Detection of human strongyloidiasis among patients with a high risk of complications attending selected tertiary care hospitals in Colombo, Sri Lanka using molecular and serological diagnostic tools.

BACKGROUND: Strongyloidiasis a neglected tropical disease is known to cause severe disease among immunosuppressed and has not been studied extensively in Sri Lanka. Parasitological diagnostic approaches based on faecal microscopy and culture often fail to detect low-intensity infections. This study investigates the presence of strongyloidiasis among selected immunocompromised individuals using parasitological, molecular and serological techniques. METHODS: Adult patients with immunocompromising conditions admitted to three tertiary care hospitals in Sri Lanka were recruited. A faecal sample and 2 ml of venous blood were collected. The faecal samples were subjected to direct faecal smear and cultures (agar plate, charcoal and Harada-Mori) and polymerase chain reaction (PCR) using species specific primers designed for Strongyloides stercoralis. The presence of Strongyloides IgG antibodies was tested in the collected serum samples using DRG Strongyloides IgG enzyme-linked immunosorbent assay (ELISA) kits. The PCR products of the positive samples were sequenced using Sanger sequencing method. RESULTS: A total of 260 patients were recruited to this study, out of which 160 provided faecal samples and 122 provided blood samples. Out of the 160 faecal samples, none were positive for strongyloidiasis by direct smear, charcoal and Harada-Mori cultures. Only one sample (0.6%) was positive by agar plate culture. Out of the 123 samples subjected to PCR, 14 (11.4%), including the culture positive patient, were positive for S. stercoralis. Sequencing results of the PCR products indicated 100% similarity to S. stercoralis. Out of the 122 serum samples subjected to ELISA, 20 (16.4%), including the culture positive patient, were positive for Strongyloides IgG antibodies. However, sociodemographic, exposure factors, clinical features were not significantly associated with the presence of strongyloidiasis infection. CONCLUSIONS: Strongyloidiasis is present among the immunocompromised population in Sri Lanka, even in the absence of a significant relationship with associated factors. It is advisable to screen such patients with highly sensitive tests such as PCR for early diagnosis and treatment.

Dirofilariasis in the hiding in oral cavity of a patient from Karnataka, India.

"Human dirofilariasis, caused by filarial worms of the genus Dirofilaria, is considered an emerging zoonotic filarial infection transmitted to humans by zoo-anthropophilic blood-sucking insects. The most common Dirofilaria species causing human infections include Dirofilaria repens and Dirofilaria immitis. In this case report, we present the case of a 60-year-old male patient who reported the presence of an intraoral swelling in the right maxillary vestibular region. Upon excision of the lesion and further microscopic and histological examination, a female Dirofilaria was identified as the causative agent."

Extracellular vesicles as biomarkers in parasitic disease diagnosis.

Parasitic diseases constitute a major global health problem, affecting millions of people worldwide. Recent advances in the study of extracellular vesicles (EVs) have opened up new strategies for biomarker discovery in protozoan and helminth infections. Analyses of EVs in cultures and biological fluids have identified numerous potential biomarkers that could be useful for early and differential diagnosis, monitoring therapeutic responses, and the overall management and control of these diseases. Despite the potential of these biomarkers, several challenges must be addressed, including limited research, the need for standardized protocols, and the reproducibility of results across studies. In many parasitic infections, EVs have been obtained from various sample types, including plasma from human patients and mouse models, as well as cultures of the parasites at different stages. EVs were isolated by various methods and predominantly characterized through proteomic analysis or RNA sequencing to assess their cargo and identify potential biomarkers. These biomarker candidates were investigated and validated using different assays such as ELISA, Western Blot, and ROC curves. Overall, the use of EVs is considered a promising new diagnostic strategy for parasite infections, but further research with larger cohorts, standardized methods, and additional validation tests are essential for effective diagnosis and management of these diseases.

Both host and parasite non-coding RNAs co-ordinate the regulation of macrophage gene expression to reduce pro-inflammatory immune responses and promote tissue repair pathways during infection with fasciola hepatica.

