Prevalence and intensity of soil-transmitted helminth infections among school-aged children in five districts in Uganda.

BACKGROUND: Soil-transmitted helminth (STH) infections, commonly caused by roundworms (Ascaris lumbricoides), whipworms (Trichuris trichiura), and hookworms (Necator americanus and Ancylostoma duodenale), were widespread among Ugandan schoolchildren in the late 1990s and early 2000s. Since 2003, the Ugandan Ministry of Health has administered biannual preventive chemotherapy to children aged 1-14 years to control these infections. Twenty years after the program's inception, there is scant data to show the long-term impact of these national deworming efforts. METHODS: To estimate the prevalence and intensity of STH infections among 10-14-year-old primary school children, school-based, cross-sectional surveys were conducted in November 2023 across five districts (Kamwenge, Sheema, Adjumani, Lamwo, and Zombo). Sixty-five children from five schools per district were selected for inclusion. Fecal egg counts were determined using the Kato-Katz microscopy technique, performed in duplicate by trained laboratory technicians. RESULTS: The survey findings revealed a high prevalence of any STH infection in Kamwenge District (21.2%, 95% confidence limits (CL): 5.7%, 36.6%), while the remaining four districts exhibited lower prevalences, ranging from 0.4% (95% CL: 0.0%, 1.2%) in Adjumani District to 5.6% (95% CL: 0.0%, 11.4%) in Sheema District. The prevalence of moderate-to-heavy-intensity infections was below 1% across all districts. A. lumbricoides was identified infrequently. Hookworm infections were primarily identified in the western districts of Kamwenge and Sheema, while T. trichiura infections were common only in Kamwenge District. Hookworm and T. trichiura infections were uncommon in the northern districts of Adjumani, Lamwo, and Zombo. CONCLUSIONS: These surveys suggest that morbidity due to STH infections among schoolchildren may be well controlled in these five districts, as evidenced by low moderate-to-heavy-intensity infection prevalence. However, the prevalence of any intensity infection remains elevated in some districts, indicating the need for continued preventive chemotherapy distribution. A reduction from biannual treatment may be warranted in four districts, per World Health Organization recommendations.

Bioinformatic, Enzymatic, and Structural Characterization of Trichuris suis Hexosaminidase HEX-2.

Hexosaminidases are key enzymes in glycoconjugate metabolism and occur in all kingdoms of life. Here, we have investigated the phylogeny of the GH20 glycosyl hydrolase family in nematodes and identified a ß-hexosaminidase subclade present only in the Dorylaimia. We have expressed one of these, HEX-2 from Trichuris suis, a porcine parasite, and shown that it prefers an aryl ß-N-acetylgalactosaminide in vitro. HEX-2 has an almost neutral pH optimum and is best inhibited by GalNAc-isofagomine. Toward N-glycan substrates, it displays a preference for the removal of GalNAc residues from LacdiNAc motifs as well as the GlcNAc attached to the α1,3-linked core mannose. Therefore, it has a broader specificity than insect fused lobe (FDL) hexosaminidases but one narrower than distant homologues from plants. Its X-ray crystal structure, the first of any subfamily 1 GH20 hexosaminidase to be determined, is closest to Streptococcus pneumoniae GH20C and the active site is predicted to be compatible with accommodating both GalNAc and GlcNAc. The new structure extends our knowledge about this large enzyme family, particularly as T. suis HEX-2 also possesses the key glutamate residue found in human hexosaminidases of either GH20 subfamily, including HEXD whose biological function remains elusive.

Understanding Drug Exposure and Trichuris trichiura Cure Rates: A Pharmacometric Approach for Albendazole-Ivermectin Co-medication in Tanzania and Côte d'Ivoire.

