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Clinical Microbiology and Infection :... Nov 2021The clinical and laboratory characterization of Strongyloides stercoralis infection at diagnosis and after treatment is still poorly defined. (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
The clinical and laboratory characterization of Strongyloides stercoralis infection at diagnosis and after treatment is still poorly defined.
OBJECTIVES
The primary objective was to describe the pattern and frequency of clinical and laboratory characteristics associated with S. stercoralis infection. The secondary objectives were (a) comparison of characteristics reported in endemic versus non-endemic areas; and (b) the evaluation of the resolution of identified characteristics after treatment.
METHODS
We searched PubMed, EMBASE, LILACS and CENTRAL up to May 2021. Eligible studies were randomized controlled trials (RCTs) for the treatment of S. stercoralis infection and prospective observational studies reporting data on symptoms caused by strongyloidiasis in individuals diagnosed with a highly specific test. Quality assessment was performed to assess the risk of bias. Demographic and clinical data were summarized using descriptive statistics. Meta-analysis was done by pooling the proportion of participants with symptoms with random effects model.
RESULTS
Twenty studies were included: nine RCTs and 13 observational studies. Overall, symptoms were reported in 50.4% cases (95% CI 47.6-53.1), and were more often reported in non-endemic (58.6%, 95% CI 55.0-62.2) than in endemic (35.7%, 95% CI 31.4-39.9) areas. The removal of an article of lower quality did not impact on figures. Frequency of symptoms tended to reduce after treatment. Three studies reported the proportion of participants with eosinophilia before and after treatment: 76.9% of participants (95% CI 73.4-80.4) had eosinophilia at diagnosis, reducing to 27.4% (95% CI 24.0-30.7) after treatment.
CONCLUSIONS
About half of infected people complain at least of one symptom and almost 70% have eosinophilia. The frequency of symptoms and eosinophilia decreased after treatment, though the association with cure is not clearly defined. Providing relief from symptoms and eosinophilia is another reason, in addition to prevention of disseminated disease, for promoting screening and treatment of individuals with strongyloidiasis.
Topics: Animals; Eosinophilia; Humans; Observational Studies as Topic; Randomized Controlled Trials as Topic; Strongyloides stercoralis; Strongyloidiasis
PubMed: 34325063
DOI: 10.1016/j.cmi.2021.07.016 -
Development and Efficacy of Droplet Digital PCR for Detection of Strongyloides stercoralis in Stool.The American Journal of Tropical... Oct 2021Human strongyloidiasis is one of the neglected tropical diseases caused by infection with soil-transmitted helminth Strongyloides stercoralis. Conventional stool...
Human strongyloidiasis is one of the neglected tropical diseases caused by infection with soil-transmitted helminth Strongyloides stercoralis. Conventional stool examination, a method commonly used for diagnosis of S. stercoralis, has low sensitivity, especially in the case of light infections. Herein, we developed the droplet digital polymerase chain reaction (ddPCR) assay to detect S. stercoralis larvae in stool and compared its performance with real-time PCR and stool examination techniques (formalin ethyl-acetate concentration technique [FECT] and agar plate culture [APC]). The ddPCR results showed 98% sensitivity and 90% specificity, and real-time PCR showed 82% sensitivity and 76.7% specificity when compared with the microscopic methods. Moreover, ddPCR could detect a single S. stercoralis larva in feces, and cross-reactions with other parasites were not observed. In conclusion, a novel ddPCR method exhibited high sensitivity and specificity for detection of S. stercoralis in stool samples. This technique may help to improve diagnosis, particularly in cases with light infection. In addition, ddPCR technique might be useful for screening patients before starting immunosuppressive drug therapy, and follow-up after treatment of strongyloidiasis.
Topics: Animals; Cross Reactions; Feces; Polymerase Chain Reaction; Strongyloides stercoralis; Strongyloidiasis
PubMed: 34662861
DOI: 10.4269/ajtmh.21-0729 -
PloS One 2021Hyperinfection and disseminated infection by the parasitic nematode Strongyloides stercoralis can be induced by iatrogenic administration of steroids and...
Hyperinfection and disseminated infection by the parasitic nematode Strongyloides stercoralis can be induced by iatrogenic administration of steroids and immunosuppression and lead to an elevated risk of mortality. Responses of free-living stages of S. stercoralis to the therapeutic corticosteroid dexamethasone (DXM) were investigated using RNA-seq transcriptomes of DXM-treated female and male worms. A total of 17,950 genes representing the transcriptome of these free-living adult stages were obtained, among which 199 and 263 were differentially expressed between DXM-treated females and DXM-treated males, respectively, compared with controls. According to Gene Ontology analysis, differentially expressed genes from DXM-treated females participate in developmental process, multicellular organismal process, cell differentiation, carbohydrate metabolic process and embryonic morphogenesis. Others are involved in signaling and signal transduction, including cAMP, cGMP-dependent protein kinase pathway, endocrine system, and thyroid hormone pathway, as based on Kyoto Encyclopedia of Genes and Genomes analysis. The novel findings warrant deeper investigation of the influence of DXM on growth and other pathways in this neglected tropical disease pathogen, particularly in a setting of autoimmune and/or allergic disease, which may require the clinical use of steroid-like hormones during latent or covert strongyloidiasis.
