence of these pathogens and analyze possible factors that may affect the infection in wild and domestic canids. A total of 373 domestic dog, 219 red fox, and 78 raccoon dog fecal samples were collected and tested for Cryptosporidium spp. and G. duodenalis presence with direct immunofluorescent staining. The dog owners filled a questionnaire on the dog’s habits and lifestyle to identify and analyze potential factors that may affect the occurrence of these parasites in dogs. Cryptosporidium spp. were found in 16.3%, 28.3%, and 28.2% and G. duodenalis in 0.7%, 27.4%, and 30.8% of the examined dogs, red foxes, and raccoon dogs, respectively. The highest prevalence was observed in puppies—15.4% and 18.5% for Cryptosporidium spp. and G. duodenalis, respectively. In all three canid species, infection with Cryptosporidium increases the risk of co-infection with Giardia and vice versa. Full article

Objective: This study aims to determine the association between anthropometric values and laboratory tests with parasitosis diagnosis and identify diagnostic models for parasitosis without relying on copro-parasitological examinations. Methods: Data were collected from 1894 children aged 0–14 who attended a medical center for low-income children in Lima, Peru, between 2021 and 2022. Anthropometric data (BMI, weight, height), laboratory data (red blood cells, hemoglobin, platelets, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, eosinophils), and parasitological examination results were analyzed. Prevalence ratios for the association between parasitosis and each anthropometric and laboratory variable were estimated using multivariable Poisson regression. Regression models were developed for each type of parasite found, and the diagnostic value was assessed using ROC curves. Results: A high prevalence of parasitosis was identified (41.9%), including Blastocystis hominis (29.1%), Endolimax nana (7.76%), Entamoeba coli (5.97%), Giardia duodenalis (6.44%), and Enterobius vermicularis (1.85%). It was found that the male sex (PRa 1.18), the age group of 2–5 years (PRa 4.83) and >5 years (PRa 4.59), the percentage of eosinophils (PRa 1.02 for every 1% increase), and height/age with −5 SD (PRa 1.34) were associated with a greater risk of parasitosis. Satisfactory values were only shown for diagnostic models associating Enterobius vermicularis and BMI, with a diagnostic value of 70.9% and 70.2% for a BMI < 12 and hematocrit > 29.8%, and BMI < 12 and hemoglobin < 10.6 g/L, respectively. Conclusions: Satisfactory diagnostic value models were only found for parasitosis by Enterobius vermicularis, suggesting the potential for reducing reliance on copro-parasitological exams in resource-limited settings. Full article

Berries represent healthy dietary options and contain bioactive compounds associated with a decreased risk of diseases. Despite representing healthy food choices, these products can be contaminated by pathogenic microorganisms, including parasites. Among foodborne parasites, Giardia duodenalis, Cryptosporidium parvum, Cyclospora cayetanensis, Toxoplasma gondii, and Echinococcus multilocularis are of significant public health importance and have been recently detected in fresh berries in Europe, including Italy. Berries can be purchased fresh or frozen, and it is worrying that even frozen berries could represent a risk for the consumer. In fact, several parasites can resist freezing temperatures and have been responsible for outbreaks of infection. The aim of this study was to investigate the presence of G. duodenalis, C. parvum, C. cayetanensis, T. gondii, and E. multilocularis in frozen berries with simplex and multiplex real-time PCR protocols. A total of 108 packages of mixed frozen berries were bought from supermarkets located in a south-eastern region of Italy. The samples were tested using two simplex real-time PCR protocols targeting C. parvum and G. duodenalis, respectively, and a multiplex real-time PCR targeting C. cayetanensis, T. gondii, and E. multilocularis. None of the investigated parasites were detected in the frozen berry samples tested. This research topic is still unexplored and of great current interest. These results represent a first attempt to investigate parasitic contamination of frozen berries sold on the Italian market, but further large-scale surveys are required. Full article

Giardia duodenalis, Cryptosporidium parvum, Blastocystis spp. and Enterocytozoon bieneusi are four common zoonotic parasites associated with severe diarrhea and enteric diseases. In this study, we developed a multiplex PCR assay for the simultaneous detection of these four zoonotic protozoans in goat stool samples and assessed its detection efficiency. Specific primers were designed from conserved gene sequences retrieved from GenBank, and the PCR conditions were optimized. Genomic DNA from 130 samples was subjected to both single-target PCR and multiplex PCR. The multiplex PCR assay successfully amplified specific gene fragments (G. duodenalis, 1400 bp; C. parvum, 755 bp; Blastocystis spp., 573 bp; E. bieneusi, 314 bp). The assay sensitivity was ≥10² copies of pathogenic DNA clones with high specificity confirmed by negative results for other intestinal parasites. The detection rates were 23.08% (30/130) for G. duodenalis, 24.62% (32/130) for C. parvum, 41.54% (54/130) for Blastocystis spp., and 12.31% (16/130) for E. bieneusi, matching the single-target PCR results. The sensitivity and predictive values were 100.00%. This multiplex PCR provided a rapid, sensitive, specific, and cost-effective approach for detecting these four parasites. It also provided essential technical support for the rapid detection and epidemiological investigation of G. duodenalis, C. parvum, Blastocystis spp., and E. bieneusi infections in goat fecal samples. Full article

Giardia doudenalis (lamblia, intestinalis) is a protozoan parasite that inhabits the lumen of the upper small intestine of vertebrates, causing chronic abdominal pains and severe diarrhea, symptoms of giardiasis, a persistent and recurrent infection. This characteristic is mainly due to the presence of membrane variant-specific surface proteins (VSPs) that give this parasite the ability to successively infect the host through antigenic variation. Using high-resolution scanning microscopy (HR-SM), we observed the presence, formation, and extension of tunneling-nanotube-like surface structures in Giardia, especially following parasite challenges with VSP antibodies. They were seen all over the parasite surface, both in vitro and in vivo, showing that G. duodenalis nanotube formation occurs in complex environments such as the gut. In addition, we also observed that some of these nanotubes displayed a periodic strangulation that produces 100 nm vesicles that seemed to be released in a process similar to that previously observed in Trypanosoma brucei. The presence of nanotube-like structures in G. duodenalis highlights yet another strategy of cellular communication utilized by these parasites, whether between themselves or with the host cell. Full article

Non-human primates (NHPs) host a variety of helminth and protist parasites that are able to cause infection in humans. Gastrointestinal parasites in NHPs living in two zoological gardens of Northern Italy were studied. An total of 96 faecal pools were collected from 26 groups of NHPs. The mini-Flotac method was applied to fecal samples to detect gastrointestinal helminthiases, while the detection of the protists Cryptosporidium spp., Blastocystis sp. and Giardia duodenalis was performed by targeting SSU rRNA through nested PCR and real-time PCR; they were further studied by sequencing the same gene for Blastocystis and βgiardine and triosephosphate isomerase (TPI) genes for Giardia. Twenty-two out of the 96 examined fecal pools (22.9%) were positive for one or more helminth species, including Hymenolepis diminuta, Trichurid, Capillariid and Strongylid eggs. All samples were negative for Cryptosporidium spp., while 16/26 (61.5%) animals were positive for G. duodenalis in the real-time PCR; the sequences obtained assigned them all to sub-assemblage BIV. Blastocystis sp. was detected in 22/26 of the NHPs (84.6%); molecular analyses attributed the isolates to ST 4, allele 92. Analyses of the feces of sympatric rats revealed the presence of the same allele, as well as of Hymenolepis diminuta eggs, raising concern about their role as parasite reservoirs in the facilities. Full article