BACKGROUND AND OBJECTIVE: Trichuriasis caused by the human whipworm Trichuris trichiura poses a significant public health concern. Albendazole-ivermectin co-medication is currently the most effective treatment. Studies conducted in Tanzania and Côte d'Ivoire unveiled differences in efficacy for albendazole-ivermectin combination therapy in both countries. A pharmacometrics approach was used to assess co-medication and study population effects on the pharmacokinetics of the two main metabolites of albendazole. An exploratory exposure-efficacy analysis was also carried out to investigate relationships between exposure measures and the egg reduction rate. METHODS: Pharmacokinetic data from studies in Tanzania and Côte d'Ivoire in adolescents (aged 12-19 years) were included in the pharmacometric analysis. Participants received a single dose of either albendazole 400 mg alone or in combination with ivermectin 200 µg/kg. A pharmacometric analysis was performed to investigate the potential effects of the study population and co-administered ivermectin on the apparent clearance of the metabolites of albendazole. Non-linear mixed-effects modeling was conducted with MonolixSuite 2023R1. The pharmacokinetic exposure measures derived from simulations with individual model parameters were used in the exploratory-exposure response analysis. RESULTS: Pharmacokinetic profiles were best described by a two-compartment model for albendazole sulfoxide and a one-compartment model for albendazole sulfone, with a transit compartment and linear elimination. While no co-medication effect was found, apparent clearance of albendazole sulfoxide (albendazole sulfone) in the Tanzanian study population was 75% (46%) higher than that in the Côte d'Ivoire study population. Exposure-efficacy response analyses indicated that peak concentration and the time-above-exposure threshold were associated with the egg reduction rate. CONCLUSIONS: Study population but not co-administered ivermectin showed an effect on apparent clearance of albendazole sulfoxide and albendazole sulfone. Polymorphisms in drug-metabolizing enzymes and host-parasite interaction may explain this result. Difference in drug exposure did not explain the disparate efficacy responses in Tanzania and Côte d'Ivoire. Peak concentration and time-above-threshold were exposure measures associated with the egg reduction rate. Further studies evaluating genetic and resistance patterns in various regions in Africa are warranted.

Genetic and environmental interactions contribute to immune variation in rewilded mice.

The relative and synergistic contributions of genetics and environment to interindividual immune response variation remain unclear, despite implications in evolutionary biology and medicine. Here we quantify interactive effects of genotype and environment on immune traits by investigating C57BL/6, 129S1 and PWK/PhJ inbred mice, rewilded in an outdoor enclosure and infected with the parasite Trichuris muris. Whereas cellular composition was shaped by interactions between genotype and environment, cytokine response heterogeneity including IFNγ concentrations was primarily driven by genotype with consequence on worm burden. In addition, we show that other traits, such as expression of CD44, were explained mostly by genetics on T cells, whereas expression of CD44 on B cells was explained more by environment across all strains. Notably, genetic differences under laboratory conditions were decreased following rewilding. These results indicate that nonheritable influences interact with genetic factors to shape immune variation and parasite burden.

Gut microbiota-mediated polyphenol metabolism is restrained by parasitic whipworm infection and associated with altered immune function in mice.

Polyphenols are phytochemicals commonly found in plant-based diets which have demonstrated immunomodulatory and anti-inflammatory properties. However, the interplay between polyphenols and pathogens at mucosal barrier surfaces has not yet been elucidated in detail. Here, we show that proanthocyanidin (PAC) polyphenols interact with gut parasites to influence immune function and gut microbial-derived metabolites in mice. PAC intake inhibited mastocytosis during infection with the small intestinal roundworm Heligmosomoides polygyrus, and altered the host tissue transcriptome at the site of infection with the large intestinal whipworm Trichuris muris, with a notable enhancement of type-1 inflammatory and interferon-driven gene pathways. In the absence of infection, PAC intake promoted the expansion of Turicibacter within the gut microbiota, increased fecal short chain fatty acids, and enriched phenolic metabolites such as phenyl-γ-valerolactones in the cecum. However, these putatively beneficial effects were reduced in PAC-fed mice infected with T. muris, suggesting concomitant parasite infection can attenuate gut microbial-mediated PAC catabolism. Collectively, our results suggest an inter-relationship between a phytonutrient and infection, whereby PAC may augment parasite-induced inflammation (most prominently with the cecum dwelling T. muris), and infection may abrogate the beneficial effects of health-promoting phytochemicals.

Evaluation of Parasight All-in-One system for the automated enumeration of helminth ova in canine and feline feces.

