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Parasitology Mar 2017The majority of the 30-100 million people infected with Strongyloides stercoralis, a soil transmitted intestinal nematode, have subclinical (or asymptomatic) infections.... (Review)
Review
The majority of the 30-100 million people infected with Strongyloides stercoralis, a soil transmitted intestinal nematode, have subclinical (or asymptomatic) infections. These infections are commonly chronic and longstanding because of the autoinfective process associated with its unique life cycle. A change in immune status can increase parasite numbers, leading to hyperinfection syndrome, dissemination, and death if unrecognized. Corticosteroid use and HTLV-1 infection are most commonly associated with the hyperinfection syndrome. Strongyloides adult parasites reside in the small intestine and induce immune responses both local and systemic that remain poorly characterized. Definitive diagnosis of S. stercoralis infection is based on stool examinations for larvae, but newer diagnostics - including new immunoassays and molecular tests - will assume primacy in the next few years. Although good treatment options exist for infection and control of this infection might be possible, S. stercoralis remains largely neglected.
Topics: Animals; Anthelmintics; Diagnostic Tests, Routine; Humans; Molecular Diagnostic Techniques; Parasitology; Prevalence; Strongyloides; Strongyloidiasis
PubMed: 27181117
DOI: 10.1017/S0031182016000834 -
The New England Journal of Medicine Jun 2017
Topics: Animals; Glucocorticoids; Humans; Immunocompromised Host; Male; Middle Aged; Opportunistic Infections; Strongyloides stercoralis; Strongyloidiasis
PubMed: 28614685
DOI: 10.1056/NEJMicm1612018 -
Journal of Microbiology, Immunology,... Jun 2019Strongyloidiasis is a major neglected tropical disease with the potential of causing lifelong infection and mortality. One of the ways for effective control of this... (Review)
Review
Strongyloidiasis is a major neglected tropical disease with the potential of causing lifelong infection and mortality. One of the ways for effective control of this disease is developing improved diagnostics, particularly using serological approaches. A serological test can achieve high diagnostic sensitivity and specificity, has the potential for point-of-care translation, and can be used as a screening tool for early detection. More research is needed to find clinically important antibody biomarkers for early disease detection, mapping, and epidemiological surveillance. This article summarizes human strongyloidiasis and the available diagnostic tools for the disease, focusing on describing the current antibody assays for strongyloidiasis. Finally, prospects of developing a more effective serodiagnostic tool for strongyloidiasis are discussed.
Topics: Animals; Antibodies, Helminth; Early Diagnosis; Enzyme-Linked Immunosorbent Assay; Humans; Immunoglobulin E; Immunoglobulin G; Sensitivity and Specificity; Serologic Tests; Strongyloides stercoralis; Strongyloidiasis
PubMed: 30482708
DOI: 10.1016/j.jmii.2018.10.001 -
Molecular and Biochemical Parasitology Jul 2022The oft-neglected human-parasitic threadworm, Strongyloides stercoralis, infects roughly eight percent of the global population, placing disproportionate medical and... (Review)
Review
The oft-neglected human-parasitic threadworm, Strongyloides stercoralis, infects roughly eight percent of the global population, placing disproportionate medical and economic burden upon marginalized communities. While current chemotherapies treat strongyloidiasis, disease recrudescence and the looming threat of anthelminthic resistance necessitate novel strategies for nematode control. Throughout its life cycle, S. stercoralis relies upon sensory cues to aid in environmental navigation and coordinate developmental progression. Odorants, tastants, gases, and temperature have been shown to shape parasite behaviors that drive host seeking and infectivity; however, many of these sensory behaviors remain poorly understood, and their underlying molecular and neural mechanisms are largely uncharacterized. Disruption of sensory circuits essential to parasitism presents a promising strategy for future interventions. In this review, we describe our current understanding of sensory behaviors - namely olfactory, gustatory, gas sensing, and thermosensory behaviors - in Strongyloides spp. We also highlight the ever-growing cache of genetic tools optimized for use in Strongyloides that have facilitated these findings, including transgenesis, CRISPR/Cas9-mediated mutagenesis, RNAi, chemogenetic neuronal silencing, and the use of fluorescent biosensors to measure neuronal activity. Bolstered by these tools, we are poised to enter an era of rapid discovery in Strongyloides sensory neurobiology, which has the potential to shape pioneering advances in the prevention and treatment of strongyloidiasis.