Topics: Animals; Dexamethasone; Female; Life Cycle Stages; Male; Second Messenger Systems; Strongyloides stercoralis; Transcriptome
PubMed: 34181669
DOI: 10.1371/journal.pone.0253701 -
Parasites & Vectors Nov 2023Ribosome biogenesis is the process of assembling ribosome complexes that regulate cell proliferation and differentiation with potential regulatory effects on...
BACKGROUND
Ribosome biogenesis is the process of assembling ribosome complexes that regulate cell proliferation and differentiation with potential regulatory effects on development. Many factors regulate ribosome biological processes. Nin one binding protein (Nob1) has received widespread attention as key genes regulating ribosome biogenesis-the 3' end of the 20S rRNA is cleaved by Nob1 at cleavage site D to form 18S rRNA, generating translationally capable 40S subunit. As a ribosome biogenesis factor, Nob1 may regulate the development of organisms, but almost nothing is known about the function of Nob1 for any parasitic nematode. We explored the functional role of NOBP-1 (the homologous gene of Nob1) encoding gene from a parasitic nematode-Strongyloides stercoralis.
METHODS
The full-length cDNA, gDNA and promoter region of Ss-nobp-1 was identified using protein BLAST in WormBase ParaSite according to the Caenorhabditis elegans NOBP-1 sequence to analyze the gene structure. RNA sequencing (RNA-seq) data in wormbase were retrieved and analyzed to assess the transcript abundance of Ss-nobp-1 in seven developmental stages of S. stercoralis. The standard method for gonadal microinjection of constructs was carried out to determine the anatomic expression patterns of Ss-nobp-1. The interaction between Ss-NOBP-1 and partner of NOBP-1 (Ss-PNO-1) was assessed by yeast two-hybridization and bimolecular fluorescence complementarity (BiFC) experiments.
RESULTS
The NOBP-1 encoding gene Ss-nopb-1 from the zoonotic parasite S. stercoralis has been isolated and characterized. The genomic DNA representing Ss-nobp-1 includes a 1599-bp coding region and encodes a protein comprising 403 amino acids (aa), which contains conserved PIN domain and zinc ribbon domain. RNA-seq analysis revealed that Ss-nobp-1 transcripts are present throughout the seven developmental stages in S. stercoralis and have higher transcription levels in iL3, L3 and P Female. Ss-nobp-1 is expressed mainly in the intestine of transgenic S. stercoralis larvae, and there is a direct interaction between Ss-NOBP-1 and Ss-PNO-1.
CONCLUSIONS
Collectively, Ss-NOBP-1 has a potential role in embryo formation and the infective process, and findings from this study provide a sound foundation for investigating its function during the development of parasitic nematode.
Topics: Animals; Female; Strongyloides stercoralis; Animals, Genetically Modified; Caenorhabditis elegans; Larva
PubMed: 37924155
DOI: 10.1186/s13071-023-05940-9 -
Parasites & Vectors May 2014The threadworm Strongyloides stercoralis, the most neglected helminth, affects an estimated 30-100 million people worldwide. Information on S. stercoralis infection is...
BACKGROUND
The threadworm Strongyloides stercoralis, the most neglected helminth, affects an estimated 30-100 million people worldwide. Information on S. stercoralis infection is scarce in tropical and sub-tropical resource poor countries, including Cambodia. We determined S. stercoralis infection prevalence and risk factors for infection in the general population in Southern Cambodia.
METHODS
A cross-sectional study was carried out between January and April 2011 among 2,861 participants living in 60 villages of Takeo province, using Koga-agar plate culture, the Baermann technique and the Kato-Katz technique on a single stool sample.
RESULTS
Eight intestinal helminth species were diagnosed. Hookworm (31.4%) and S. stercoralis (21.0%) occurred most frequently. Prevalence of S. stercoralis infection increased with age. In all age groups a higher prevalence was found among males than among females (OR: 1.7; 95% CI: 1.4 - 2.0; P < 0.001). Participants who had a latrine at home were significantly less frequently infected with S. stercoralis than those who did not (OR: 0.7; 95% CI: 0.4 - 0.8; P = 0.003). Muscle pain (OR: 1.3; 95% CI: 1.0 - 1.6; P = 0.028) and urticaria (OR: 1.4; 95% CI: 1.1 - 1.8; P = 0.001) were significantly associated with S. stercoralis infection.
CONCLUSIONS
S. stercoralis is highly prevalent among the general Cambodian population and should no longer be neglected. Access to adequate diagnosis and treatment is urgently needed.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Animals; Cambodia; Child; Child, Preschool; Feces; Female; Humans; Infant; Male; Middle Aged; Odds Ratio; Prevalence; Risk Factors; Strongyloides stercoralis; Strongyloidiasis; Young Adult
PubMed: 24886763
DOI: 10.1186/1756-3305-7-221 -
PLoS Neglected Tropical Diseases Sep 2019Strongyloidiasis is a neglected tropical disease caused by the human infective nematodes Strongyloides stercoralis, Strongyloides fuelleborni fuelleborni and...
Strongyloidiasis is a neglected tropical disease caused by the human infective nematodes Strongyloides stercoralis, Strongyloides fuelleborni fuelleborni and Strongyloides fuelleborni kellyi. Previous large-scale studies exploring the genetic diversity of this important genus have focused on Southeast Asia, with a small number of isolates from the USA, