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.

A combined amplicon approach to nematode polyparasitism occurring in captive wild animals in southern China.

BACKGROUND: Gastrointestinal tract (GIT) nematodes prefer to live in the intestines of wild animals, causing damage and even death, and posing a zoonotic risk. The polyparasitism of GIT nematodes results in the complex dynamics of the nematode communities that occur naturally in wild animals. However, the nematode community in captive wild animals is poorly understood. METHODS: We combined  microscopic examination and amplicon sequencing for community diversity. RESULTS: We characterized GIT nematode assemblages to one order, one family, four genera, and ten species, in 512 fecal samples of 121 species from captive wild animals in southern China. The positive rate of GIT nematodes was 20.7% (106/512), including 42.3% (11/26) in reptiles, 26.5% (39/147) in herbivores, 25.0% (25/100) in non-human primates, 20.0% (5/25) in omnivores, 12.2% (9/74) in carnivores, and 12.1% (17/140) in avians. The dominant nematodes were Haemonchus contortus in herbivores and Trichuris species in primates. The nematode communities of arboreal primates differed from their terrestrial counterparts, reflecting both host phylogeny and ecological constraints. Soil-transmitted Strongyloides species were widespread throughout the herbivore, primate, avian, and carnivore communities, and tended to infect omnivorous primates and terrestrial herbivores. In addition, new Trichuris and Heterakis species were found in the nematode communities of captive porcupines and peafowls. CONCLUSION: This study highlights the variation in the composition of the GIT nematode community and strengthens the attention to the harms induced by zoonotic nematodes and co-infective nematodes with low species richness.

An Unpleasant Souvenir: Whipworm as an Incidental Finding During a Screening Colonoscopy.

Trichuriasis is a neglected tropical disease caused by Trichuris trichiura that spreads through the ingestion of embryonated eggs in contaminated soil, water, or food. In nonendemic areas, T trichiura infestation is very rare and sporadic and is often diagnosed in immigrants from endemic countries such as the Philippines. Whipworms feed on human blood and also erode the colonic mucosa, thereby evoking an inflammatory response. In milder forms, trichuriasis can be asymptomatic and often an incidental diagnosis on screening colonoscopy. Heavily infested patients usually present with abdominal pain, nausea, vomiting, tenesmus, chronic diarrhea, iron deficiency anemia, or stunted growth. T trichiura worms can be removed with biopsy forceps during a colonoscopy; however, most patients require a course of albendazole, mebendazole, or ivermectin. We describe a unique case of T trichiura as an incidental finding during a screening colonoscopy. The whipworms were retrieved using biopsy forceps and the patient was treated with albendazole. At the time of the colonoscopy, the patient did not exhibit any specific symptoms related to the worm infestation.

A genome-scale metabolic model of parasitic whipworm.

Genome-scale metabolic models are widely used to enhance our understanding of metabolic features of organisms, host-pathogen interactions and to identify therapeutics for diseases. Here we present iTMU798, the genome-scale metabolic model of the mouse whipworm Trichuris muris. The model demonstrates the metabolic features of T. muris and allows the prediction of metabolic steps essential for its survival. Specifically, that Thioredoxin Reductase (TrxR) enzyme is essential, a prediction we validate in vitro with the drug auranofin. Furthermore, our observation that the T. muris genome lacks gsr-1 encoding Glutathione Reductase (GR) but has GR activity that can be inhibited by auranofin indicates a mechanism for the reduction of glutathione by the TrxR enzyme in T. muris. In addition, iTMU798 predicts seven essential amino acids that cannot be synthesised by T. muris, a prediction we validate for the amino acid tryptophan. Overall, iTMU798 is as a powerful tool to study not only the T. muris metabolism but also other Trichuris spp. in understanding host parasite interactions and the rationale design of new intervention strategies.

Standard- and large-sized eggs of Trichuris trichiura in the feces of schoolchildren in the Yangon Region, Myanmar: Morphological and molecular analyses.

