Formalin-ethyl Acetate Concentration Research Articles

High Efficacy of Ivermectin for Strongyloidiasis Treatment.

Infection with Strongyloides stercoralis is often asymptomatic but can be life-threatening in immunocompromised patients, which can be prevented by ivermectin (IVM) treatment. The efficacy of IVM has been reported to have lessened over time in some regions as a consequence of prolonged use and mass treatment campaigns. Ivermectin has been used in Thailand for more than a decade; therefore, we investigated the efficacy of a single dose (200 µg/kg) of IVM against in asymptomatic strongyloidiasis in northeastern Thailand. Fecal samples were collected before and 2 weeks after treatment and were analyzed for the presence of Strongyloides using a modified agar plate culture and the formalin-ethyl acetate concentration technique. Our results showed that single-dose IVM treatment successfully eliminated S. stercoralis infection in asymptomatic individuals in the endemic area with a 100% cure rate, indicating the high efficacy of IVM treatment in strongyloidiasis in northeast Thailand.

Microscopic and molecular epidemiology of gastrointestinal nematodes in dairy and beef cattle in Pak Chong district, Nakhon Ratchasima province, Thailand.

Gastrointestinal (GI) nematode infection remains an important problem in livestock, particularly cattle. The infection may lead to serious health complications and affect animal products. The objective of this study was to investigate GI nematode infection and its associated risk factors in dairy and beef cattle farmed in Pak Chong District of Nakhon Ratchasima Province, northeast Thailand. Fecal specimens were collected from 101 dairy cattle and 100 beef cattle. Formalin-ethyl acetate concentration techniques were used to process the samples and the samples were observed under a light microscope. Samples were subjected to molecular identification of specific genera using conventional polymerase chain reaction and DNA sequencing. The overall prevalence of GI nematode infection was 33.3%. The strongyle nematode was the most significant GI nematode in this area with a prevalence of 28.4%. The prevalence of strongyle nematodes was 58.0% in beef cattle and only 7.9% in dairy cattle. Trichuris spp. was another nematode found in both types of cattle with an overall prevalence of 5.0% with 9.0% in beef cattle and 1.0% in dairy cattle. The results of the epidemiological study indicate that the age of cattle, food, water sources, farming system, and housing floor are the most important risk factors. Among the strongyle nematodes, Ostertagia spp. was the most prevalent (82.0%), followed by Haemonchus spp. (62.3%) and Trichostrongylus spp. (8.2%), respectively. Infection with GI nematodes still exists in this area, particularly in beef cattle. Our reported data may benefit local parasitic control policies in the future.

Gastrointestinal parasites of dogs and foxes in the Zanjan province of Iran: With an emphasis on Echinococcus species

Canids harbor many zoonotic parasites and play an important role in the spread of parasites in the human environment. Estimation of parasitic infection among canids as definitive hosts may help competent authorities design efficient control programs. This study was conducted to determine the prevalence of intestinal parasites in dogs and foxes with an emphasis on Echinococcus spp. A total of 500 fecal samples of dogs and 30 fecal samples of foxes were studied in the summer, autumn, and winter of 2021 in the Zanjan province using the formalin-ethyl acetate concentration technique, followed by multiplex PCR. The overall prevalence of gastrointestinal parasite infection was estimated to be 19.05%. The prevalence was 24.8%, 10.2%, and 26.7% in stray, shelter dogs and foxes, respectively. No parasites were found among pet and guard dog samples. PCR results on Taenidae eggs showed that 2.4% of samples were positive for Echinococcus granulosus and none contained E. multilocularis. Noteworthy is that E. granulosus was identified only in stray dog samples. The higher prevalence of E. granulosus infection in stray dogs in this province emphasizes the importance of monitoring the food sources consumed by these animals.

Ov-RPA-CRISPR/Cas12a assay for the detection of Opisthorchis viverrini infection in field-collected human feces.