BACKGROUND:  Digital imaging combined with deep-learning-based computational image analysis is a growing area in medical diagnostics, including parasitology, where a number of automated analytical devices have been developed and are available for use in clinical practice. METHODS: The performance of Parasight All-in-One (AIO), a second-generation device, was evaluated by comparing it to a well-accepted research method (mini-FLOTAC) and to another commercially available test (Imagyst). Fifty-nine canine and feline infected fecal specimens were quantitatively analyzed by all three methods. Since some samples were positive for more than one parasite, the dataset consisted of 48 specimens positive for Ancylostoma spp., 13 for Toxocara spp. and 23 for Trichuris spp. RESULTS: The magnitude of Parasight AIO counts correlated well with those of mini-FLOTAC but not with those of Imagyst. Parasight AIO counted approximately 3.5-fold more ova of Ancylostoma spp. and Trichuris spp. and 4.6-fold more ova of Toxocara spp. than the mini-FLOTAC, and counted 27.9-, 17.1- and 10.2-fold more of these same ova than Imagyst, respectively. These differences translated into differences between the test sensitivities at low egg count levels (< 50 eggs/g), with Parasight AIO > mini-FLOTAC > Imagyst. At higher egg counts Parasight AIO and mini-FLOTAC performed with comparable precision (which was significantly higher that than Imagyst), whereas at lower counts (> 30 eggs/g) Parasight was more precise than both mini-FLOTAC and Imagyst, while the latter two methods did not significantly differ from each other. CONCLUSIONS: In general, Parasight AIO analyses were both more precise and sensitive than mini-FLOTAC and Imagyst and quantitatively correlated well with mini-FLOTAC. While Parasight AIO produced lower raw counts in eggs-per-gram than mini-FLOTAC, these could be corrected using the data generated from these correlations.

Trichuris Globulosa Von Linstow, 1901 from one-humped camel (Camelus dromedarius) in Egypt: prevalence, morphological and molecular study.

BACKGROUND: Trichuris spp. (whipworms) are soil-transmitted helminths distributed worldwide, parasitizing several mammalian hosts such as ruminants, primates, and rodents. Trichuris spp. is one of the most common intestinal parasites affecting both humans and animals, and it can spread directly through the fecal-oral route, resulting in severe illness and financial loss. So, this work aims to detect the frequency of Trichuris spp. in camels in Beheira Governorate, Egypt, and to identify Trichuris spp. through morphometrical studies, molecular analysis, and phylogenetic analysis. RESULTS: A total of 35 dromedaries out of 127 investigated had Trichuris spp. infection, meaning that the overall prevalence was 27.56%. The age of the camel affected the infection rate, older animals (> 5 years) having a higher prevalence of infection (24%) than animals of ages (< 3 years) (20%) than animals of ages (3-5 years) (19.14%). According to season: Trichuris spp. showed a unique pattern in camels in different seasons: summer (31.25%) > autumn (28.13%) > spring (25.8%) > winter (25%) indicating year-round infection. T. globulosa was identified morphometrically from camels in Beheira Governorate, Egypt. The BLAST analysis revealed the presence of T. globulosa isolate from camels using the Genbank database depending on nuclear small subunit ribosomal RNA (18s) and cytochrome b (Cytb) genes. CONCLUSION: A high prevalence of T. globulosa was found in camels in Beheira Governorate, Egypt. This is the first report to confirm the identification of T. globulosa from camel based on morphometrical studies and molecular and phylogenetic analysis in Egypt. More thorough studies on the incidence, molecular, and genetic analysis of Trichuris spp. in Egypt are required in addition to camel control programs.

Functional characterization of helminth-associated Clostridiales reveals covariates of Treg differentiation.

BACKGROUND: Parasitic helminths influence the composition of the gut microbiome. However, the microbiomes of individuals living in helminth-endemic regions are understudied. The Orang Asli, an indigenous population in Malaysia with high burdens of the helminth Trichuris trichiura, display microbiotas enriched in Clostridiales, an order of spore-forming obligate anaerobes with immunogenic properties. We previously isolated novel Clostridiales that were enriched in these individuals and found that a subset promoted the Trichuris life cycle. In this study, we aimed to further characterize the functional properties of these bacteria. RESULTS: Clostridiales isolates were profiled for their ability to perform 57 enzymatic reactions and produce short-chain fatty acids (SCFAs) and hydrogen sulfide, revealing that these bacteria were capable of a range of activities associated with metabolism and host response. Consistent with this finding, monocolonization of mice with individual isolates identified bacteria that were potent inducers of regulatory T-cell (Treg) differentiation in the colon. Comparisons between variables revealed by these studies identified enzymatic properties correlated with Treg induction and Trichuris egg hatching. CONCLUSION: We identified Clostridiales species that are sufficient to induce high levels of Tregs. We also identified a set of metabolic activities linked with Treg differentiation and Trichuris egg hatching mediated by these newly isolated bacteria. Altogether, this study provides functional insights into the microbiotas of individuals residing in a helminth-endemic region. Video Abstract.

Efficacy of Single-Dose Albendazole and Albendazole Plus Ivermectin for Soil-Transmitted Helminth Infection in Children in the Peruvian Amazon.