Standard- and large-sized eggs of Trichuris trichiura were found in the feces of schoolchildren in Yangon, Myanmar during epidemiological surveys and mass deworming with albendazole in 2017-2019. The standard-sized eggs were identified as those of T. trichiura, but it was necessary to exclude the possibility of the large-sized eggs belonging to Trichuris vulpis, a dog whipworm. We conducted morphological and molecular studies to determine the species of the 2 types of Trichuris eggs. Individual eggs of both sizes were isolated from Kato-Katz fecal smears (n=20) and mechanically destroyed using a 23G injection needle. Nuclear DNA was extracted, and the 18S rRNA region was sequenced in 15 standard-sized eggs and 15 large-sized eggs. The average size of standard-sized eggs (T. trichiura) was 55.2×26.1 µm (range: 51.7-57.6×21.3-28.0 µm; n=97), whereas the size of large-sized eggs was 69.3×32.0 µm (range: 65.1-76.4×30.1-34.5 µm; n=20), slightly smaller than the known size of T. vulpis. Regarding standard-sized eggs, the 18S rRNA nucleotide sequences exhibited 100% homology with T. trichiura deposited in GenBank and 88.6-90.5% homology with T. vulpis. Regarding large-sized eggs, the nucleotide sequences showed 99.8-100% homology with T. trichiura in GenBank and 89.6-90.7% homology with T. vulpis. Both standard- and large-sized eggs of Trichuris spp. found in Myanmar schoolchildren during 2017-2019 were morphologically and molecularly confirmed to belong to T. trichiura. The conversion of eggs from smaller to large sizes might be due to anthelmintic treatments with albendazole.

First molecular data on the human roundworm Ascaris lumbricoides species complex from the Bronze and Iron Age in Hallstatt, Austria.

Palaeoparasitological studies can provide valuable information on the emergence, distribution, and elimination of parasites during a particular time in the past. In the prehistoric salt mines of Hallstatt, located in the Austrian Alps, human faeces have been conserved in salt. The aim of this study was to recover ancient DNA of intestinal parasites from these coprolites. Altogether, 35 coprolites from the Hallstatt salt mines, dating back to the Bronze Age mining phase (1158-1063 BCE) and the Iron Age mining phase (750-662 BCE), respectively, were analysed by microscopy and molecular methods. In 91% of the coprolite samples, eggs of soil-transmitted helminths (STH), namely of Trichuris and/or Ascaris were detected by light microscopy. The Ascaris eggs were exceptionally well preserved. For further analysis, DNA was extracted from the palaeofaecal samples and species-specific primers targeting different genes were designed. While amplification of Trichuris DNA remained unsuccessful, sequence data of A. lumbricoides species complex were successfully obtained from 16 coprolites from three different genes, the mitochondrial cytochrome c oxidase subunit 1 gene (cox1), the mitochondrial cytochrome B gene (cytB) and the mitochondrial NADH dehydrogenase subunit 1 gene (nadh1). Importantly, these included two Ascaris sequences from a coprolite from the Bronze Age, which to the best of our knowledge are the first molecular data of this genus from this period.

Trichuris WAP and CAP proteins: Potential whipworm vaccine candidates?