Parasitic worms (helminths) establish chronic infection within mammalian hosts by strategically regulating their host's immune responses. Deciphering the mechanisms by which host non-coding RNAs (ncRNA) co-ordinate the activation and regulation of immune cells is essential to understanding host immunity and immune-related pathology. It is also important to comprehend how pathogens secrete specific ncRNAs to manipulate gene expression of host immune cells and influence their response to infection. To investigate the contribution of both host and helminth derived ncRNAs to the activation and/or regulation of innate immune responses during a parasite infection, we examined ncRNA expression in the peritoneal macrophages from mice infected with Fasciola hepatica. We discovered the presence of several parasitic-derived miRNAs within host macrophages at 6 hrs and 18 hrs post infection. Target prediction analysis showed that these Fasciola miRNAs regulate host genes associated with the activation of host pro-inflammatory macrophages. Concomitantly, there was a distinct shift in host ncRNA expression, which was significant at 5 days post-infection. Prediction analysis suggested that these host ncRNAs target a different cohort of host genes compared to the parasite miRNAs, although the functional outcome was predicted to be similar i.e. reduced pro-inflammatory response and the promotion of a reparative/tolerant phenotype. Taken together, these observations uncover the interplay between host and parasitic ncRNAs and reveal a complementary regulation of the immune response that allows the parasite to evade immune detection and promote tissue repair for the host. These findings will provide a new understanding of the molecular interaction between parasites and host.

Hematological and biochemical profiles, infection and habitat quality in an urban rat population.

Host condition is key in understanding disease dynamics. In an urban population of Rattus norvegicus, we aimed to assess whether infection of Leptospira interrogans and helminths was associated with patterns of host hematological and hormone-biochemical stress-related conditions. Rat kidney imprints and urine were used to identify and quantify L. interrogans, and feces samples for helminth eggs and corticosterone metabolites. Blood samples were taken for complete blood counts and specific biochemicals in rats' sera. Principal Component Analyses were performed to check whether rats would be grouped according to health profiles. We obtained hematological and hormone-biochemical data from 95 and 61 rats, respectively. Hematological PCA revealed distinct rat groups: typical (T), eosinophil deficient (Eos-D), eosinophil- and monocyte- deficient (EM-D) and monocyte deficient with high immature neutrophils (Mon-D). No association between L. interrogans or helminths and rat health profiles was observed, except with Trichiuridae, which mean intensity was significantly higher when all deficient groups were pooled together compared to the T-group. The poorest condition group was found in areas with fewer rat burrows than the T-group, indicating EM-D had a reduced ability to occupy "good" quality habitats. In natural populations, hematological profiles may reflect host's overall condition, instead of responses to specific infections.

A novel kit for enrichment of fecal helminth eggs.

We developed a new concentration kit, called the ParaEgg (PE), for easy detection trematode eggs from fecal samples in endemic areas of clonorchiasis and metagonimiasis in Korea. To create a standard of detection efficiency, 120 fecal samples were examined using the water-ether concentration method (WECM). The PE kit and Mini ParaSep (PS) kit were used to compare the detection sensitivity of 100 egg-positive and 20 egg-negative samples in WECM. Additionally, stool samples, which were intentionally spiked with 10, 20, and 30 Clonorchis sinensis eggs, were evaluated to assess the sensitivity in lowinfection cases. The PE and PS kits showed detection rates of 100% and 92%, respectively, from 100 egg-positive samples in WECM. Meanwhile, eggs were detected in 3 (PE) and 2 (PS) out of 20 egg-negative samples in WECM. The PE kit detected the highest number of eggs per gram of feces (727 on average), followed by the WECM (524) and PS kit (432). In fecal samples that were intentionally spiked with 10, 20, and 30 C. sinensis eggs, PE only detected eggs 2 out of 5 samples in 10 eggs spiked (40%), and the detection rates were 80% and 100%, respectively. The PE kit enabled a more accurate identification of trematode eggs because of the clearance of small fecal debris in the microscopic field. In conclusion, the PE kit is obviously helpful to detect and identify trematode eggs in stool examinations especially in endemic areas of clonorchiasis and metagonimiasis.

Health-promoting worms? Prospects and pitfalls of helminth therapy.

In this manuscript, we explore the potential therapeutic use of helminths. After analyzing helminths' role in connection with human health from the perspective of their symbiotic and evolutionary relationship, we critically examine some studies on their therapeutic applications. In doing so, we focus on some prominent mechanisms of action and potential benefits, but also on the exaggerations and theoretical and methodological difficulties of such proposals. We conclude that further studies are needed to fully explore the potential benefits of this perspective, and we encourage the scientific community in doing so.