In countries where soil-transmitted helminth (STH) infections are endemic, deworming programs are recommended to reduce morbidity; however, increasing levels of resistance to benzimidazoles are of concern. In an observational study in Peru, we studied the clinical efficacy of 400 mg of albendazole 20 days after treatment among children aged 2-11 years. Of 426 participants who provided samples, 52.3% were infected with a STH, 144 (33.8%) were positive for Ascaris (41.8% light, 50.8% moderate, and 7.4% heavy infections), 147 (34.5%) were positive for Trichuris (75.2% light, 22.5% moderate, and 2.3% heavy infections), and 1.1% were positive for hookworm species (100% light infections). Additional stool samples were examined at 20, 90, and 130 days after the initial treatment. At 20 days post-administration of albendazole, the cure rate (CR) of Ascaris infection was 80.1% (95% CI: 73.5-86.7), and the egg reduction rate (ERR) was 70.8% (95% CI: 57.8-88.7); the CR for Trichuris infection was 27.1% (95% CI: 20.0-34.3), and the ERR was 29.8% (95% CI: -1.40 to 57.5). Among participants with persistent or recurrent infections with Trichuris, the combined therapy of albendazole (400 mg) and ivermectin at 600 µg/dose increased overall CR for Trichuris infection to 75.2% (95% CI: 67.3-83.2%) with an ERR of 84.2% (95% CI: 61.3-93.8%). Albendazole administration alone for the control of STH was associated with high rates of treatment failure, especially for Trichuris. Combined single doses of albendazole and ivermectin was observed to have improved efficacy.

Soil-Transmitted Helminth Infections in Shanghai, China: Surveillance from 2014 to 2023.

Soil-transmitted helminthiasis remains a notable health problem in developing countries. In 1990 in Shanghai, a city in eastern China, 47% of the population was affected. Due to a series of comprehensive approaches, the prevalence decreased to 0.5% in 2009. We collected 10-year surveillance data to assess the epidemic situation of soil-transmitted helminth (STH) infections in Shanghai. Stool samples and questionnaires from participants were collected. The Kato-Katz technique was used to detect infections with Ascaris lumbricoides, hookworm (Ancylostoma duodenale and Necator americanus), and Trichuris trichiura. From 2014 to 2023, a total of 77,685 participants were screened for parasitic infections, and the overall prevalence of STH infections decreased from 0.1% to 0% in Shanghai. Of 77,685 participants, 25 (0.03%) were positive for intestinal helminths, with the most common parasite being A. lumbricoides (72.0%). Generally, elderly participants from rural areas with lower education levels were more likely to be infected with STHs. A total of 2,914 questionnaires were collected, and most respondents (72.6%) had good knowledge about the transmission routes of STHs. However, 12.3% of participants did not know the damage to health caused by STHs, and 19.3% had no idea of how to prevent infection. These data demonstrate the current state of STH infections in Shanghai. The results suggest that various comprehensive measures should be encouraged, continuously implemented, and strengthened accordingly so that STH elimination can be integrated into the Healthy China initiative by 2030.

Epidemiology of soil-transmitted helminthiasis among school-aged children in pastoralist communities of Kenya: A cross-sectional study.

INTRODUCTION: Soil-transmitted helminthiasis (STH) are a major public health problem in Sub-Saharan Africa. In Kenya, the National School Based Deworming Program (NSBDP) was launched in 2012 with a goal of reducing STH prevalence in school-aged children (SAC) to <1%, however monitoring and evaluation results have consistently showed > 20% prevalence in Narok County. We conducted a study to investigate factors associated with STH infections among SAC in Narok County. METHODOLOGY: A cross-sectional study was conducted among 514 SAC from five schools in Trans Mara West sub-county, Narok County. The sub-county was selected because it had participating schools within the NSBDP with a high prevalence of STH infection. Participants were selected using systematic random sampling. Stool samples collected from participants were examined for STH eggs using Kato-Katz technique. An open data kit questionnaire was used to collect socio-demographics, household, and STH knowledge information from 139 of the 514 SAC. Descriptive statistics was used to summarize the data, prevalence and mean intensity of infections were calculated, and logistic regression used to determine factors associated with STH infections. RESULTS: The overall prevalence of any STH infection was 24.6% (95%CI: 21.1-28.6). Trichuris trichiura 14.4% (95%CI: 11.7-17.8), Ascaris lumbricoides 12.5% (95%CI: 9.9-15.7) and hookworm 0%. From multivariable analysis the only factors significantly associated with increased risk of STH infection were, children attending Karda and Nkarano schools with aOR = 5.29 (95%CI: 1.45-19.24); p = 0.011 and aOR = 4.53 (95%CI: 1.29-15.97); p = 0.019 respectively. For A. lumbricoides, children attending Nkarano School were associated with a significant risk of infection with aOR = 7.81 (95%CI: 1.81-33.63); p = 0.006. CONCLUSIONS: Despite the ongoing work of NSBDP, the STH prevalence is still ≥ 20% in Trans Mara West sub-county Narok County, among SAC. This underscores the need for continued annual MDA. Additionally, if possible, drug combinations may effectively manage T. trichiura, the region's most common helminth. The study found a correlation between children attending specific schools and STH infection risk, suggesting the importance of health education and improved water, sanitation, and hygiene practices holistically both in schools and associated catchment areas that can act as STH reservoirs to alleviate the burden of STH.

Serological diagnosis of soil-transmitted helminth (Ascaris, Trichuris and hookworm) infections: A scoping review.

BACKGROUND: The World Health Organization emphasizes the importance of integrated monitoring and evaluation in neglected tropical disease (NTD) control programs. Serological assays offer a potential solution for integrated diagnosis of NTDs, particularly for those requiring mass drug administration (MDA) as primary control and elimination strategy. This scoping review aims (i) to provide an overview of assays using serum or plasma to detect infections with soil-transmitted helminths (STHs) in both humans and animals, (ii) to examine the methodologies used in this research field and (iii) to discuss advancements in serological diagnosis of STHs to guide prevention and control programs in veterinary and human medicine. METHODOLOGY: We conducted a systematic search in the Ovid MEDLINE, Embase and Cochrane Library databases, supplemented by a Google search using predefined keywords to identify commercially available serological assays. Additionally, we performed a patent search through Espacenet. PRINCIPAL FINDINGS: We identified 85 relevant literature records spanning over 50 years, with a notable increased interest in serological assay development in recent years. Most of the research efforts concentrated on diagnosing Ascaris infections in both humans and pigs, primarily using ELISA and western blot technologies. Almost all records targeted antibodies as analytes, employing proteins and peptides as analyte detection agents. Approximately 60% of sample sets described pertained to human samples. No commercially available tests for Trichuris or hookworms were identified, while for Ascaris, there are at least seven different ELISAs on the market. CONCLUSIONS: While a substantial number of assays are employed in epidemiological research, the current state of serological diagnosis for guiding STH prevention and control programs is limited. Only two assays designed for pigs are used to inform efficient deworming practices in pig populations. Regarding human diagnosis, none of the existing assays has undergone extensive large-scale validation or integration into routine diagnostics for MDA programs.

Myeloid A20 is critical for alternative macrophage polarization and type-2 immune-mediated helminth resistance.

Background: Protective immunity against intestinal helminths requires induction of robust type-2 immunity orchestrated by various cellular and soluble effectors which promote goblet cell hyperplasia, mucus production, epithelial proliferation, and smooth muscle contractions to expel worms and re-establish immune homeostasis. Conversely, defects in type-2 immunity result in ineffective helminth clearance, persistent infection, and inflammation. Macrophages are highly plastic cells that acquire an alternatively activated state during helminth infection, but they were previously shown to be dispensable for resistance to Trichuris muris infection. Methods: We use the in vivo mouse model A20myel-KO, characterized by the deletion of the potent anti-inflammatory factor A20 (TNFAIP3) specifically in the myeloid cells, the excessive type-1 cytokine production, and the development of spontaneous arthritis. We infect A20myel-KO mice with the gastrointestinal helminth Trichuris muris and we analyzed the innate and adaptive responses. We performed RNA sequencing on sorted myeloid cells to investigate the role of A20 on macrophage polarization and type-2 immunity. Moreover, we assess in A20myel-KO mice the pharmacological inhibition of type-1 cytokine pathways on helminth clearance and the infection with Salmonella typhimurium. Results: We show that proper macrophage polarization is essential for helminth clearance, and we identify A20 as an essential myeloid factor for the induction of type-2 immune responses against Trichuris muris. A20myel-KO mice are characterized by persistent Trichuris muris infection and intestinal inflammation. Myeloid A20 deficiency induces strong classical macrophage polarization which impedes anti-helminth type-2 immune activation; however, it promotes detrimental Th1/Th17 responses. Antibody-mediated neutralization of the type-1 cytokines IFN-γ, IL-18, and IL-12 prevents myeloid-orchestrated Th1 polarization and re-establishes type-2-mediated protective immunity against T. muris in A20myel-KO mice. In contrast, the strong Th1-biased immunity in A20myel-KO mice offers protection against Salmonella typhimurium infection. Conclusions: We hereby identify A20 as a critical myeloid factor for correct macrophage polarization and appropriate adaptive mucosal immunity in response to helminth and enteric bacterial infection.

The adaptive immune response to Trichuris in wild versus laboratory mice: An established model system in context.

Laboratory model organisms have provided a window into how the immune system functions. An increasing body of evidence, however, suggests that the immune responses of naive laboratory animals may differ substantially to those of their wild counterparts. Past exposure, environmental challenges and physiological condition may all impact on immune responsiveness. Chronic infections of soil-transmitted helminths, which we define as establishment of adult, fecund worms, impose significant health burdens on humans, livestock and wildlife, with limited treatment success. In laboratory mice, Th1 versus Th2 immune polarisation is the major determinant of helminth infection outcome. Here we compared antigen-specific immune responses to the soil-transmitted whipworm Trichuris muris between controlled laboratory and wild free-ranging populations of house mice (Mus musculus domesticus). Wild mice harbouring chronic, low-level infections produced lower levels of cytokines in response to Trichuris antigen than laboratory-housed C57BL/6 mice. Wild mouse effector/memory CD4+ T cell phenotype reflected the antigen-specific cytokine response across the Th1/Th2 spectrum. Increasing egg shedding was associated with body condition loss. However, local Trichuris-specific Th1/Th2 balance was positively associated with worm burden only in older wild mice. Thus, although the fundamental relationships between the CD4+ T helper cell response and resistance to T. muris infection are similar in both laboratory and wild M. m. domesticus, there are quantitative differences and age-specific effects that are analogous to human immune responses. These context-dependent immune responses demonstrate the fundamental importance of understanding the differences between model and natural systems for translating mechanistic models to 'real world' immune function.

A randomized assessors-blind clinical trial to evaluate the safety and the efficacy of albendazole alone and in combination with mebendazole or pyrantel for the treatment of Trichuris trichiura infection in school-aged children in Lambaréné and surroundings.

Helminthiasis remains a public health issue in endemic areas. Various drugs have been proposed to improve efficacy against helminths. The study aimed to assess the safety and efficacy of three different anthelmintic combinations to treat Trichuris trichiura infections. We conducted a randomized assessors-blind clinical trial involving children aged 2-17 years with T. trichiura. Participants were randomly assigned to one of three treatment arms. On the first and third days, all participants got albendazole 400 mg, and on the second day, albendazole (arm A), mebendazole 500 mg (arm B), or pyrantel 125 mg/kg (arm C). We assessed treatment efficacy using the cure rate (CR) and egg reduction rate (ERR) at 3 and 6 weeks post-treatment. At 3 weeks post-treatment, ERR and CR were highest in study arm A [ERR = 94%, 95% confidence interval (CI): 92-95; CR = 71%; 95% CI: 58-81] compared to the B and C arms. Decrease in ERR was significant only for arm B versus arm A (P-value <0.001); decrease in ERR was significant for arms B and C (P-value <0.001). No statistical difference was observed in CR when comparing arms A and B (P-value =1.00) and C (P-value =0.27). At 6 weeks, a decrease in ERR was observed in three arms, significant only for arm C, 81% (95% CI: 78-83). A significant increase in egg counts was observed between 3 and 6 weeks post-treatment. All treatments were safe with mild adverse events. Albendazole 400 mg/day (arm A) showed the highest efficacy against trichuriasis. Nonetheless, this treatment regimen was able to cure half of the treated individuals highlighting concerns about controlling the transmission of T. trichiura.CLINICAL TRIALRegistered at ClinicalTrials.gov (NCT04326868).

Estimating Prevalence and Infection Intensity of Soil-Transmitted Helminths Using Quantitative Polymerase Chain Reaction and Kato-Katz in School-Age Children in Angola.