Trichuris trichiura and T. suis are gastrointestinal dwelling roundworms that infect humans and pigs, respectively. Heavy infections cause gastrointestinal symptoms and impaired growth and development. Vaccination has the potential to reduce the disease burden of whipworm infection; however, there are currently no commercially available vaccines against these parasites and very few against other gastrointestinal-dwelling nematodes of medical and agricultural importance. The naturally occurring mouse whipworm, T. muris, has been used for decades to model human trichuriasis, and the immunogenic potential of the excretory/secretory material (E/S, which can be collected following ex vivo culture of worms) has been studied in the context of vaccine candidate identification. Despite this, researchers are yet to progress an effective vaccine candidate to clinical trials. The T. muris, T. trichiura, and T. suis genomes each encode between 10 and 27 whey acidic protein (WAP) domain-containing proteins and 15 to 34 cysteine-rich secretory protein/antigen 5/pathogenesis related-1 (CAP) family members. WAP and CAP proteins have been postulated to play key roles in host-parasite interactions and may possess immunomodulatory functions. In addition, both protein families have been explored in the context of helminth vaccines. Here, we use phylogenetic and functional analysis to investigate the evolutionary relationship between WAP and CAP proteins encoded by T. muris, T. trichiura, and T. suis. We highlight several WAP and CAP proteins that warrant further study to understand their biological function and as possible vaccine candidates against T. trichiura and/or T. suis, based on the close evolutionary relationship with WAP or CAP proteins identified within T. muris E/S products.

Iron deficiency and soil-transmitted helminth infection: classic and neglected connections.

Beyond participating in the oxygen transport by red blood cells, iron is an essential micronutrient and contributes to different physiological pathways and processes, such as cell proliferation, DNA repair, and other homeostatic functions. Iron deficiency affects millions of people, especially children and pregnant women. The consequences of iron deficiency are diverse, including inadequate child development, impaired cognition, and reduced productivity. Several factors contribute to iron deficiency, such as iron-poor diet, genetic factors, and infection with soil-transmitted helminths (STHs), especially roundworms (Ascaris lumbricoides), hookworms (Necator americanus and Ancylostoma duodenale), and whipworms (Trichuris trichiura). This review updates and summarizes the role of STHs as drivers of iron deficiency. Also, the poorly explored connections between STH infection, geophagia (a pica manifestation), immune response, and iron deficiency are discussed, highlighting how iron deficiency may act as a risk factor for infections by STHs, in addition to being a consequence of intestinal parasitic infections. Finally, strategies for control and management of iron deficiency and STH infection are described.

Intractable diarrhoea due to co-infection with Cystoisospora belli and Trichuris trichiura unraveling a severely compromised host immune status.

Cystoisospora belli is an obligate intracellular coccidian parasite known to cause chronic persistent diarrhoea in immunocompromised individuals such as human immunodeficiency virus (HIV) infection, long term corticosteroid therapy, cancer chemotherapy and solid organ transplant recipients. Trichuris trichiura is a soil transmitted helminth, which predominantly causes asymptomatic or mild infections but heavy worm load can sometimes lead to chronic diarrhoea, tenesmus or rectal prolapse. We report a case of co-infection with Cystoisospora belli and Trichuris trichiura in an adult patient causing intractable diarrhea, which led to the unraveling of a severely compromised immune status in the patient enabling an appropriate therapeutic approach and further management.

Antigens from the parasitic nematode Trichuris suis induce metabolic reprogramming and trained immunity to constrain inflammatory responses in macrophages.

Regulation of macrophage (Mɸ) function can maintain tissue homeostasis and control inflammation. Parasitic worms (helminths) are potent modulators of host immune and inflammatory responses. They have evolved various strategies to promote immunosuppression, including redirecting phagocytic cells toward a regulatory phenotype. Although soluble products from the whipworm Trichuris suis (TSPs) have shown significant effects on Mɸ function, the mechanisms underlying these modulatory effects are still not well understood. In this study, we find that TSPs suppressed inflammatory cytokines (TNF and IL-6) in Mɸs stimulated with a broad panel of TLR agonists, whilst inducing IL-10. Moreover, M1 markers such as MHCII, CD86, iNOS, and TNF were downregulated in TSP-treated Mɸs, without polarizing them towards an M2-like phenotype. We showed that TSPs could establish a suppressed activation state of Mɸs lasting at least for 72 h, indicating an anti-inflammatory innate training. Moreover, we found that TSPs, via repression of intracellular TNF generation, decreased its secretion rather than interfering with the release of surface-bound TNF. Metabolic analysis showed that TSPs promote oxidative phosphorylation (OXPHOS) without affecting glycolytic rate. Collectively, these findings expand our knowledge on helminth-induced immune modulation and support future investigations into the anti-inflammatory properties of TSPs for therapeutic purposes.