Prevalence and distribution of intestinal parasitic infections in taeniasis endemic area of North Sumatera, Indonesia.

A group of helminthic and intestinal protozoa causes intestinal parasitic infections (IPIs), affecting more than 2.5 billion people worldwide. IPIs are diseases closely associated with poor hygiene and sanitation, concentrated in underdeveloped regions and among populations with low socioeconomic status. Consequently, most prevalence is in Sub-Saharan Africa and Asia, with local habits or risk factors that could affect its prevalence. The aim of this study was to determine how hygienic practices, sanitation, and local behavior of eating raw meat (hinasumba) contributed to the prevalence of IPI. A cross-sectional study was conducted in the Simalungun District of North Sumatera Province, involving 428 people of Batak Simalungun. There were 15 villages randomly selected across the district based on the local registry, which consequently, non-purposive sampling was conducted. Face-to-face interviews assessed various risk factors, such as demographic characteristics, water source, traditional raw meat consumption, or hinasumba as local risk factors, hygienic practices, and sanitation. The findings indicated that an overall prevalence rate of IPI was 42.9%, consisting of 87.5% with helminthic infection and 12.5% with protozoal infection. More than half of IPI cases were associated with Taenia sp. infections (21.8%), followed by hookworms' infections with a 6.1% positivity rate. Based on multivariate analysis, farming and consuming traditional delicacies, namely hinasumba, increased the likelihood of IPI occurrence among the population by 1.7 and 3 times, respectively. It can be concluded that the high prevalence of taeniasis in the study area was associated with local behavior and hinasumba consumption, which may contribute to determining the dominance of specific IPI species.

Construction and validation of a novel multi-epitope in silico vaccine design against the paramyosin protein of Opisthorchis viverrini using immunoinformatics analyses.

Liver fluke infection caused by Opisthorchis viverrini (O. viverrini) remains a significant but neglected health threat across Southeastern Asia. The early infective anabolic growth stage of O. viverrini expresses and exposes proteins integral for the growth and maturation of immature worms to the adult catabolic stage. Among these proteins, paramyosin emerged as a distinct immunogenic protein during opisthorchiasis. The functional region of the paramyosin protein known as myosin tail was selected to design a multi-epitope vaccine (MEV) to elicit T and B cell immune responses in susceptible human hosts utilizing various immunoinformatics and in silico vaccinology tools. The vaccine candidate had several B- and T-cell epitopes that stimulate both humoral and cellular immune responses. Moreover, in silico structural, docking, and dynamic analyses showed that the construct interacted with target immune receptors effectively, which may result in sufficient immunological stimulation. Analysis of simulated coverage efficacy also supports vaccine application in the field. Cloning and expression of the vaccine candidate were determined to be viable based on physicochemical and in silico assessments. These results reveal that the vaccine candidate developed herein is stable and potentially useful in addressing opisthorchiasis. The promising result of this study establishes a strong platform for initiating laboratory and efficacy trials for the vaccine candidate.

Helminth-derived molecules: pathogenic and pharmacopeial roles.

Parasitic helminths, taxonomically comprising trematodes, cestodes, and nematodes, are multicellular invertebrates widely disseminated in nature and have afflicted people continuously for a long time. Helminths play potent roles in the host through generating a variety of novel molecules, including some excretory/secretory products and others that are involved in intracellular material exchange and information transfer as well as the initiation or stimulation of immune and metabolic activation. The helminth-derived molecules have developed powerful and diverse immunosuppressive effects to achieve immune evasion for parasite survival and establish chronic infections. However, they also improve autoimmune and allergic inflammatory responses and promote metabolic homeostasis by promoting metabolic reprogramming of various immune functions, and then inducing alternatively activated macrophages, T helper 2 cells, and regulatory T cells-mediated immune responses. Therefore, a deeper exploration of the immunopathogenic mechanism and immune regulatory mechanisms of helminth-derived molecules exerted in the host is crucial for understanding host-helminth interactions as well as the development of therapeutic drugs for infectious or non-infectious diseases. In this review, we focus on the properties of helminth-derived molecules to give an overview of the most recent scientific knowledge about their pathogenic and pharmacopeial roles in immune-metabolic homeostasis.

