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1.
Cell Host Microbe ; 32(5): 639-650, 2024 May 08.
Article En | MEDLINE | ID: mdl-38723604

There is rapidly growing awareness of microbiome assembly and function in early-life gut health. Although many factors, such as antibiotic use and highly processed diets, impinge on this process, most research has focused on people residing in high-income countries. However, much of the world's population lives in low- and middle-income countries (LMICs), where, in addition to erratic antibiotic use and suboptimal diets, these groups experience unique challenges. Indeed, many children in LMICs are infected with intestinal helminths. Although helminth infections are strongly associated with diverse developmental co-morbidities and induce profound microbiome changes, few studies have directly examined whether intersecting pathways between these components of the holobiont shape health outcomes in early life. Here, we summarize microbial colonization within the first years of human life, how helminth-mediated changes to the gut microbiome may affect postnatal growth, and why more research on this relationship may improve health across the lifespan.


Gastrointestinal Microbiome , Helminthiasis , Helminths , Gastrointestinal Microbiome/physiology , Humans , Helminths/physiology , Animals , Infant , Intestinal Diseases, Parasitic
2.
Parasitol Res ; 123(5): 208, 2024 May 10.
Article En | MEDLINE | ID: mdl-38724709

In freshwater ecosystems, parasite infection patterns are influenced by factors including spatial-temporal variations, host diet, and habitat. Fish often change diets, affecting their parasite communities. This study focused on non-native host fish Geophagus sveni, aiming to characterize diet and endoparasitic helminth fauna patterns in the invaded area, investigating spatial and seasonal possible differences of endoparasite infections and correlating with host diet, in São José dos Dourados River and Tietê River areas. The host fish were collected in these areas during the dry and rainy season using gillnets. The endoparasites were collected and preserved in alcohol and identified using taxonomic methods, and stomach contents were examined for diet analysis. Parasitism descriptors were calculated and evaluated spatially and seasonally by ANOVA and the Kruskal-Wallis tests. PERMANOVA assessed G. sveni diet differences, and RDA correlated the endohelminth abundance with the host diet. Two endoparasites were recorded: metacercariae of Austrodiplostomum compactum (Trematoda) and larvae and adults of Raphidascaris (Sprentascaris) lanfrediae (Nematoda). Spatial differences were observed for the mean abundance and prevalence of R. (S.) lanfrediae and A. compactum prevalence. Seasonal variations of parasitic descriptors occurred for the nematode in the Tietê River area. The detritus and aquatic insects were the most consumed items by G. sveni. Detritus consumption positively correlates with nematode abundance. The findings indicate that factors such as artificial channels and rainfall, which can influence resource availability, may affect the fish's diet and potentially influence the structure of its endoparasite community. The study emphasizes the importance of understanding trophic chain-transmitted parasites and calls for further research in Neotropical environments.


Diet , Fish Diseases , Helminthiasis, Animal , Rivers , Seasons , Animals , Rivers/parasitology , Fish Diseases/parasitology , Fish Diseases/epidemiology , Helminthiasis, Animal/parasitology , Helminthiasis, Animal/epidemiology , Trematoda/isolation & purification , Trematoda/classification , Brazil/epidemiology , Nematoda/isolation & purification , Nematoda/classification , Helminths/isolation & purification , Helminths/classification , Gastrointestinal Contents/parasitology
3.
Vet Parasitol Reg Stud Reports ; 51: 101035, 2024 Jun.
Article En | MEDLINE | ID: mdl-38772641