Opisthorchis viverrini infection is traditionally diagnosed using the Kato-Katz method and formalin ethyl-acetate concentration technique. However, the limited sensitivity and specificity of these techniques have prompted the exploration of various molecular approaches, such as conventional polymerase chain reaction (PCR) and real-time PCR, to detect O.viverrini infection. Recently, a novel technique known as recombinase polymerase amplification (RPA)-clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein (Cas) (RPA-CRISPR/Cas) assay was developed as a point-of-care tool for the detection of various pathogens, including viruses and bacteria such as severe acute respiratory syndrome coronavirus 2 and Mycobacterium tuberculosis. This technology has demonstrated high sensitivity and specificity. Therefore, we developed and used the RPA-CRISPR/Cas assay to detect O.viverrini infection in field-collected human feces. To detect O.viverrini infection in fecal samples, we developed a CRISPR/Cas12a (RNA-guided endonuclease) system combined with RPA (Ov-RPA-CRISPR/Cas12a). Several fecal samples, both helminth-positive and helminth-negative, were used for the development and optimization of amplification conditions, CRISPR/Cas detection conditions, detection limits, and specificity of the RPA-CRISPR/Cas12a assay for detecting O.viverrini infection. The detection results were determined using a real-time PCR system based on fluorescence values. Additionally, as the reporter was labeled with fluorescein, the detection results were visually inspected using an ultraviolet (UV) transilluminator. A receiver operating characteristic curve (ROC) was used to determine the optimal cutoff value for fluorescence detection. The diagnostic performance, including sensitivity and specificity, of the Ov-RPA-CRISPR/Cas12a assay was evaluated on the basis of comparison with standard methods. The Ov-RPA-CRISPR/Cas12a assay exhibited high specificity for detecting O.viverrini DNA. On the basis of the detection limit, the assay could detect O.viverrini DNA at concentrations as low as 10-1ng using the real-time PCR system. However, in this method, visual inspection under UV light required a minimum concentration of 1ng. To validate the Ov-RPA-CRISPR/Cas12a assay, 121 field-collected fecal samples were analyzed. Microscopic examination revealed that 29 samples were positive for O.viverrini-like eggs. Of these, 18 were confirmed as true positives on the basis of the Ov-RPA-CRISPR/Cas12a assay and microscopic examination, whereas 11 samples were determined as positive solely via microscopic examination, indicating the possibility of other minute intestinal fluke infections. The Ov-RPA-CRISPR/Cas12a assay developed in this study can successfully detect O.viverrini infection in field-collected feces. Due to the high specificity of the assay reported in this study, it can be used as an alternative approach to confirm O.viverrini infection, marking an initial step in the development of point-of-care diagnosis.

Examination of Diagnostic Performance of New IgG4 Rapid Test Compared with IgG- and IgG4-ELISAs to Investigate Epidemiology of Strongyloidiasis in Northeast Thailand.

Strongyloidiasis, caused by Strongyloides stercoralis, is a neglected tropical disease with a global distribution. The infection can be fatal in immunocompromised individuals, and accurate diagnosis leading to timely treatment can save lives. Serodiagnosis is a sensitive method for diagnosis and is recommended for screening high-risk individuals. A point-of-care rapid test will facilitate the screening activities, especially in low-resource settings. This study aims to apply a new IgG4 immunochromatographic test using S. stercoralis recombinant antigen (SsRapid® cassette test) and to compare it with in-house IgG and IgG4 enzyme-linked immunosorbent assays (IgG- and IgG4-ELISAs) using native Strongyloides ratti antigen to investigate the epidemiology of strongyloidiasis in northeast Thailand. A total of 300 people participated, with 136 males and 164 females of a similar mean age. The reference tests were fecal examinations using the formalin-ethyl acetate concentration technique and an agar plate culture technique. The prevalence of S. stercoralis determined by SsRapid (81.7%) was significantly higher than that by fecal examinations (43.3%) or by antibody detection by IgG-ELISA (53.0%) or IgG4-ELISA (44.0%). The diagnostic sensitivities of SsRapid, IgG-ELISA, and IgG4-ELISA were found to be 93.9%, 77.7%, and 63.1%, respectively. The rate of positive tests by the SsRapid was significantly correlated to the levels of Strongyloides-specific IgG4 and IgG antibodies. By all diagnostic methods, male participants had a significantly higher prevalence of strongyloidiasis than females. Age was significantly associated with the concentration of specific serum IgG but not with the SsRapid grading score. In conclusion, SsRapid was shown to be a sensitive and valuable diagnostic test for the epidemiology study of strongyloidiasis.

Prevalence and diversity of gastrointestinal parasites on pig farms in Kalasin Province, Thailand.

Gastrointestinal (GI) parasite infections are the foremost and prevalent diseases that affect pigs in Thailand. This study aimed to determine the prevalence of GI parasites among pigs in Kalasin Province. This study is the first attempt to understand the occurrence of GI parasites in pigs within Kalasin province using fecal samples as the methodology. We collected 324 fecal samples directly from the rectums of pigs from May to July 2023. The formalin-ethyl acetate concentration and floatation methods were used to examine these samples. The eggs or oocysts were identified by observing their morphology and size under a light microscope. Of the 324 fecal samples examined, 276 tested positive for gastrointestinal parasitic infections, resulting in a prevalence rate of 85.19%. Nematodes were the most prevalent, with Strongyle-type infections being the highest in 267 cases (82.41%), followed by Ascaris suum in 222 cases (68.52%), and Trichuris spp. in 152 cases (46.91%). Strongyloides spp. infections were also observed in 92 cases (28.40%). However, trematode infection was relatively rare, with only Fasciola spp. found in 15 cases (4.63%). We identified Eimeria spp. in 87 cases (26.85%), Iodamoeba spp. in 70 cases (21.60%), Balantidium coli in 67 cases (20.68%), and Isospora spp. in 52 cases (16.05%). Notably, most of the positive fecal samples showed double infections with a prevalence rate of approximately 38.27%. Single infections were the next most common, accounting for 25.31% of the cases, followed by 3 parasites (14.81%) and 4-5 parasites (6.79%). This study underscores the high endemicity of GI parasites among pigs in Kalasin province. To improve prevention and control measures, it is recommended to establish a health monitoring program that includes deworming and emphasizes good hygiene practices. The insights gained from this study will contribute to the enhancement of pig farming practices in Kalasin province, ultimately leading to improved production and profitability. In addition, future research should focus on detecting these parasites in Kalasin and exploring their relationship with human transmission cycle.