Human Infection with the Nematode Gongylonema sp.: A Case Report from Bulgaria.

We report a case of infection with the zoonotic nematode Gongylonema sp. in a 24-year-old woman from Varna, Bulgaria. Two days before seeking medical attention, the patient had noticed a filamentous mass in her buccal mucosa that migrated when touched with the tongue. She manually removed a thread-like worm from the mucosa near her lower lip. Albendazole was prescribed for three days. The patient had no history of travelling abroad or contact with animals. To our knowledge, this is the sixth case that has been reported in the country.

The rebalancing of the immune system at the maternal-fetal interface ameliorates autism-like behavior in adult offspring.

Maternal immune activation (MIA) is critical for imparting neuropathology and altered behaviors in offspring; however, maternal-fetal immune cell populations have not been thoroughly investigated in MIA-induced autism spectrum disorders (ASDs). Here, we report the single-cell transcriptional landscape of placental cells in both PBS- and poly(I:C)-induced MIA dams. We observed a decrease in regulatory T (Treg) cells but an increase in the M1 macrophage population at the maternal-fetal interface in MIA dams. Based on the Treg-targeting approach, we investigate an immunoregulatory protein, the helminth-derived heat shock protein 90α (Sjp90α), that induces maternal Treg cells and subsequently rescues the autism-like behaviors in adult offspring. Furthermore, in vivo depletion of maternal macrophages attenuates placental inflammatory reaction and reverses behavioral abnormalities in adult offspring. Notably, Sjp90α induces CD4+ T cell differentiation via scavenger receptor A (SR-A) on the macrophage in vitro. Our findings suggest a maternal Treg-targeted approach to alleviate MIA-induced autism-like behavior in adult offspring.

Akkermansia in the gastrointestinal tract as a modifier of human health.

Akkermansia sp are common members of the human gut microbiota. Multiple reports have emerged linking the abundance of A. muciniphila to health benefits and disease risk in humans and animals. This review highlights findings linking Akkermansia species in the gastrointestinal (GI) tract to health outcomes across a spectrum of disorders, encompassing those that affect the digestive, respiratory, urinary, and central nervous systems. The mechanism through which Akkermansia exerts a beneficial versus a detrimental effect on health is likely dependent on the genetic makeup of the host metabolic capacity and immunomodulatory properties of the strain, the competition or cooperation with other members of the host microbiota, as well as synergy with co-administered therapies.

Prevalence and associated risk factors of soil-transmitted helminth infections among schoolchildren in Mekan Eyesus town, northwestern Ethiopia.

Background: Little attention has been paid to determining the prevalence and associated factors of soil-transmitted helminth (STH) infections in some developing countries. This study was, therefore, carried out to determine the prevalence and associated factors of STH infections among schoolchildren attending three primary schools in Mekane Eyesus town, northwestern Ethiopia. Methods: A school-based cross-sectional study was conducted from March to June 2023 in Mekane Eyesus town. Stool samples were collected from 401 children from three primary schools in the town. Wet-mount and formol ether concentration techniques were used to diagnose stool samples, and a structured questionnaire was used to collect data on socio-demographic characteristics and risk factors for STH infections. Results: The overall prevalence of STH infection in this study was 18.2 % (73/401). The most common helminth species detected was Ascaris lumbricoides (A. lumbricoides) (7.5 % (30/401)). Not trimming fingernails regularly (adjusted odds ratio (AOR) = 3.75, 95 % CI = 1.87-7.50), having illiterate fathers (AOR = 2.29, 95 % CI = 1.18-4.44), and being aged 15-17 years (AOR = 2.37, 95 % CI = 1.06-5.30) were associated with increased odds of STH infection. Children who wash their hands after defecation (AOR = 0.43, 95 % CI = 0.21-0.88) and those whose mothers were housewives (AOR = 0.22, 95 % CI = 0.08-0.58) had lower odds of STH infection. Conclusion: This study found a high prevalence of STH infection among schoolchildren in Mekane Eyesus town. Thus, STH infection preventive measures, including deworming of schoolchildren, should be implemented in the study area. Moreover, giving health-related knowledge about STH infection prevention strategies, such as regular fingernail trimming and hand washing after defecating, is vital for reducing the prevalence of STH infections in the study area.