Quantitative polymerase chain reaction (qPCR) is gaining recognition in soil-transmitted helminth (STH) diagnostics, especially for Strongyloides stercoralis and differentiating hookworm species. However, sample preservation and DNA extraction may influence qPCR performance. We estimated STH prevalence and infection intensity by using qPCR in schoolchildren from Huambo, Uige, and Zaire, Angola, and compared its performance with that of the Kato-Katz technique (here termed Kato-Katz). Stool samples from 3,063 children (219 schools) were preserved in 96% ethanol and analyzed by qPCR, of which 2,974 children (215 schools) had corresponding Kato-Katz results. Cluster-adjusted prevalence and infection intensity estimates were calculated by qPCR and Kato-Katz, with cycle threshold values converted to eggs per gram for qPCR. Cohen's kappa statistic evaluated agreement between qPCR and Kato-Katz. DNA extraction and qPCR were repeated on 191 (of 278) samples that were initially qPCR negative but Kato-Katz positive, of which 112 (58.6%) became positive. Similar prevalence for Ascaris lumbricoides (37.5% versus 34.6%) and Trichuris trichiura (6.5% versus 6.1%) were found by qPCR and Kato-Katz, respectively, while qPCR detected a higher hookworm prevalence (11.9% versus 2.9%). The prevalence of moderate- or high-intensity infections was higher by Kato-Katz than by qPCR. Agreement between qPCR and Kato-Katz was very good for A. lumbricoides, moderate for T. trichiura, and fair for hookworm. Strongyloides stercoralis prevalence was 4.7% (municipality range, 0-14.3%), and no Ancylostoma ceylanicum was detected by qPCR. Despite suboptimal performance, presumably due to fixative choice, qPCR was fundamental in detecting S. stercoralis and excluding zoonotic A. ceylanicum. Further evaluations on sample fixatives and DNA extraction methods are needed to optimize and standardize the performance of qPCR.

A survey of gastrointestinal helminth infestation in smallholder backyard pigs and the first molecular identification of the two zoonotic helminths Ascaris suum and Trichuris suis in Myanmar.

BACKGROUND: Parasitic infestations have a substantial economic impact on pig production. This study aimed to investigate the gastrointestinal (GI) helminths in pigs and to molecularly characterise two important nematodes, Ascaris and Trichuris species. MATERIALS AND METHODS: A total of 500 pig faecal samples were collected from small holder backyard pig farms in five townships within Nay Pyi Taw, Myanmar. Microscopic examination was conducted to estimate the prevalence of GI helminth infestation in the pigs. DNA extraction and PCR were performed on faecal samples that were morphologically positive for Ascaris and Trichuris eggs. Molecular analysis was then conducted to characterise A. suum and T. suis, the most common and zoonotic helminths. RESULTS: According to microscopic examination, 69.2% (346/500) were positive for GI helminth eggs. The GI helminth species observed were A. suum, Strongyle, Strongyloides spp., T. suis, Metastrongylus spp., Hyostrongylus spp., Fasciolopsis spp., Paragonimus spp., and Schistosoma spp., with occurrences of 34.8%, 29.6%, 21.4%, 20.0%, 4.0%, 1.6%, 1.0%, 1.0%, and 0.4%, respectively. Mixed infections of GI helminths were noted in 31.0% of the samples. Overall, sampled pigs excreted mostly low levels (< 100 EPG) or moderate levels (> 100-500 EPG) of GI helminth eggs. The highest mean EPG for each parasite species was noted in A. suum. The presence of A. suum and T. suis was confirmed molecularly. The sequences of the internal transcribed spacer 1 (ITS1) region of A. suum showed high similarity with previously reported sequences. Likewise, the sequences of T. suis exhibited high similarity with the sequences reported from humans and pigs. Age was noted as an associated factor (P < 0.05) for GI helminth infection status. CONCLUSIONS: In this report, A. suum and T. suis were molecularly identified for the first time in Myanmar. It is important to extend the information among the farmers to be aware of the necessity of preventing zoonotic parasites by practicing regular deworming, proper use of anthelmintics and maintaining hygienic conditions in their pig farms.

Diagnosis of soil-transmitted helminth infections with digital mobile microscopy and artificial intelligence in a resource-limited setting.