Intestinal Perforation and Perianal Ulcer Due to Parasitic Infection / Perforación intestinal y úlcera perianal por infección parasitaria

Abstract Balantidium coli is the largest protozoan and the only ciliated parasite that infects humans. It causes balantidiasis, a disease humans acquire by fecal-oral transmission from its usual host: the pig. We report the case of an immunocompetent schoolgirl who presented with peritonitis due to intestinal perforation, with perianal ulceration secondary to polyparasitism caused by Balantidium coli, Enterobius vermicularis, and Trichuris trichiura. It is a rare, potentially preventable complication with extremely high mortality rates. The patient required eight surgical interventions.

Resumen Balantidium coli es el protozoario más grande y el único parásito ciliado que infecta a los seres humanos. Es el causante de la balantidiasis, enfermedad adquirida por los humanos por transmisión fecal-oral desde su hospedero habitual: el cerdo. Reportamos el caso de una escolar inmunocompetente, que presentó peritonitis por perforación intestinal, con ulceración perianal secundaria a poliparasitismo por Balantidium coli, Enterobius vermicularis y Trichuris trichiura. Esta es una complicación poco frecuente, potencialmente prevenible y con tasas de mortalidad extremadamente altas. La paciente requirió 8 intervenciones quirúrgicas.

Endoparasites of the European brown hare (Lepus europaeus Pallas, 1778 L.) (Lagomorpha: Leporidae) from Bulgaria.

In recent decades in Europe there has been a decline in the population of European brown hare (Lepus europaeus L.). Diseases, including parasitoses, are one of the factors considered to be the cause for the phenomenon. In this connection the aim of the present work was to update the data on the composition and distribution of endoparasites of this small mammal in Bulgaria against the background of the situation in Europe. Thirty sets of abdominal organs and forty seven faecal samples of hares from different regions of the country were investigated for presence of parasites. The faeces were analyzed with the coproscopical methods of Fulleborn, serial sedimentations, and the modified Baermann technique. Helminthological necropsies of the abdominal organs were carried out through the common technique. Parasites of the following taxa were established: Trematoda (Dicrocoelium dendriticum), Cestoda (Cysticercus pisiformis, Mosgovoyia pectinata), Nematoda (Trichuris sylvilagi, Strongylidae, Strongyloides sp., Protostrongylus spp.), Protozoa (Eimeria spp.) and Arthropoda (Pentastomum dentatum). Strongyloides sp. is reported for the first time as a part of the parasite fauna of the European brown hare in Bulgaria. Trichuris sylvilagi was the most prevalent parasite (63.3%), followed by gastrointestinal strongylids (57.43%), Eimeria spp. (55.3%), Protostrongylus spp. and Strongyloides sp. (31.9%), D. dendriticum (14.3%), C. pisiformis (10%), and M. pectinata (6.67%). The studies showed that eimeriid coccidia, gastrointestinal strongylids, and trichurids are the most common endoparasites among the population of the European brown hare both in Bulgaria and the European continent.

Trichuris trichiura Incidentally Detected by Colonoscopy and Identified by a Genetic Analysis.

Although trichuriasis, a zoonotic disease, has recently become rare in Japan due to improved environmental hygiene, we herein report a 79-year-old man in whom a worm was incidentally found in the ascending colon during colonoscopy for positive fecal occult blood and was endoscopically removed. A genetic analysis identified the worm as Trichuris trichiura possessing mixed sequences from non-human primate and human origins. Despite controversy regarding Trichuris trichiura infection originating from Japanese macaques, according to some studies, it originates primarily from humans. This report suggests the efficacy of a genetic analysis for identifying infection sources.

Evaluation of vegetables grown in dry mountainous regions for soil transmitted helminths contamination / Avaliação de vegetais para contaminação por helmintos transmitida pelo solo em quatro distritos da divisão de Malakand: noroeste do Paquistão

Infection caused by geo-helminth parasites are called geohelminthiasis are one of the global health problems. Vegetables eaten raw is the principal source of transmission of geo-helminth parasites. Pakistani people believe that eating raw vegetables are a significant source to get important vitamins and minerals. Based on the high incidence of pathogenic parasites and cultivating different vegetable types in the study areas, we conducted this study to evaluate the geo-helminth contamination of raw vegetables in northwest Khyber Pakhtunkhwa, Pakistan. This is a descriptive study comprised, 1942 samples of 25 various types of vegetables. The samples were examined in physiological saline solution using sedimentation and centrifugation methods. The findings were analyzed by Graph-Pad version 5. P value less than 0.05 (95% CI) was considered significant. Results showed that 16.5% (n=322) of all vegetables were contaminated with one or more type of geo-helminth parasites. Garlic was the highest (35%) and cauliflower the lowest (4%) contaminated samples respectively. Ascaris lumbricoides was the most common geo helminth found followed by hook worm species while Trichuris trichura was the least in all the vegetable samples. Leafy vegetables were highly contaminated 25.3% than vegetables with root parts 21.2% and fruity 9.09%. More than half of the contaminated vegetables were contaminated with single species of geo-helminth (P0.05) species of geo-helminth parasites. Education level of vendors and means of display were not significantly associated while types of vegetable used were significantly associated with the prevalence of parasites. The findings of this study provide evidence that consumption of raw [...].

As infecções causadas por parasitas geo-helmínticos são chamados de geohelmintíases e são um dos problemas de saúde globais. Os vegetais comidos crus são a principal fonte de transmissão dos parasitas geo-helmínticos. O povo paquistanês acredita que comer vegetais crus é uma fonte significativa para obter vitaminas e minerais importantes. Com base na alta incidência de parasitas patogênicos e no cultivo de diferentes tipos de vegetais nas áreas de estudo, conduzimos este estudo para avaliar a contaminação por geo-helmintos de vegetais crus no noroeste de Khyber Pakhtunkhwa, Paquistão. Trata-se de um estudo descritivo composto por 1942 amostras de 25 tipos diversos de vegetais. As amostras foram examinadas em solução salina fisiológica utilizando métodos de sedimentação e centrifugação. Os achados foram analisados pelo Graph-Pad versão 5. O valor de P menor que 0,05 (IC 95%) foi considerado significativo. Os resultados mostraram que 16,5% (n = 322) de todas as hortaliças estavam contaminadas com um ou mais tipos de parasitas geo-helmínticos. O alho foi a amostra mais contaminada (35%) e a couve-flor a menos (4%), respectivamente. Ascaris lumbricoides foi o geo-helmíntico mais comum encontrado, seguido por espécies de verme-anzol, enquanto Trichuris trichura foi o menos encontrado em todas as amostras de vegetais. Os vegetais folhosos foram altamente contaminados 25,3% do que os vegetais com partes de raiz 21,2% e frutados 9,09%. Mais da metade dos vegetais contaminados estavam contaminados com uma única espécie de geo-helmintos (P 0,05) espécies de parasitas geo-helmínticos. O nível de escolaridade dos vendedores e os meios de exibição não [...].