Mathematical Modeling of Mating Probability and Fertile Egg Production in Helminth Parasites.

In this work, we obtained a general formulation for the mating probability and fertile egg production in helminth parasites, focusing on the reproductive behavior of polygamous parasites and its implications for transmission dynamics. By exploring various reproductive variables in parasites with density-dependent fecundity, such as helminth parasites, we departed from the traditional assumptions of Poisson and negative binomial distributions to adopt an arbitrary distribution model. Our analysis considered critical factors such as mating probability, fertile egg production, and the distribution of female and male parasites among hosts, whether they are distributed together or separately. We show that the distribution of parasites within hosts significantly influences transmission dynamics, with implications for parasite persistence and, therefore, with implications in parasite control. Using statistical models and empirical data from Monte Carlo simulations, we provide insights into the complex interplay of reproductive variables in helminth parasites, enhancing our understanding of parasite dynamics and the transmission of parasitic diseases.

Large-bodied gastric spirurids (Nematoda, Spirurida) predict structure in the downstream gastrointestinal helminth community of wild spiny mice (Acomys dimidiatus).

The dominant helminths infecting spiny mice (Acomys dimidiatus) in the montane wadis of the Sinai Peninsula of Egypt are spirurid nematodes, notably Protospirura muricola and Mastophorus muris. Both are relatively large robust stomach worms that accumulate in hosts resulting in high worm burdens. To ascertain whether the presence of spirurid worms or their burdens alters the host's likelihood of infection with other helminth species, we analysed a database containing quantitative data on helminth parasites of these mice (n = 431). This comprised of worm burdens recorded during 4 surveys, conducted at 4-year intervals, in 4 wadis, during late summer of each year. The presence of spirurid worms did not significantly alter species richness with other helminth species nor the likelihood of mice carrying other nematode species. However, there was a significant association, particularly of P. muricola, with the presence of intestinal stages of cestodes, and with the acanthocephalan Moniliformis acomysi. After controlling for intrinsic and extrinsic factors, mice harbouring spirurid worms had greater worm burdens of other helminths compared with mice without spirurids. Moreover, spirurid worm burdens showed a significant positive covariation with similarly adjusted species richness of other helminths, non-spirurid helminths, non-spirurid nematodes, oxyuroid nematodes and intestinal stage cestode worm burdens. We interpret these results as an indication that the key driver for co-occurrence of spirurids with other helminths is likely to be transmission via common arthropod hosts (for cestodes and acanthocephalans), but also that mice carrying the heavier spirurid worm burdens become more susceptible to directly transmitted nematodes such as the Oxyuroidea.

Helminth derivative tuftsin-phopshorylcholine to treat autoimmunity.

Autoimmune diseases (AIDs) affect 5 to 10% of the population. There are more than ∼100 different autoimmune diseases. The AIDs are one of the top 10 causes of death in women under 65; 2nd highest cause of chronic illness; top cause of morbidity in women in the US. The NIH estimates annual direct healthcare costs for autoimmune diseases about $100 billion, in comparison, with cancers investment of $57 billion, heart and stroke cost of $200 billion. The current treatments for autoimmune diseases encompasses: steroids, chemotherapy, immunosuppressants, biological drugs, disease specific drugs (like acethylcholine-estherase for myasthenia gravis). The treatments for autooimmune diseases supress the patient immune network, which leads the patients to be more susceptible to infections. Hence, there is a need to develop immunomodulatory small molecules with minimal side effects to treat autoimmune diseases. The helminths developed secreting compounds which modulate the human defense pathways in order to develop tolerance and survive in the host environment. We have imitated the immunomodulatory activity of the helminth by using a derivative of the helminth secretory molecule. A bi-functional small molecule -tuftsin (T)-phosphorylcholine (PC), coined as TPC, was constructed. This chimeric molecule showed its immunomodulatory activity in 4 murine models of autoimmune diseases, attenuating the clinical score and the inflammatory response by immunomodutating the host immune system. Ex-vivo in human peripheral blood mononuclear cells (PBMCs) and biopsies originated from arteries of patients with giant cell arteritis. This paper decipher the mode of action of TPC immunomodulatory activity. Our data propose the potential for this small molecule to be a novel therapy for patients with autoimmune diseases.