Topics: Animals; Humans; Life Cycle Stages; Nematoda; Strongyloides stercoralis; Strongyloidiasis; Symbiosis
PubMed: 35697205
DOI: 10.1016/j.molbiopara.2022.111491 -
Philosophical Transactions of the Royal... Jan 2024The availability of high-quality data of helminth genomes provided over the past two decades has supported and accelerated large-scale 'omics studies and, consequently,... (Review)
Review
The availability of high-quality data of helminth genomes provided over the past two decades has supported and accelerated large-scale 'omics studies and, consequently, the achievement of a more in-depth molecular characterization of a number of pathogens. This has also involved spp. and since their genome was made available transcriptomics has been rather frequently applied to investigate gene expression regulation across their life cycle. proteomics characterization has instead been somehow neglected, with only a few reports performing high-throughput or targeted analyses associated with protein identification by tandem mass spectrometry. Such investigations are however necessary in order to discern important aspects associated with human strongyloidiasis, including understanding parasite biology and the mechanisms of host-parasite interaction, but also to identify novel diagnostic and therapeutic targets. In this review article, we will give an overview of the published proteomics studies investigating strongyloidiasis at different levels, spanning from the characterization of the somatic proteome and excretory/secretory products of different parasite stages to the investigation of potentially immunogenic proteins. Moreover, in the effort to try to start filling the current gap in host-proteomics, we will also present the first serum proteomics analysis in patients suffering from human strongyloidiasis. This article is part of the Theo Murphy meeting issue ': omics to worm-free populations'.
Topics: Animals; Humans; Strongyloides; Strongyloidiasis; Proteomics; Parasites; Host-Parasite Interactions
PubMed: 38008115
DOI: 10.1098/rstb.2022.0447 -
BioMed Research International 2016The course of infection is usually asymptomatic with a low discharge of rhabditoid larva in feces. However, the deleterious effects of alcohol consumption seem to... (Review)
Review
The course of infection is usually asymptomatic with a low discharge of rhabditoid larva in feces. However, the deleterious effects of alcohol consumption seem to enhance the susceptibility to infection, as shown by a fivefold higher strongyloidiasis frequency in alcoholics than in nonalcoholics. Moreover, the association between infection and alcoholism presents a risk for hyperinfection and severe strongyloidiasis. There are several possible mechanisms for the disruption of the host-parasite equilibrium in ethanol-addicted patients with chronic strongyloidiasis. One explanation is that chronic ethanol intake stimulates the hypothalamic-pituitary-adrenal (HPA) axis to produce excessive levels of endogenous cortisol, which in turn can lead to a deficiency in type 2 T helper cells (Th2) protective response, and also to mimic the parasite hormone ecdysone, which promotes the transformation of rhabditiform larvae to filariform larvae, leading to autoinfection. Therefore, when untreated, alcoholic patients are continuously infected by this autoinfection mechanism. Thus, the early diagnosis of strongyloidiasis and treatment can prevent serious forms of hyperinfection in ethanol abusers.
Topics: Alcoholism; Animals; Humans; Hypothalamo-Hypophyseal System; Pituitary-Adrenal System; Risk Factors; Strongyloides stercoralis; Strongyloidiasis; Th2 Cells
PubMed: 28105424
DOI: 10.1155/2016/4872473 -
PLoS Neglected Tropical Diseases Aug 2014Strongyloides stercoralis, an intestinal parasitic nematode, infects more than 100 million people worldwide. Strongyloides are unique in their ability to exist as a... (Review)
Review
BACKGROUND
Strongyloides stercoralis, an intestinal parasitic nematode, infects more than 100 million people worldwide. Strongyloides are unique in their ability to exist as a free-living and autoinfective cycle. Strongyloidiasis can occur without any symptoms or as a potentially fatal hyperinfection or disseminated infection. The most common risk factors for these complications are immunosuppression caused by corticosteroids and infection with human T-lymphotropic virus or human immunodeficiency virus. Even though the diagnosis of strongyloidiasis is improved by advanced instrumentation techniques in isolated and complicated cases of hyperinfection or dissemination, efficient guidelines for screening the population in epidemiological surveys are lacking.
METHODOLOGY AND RESULTS
In this review, we have discussed various conventional methods for the diagnosis and management of this disease, with an emphasis on recently developed molecular and serological methods that could be implemented to establish guidelines for precise diagnosis of infection in patients and screening in epidemiological surveys. A comprehensive analysis of various cases reported worldwide from different endemic and nonendemic foci of the disease for the last 40 years was evaluated in an effort to delineate the global prevalence of this disease. We also updated the current knowledge of the various clinical spectrum of this parasitic disease, with an emphasis on newer molecular diagnostic methods, treatment, and management of cases in immunosuppressed patients.
CONCLUSION
Strongyloidiasis is considered a neglected tropical disease and is probably an underdiagnosed parasitic disease due to its low parasitic load and uncertain clinical symptoms. Increased infectivity rates in many developed countries and nonendemic regions nearing those in the most prevalent endemic regions of this parasite and the increasing transmission potential to immigrants, travelers, and immunosuppressed populations are indications for initiating an integrated approach towards prompt diagnosis and control of this parasitic disease.