The current investigation was carried out during the period from July 2022 to March 2023, aiming to investigate the prevalence of gastrointestinal helminths in domestic birds collected from traditional markets in Guilan province. One hundred forty-eight domestic birds, including chickens (Gallus gallus domesticus), domestic ducks (Anas platyrhynchos domesticus), greylag geese (Anser anser), and domestic turkeys (Meleagris gallopavo domesticus) were examined. Totally, 42.56% of the investigated birds were positive for helminthic parasites. Morphological analysis revealed varying infection rates among birds: Echinostoma revolutum (5.40%), Hypoderaeum conoideum (2.02%), Cloacotaenia megalops (0.67%), Hymenolepididae family (4.05%), Ascaridia galli (16.89%), and Heterakis gallinarum (4.72%). The investigation involved molecular analysis of the 18S and ITS1 + 5.8S + ITS2 rRNA gene regions. The findings indicated that the 18S region of nematode isolates exhibited a similarity of 92 to 100% with sequences in the GenBank, whereas trematode and cestode isolates showed a gene similarity ranging from 88 to 99%. The ITS regions of nematode, trematode, and cestode isolates exhibited genetic similarities ranging from 87 to 100%, 73-99%, and 75-99%, respectively. Furthermore, phylogenetic analysis confirmed the categorization of the identified species within the Ascaridiidae, Heterakidae, Hymenolepididae, and Echinostomatidae families, indicating their close affinity with previously documented species. Implementing precise control measures such as consistent monitoring, adequate sanitation protocols, and administering anthelmintic treatments is crucial for effectively managing parasitic infections in free-range and backyard poultry farms. Additionally, conducting further surveys is advisable to assess the impact of these parasites on the health and productivity of poultry in the investigated area.


Helminthiasis, Animal , Animals , Helminthiasis, Animal/parasitology , Helminthiasis, Animal/epidemiology , Iran/epidemiology , One Health , Helminths/isolation & purification , Helminths/genetics , Helminths/classification , Prevalence , Poultry Diseases/parasitology , Poultry Diseases/epidemiology , Phylogeny , Bird Diseases/parasitology , Bird Diseases/epidemiology , Ducks/parasitology
4.
Gut Microbes ; 16(1): 2338947, 2024.
Article En | MEDLINE | ID: mdl-38717824

The gut microbiota has coevolved with the host for hundreds of millions of years, playing a beneficial role in host health. Human parasitic helminths are widespread and pose a pervasive global public health issue. Although Type 2 immunity provides partial resistance to helminth infections, the composition of the gut microbiota can change correspondingly. Therefore, it raises the question of what role the gut microbiota plays during helminth infection. Akkermansia muciniphila has emerged as a notable representative of beneficial microorganisms in the gut microbiota. Recent studies indicate that A. muciniphila is not merely associated with helminth infection but is also causally linked to infection. Here, we provide an overview of the crosstalk between A. muciniphila and enteric helminth infection. Our goal is to enhance our understanding of the interplay among A. muciniphila, helminths, and their hosts while also exploring the potential underlying mechanisms.


Akkermansia , Gastrointestinal Microbiome , Humans , Animals , Helminths/immunology , Helminths/genetics , Helminthiasis/immunology , Verrucomicrobia/genetics , Verrucomicrobia/immunology
5.
Chemosphere ; 358: 142219, 2024 Jun.
Article En | MEDLINE | ID: mdl-38704040

The worldwide used herbicide Glyphosate can interact with environmental variables, but there is limited information on the influence of environmental stressors on its toxicity. Environmental changes could modify glyphosate effects on non-target organisms, including parasites such as gordiids. The freshwater microscopic larvae of the gordiid Chordodes nobilii are sensitive to several pollutants and environmental variables, but their combined effect has not been evaluated yet. The aim of this study was to evaluate the impact of temperature, pH and exposure time on the toxicity of Glyphosate to C. nobilii larvae. A protocol was followed to evaluate the infectivity of larvae treated with factorial combinations of concentration (0 and 0.067 mg/L), exposure time (24 and 48 h), temperature (18, 23 and 28 °C), and pH (7, 8 and 9). The reference values were 23 °C, pH 8 and 48 h. The interaction effect on the infectivity of gordiid larvae was assessed post-exposure using Aedes aegyptii larvae as host. Results were evaluated using GLMM, which does not require data transformation. The modeling results revealed three highly significant triple interactions. Glyphosate toxicity varied depending on the combination of variables, with a decrease being observed after 24 h-exposure at pH 7 and 23 °C. Glyphosate and 28 °C combination led to slightly reduced infectivity compared to temperature alone. This study is the first to report the combined effects of glyphosate, temperature, pH and time on a freshwater animal. It demonstrates that a specific combination of factors determines the effect of glyphosate on a non-target organism. The potential use of C. nobilli as a bioindicator is discussed. In the context of global warming and considering that the behavioral manipulation of terrestrial hosts by gordiids can shape community structure and the energy flow through food webs, our results raise concerns about possible negative effects of climate change on host-parasite dynamics.