The amalgam of naive CD4+ T cell transcriptional states is reconfigured by helminth infection to dampen the amplitude of the immune response.

Naive CD4+ T cells in specific pathogen-free (SPF) mice are characterized by transcriptional heterogeneity and subpopulations distinguished by the expression of quiescence, the extracellular matrix (ECM) and cytoskeleton, type I interferon (IFN-I) response, memory-like, and T cell receptor (TCR) activation genes. We demonstrate that this constitutive heterogeneity, including the presence of the IFN-I response cluster, is commensal independent insofar as being identical in germ-free and SPF mice. By contrast, Nippostrongylus brasiliensis infection altered this constitutive heterogeneity. Naive T cell-intrinsic transcriptional changes acquired during helminth infection correlated with and accounted for decreased immunization response to an unrelated antigen. These compositional and functional changes were dependent variables of helminth infection, as they disappeared at the established time point of its clearance in mice. Collectively, our results indicate that the naive T cell pool is subject to dynamic transcriptional changes in response to certain environmental cues, which in turn permutes the magnitude of the immune response.

Epizootiological monitoring of wolf helminths in Northern and Central Kazakhstan.

Background and Aim: Wolves (Canis lupus) play a role in nature, including the regulation of the number of ungulates and the use of dead animals. In addition, wolves are a natural link and carrier for the spread of many parasitic invasions. Hence, the main task in preventing the spread of parasitic invasions is to regulate the wolf population. This study aimed to monitor the endoparasitological fauna of wild wolves inhabiting Northern and Central Kazakhstan. Materials and Methods: Overall, 81 wolves were investigated for parasitic worms using the K. I. Scriabin method. Wolf intestinal materials were collected from the following six regions: North Kazakhstan, Pavlodar, Kostanay, Akmola, Ulytau, and Karaganda. The genetic diversity of the parasites was identified using a polymerase chain reaction with specific primers. After data collection, a comprehensive statistical analysis was performed. Results: Several helminth types were identified in wolves, including Echinococcus granulosus, Taenia hydatigena, Mesocestoides spp., Toxascaris leonina, Trichinella nativa, Alaria alata, and Dirofilaria repens. Based on the results of this study, young male wolves aged 1-4 years were the most vulnerable to helminthiasis. Wolves living in steppe and semi-desert regions are often exposed to helminth infections. The prevalence of T. nativa in the wolves was 20.4%. This study also revealed the presence of echinococcosis among wolf populations in Karaganda and Kostanay, with prevalence rates of 4.1% and 4.7%, respectively. The overall prevalence of tapeworms in wolves was 54.3%. Conclusion: This study highlights the significance of understanding the potential risks associated with helminth infections in wild carnivores because helminths can act as disease reservoirs and pose a threat to humans, livestock, and other wild carnivores. These results can contribute to the development of effective control and management strategies for helminth infections in wolves, which can infect humans and livestock.

Exploring extracellular vesicles in zoonotic helminth biology: implications for diagnosis, therapeutic and delivery.

Extracellular vesicles (EVs) have emerged as key intercellular communication and pathogenesis mediators. Parasitic organisms' helminths, cause widespread infections with significant health impacts worldwide. Recent research has shed light on the role of EVs in the lifecycle, immune evasion, and disease progression of these parasitic organisms. These tiny membrane-bound organelles including microvesicles and exosomes, facilitate the transfer of proteins, lipids, mRNAs, and microRNAs between cells. EVs have been isolated from various bodily fluids, offering a potential diagnostic and therapeutic avenue for combating infectious agents. According to recent research, EVs from helminths hold great promise in the diagnosis of parasitic infections due to their specificity, early detection capabilities, accessibility, and the potential for staging and monitoring infections, promote intercellular communication, and are a viable therapeutic tool for the treatment of infectious agents. Exploring host-parasite interactions has identified promising new targets for diagnostic, therapy, and vaccine development against helminths. This literature review delves into EVS's origin, nature, biogenesis, and composition in these parasitic organisms. It also highlights the proteins and miRNAs involved in EV release, providing a comprehensive summary of the latest findings on the significance of EVs in the biology of helminths, promising targets for therapeutic and diagnostic biomarkers.