Prevalence of intestinal parasitic diseases in school children of rural areas of district Lower Dir, Pakistan / Prevalência de doenças parasitárias intestinais em escolares de áreas rurais do distrito de Lower Dir, Paquistão

Present study was conducted among school children to recognize the prevalence of IPIs in rural communities of district Dir Lower, Pakistan. A sum of 324 samples of stool were collected (210 boys and 114 girls). Used direct smear method and formol ether sedimentation concentration technique for processing the samples. The result shows that 82% (n=266) were found infected comprised 64.8% male and 35.1% females. Children of the age group 10 to 12 years were found extremely infected 94.2% while 4-6 year age group were having minimum ratio of infection 72%. Current study shows mono parasitism in 50.6% of the students while 22.2% were infected with 2 species and 7.40% were infected with three species of parasites. Seven species of intestinal parasites were reported include Ascaris lumbricoid in male (n=122) 58.0% and in female (n=65) 57.0% followed by Hook worm (n=88) 41.9% and (n=44) 38.5%; Tania saginata (n=44) 20.9% and (n=24) 21.0%; Entrobius vermicularis (n=32) 15.2% and (n=16) 14.0%; Trichuris trichura (n=25) 11.9% and (n=22) 19.2%; Hymenolepis nana (n=24) 11.4% and (n=18) 15.7% and Entameoba histolytica (n=16) 7.61% and (n=14) 12.2% in male and females respectively. The study indicates that most occurring intestinal parasite in the current study were Ascaris lumbricoides 58.0% (n=122) followed by hookworms 41.9% (n=88). Male students were more infected than females in the present study.

O presente estudo foi conduzido entre crianças em idade escolar para reconhecer a prevalência de IPIs em comunidades rurais do distrito de Dir Lower, Paquistão. Foram coletadas 324 amostras de fezes (210 meninos e 114 meninas). Método de esfregaço direto usado e técnica de concentração de sedimentação de formol éter para processar as amostras. O resultado mostra que 82% (n = 266) dos infectados eram 64,8% do sexo masculino e 35,1% do feminino. Crianças da faixa etária de 10 a 12 anos foram encontradas extremamente infectadas 94,2%, enquanto a faixa etária de 4 a 6 anos apresentava proporção mínima de infecção de 72%. O estudo atual mostra monoparasitismo em 50,6% dos alunos, enquanto 22,2% estavam infectados com 2 espécies e 7,40% estavam infectados com três espécies de parasitas. Sete espécies de parasitas intestinais foram relatadas incluindo Ascaris lumbricoid em machos (n = 122) 58,0% e em fêmeas (n = 65) 57,0% seguido por anzol (n = 88) 41,9% e (n = 44) 38,5%; Tania saginata (n = 44) 20,9% e (n = 24) 21,0%; Entrobius vermicularis (n = 32) 15,2% e (n = 16) 14,0%; Trichuris trichura (n = 25) 11,9% e (n = 22) 19,2%; Hymenolepis nana (n = 24) 11,4% e (n = 18) 15,7% e Entameoba histolytica (n = 16) 7,61% e (n = 14) 12,2% em homens e mulheres, respectivamente. O estudo indica que os parasitas intestinais que mais ocorreram no presente estudo foram Ascaris lumbricoides 58,0% (n = 122), seguidos por ancilóstomos 41,9% (n = 88). Estudantes do sexo masculino foram mais infectados do que do sexo feminino no presente estudo.

Double parasite in appendicectomy specimen: Causal factor or incidental finding?

Appendicitis is the most common cause of acute abdomen leading to invasive surgery. While the mainstay treatment of appendicitis is appendicectomy, there are a few conditions where conservative medical treatment cures the patient. One such condition is intestinal parasitosis, where only pharmacotherapy causes remission. Although Enterobius vermicularis is the commonest parasite in this regard, others such as Schistosoma, Taenia, Ascaris and Trichuris can also be found. Coexistence of two parasites in appendicectomy specimen is distinctly rare. We present one such case here of double infestation with Enterobius and Trichuris in the appendix.