Glycine , Glyphosate , Herbicides , Larva , Temperature , Glycine/analogs & derivatives , Glycine/toxicity , Animals , Herbicides/toxicity , Larva/drug effects , Water Pollutants, Chemical/toxicity , Hydrogen-Ion Concentration , Helminths/drug effects , Helminths/physiology , Aedes/drug effects , Parasites/drug effects
6.
Syst Parasitol ; 101(3): 34, 2024 May 03.
Article En | MEDLINE | ID: mdl-38700784

Although most Latin binomial names of species are valid, many are eventually unaccepted when they are found to be synonyms of previously described species, or superseded by a new combination when the species they denote are moved to a different genus. What proportion of parasite species names become unaccepted over time, and how long does it take for incorrect names to become unaccepted? Here, we address these questions using a dataset comprising thousands of species names of parasitic helminths from four higher taxa (Acanthocephala, Nematoda, Cestoda, and Trematoda). Overall, among species names proposed in the past two-and-a-half centuries, nearly one-third have since been unaccepted, the most common reason being that they have been superseded by a new combination. A greater proportion of older names (proposed pre-1950) have since been unaccepted compared to names proposed more recently, however most taxonomic acts leading to species names being unaccepted (through either synonymy or reclassification) occurred in the past few decades. Overall, the average longevity of helminth species names that are currently unaccepted was 29 years; although many remained in use for over 100 years, about 50% of the total were invalidated within 20 years of first being proposed. The patterns observed were roughly the same for all four higher helminth taxa considered here. Our results provide a quantitative illustration of the self-correcting nature of parasite taxonomy, and can also help to calibrate future estimates of total parasite biodiversity.


Helminths , Terminology as Topic , Animals , Helminths/classification , Species Specificity , Classification
7.
Trends Parasitol ; 40(5): 386-400, 2024 May.
Article En | MEDLINE | ID: mdl-38609741

Obesity is a worldwide pandemic and major risk factor for the development of metabolic syndrome (MetS) and type 2 diabetes (T2D). T2D requires lifelong medical support to limit complications and is defined by impaired glucose tolerance, insulin resistance (IR), and chronic low-level systemic inflammation initiating from adipose tissue. The current preventative strategies include a healthy diet, controlled physical activity, and medication targeting hyperglycemia, with underexplored underlying inflammation. Studies suggest a protective role for helminth infection in the prevention of T2D. The mechanisms may involve induction of modified type 2 and regulatory immune responses that suppress inflammation and promote insulin sensitivity. In this review, the roles of helminths in counteracting MetS, and prospects for harnessing these protective mechanisms for the development of novel anti-diabetes drugs are discussed.


Diabetes Mellitus, Type 2 , Helminths , Metabolic Syndrome , Animals , Humans , Helminths/immunology , Helminths/physiology , Metabolic Syndrome/immunology , Metabolic Syndrome/metabolism , Metabolic Syndrome/parasitology , Diabetes Mellitus, Type 2/immunology , Diabetes Mellitus, Type 2/metabolism , Helminthiasis/immunology , Helminthiasis/parasitology , Obesity/immunology , Obesity/metabolism , Host-Parasite Interactions/immunology , Insulin Resistance
8.
Front Public Health ; 12: 1283054, 2024.
Article En | MEDLINE | ID: mdl-38577281