Topics: Animals; Female; Humans; Male; Prevalence; Serologic Tests; Strongyloides; Strongyloidiasis
PubMed: 25121962
DOI: 10.1371/journal.pntd.0003018 -
Molecular and Biochemical Parasitology Nov 2022Caenorhabditis elegans is a uniquely powerful tool to aid understanding of fundamental nematode biology. While C. elegans boasts an unrivalled array of functional... (Review)
Review
Caenorhabditis elegans is a uniquely powerful tool to aid understanding of fundamental nematode biology. While C. elegans boasts an unrivalled array of functional genomics tools and phenotype bioassays the inherent differences between free-living and parasitic nematodes underscores the need to develop these approaches in tractable parasite models. Advances in functional genomics approaches, including RNA interference and CRISPR/Cas9 gene editing, in the parasitic nematodes Strongyloides ratti and Strongyloides stercoralis provide a unique and timely opportunity to probe basic parasite biology and reveal novel anthelmintic targets in species that are both experimentally and therapeutically relevant pathogens. While Strongyloides functional genomics tools have progressed rapidly, the complementary range of bioassays required to elucidate phenotypic outcomes post-functional genomics remain more limited in scope. To adequately support the exploitation of functional genomic pipelines for studies of gene function in Strongyloides a comprehensive set of species- and parasite-specific quantitative bioassays are required to assess nematode behaviours post-genetic manipulation. Here we review the scope of the current Strongyloides bioassay toolbox, how established Strongyloides bioassays have advanced knowledge of parasite biology, opportunities for Strongyloides bioassay development and, the need for investment in tractable model parasite platforms such as Strongyloides to drive the discovery of novel targets for parasite control.
Topics: Animals; Parasites; Caenorhabditis elegans; Nematoda; Genomics; Strongyloides stercoralis; Biological Assay
PubMed: 36240960
DOI: 10.1016/j.molbiopara.2022.111526 -
Strongyloidiasis Hyperinfection Syndrome in COVID-19 Positive Migrants Treated with Corticosteroids.Journal of Immigrant and Minority Health Dec 2022The aim of this study is to highlight the potentially fatal risk of Strongyloidiasis Hyperinfection Syndrome for hospitalized immigrant patients with moderate to severe... (Review)
Review
The aim of this study is to highlight the potentially fatal risk of Strongyloidiasis Hyperinfection Syndrome for hospitalized immigrant patients with moderate to severe COVID-19 disease and undiagnosed Strongyloidiasis. We reviewed electronic medical records of immigrants from 2010 to 2022 and extracted the number of patients with eosinophilia, strongyloidiasis and COVID-19 infection, outpatient and hospitalized. While 885 outpatients were diagnosed with eosinophilia, only 356 (40.2%) were tested for strongyloidiasis and 160 (44.9%) yielded a reactive serology. COVID-19 infection was reported in 6,412 patients. 1135 (17.7%) of these patients sought hospital care. Patients with undiagnosed strongyloidiasis are at risk for a potentially fatal parasitosis if treated with systemic corticosteroids for COVID-19. This supports clinical guidelines in hospital settings for those with severe COVID-19. Strongyloidiasis should be considered by taking a thorough travel or migration history and testing before giving immunosuppressive drugs.
Topics: Animals; Humans; Strongyloidiasis; Strongyloides stercoralis; Transients and Migrants; COVID-19; Eosinophilia; Adrenal Cortex Hormones
PubMed: 35939223
DOI: 10.1007/s10903-022-01386-w -
The American Journal of Tropical... Aug 2018Human strongyloidiasis is widely prevalent in tropical and subtropical regions worldwide but is not endemic in Hawaii. Subclinical, chronic infections may be lifelong;... (Review)
Review
Human strongyloidiasis is widely prevalent in tropical and subtropical regions worldwide but is not endemic in Hawaii. Subclinical, chronic infections may be lifelong; immunosuppressive therapy, particularly with glucocorticoids, may lead to serious or fatal disseminated disease, which is preventable. We performed a retrospective analysis of patients tested for immunoglobulin G antibody in an academic medical center in Honolulu, Hawaii, from 2005 to 2012. Of the 475 patients tested, 78 (16%) were seropositive. The largest proportion of seropositive cases was found among Micronesians (30%), Polynesians (26%), Filipinos (13%), and Southeast Asians (11%). Among the seropositive patients, the most likely reason for clinicians to order testing was blood eosinophilia. Stool parasite examination results were available for 58% of seropositive patients of which 11% were positive for larvae. Antihelminthic therapy, usually ivermectin, was ordered for 71% of patients. After treatment, blood eosinophilia and serology results were reassessed for 76% and 35% of patients, respectively; both tests tended to show improvement. Travelers and immigrants from -endemic areas, including Micronesia and Polynesia, should have serodiagnostic testing for latent strongyloidiasis, and if positive, treated empirically with ivermectin, particularly when corticosteroids or other immunosuppressive therapies are anticipated.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Animals; Anthelmintics; Antibodies, Helminth; Child; Enzyme-Linked Immunosorbent Assay; Eosinophilia; Female; Hawaii; Humans; Immunoglobulin G; Male; Middle Aged; Retrospective Studies; Serologic Tests; Strongyloides stercoralis; Strongyloidiasis; Young Adult
PubMed: 29943712
DOI: 10.4269/ajtmh.18-0157