Automatic detection of Opisthorchis viverrini egg in stool examination using convolutional-based neural networks.

Human opisthorchiasis is a dangerous infectious chronic disease distributed in many Asian areas in the water-basins of large rivers, Siberia, and Europe. The gold standard for human opisthorchiasis laboratory diagnosis is the routine examination of Opisthorchis spp. eggs under a microscope. Manual detection is laborious, time-consuming, and dependent on the microscopist's abilities and expertise. Automatic screening of Opisthorchis spp. eggs with deep learning techniques is a useful diagnostic aid. Herein, we propose a convolutional neural network (CNN) for classifying and automatically detecting O. viverrini eggs from digitized images. The image data acquisition was acquired from infected human feces and was processed using the gold standard formalin ethyl acetate concentration technique, and then captured under the microscope digital camera at 400x. Microscopic images containing artifacts and O.viverrini egg were augmented using image rotation, filtering, noising, and sharpening techniques. This augmentation increased the image dataset from 1 time to 36 times in preparation for the training and validation step. Furthermore, the overall dataset was subdivided into a training-validation and test set at an 80:20 ratio, trained with a five-fold cross-validation to test model stability. For model training, we customized a CNN for image classification. An object detection method was proposed using a patch search algorithm to detect eggs and their locations. A performance matrix was used to evaluate model efficiency after training and IoU analysis for object detection. The proposed model, initially trained on non-augmented data of artifacts (class 0) and O. viverrini eggs (class 1), showed limited performance with 50.0% accuracy, 25.0% precision, 50.0% recall, and a 33.0% F1-score. After implementing data augmentation, the model significantly improved, reaching 100% accuracy, precision, recall, and F1-score. Stability assessments using 5-fold cross-validation indicated better stability with augmented data, evidenced by an ROC-AUC metric improvement from 0.5 to 1.00. Compared to other models such as ResNet50, InceptionV3, VGG16, DenseNet121, and Xception, the proposed model, with a smaller file size of 2.7 MB, showed comparable perfect performance. In object detection, the augmented data-trained model achieved an IoU score over 0.5 in 139 out of 148 images, with an average IoU of 0.6947. This study demonstrated the successful application of CNN in classifying and automating the detection of O. viverrini eggs in human stool samples. Our CNN model's performance metrics and true positive detection rates were outstanding. This innovative application of deep learning can automate and improve diagnostic precision, speed, and efficiency, particularly in regions where O. viverrini infections are prevalent, thereby possibly improving infection sustainable control and treatment program.

High-throughput detection of parasites and ova in stool using the fully automatic digital feces analyzer, orienter model fa280

BackgroundIntestinal parasitic infections can harm health by causing malnutrition, anemia, impaired growth and cognitive development, and alterations in microbiota composition and immune responses. Therefore, it is crucial to examine stool samples to diagnose parasitic infections. However, the traditional microscopic detection method is time-consuming, labor-intensive, and dependent on the expertise and training of microscopists. Hence, there is a need for a low-complexity, high-throughput, and cost-effective alternative to labor-intensive microscopic examinations.MethodsThis study aimed to compare the performance of a fully automatic digital feces analyzer, Orienter Model FA280 (People’s Republic of China) with that of the formalin-ethyl acetate concentration technique (FECT). We assessed and compared the agreement between the FA280 and the FECT for parasite detection and species identification in stool samples. The first part of the study analyzed 200 fresh stool samples for parasite detection using the FECT and FA280. With the FA280, the automatic feces analyzer performed the testing, and the digital microscope images were uploaded and automatically evaluated using an artificial intelligence (AI) program. Additionally, a skilled medical technologist conducted a user audit of the FA280 findings. The second set of samples comprised 800 preserved stool samples (preserved in 10% formalin). These samples were examined for parasites using the FECT and FA280 with a user audit.ResultsFor the first set of stool samples, there was no statistically significant difference in the pairwise agreements between the FECT and the FA280 with a user audit (exact binomial test, P = 1). However, there were statistically significant differences between the pairwise agreements for the FECT and the FA280 with the AI report (McNemar’s test, P < 0.001). The agreement for the species identification of parasites between the FA280 with AI report and FECT showed fair agreement (overall agreement = 75.5%, kappa [κ] = 0.367, 95% CI 0.248–0.486). On the other hand, the user audit for the FA280 and FECT showed perfect agreement (overall agreement = 100%, κ = 1.00, 95% CI 1.00–1.00). For the second set of samples, the FECT detected significantly more positive samples for parasites than the FA280 with a user audit (McNemar’s test, P < 0.001). The disparity in results may be attributed to the FECT using significantly larger stool samples than those used by the FA280. The larger sample size used by the FECT potentially contributed to the higher parasite detection rate. Regarding species identification, there was strong agreement between the FECT and the FA280 with a user audit for helminths (κ = 0.857, 95% CI 0.82–0.894). Similarly, there was perfect agreement for the species identification of protozoa between the FECT and the FA280 with user audit (κ = 1.00, 95% CI 1.00–1.00).ConclusionsAlthough the FA280 has advantages in terms of simplicity, shorter performance time, and reduced contamination in the laboratory, there are some limitations to consider. These include a higher cost per sample testing and a lower sensitivity compared to the FECT. However, the FA280 enables rapid, convenient, and safe stool examination of parasitic infections.Graphical