Revisão integrativa sobre doenças parasitárias em crianças de creches brasileiras / Integrative review on parasitic diseases in children in brazilian day care centers

As parasitoses intestinais constituem um importante problema de Saúde Pública, especialmente entre os pré-escolares, devido à imaturidade do sistema imune. Assim, este estudo objetivou realizar uma revisão integrativa dos estudos publicados entre os anos de 2010 a 2017 sobre parasitoses intestinais e os fatores associados ao desenvolvimento em crianças matriculadas em creches brasileiras. Foi realizada busca bibliográfica através das bases de dados Medline, Lilacs e SciELO, utilizando os descritores: infecção, parasitoses, diarreia e creches, e seus correspondentes em inglês: "infection", "parasitc diseases", "diarrhea" e "child day care centers". No caso das buscas no Medline o descritor Brazil também foi usado. Foram identificados 59 estudos, dos quais 11 foram incluídos no presente trabalho. Foi observado variação de 19,4% a 98,4% de parasitos e, a Giardia duodenalis foi o mais prevalente em crianças entre um e seis anos de idade, gênero masculino, com baixo peso, advindas de residências com alta densidade familiar e nível socioeconômico baixo. As análises mostraram a importância da compreensão dos fatores de risco para a incidência de parasitos, indicando a necessidade da promoção de estratégias efetivas para prevenção e controle das infecções parasitárias no país, visto que, tais infecções influenciam diretamente no desenvolvimento da criança, e em alguns casos, evoluindo a óbito.

Intestinal parasitosis is an important public health issue especially among pre-school children due to the immaturity of their immune system. Thus, this study aimed at carrying out an integrative review of studies published between 2010 and 2017 regarding intestinal parasites and associated factors in children registered in Brazilian day care centers. A bibliographic survey was performed through the Medline, Lilacs, and SciELO databases using the following descriptors: infection, parasitic diseases, diarrhea, and child day care centers, as well as their corresponding translations in Portuguese: "infecção", "parasitoses", "diarreia" and "creches". In the case of Medline searches, the descriptor Brazil was also used. Fifty-nine studies were identified, from which, 11 were included in this study. A variation of 19.4% to 98.4% of parasites could be observed, with Giardia duodenalis being the most prevalent in children between one and six years old, male, with low weight, coming from homes with high family density and low socioeconomic status. The analyzes showed the importance of understanding the risk factors for the incidence of parasites, showing the need to promote effective strategies for the prevention and control of parasitic infections in the country, since such infections have direct influence on the child's development, and in some cases, even evolving to death.

Parasite worm antigens instruct macrophages to release immunoregulatory extracellular vesicles.

Emerging evidence suggests that immune cells not only communicate with each other through cytokines, chemokines, and cell surface receptors, but also by releasing small membranous structures known as extracellular vesicles (EVs). EVs carry a variety of different molecules that can be taken up by recipient cells. Parasitic worms are well known for their immunomodulatory properties, but whether they can affect immune responses by altering EV-driven communication between host immune cells remains unclear. Here we provide evidence that stimulation of bone marrow-derived macrophages (BMDMs) with soluble products of Trichuris suis (TSPs), leads to the release of EVs with anti-inflammatory properties. Specifically, we found that EVs from TSP-pulsed BMDMs, but not those from unstimulated BMDMs can suppress TNFα and IL-6 release in LPS-stimulated BMDMs and BMDCs. However, no polarization toward M1 or M2 was observed in macrophages exposed to EVs. Moreover, EVs enhanced reactive oxygen species (ROS) production in the exposed BMDMs, which was associated with a deregulated redox homeostasis as revealed by pathway analysis of transcriptomic data. Proteomic analysis identified cytochrome p450 (CYP450) as a potential source of ROS in EVs from TSP-pulsed BMDMs. Finally, pharmacological inhibition of CYP450 activity could suppress ROS production in those BMDMs. In summary, we find that TSPs can modulate immune responses not only via direct interactions but also indirectly by eliciting the release of EVs from BMDMs that exert anti-inflammatory effects on recipient cells.