Background: According to the Global Burden of Disease (GBD) 2019 report, up to 1.5 million disability-adjusted life years (DALYs) are lost due to soil-transmitted helminths (STHs), and 5.9 million people are at risk of acquiring STHs. Regions with the highest prevalence of STH infections include Sub-Saharan Africa, China, South America, and Asia. While there are numerous fragmented studies on STH, comprehensive information on the prevalence and geographic distribution of different species, as well as their regional variations in the context of STHs is limited. The present systematic review and meta-analysis study attempts to provide a summary of the prevalence, geographical variation, and determinants of STHs among schoolchildren aged 5 to 18 years. Methods: An extensive literature search was carried out using PubMed, Embase, Cinhal, and Psychinfo for studies published between 1999 and 2022 that reported the rate of STH infection in school-going children aged 5-18 years. A random effects model was employed in this meta-analysis due to expected heterogeneity. Subgroup analysis was carried out based on sex and STH species because of expected geographical variation. Results: A total of 19,725 of the 49,630 children examined were infected with STH, yielding an overall pooled prevalence of 37.16% (95% CI: 29.74-44.89). The prevalence was highest in the Western Pacific region at 50.41% (95% CI: 33.74-67.04) followed by Europe at 39.74% (95% CI: 20.40-61.0) and Africa at 37.10% (95% CI: 26.84-47.95). Ascaris lumbricoides was found to be the most prevalent helminth with a prevalence of 24.07% (95% CI: 17.07-31.83). Conclusion: The Western Pacific region is classified as a High-risk Zone (HRZ), while Southeast Asia, Africa, Europe, and the Eastern Mediterranean are classified as moderate-risk zones (MRZs). We found a 12% reduction in the pooled prevalence of STH infection from 1999 to 2012. Ascaris lumbricoides was the predominant species among schoolchildren. Mass Drug Administration (MDA) of Albendazole tablets and improved water, sanitation, and hygiene (WASH) practices are effective in controlling and preventing STH. Ensuring their implementation and access is crucial to addressing the problem. Systematic review registration: https://www.crd.york.ac.uk/prospero/#loginpage, CRD42022333341.


Helminthiasis , Helminths , Animals , Child , Humans , Ascaris lumbricoides , Developing Countries , Helminthiasis/epidemiology , Helminthiasis/prevention & control , Prevalence , Soil/parasitology , Child, Preschool , Adolescent
9.
Clin Infect Dis ; 78(Supplement_2): S146-S152, 2024 Apr 25.
Article En | MEDLINE | ID: mdl-38662703

Globally, there are over 1 billion people infected with soil-transmitted helminths (STHs), mostly living in marginalized settings with inadequate sanitation in sub-Saharan Africa and Southeast Asia. The World Health Organization recommends an integrated approach to STH morbidity control through improved access to sanitation and hygiene education and the delivery of preventive chemotherapy (PC) to school-age children delivered through schools. Progress of STH control programs is currently estimated using a baseline (pre-PC) school-based prevalence survey and then monitored using periodical school-based prevalence surveys, known as Impact Assessment Surveys (IAS). We investigated whether integrating geostatistical methods with a Markov model or a mechanistic transmission model for projecting prevalence forward in time from baseline can improve IAS design strategies. To do this, we applied these 2 methods to prevalence data collected in Kenya, before evaluating and comparing their performance in accurately informing optimal survey design for a range of IAS sampling designs. We found that, although both approaches performed well, the mechanistic method more accurately projected prevalence over time and provided more accurate information for guiding survey design. Both methods performed less well in areas with persistent STH hotspots where prevalence did not decrease despite multiple rounds of PC. Our findings show that these methods can be useful tools for more efficient and accurate targeting of PC. The general framework built in this paper can also be used for projecting prevalence and informing survey design for other neglected tropical diseases.


Helminthiasis , Markov Chains , Soil , Humans , Helminthiasis/epidemiology , Helminthiasis/transmission , Prevalence , Kenya/epidemiology , Soil/parasitology , Child , Helminths/isolation & purification , Animals , Models, Statistical , Adolescent , Schools
10.
PLoS Negl Trop Dis ; 18(4): e0011500, 2024 Apr.
Article En | MEDLINE | ID: mdl-38603720

BACKGROUND: The exposure to parasites may influence the immune response to vaccines in endemic African countries. In this study, we aimed to assess the association between helminth exposure to the most prevalent parasitic infections, schistosomiasis, soil transmitted helminths infection and filariasis, and the Ebola virus glycoprotein (EBOV GP) antibody concentration in response to vaccination with the Ad26.ZEBOV, MVA-BN-Filo vaccine regimen in African and European participants using samples obtained from three international clinical trials. METHODS/PRINCIPAL FINDINGS: We conducted a study in a subset of participants in the EBL2001, EBL2002 and EBL3001 clinical trials that evaluated the Ad26.ZEBOV, MVA-BN-Filo vaccine regimen against EVD in children, adolescents and adults from the United Kingdom, France, Burkina Faso, Cote d'Ivoire, Kenya, Uganda and Sierra Leone. Immune markers of helminth exposure at baseline were evaluated by ELISA with three commercial kits which detect IgG antibodies against schistosome, filarial and Strongyloides antigens. Luminex technology was used to measure inflammatory and activation markers, and Th1/Th2/Th17 cytokines at baseline. The association between binding IgG antibodies specific to EBOV GP (measured on day 21 post-dose 2 and on Day 365 after the first dose respectively), and helminth exposure at baseline was evaluated using a multivariable linear regression model adjusted for age and study group. Seventy-eight (21.3%) of the 367 participants included in the study had at least one helminth positive ELISA test at baseline, with differences of prevalence between studies and an increased prevalence with age. The most frequently detected antibodies were those to Schistosoma mansoni (10.9%), followed by Acanthocheilonema viteae (9%) and then Strongyloides ratti (7.9%). Among the 41 immunological analytes tested, five were significantly (p < .003) lower in participants with at least one positive helminth ELISA test result: CCL2/MCP1, FGFbasic, IL-7, IL-13 and CCL11/Eotaxin compared to participants with negative helminth ELISA tests. No significant association was found with EBOV-GP specific antibody concentration at 21 days post-dose 2, or at 365 days post-dose 1, adjusted for age group, study, and the presence of any helminth antibodies at baseline. CONCLUSIONS/SIGNIFICANCE: No clear association was found between immune markers of helminth exposure as measured by ELISA and post-vaccination response to the Ebola Ad26.ZEBOV/ MVA-BN-Filo vaccine regimen. TRIAL REGISTRATION: NCT02416453, NCT02564523, NCT02509494. ClinicalTrials.gov.


Antibodies, Viral , Ebola Vaccines , Hemorrhagic Fever, Ebola , Adolescent , Adult , Animals , Child , Child, Preschool , Female , Humans , Male , Middle Aged , Young Adult , Africa , Antibodies, Helminth/blood , Antibodies, Viral/blood , Cytokines/immunology , Ebola Vaccines/immunology , Ebola Vaccines/administration & dosage , Ebolavirus/immunology , Ebolavirus/genetics , Enzyme-Linked Immunosorbent Assay , Helminthiasis/immunology , Helminthiasis/prevention & control , Helminths/immunology , Helminths/genetics , Hemorrhagic Fever, Ebola/prevention & control , Hemorrhagic Fever, Ebola/immunology , Immunoglobulin G/blood , Aged
11.
BMC Immunol ; 25(1): 21, 2024 Apr 18.
Article En | MEDLINE | ID: mdl-38637733

Helminth-derived proteins have immunomodulatory properties, influencing the host's immune response as an adaptive strategy for helminth survival. Helminth-derived proteins modulate the immune response by inducing anti-inflammatory cytokines, promoting regulatory T-cell development, and ultimately favouring a Th2-biased immune response. This systematic review focused on helminth-derived proteins and explored their impact on reducing inflammatory responses in mouse models of colitis. A systematic search across Medline, EMBASE, Web of Science, and Cochrane Library identified fourteen relevant studies. These studies reported immunomodulatory changes, including increased production of anti-inflammatory cells and cytokines. In mouse models of colitis treated with on helminth-derived proteins, significant improvements in pathological parameters such as body weight, colon length, and microscopic inflammatory scores were observed compared to control groups. Moreover, helminth-derived proteins can enhance the function of Tregs and alleviate the severity of inflammatory conditions. The findings underscore the pivotal role of helminth-derived proteins in immunomodulation, specifically in the axis of cytokine secretion and immune cell polarization. The findings offer new opportunities for treating chronic inflammatory conditions such Crohn's disease.


Colitis , Helminth Proteins , Animals , Mice , Colitis/therapy , Cytokines/metabolism , Disease Models, Animal , Helminth Proteins/therapeutic use , Helminths , Immune System/metabolism , Immunologic Factors
12.
PeerJ ; 12: e17196, 2024.
Article En | MEDLINE | ID: mdl-38563013

Cancer is one of the leading causes of death, with an estimated 19.3 million new cases and 10 million deaths worldwide in 2020 alone. Approximately 2.2 million cancer cases are attributed to infectious diseases, according to the World Health Organization (WHO). Despite the apparent involvement of some parasitic helminths (especially trematodes) in cancer induction, there are also records of the potential suppressive effects of helminth infections on cancer. Tapeworms such as Echinococcus granulosus, Taenia crassiceps, and more seem to have the potential to suppress malignant cell development, although in a few cases the evidence might be contradictory. Our review aims to summarize known epidemiological data on the cancer-helminth co-occurrence in the human population and the interactions of tapeworms with cancers, i.e., proven or hypothetical effects of tapeworms and their products on cancer cells in vivo (i.e., in experimental animals) or in vitro. The prospect of bioactive tapeworm molecules helping reduce the growth and metastasis of cancer is within the realm of future possibility, although extensive research is yet required due to certain concerns.


Cestoda , Cestode Infections , Helminthiasis , Helminths , Neoplasms , Taenia , Animals , Humans , Neoplasms/epidemiology
13.
PLoS Negl Trop Dis ; 18(4): e0012048, 2024 Apr.
Article En | MEDLINE | ID: mdl-38564496

BACKGROUND: Numerous studies indicate a potential protective role of helminths in diabetes mellitus (DM) progression. The complement system, vital for host defense, plays a crucial role in tissue homeostasis and immune surveillance. Dysregulated complement activation is implicated in diabetic complications. We aimed to investigate the influence of the helminth, Strongyloides stercoralis (Ss) on complement activation in individuals with type 2 DM (T2D). METHODOLOGY: We assessed circulating levels of complement proteins (C1q, C2, C3, C4, C4b, C5, C5a, and MBL (Lectin)) and their regulatory components (Factor B, Factor D, Factor H, and Factor I) in individuals with T2D with (n = 60) or without concomitant Ss infection (n = 58). Additionally, we evaluated the impact of anthelmintic therapy on these parameters after 6 months in Ss-infected individuals (n = 60). RESULTS: Ss+DM+ individuals demonstrated reduced levels of complement proteins (C1q, C4b, MBL (Lectin), C3, C5a, and C3b/iC3b) and complement regulatory proteins (Factor B and Factor D) compared to Ss-DM+ individuals. Following anthelmintic therapy, there was a partial reversal of these levels in Ss+DM+ individuals. CONCLUSION: Our findings indicate that Ss infection reduces complement activation, potentially mitigating inflammatory processes in individuals with T2D. The study underscores the complex interplay between helminth infections, complement regulation, and diabetes mellitus, offering insights into potential therapeutic avenues.


Anthelmintics , Diabetes Mellitus, Type 2 , Helminths , Strongyloides stercoralis , Strongyloidiasis , Animals , Humans , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/drug therapy , Complement Factor B , Complement Factor D/therapeutic use , Complement C1q , Strongyloidiasis/complications , Strongyloidiasis/drug therapy , Complement Activation , Anthelmintics/therapeutic use , Lectins
14.
Proc Biol Sci ; 291(2020): 20232946, 2024 Apr 10.
Article En | MEDLINE | ID: mdl-38565156

Telomere length (TL) is a biomarker hypothesized to capture evolutionarily and ecologically important physiological costs of reproduction, infection and immunity. Few studies have estimated the relationships among infection status, immunity, TL and fitness in natural systems. The hypothesis that short telomeres predict reduced survival because they reflect costly consequences of infection and immune investment remains largely untested. Using longitudinal data from a free-living Soay sheep population, we tested whether leucocyte TL was predicted by infection with nematode parasites and antibody levels against those parasites. Helminth parasite burdens were positively associated with leucocyte TL in both lambs and adults, which is not consistent with TL reflecting infection costs. We found no association between TL and helminth-specific IgG levels in either young or old individuals which suggests TL does not reflect costs of an activated immune response or immunosenescence. Furthermore, we found no support for TL acting as a mediator of trade-offs between infection, immunity and subsequent survival in the wild. Our results suggest that while variation in TL could reflect short-term variation in resource investment or environmental conditions, it does not capture costs of infection and immunity, nor does it behave like a marker of an individual's helminth-specific antibody immune response.


Helminths , Sheep, Domestic , Animals , Sheep , Telomere Shortening , Reproduction , Telomere
15.
PLoS Negl Trop Dis ; 18(4): e0012041, 2024 Apr.
Article En | MEDLINE | ID: mdl-38602896

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.


Helminthiasis , Helminths , Child , Animals , Humans , Artificial Intelligence , Soil/parasitology , Microscopy , Resource-Limited Settings , Feces/parasitology , Trichuris , Helminthiasis/diagnosis , Helminthiasis/parasitology , Ascaris lumbricoides , Ancylostomatoidea , Prevalence
16.
BMC Vet Res ; 20(1): 139, 2024 Apr 06.
Article En | MEDLINE | ID: mdl-38582856

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.


Ascaris suum , Helminths , Swine Diseases , Humans , Animals , Swine , Trichuris/genetics , Myanmar , Ovum , Feces/parasitology , Swine Diseases/prevention & control
17.
J Helminthol ; 98: e30, 2024 Apr 08.
Article En | MEDLINE | ID: mdl-38584420

Six species of freshwater turtles dominate the Chaco-Pampa Plain in southern South America and their parasites have been relatively understudied, with most records concentrated in Brazil. Particularly in Argentina, there are only scattered records of parasites for most of the turtles that inhabit the region, leaving a large knowledge gap. The purpose of the present contribution is to increase the knowledge of the internal parasites of six species of freshwater turtles from Argentina, after 15 years of fieldwork, by providing new hosts and additional geographic records for many host-parasite relationships. Some molecular sequences of the studied parasites were provided as a tool for better species identification. We processed 433 stomach and fecal samples from live individuals and visceral and soft tissue samples from 54 dissected turtles collected from a wide range and different ecoregions. We found 6230 helminths belonging to 18 taxa (one cestode, 11 digeneans and six nematodes). Fourteen new parasite-host associations are reported here, and for the first time parasites are recorded for Phrynops williamsi. This work contributes significantly to the knowledge of the parasitofauna in freshwater turtles in Argentina, providing a detailed list of parasites present in each turtle species and reporting molecular characters for future studies.


Helminths , Parasites , Turtles , Animals , Turtles/parasitology , Helminths/genetics , Fresh Water , Brazil
18.
J Helminthol ; 98: e32, 2024 Apr 15.
Article En | MEDLINE | ID: mdl-38618914

Two new species of the genus Sectonema found in northern Iran are characterized, including morphological descriptions and molecular (18S-, 28S-rDNA) analyses. Sectonema tehranense sp. nov. is distinguished by its 7.22 - 8.53 mm long body, lip region offset by constriction and 24 - 31 µm wide with perioral lobes and abundant setae- or cilia-like projections covering the oral field, mural tooth 15.5 - 17 µm long at its ventral side, neck 1091 - 1478 µm long, pharyngeal expansion occupying 61 - 71% of the total neck length, female genital system diovarian, uterus simple and 3.9 - 4.2 times the corresponding body diameter long, transverse vulva (V = 49 - 59), tail short and rounded (44 - 65 µm, c = 99 - 162, c' = 0.6 - 0.8), spicules 111 - 127 µm long, and 7 - 10 spaced ventromedian supplements with hiatus. Sectonema noshahrense sp. nov. displays a 4.07 - 4.73 mm long body, lip region offset by constriction and 23 - 25 µm wide with perioral lobes and abundant setae- or cilia-like projections covering the oral field, odontostyle 14 - 14.5 µm long, neck 722 - 822 µm long, pharyngeal expansion occupying 66 - 68% of the total neck length, female genital system diovarian, uterus simple and 2.4 - 2.7 times the corresponding body diameter long, transverse vulva (V = 54 - 55), tail convex conoid (39 - 47 µm, c = 91 - 111, c' = 0.8 - 0.9), spicules 82 µm long, and seven spaced ventromedian supplements with hiatus. Molecular analyses confirm a maximally supported (Epacrolaimus + Metaporcelaimus + Sectonema) clade and a tentative biogeographical pattern, with sequences of Indolamayan taxa forming a clade separated from those of Palearctic ones. Parallel or convergent evolution processes might be involved in the phylogeny of the species currently classified under Sectonema. This genus is certainly more heterogeneous than previously assumed.