Accuracy of a new rapid diagnostic test for urinary antigen detection and assessment of drug treatment in opisthorchiasis

BackgroundScreening for opisthorchiasis, a parasitic worm infection affecting many millions of people in Southeast Asia, has traditionally relied on faecal egg examination such as the formalin-ethyl acetate concentration technique (FECT) and Kato-Katz method. Although the urinary enzyme-linked immunosorbent assay (ELISA) has been used more recently, we developed a urinary antigen-based rapid diagnostic test (RDT) to simplify diagnosis and as a point-of-care testing (POCT) and field applications for surveillance and control of opisthorchiasis.MethodsA urinary Opisthorchis viverrini (OV)-RDT was developed using immunochromatographic methodology with a specific monoclonal antibody against OV. The diagnostic performance of the urinary OV-RDT was compared to that of quantitative faecal FECT and urinary antigen ELISA (n = 493). Cross-reactivities of urinary OV-RDT with other helminthiases coexisted with O. viverrini were determined (n = 96). A field trial in the application of urinary OV-RDT was compared with urinary antigen ELISA at baseline screening and assessment of drug treatment outcomes in opisthorchiasis (n = 1629). The McNemar chi-square, Kruskal–Wallis and Cohen’s kappa coefficient (κ-value) tests were used for statistical analyses.ResultsUrinary OV-RDT had sensitivity of 94.2% and specificity of 93.2%, compared to faecal FECT. Urinary OV-RDT had high diagnostic agreement (Kappa = 0.842–0.874, P < 0.001) and quantitative correlation with urinary antigen ELISA (Kruskal–Wallis tests = 316.2, P < 0.0001) and faecal FECT (Kruskal–Wallis tests = 362.3, P < 0.0001). The positive rates by OV-RDT, ELISA and FECT were 48.9%, 52.5% and 49.3%, respectively. Cross-reactions of urinary OV-RDT with other helminthiases were few (2%). Field trials of urinary OV-RDT yielded comparable prevalence of O. viverrini between urinary OV-RDT (53.2%) and urinary antigen ELISA (54.0%). OV screening showed high diagnostic agreement (kappa > 0.8, P < 0.0001) between urinary OV-RDT and urinary antigen ELISA. The cure rates of opisthorchiasis at 1 month post-praziquantel treatment determined by urinary OV-RDT (86.6%) and urinary antigen ELISA (80.5%) were similar (P > 0.05).ConclusionsThe urinary OV-RDT test has high potential as a new tool for screening and evaluating treatment outcomes in opisthorchiasis. The ease of sample collection and simplicity of urinary OV-RDT may facilitate mass screening, control and elimination of opisthorchiasis, thereby contributing to a reduction in the disease burden in Southeast Asia.Graphical

Diagnostic performance of Strongyloides-specific IgG4 detection in urine for diagnosis of human strongyloidiasis

BackgroundDetection of parasite-specific IgG in urine is a sensitive method for diagnosis of strongyloidiasis and gives similar accuracy to serum IgG. However, there are no data concerning detection of IgG subclass in urine. To further explore the utility of diagnosis from urine samples, we evaluated the diagnostic performance of IgG4 in urine compared with parasitological and other immunological methods.MethodsThe urine and sera included proven strongyloidiasis (group 1, n = 93), other parasitic infections (group 2, n = 40) and parasite negatives (group 3, n = 93). The performance of Strongyloides-specific IgG4 in urine for diagnosis of strongyloidiasis using fecal examinations as the reference standard was assessed.ResultsWith fecal examination as a gold standard, Strongyloides-specific IgG4 in urine had 91.4% sensitivity and 93.2% specificity while serum IgG4 had 93.6% sensitivity and 91.0% specificity. IgG4 in both urine and serum had almost perfect diagnostic agreements with fecal examination (Cohen's kappa coefficient was > 0.8). Cross-reactivity to Opisthorchis viverrini and Taenia spp. of IgG4 in urine were 7.5% and 12.5% in serum. Concurrent analyses of total IgG in urine and serum showed that the sensitivities (97.9–100%) and specificities (88.7–91.0%) were similar (P > 0.05). The sensitivity for parasitological examination by the formalin-ethyl acetate concentration technique (FECT) was 49.5% and that for agar plate culture technique (APC) it was 92.6%.ConclusionOur findings showed that specific IgG4 detection in urine yielded similar diagnostic performance to the same biomarkers in serum. This suggests that accurate diagnosis of strongyloidiasis can be performed using urine samples and IgG4 is a valid choice of diagnostic marker. Further assessment is required to assess the utility of urine IgG4 for measuring the response treatment in strongyloidiasis.Graphical