BACKGROUND: Infections caused by soil-transmitted helminths (STHs) are the most prevalent neglected tropical diseases and result in a major disease burden in low- and middle-income countries, especially in school-aged children. Improved diagnostic methods, especially for light intensity infections, are needed for efficient, control and elimination of STHs as a public health problem, as well as STH management. Image-based artificial intelligence (AI) has shown promise for STH detection in digitized stool samples. However, the diagnostic accuracy of AI-based analysis of entire microscope slides, so called whole-slide images (WSI), has previously not been evaluated on a sample-level in primary healthcare settings in STH endemic countries. METHODOLOGY/PRINCIPAL FINDINGS: Stool samples (n = 1,335) were collected during 2020 from children attending primary schools in Kwale County, Kenya, prepared according to the Kato-Katz method at a local primary healthcare laboratory and digitized with a portable whole-slide microscopy scanner and uploaded via mobile networks to a cloud environment. The digital samples of adequate quality (n = 1,180) were split into a training (n = 388) and test set (n = 792) and a deep-learning system (DLS) developed for detection of STHs. The DLS findings were compared with expert manual microscopy and additional visual assessment of the digital samples in slides with discordant results between the methods. Manual microscopy detected 15 (1.9%) Ascaris lumbricoides, 172 (21.7%) Tricuris trichiura and 140 (17.7%) hookworm (Ancylostoma duodenale or Necator americanus) infections in the test set. Importantly, more than 90% of all STH positive cases represented light intensity infections. With manual microscopy as the reference standard, the sensitivity of the DLS as the index test for detection of A. lumbricoides, T. trichiura and hookworm was 80%, 92% and 76%, respectively. The corresponding specificity was 98%, 90% and 95%. Notably, in 79 samples (10%) classified as negative by manual microscopy for a specific species, STH eggs were detected by the DLS and confirmed correct by visual inspection of the digital samples. CONCLUSIONS/SIGNIFICANCE: Analysis of digitally scanned stool samples with the DLS provided high diagnostic accuracy for detection of STHs. Importantly, a substantial number of light intensity infections were missed by manual microscopy but detected by the DLS. Thus, analysis of WSIs with image-based AI may provide a future tool for improved detection of STHs in a primary healthcare setting, which in turn could facilitate monitoring and evaluation of control programs.

The global prevalence of Trichuris trichiura infection in humans (2010-2023): A systematic review and meta-analysis.

This systematic review and meta-analysis study aimed to evaluate global Trichuris infection prevalence, assessing progress towards the WHO's 2030 target. We searched international databases from 2010-2023, categorizing data by regions and socio-economic variables using a random-effects model. Analyzing 757 articles covering 7154,842 individuals from 78 countries, the study found a pooled global prevalence of (6.64-7.57%), with the highest rates in the Caribbean (21.72%; 8.90-38.18%) and South-East Asia (20.95; 15.71-26.71%) regions. Southern Africa (9.58; 2.11-21.46%), Latin America (9.58; 2.11-21.46%), and Middle Africa Middle Africa (8.94; 6.31-11.98%) also exhibited high prevalence. Eastern Europe had the lowest prevalence at 0.16% (0.09-0.24). Approximately 513 (480-547) million people worldwide were estimated to harbor Trichuris. Moreover ∼1.5% of people tested worldwide (2010-2023) had a moderate to heavy intensity of infection. The study emphasizes the persistent global health threat of Trichuris infection, urging tailored strategies for effective control and prevention on a global scale.

Egg excretion patterns of soil-transmitted helminth infections in humans following albendazole-ivermectin and albendazole treatment.

BACKGROUND: Control efforts of soil-transmitted helminthiases rely primarily on large scale administration of anthelminthic drugs. The assessment of drug efficacies and understanding of drug behavior is pivotal to the evaluation of treatment successes, both in preventive chemo-therapy programs as well as in research of novel treatment options. The current WHO guidelines recommend an interval of 14-21 days between the treatment and follow-up, yet no in-depth analysis of egg excretion patterns of Trichuris trichiura after treatment has been conducted to date. METHODS: Within the framework of a multi-country trial to assess the efficacy and safety of albendazole-ivermectin combination therapy vs albendazole monotherapy against T. trichiura infections, we conducted a study collecting daily stool samples over the period of 28 days post-treatment in 87 participants in Pak Khan, Lao PDR. Egg counts were derived by duplicate Kato-Katz on-site for T. trichiura, hookworm and Ascaris lumbricoides and stool sample aliquots were subsequently analyzed by qPCR for the detection of T. trichiura infections. Sensitivity and specificity was calculated for each day separately using data derived by Kato-Katz to determine the optimal timepoint at which to assess drug efficacy. RESULTS: Egg excretion patterns varied across treatment arms. For T. trichiura, only the albendazole-ivermectin treatment led to a considerable reduction in mean egg counts, whereas both treatments reduced hookworm egg counts and A. lumbricoides were cleared in all participants after day 7. For T. trichiura, we found sensitivity to be highest at days 18 and 22 when using egg counts as outcome and days 19 and 24 when using qPCR. Specificity was high (>0.9) from day 14 onwards. For hookworm, the highest sensitivity and specificity were found at days 17 and 25, respectively. CONCLUSIONS: Based on our study, the ideal time period to assess drug efficacy for soil-transmitted helminth infections would be between day 18 and 24. The current WHO recommendation of 14 to 21 days is likely to yield acceptable outcome measures for soil-transmitted helminth infections. TRIAL REGISTRATION: NCT03527732.