Helminths , Nematoda , Female , Animals , Iran , Cytoskeleton , DNA, Ribosomal/genetics , Nematoda/genetics
19.
BMC Infect Dis ; 24(1): 435, 2024 Apr 24.
Article En | MEDLINE | ID: mdl-38658830

BACKGROUND: Soil-transmitted helminthiasis (STH) refers to a set of parasitic illnesses caused by nematode worms and spread to people through faeces-contaminated soil. It is highly prevalent in low- and middle-income countries due to a lack of environmental sanitation and personal hygiene. Pregnant women are among the risk groups for infection by soil-transmitted helminths. Former studies of the disease burden among pregnant women in Ethiopia didn't indicate the intensity of parasitic infection. The aim of this study was to assess the prevalence and associated factors of soil-transmitted helminths among pregnant women. METHODS: An institution-based cross-sectional study was conducted among 416 randomly selected pregnant women. The data were collected using a structured interview-administered questionnaire and a laboratory test. The Kato-Katz technique was used to diagnose soil-transmitted helminthiasis and determine the intensity of the infection. The collected data were entered into Epi-Data version 4.6 and exported to SPSS version 25 for analysis. Multivariate logistic regression analysis was used to identify independent predictors of soil-transmitted helminths at a p-value < 0.05. RESULTS: The overall prevalence of soil-transmitted helminths among pregnant women was 30%. (95%, CI: 26-34%). Living in a rural area (AOR = 3.35; 95% CI = 1.83-6.13), drinking from an unprotected water source (AOR = 2.52; 95% CI = 1.45-4.37), not washing one's hand after the toilet (AOR = 2.75; 95% CI = 1.55-4.88), lacking health information (AOR = 1.70; 95% CI = 1.01-2.85), working as a daily labourer (AOR = 2.88; 95% CI = 1.01-8.20), and walking barefoot (AOR = 4.00; 95% CI = 2.29-7.00) were significantly associated with the presence of soil-transmitted helminths among pregnant women. CONCLUSION: The prevalence of STH was significantly moderate in the study area, where pregnant women were mostly affected by ascariasis and hookworms. Living in a rural area, being a daily labourer, walking barefoot, not washing hands after the toilet, drinking from an unprotected water source, and lacking health information were the determining factors. Interventions including health education, the expansion of pure drinking water sources, the promotion of personal hygiene, and the wearing of shoes are recommended to reduce the burden of soil-transmitted helminths in the study area.


Helminthiasis , Soil , Humans , Female , Ethiopia/epidemiology , Cross-Sectional Studies , Pregnancy , Adult , Helminthiasis/epidemiology , Helminthiasis/transmission , Soil/parasitology , Young Adult , Prevalence , Risk Factors , Adolescent , Animals , Helminths/isolation & purification , Helminths/classification , Pregnancy Complications, Parasitic/epidemiology , Feces/parasitology , Surveys and Questionnaires
20.
PLoS Negl Trop Dis ; 18(4): e0012049, 2024 Apr.
Article En | MEDLINE | ID: mdl-38574166

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.


Helminthiasis , Helminths , Humans , Animals , Swine , Ancylostomatoidea , Trichuris , Ascaris , Soil/parasitology , Ascaris lumbricoides , Feces/parasitology , Helminthiasis/drug therapy , Prevalence
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