Comparison of a Urine Antigen Assay and Multiple Examinations with the Formalin-Ethyl Acetate Concentration Technique for Diagnosis of Opisthorchiasis.

Detection of worm antigen in urine is a sensitive diagnostic method for opisthorchiasis, particularly for light-intensity infections; however, the presence of eggs in feces is essential for validating results from the antigen assay. To address the issue of low sensitivity of fecal examination, we modified the protocol for the formalin-ethyl acetate concentration technique (FECT) and compared it against urine antigen measurements for detection of the parasite Opisthorchis viverrini. First, we optimized the FECT protocol by increasing the number of drops for examinations from the standard two drops to a maximum of eight. We were able to detect additional cases after examination of ≥ 3 drops, and the prevalence of O. viverrini saturated after examination of ≥ 5 drops. We then compared the optimized FECT protocol (examining five drops of suspension) against urine antigen detection for the diagnosis of opisthorchiasis in field-collected samples. The optimized FECT protocol detected O. viverrini eggs in 25 of 82 individuals (30.5%) who had positive urine antigen tests but were fecal egg negative by the standard FECT protocol. The optimized protocol also retrieved O. viverrini eggs in 2 of 80 antigen-negative cases (2.5%). In comparison with the composite reference standard (combined FECT and urine antigen detection), the diagnostic sensitivity of examining two and five drops of FECT and the urine assay was 58.2, 67, and 98.8%, respectively. Our results show that multiple examinations of fecal sediment increase the diagnostic sensitivity of FECT and thus provide further support for the reliability and utility of the antigen assay for diagnosis and screening of opisthorchiasis.

Incidence of fish-borne trematode infections and associated factors: results from a cohort study in highly endemic communities in northern Vietnam

Fish-borne trematodes (FiBT) are an important group of zoonotic parasites negatively affecting human health, mainly in Asia. Most studies on FiBT have applied a cross-sectional design, which provides weaker evidence on potential risk factors for transmission than a cohort study. This cohort study aimed to estimate the incidence and identify associated risk factors for FiBT infection in Vietnam. Between April 2018 and May 2019, two communes in Yen Bai province, a highly endemic area for FiBT, were visited for sampling. Participants with a negative stool result for FiBT at baseline, were invited for follow-up and data collection, at months 4, 9, and 13. Stools were examined using Kato-Katz and formalin-ethyl acetate concentration techniques to detect FiBT eggs, whereas a questionnaire was used for interviewing participants to determine the risk factors for FiBT infection during each follow-up period. The incidence risk and the incidence rate were calculated, and univariate and multivariable models were run to identify the risk factors for FiBT. A total of 194 people, negative for FiBT eggs at the baseline survey, were invited to participate in the study, and 111 people agreed to enroll in the follow-up. The incidence risk at months 4, 9, and 13 was 9.0%, 6.4%, and 5.1%, respectively. We finally used data from 95 participants for the risk factor analysis, excluding 16 people lost for the follow-up. Overall, 20 people became infected with FiBT (IR = 21.1%). The incidence rate of FiBT infection was 21.4/100 person-year. In the univariate analysis, consumption of raw fish was the main risk factor (RR = 4.59, 95%CI = 1.95-10.82), followed by being male (RR = 3.41, 95%CI = 1.56-7.45) and drinking alcohol (RR = 3.25, 95%CI = 1.49-7.11). In the multivariable analysis, only consumption of raw-fish dishes was significantly associated with FiBT infection. The people who consumed raw fish were 3.44 (95%CI = 1.11-10.70) times more at risk of infection with FiBT as compared to individuals who did not consume raw fish. It can be concluded that the FiBT incidence is high in the study area. More awareness campaigns are needed to stop eating raw fish in these areas to reduce FBT infection.

Epidemiology of strongyloidiasis determined by parasite-specific IgG detections by enzyme-linked immunosorbent assay on urine samples using Strongyloides stercoralis, S. ratti and recombinant protein (NIE) as antigens in Northeast Thailand.

Detection of anti-Strongyloides IgG in urine by enzyme-linked immunosorbent assay (ELISA) for diagnosis of strongyloidiasis reportedly has comparable performance to conventional serum assays. Initial comparisons of urine assays using commercial ELISA kits designated for serology have shown its diagnostic potential but sub-optimal accuracy. In the present study, we optimized urine ELISA protocols based on different antigen types and evaluated their accuracies in determining the epidemiology of strongyloidiasis in Northeast Thailand. Paired urine and fecal samples of 966 individuals from the study community were collected for three consecutive days and tested for strongyloidiasis. We compared three ELISA protocols using different antigens including crude S. stercoralis antigen (Ss-ELISA), crude S. ratti antigen (Sr-ELISA) and recombinant NIE antigen (NIE-ELISA) and fecal examination by agar plate-culture (APCT) technique and formalin-ethyl acetate concentration technique (FECT). The optimized ELISA protocols using three different antigen sources yielded significantly higher prevalence rates of strongyloidiasis (58.9-65.1%) than those by fecal examination methods (19.7%). The prevalence of strongyloidiasis determined by ELISA protocols significantly increased with age (p value < 0.0001) and males had higher prevalence than females (p value < 0.0001). Diagnostic agreements between ELISA protocols were moderate (κ = 0.461-0.586) and the agreement between each ELISA protocol and fecal examinations were slight (κ = 0.139-0.210). The results obtained by urine ELISA protocols using three different antigens showed comparable diagnostic performances, provided further supports for the utility of urine as an alternative clinical specimen for diagnosis of strongyloidiasis.

Investigation of intestinal parasites by conventional and molecular methods in children with gastrointestinal system complaints

Intestinal parasitic infections are a global health problem that causes morbidity and mortality, especially in children living in rural areas. In this study, stool samples of pediatric patients with gastrointestinal complaints were examined by conventional and molecular methods to determine the prevalence of intestinal parasites. A total of 100 pediatric patients with gastrointestinal complaints and 50 healthy children were included in the study. Stool samples were collected from each child and examined by direct microscopic examination (native-Lugol method), formol-ethyl acetate concentration technique, Kinyoun's acid-fast staining, and Wheatley trichrome staining methods. Real-time PCR was used for the detection of Blastocystis spp. and D. fragilis in the stool samples. Sanger sequencing was used to identify Blastocystis spp. subtypes. One or more intestinal parasites were found in 12% (n = 100) of the patient group and 1% (n = 50) of the control group using conventional techniques. By using real-time PCR, Blastocystis spp. was discovered in 14% (14/100) of the patient group and 8% (4/50) of the control group. There was no significant difference in the frequency of Blastocystis spp. between the two groups. The most prevalent Blastocystis subtype was ST1 and the most frequent allele was a2 among the samples successfully amplified and sequenced. D. fragilis was detected in 17% (17/100) of the patient group and 8% (4/50) of the control group by real-time PCR. The prevalence of D. fragilis was not significantly different between the patient and control groups, as well. Blastocystis spp. and D. fragilis were found in high prevalence in pediatric patients with gastrointestinal complaints in this study. Although the role of these protists as a pathogen in humans is still controversial, it is supposed to the presence of the parasites are associated with gastrointestinal disorders such as diarrhea, abdominal pain, nausea, and vomiting. More case-control studies are needed to understand the pathogenic or commensal role of these parasites on the intestinal microbiota, especially in both patients with gastrointestinal disorders and healthy individuals.

Efficacy of Nitazoxanide, Nitazoxanide-Garlic Combination and Tinidazole in Treatment of Giardia duodenalis and Blastocystis hominis: Coproscopic Assessment.

Giardia duodenalis and Blastocystis hominis are among the most common intestinal protozoa worldwide. Treatment of infection by metronidazole (MTZ) has some limitations. The objective of this study was to detect the prevalence of Blastocystis and giardiasis among school-age children from December 2021 till March 2022 from Motoubes, Kafrelsheikh, Egypt, and determine the efficacy of nitazoxanide (NTZ), NTZ plus garlic and tinidazole (TIN) on Blastocystis and giardiasis infection. Stool samples were collected from 390 children and microscopically examined using formalin-ethyl acetate concentration and culturing on Jones' medium for B. hominis. Those who tested positive for giardiasis (120 children, 30.7%) (Group I) or Blastocystis (180 children, 46.1%) (Group II) were equally divided into four subgroups. The first subgroup received NTZ orally, every 12 hours for three successive days. The second subgroup received NTZ in the same dose as the first subgroup plus dry garlic powder every 12 hours for three successive days. The third subgroup received TIN as a single oral dose, and a fourth control subgroup. Successful cure was considered if no Blastocystis or giardiasis stages were found in post-treatment faecal specimens. Cure rate was significantly higher in TIN treated groups (75.5% and 96.6%) than NTZ (57.7% and 40%) or NTZ plus garlic treated groups (55.5% and 43%) in both Blastocystis and giardiasis, respectively (P<0.05). TIN, once, is more efficacious than NTZ or NTZ plus garlic in the treatment of Blastocystis and giardiasis in children.

The Intensity of Infection and Public Health Perception of Potentially Zoonotic Intestinal Parasites of Dogs in Kwara Central, Nigeria

Background: The close relationship between dogs and humans and the possibility of intestinal parasite transmission from dogs to humans calls for frequent assessment of these potential zoonotic intestinal parasites in dogs and the possibility of their transmission to humans. Objectives: This study aimed to determine the presence, intensity of infection, and public health perception of potentially zoonotic intestinal parasites in dogs of Kwara Central, Nigeria. Methods: The study was conducted in 28 locations in Kwara Central Senatorial District of Kwara State, Nigeria. Three hundred and five healthy dogs were sampled. Two hundred and thirty respondents (dog owners or handlers) were questioned using a well-structured questionnaire containing open-ended and closed-ended questions. Fecal samples from the sampled dogs were subjected to the direct fecal smear technique, simple fecal centrifugation flotation technique, formalin-ethyl acetate concentration technique, and the modified Ziehl-Neelsen staining technique. Oocysts or eggs per gram of feces were counted using the modified McMaster technique. Results: Seven different intestinal parasites (Ancylostoma spp., Cryptosporidium spp., Dipylidium caninum, Isospora spp., Strongyloides stercoralis, Toxocara spp., and Uncinaria stenocephala) were detected, with a prevalence ranging from 2.30% to 25.25%. Of these parasites, 6 were zoonotic. The mean intensities of infection were 91.43 eggs per gram (EPG) for D. caninum¸ 96.52 EPG for S. stercoralis, 129.36 ±28.12 oocysts per gram (OPG) for Isospora spp., 165.17±19.88 for Toxocara spp., 240.00±44.42 for EPG for U. stenocephala, and 303.64±31.83 EPG for Ancylostoma spp. Some dog owners and handlers were not cautious about possible zoonotic parasite transmission from dogs. Conclusion: Zoonotic intestinal parasites of dogs are present and prevalent in Kwara Central, Nigeria. There is a need to educate the public on the possibility of zoonotic parasite transmission to humans.

An Epidemiological Survey of Intestinal Parasitic Infection and the Socioeconomic Status of the Ethnic Minority People of Moken and Orang Laut.

Ethnic minority groups are often subjected to exclusion, social and healthcare marginalization, and poverty. There appears to be important linkages between ethnic minority groups, poor socioeconomic status, and a high prevalence of parasitic infection. Data regarding the prevalence and health effects of IPIs are necessary in the development and implementation of targeted prevention and control strategies to eradicate intestinal parasitic infection in the high-risk population. Thus, we investigated for the first time the intestinal parasitic infection status (IPIs), the socioeconomic status, and sanitary condition in the communities of Moken and Orang Laut, the ethnic minority peoples living on the coast of southwest Thailand. A total of 691 participants participated in the present study. The information concerning socioeconomic status and sanitary condition of the study population was obtained by personal interviews using a picture questionnaire. Stool samples were collected and examined for intestinal parasitic infection using direct wet smear and formalin-ethyl acetate concentration techniques. The results revealed that 62% of the study population were infected with one or more types of intestinal parasites. The highest prevalence of intestinal parasitic infections was found in the 11-20-year-old age range group. A statistically significant difference of IPIs among the three communities were observed (p < 0.0001). There was a statistical difference concerning 44 multiple infections of soil-transmitted helminths (STHs) (p < 0.001), whereas no statistically significant difference in multiple infections of protozoa was observed (p > 0.55). The results also displayed the significant difference in socioeconomic status and sanitary condition among the Moken living in Ranong and Phang Nga and the Orang Laut living in the Satun province (p < 0.001). Our study found no direct association between parasitic infection status and ethnic/geographic features; however, socioeconomic status is the key factor associated with prevalence of intestinal parasitic infection, with the observation that the higher prevalence of IPIs is due to a low socioeconomic status, consequently leading to poor hygiene and sanitation practices. The picture questionnaire played a major role in information gathering, especially from those of low or no education. Lastly, data pertaining to the species of the parasites and the mode of transmission assisted in the identification of group-specific vulnerabilities and shortcomings that can be utilized in education and corrected to reduce the prevalence of infection in the study areas.

Monks: A Population at Risk for Liver Fluke and Skin-Penetrating Helminths.

Monks cannot cook received raw meat dishes and should walk barefoot while working. This population lacks both a survey of parasitic infection and a proper prevention and control policy. Five hundred and fourteen monks from the Ubolratana, Ban Haet, and Ban Phai Districts of Kh on Kaen Province were enrolled in this study. A stool container and questionnaire were collected from each study participant. Stool samples were processed by formalin ethyl acetate concentration and agar plate culture techniques. We then analyzed the results and risk factors to demonstrate associations. The prevalence of overall parasites, liver flukes, and skin-penetrating helminths were 28.8%, 11.1%, and 19.3%, respectively. Raw fish dish offerings were associated with opisthorchiasis (ORcrude 3.32; 95% CI 1.53-7.20). The risk factors for skin-penetrating helminths were older age (ORcrude 5.02; 95% CI 2.2-11.17), being a long-term ordinate (ORcrude 3.28; 95% CI 1.15-9.34), smoking (ORcrude 2.03; 95% CI 1.23-3.36), and chronic kidney disease with other underlying disease (ORcrude 20.7; 95% CI 2.54-190.1). The protective factors for skin-penetrating helminths were secular education above primary education (ORcrude 0.41; 95% CI 0.25-0.65) and having received health education about parasitic infection (ORcrude 0.47; 95% CI 0.28-0.80). Wearing shoes at times other than alms work does not show a protective effect against skin-penetrating helminths (ORcrude 0.86; 95% CI 0.51-1.46). These findings support the recommendation for a strict Rule of Discipline regarding raw meat ingestion and allowing shoes to be worn for protection against skin-penetrating helminths in high-risk situations.

Improved latrines minimally impact Schistosoma mekongi transmission in Mekong islands

Schistosoma mekongi and other intestinal helminth infections remain public health concerns in Lao People's Democratic Republic, especially in remote areas where access to sanitation is limited.We performed an experimental study in four villages where latrine construction was coupled with two rounds of mass drug administration (MDA) with praziquantel and albendazole, and compared with two control villages that only received two rounds of MDA. The prevalence of helminth infections before (baseline) and after (follow-up) intervention were compared. Additionally, the prevalence in intervention and control villages were compared 12 months post-intervention. Kato–Katz, formalin-ethyl acetate concentration and Baermann techniques were employed to assess helminth infections.We found infection prevalence of S. mekongi in the intervention and control villages was 28.6% and 1.8%, respectively. The prevalences of other helminth infections were as follows: Opisthorchis viverrini, 79.5% and 71.8%; hookworm, 48.8% and 65.6%; and Strongyloides stercoralis, 43.1% and 38.3%. Other helminth species were detected in less than 5% of the study participants. Latrine intervention coupled with two rounds of MDA in the intervention villages reduced the prevalence of S. mekongi infection by 6.0% (from 28.6% to 22.6%; P < 0.001), O. viverrini infection by 11.3% (from 79.5% to 68.2%; P < 0.001), hookworm infection by 22.6% (from 48.8% to 26.2%; P < 0.001), and S. stercoralis infection by 12.0% (from 43.1% to 31.1%; P < 0.001). The observed reductions were not significantly different when compared to the control villages, where only two rounds of MDA were implemented (P > 0.05). Study participants in both groups commonly engaged in behaviours such as open defecation, bathing in the Mekong River, consuming raw or undercooked fish dishes and walking barefoot. These practices and behaviours are associated with helminth infections. Concluding, this study showed only a marginal impact associated with latrine use in intervention communities. There is a need for longer term studies with integrated interventions, such as effective health education to foster behavioural changes related to open defecation, raw or undercooked food consumption, wearing protected footwear outdoors, and personal hygiene.

Trichostrongylosis: a zoonotic disease of small ruminants.

In the present world a significant threat to human health is posed by zoonotic diseases. Helminth parasites of ruminants are one of the most common zoonotic organisms on the planet. Among them, trichostrongylid nematodes of ruminants, found worldwide, parasitize humans in different parts of the world with varying rates of incidence, particularly among rural and tribal communities with poor hygiene, pastoral livelihood and poor access to health services. In the Trichostrongyloidea superfamily, Haemonchus contortus, Teladorsagia circumcincta, Marshallagia marshalli, Nematodirus abnormalis and Trichostrongylus spp. are zoonotic in nature. Species of the genus Trichostrongylus are the most prevalent gastrointestinal nematode parasites of ruminants that transmit to humans. This parasite is prevalent in pastoral communities around the world and causes gastrointestinal complications with hypereosinophilia which is typically treated with anthelmintic therapy. The scientific literature from 1938 to 2022 revealed the occasional incidence of trichostrongylosis throughout the world with abdominal complications and hypereosinophilia as the predominant manifestation in humans. The primary means of transmission of Trichostrongylus to humans was found to be close contact with small ruminants and food contaminated by their faeces. Studies revealed that conventional stool examination methods such as formalin-ethyl acetate concentration or Willi's technique combined with polymerase chain reaction-based approaches are important for the accurate diagnosis of human trichostrongylosis. This review further found that interleukin 33, immunoglobulin E, immunoglobulin G1, immunoglobulin G2, immunoglobulin M, histamine, leukotriene C4, 6-keto prostaglandin F1α, and thromboxane B2 are vital in the fight against Trichostrongylus infection with mast cells playing a key role. This review focuses on the prevalence, pathogenicity and immunological aspects of Trichostrongylus spp. in humans.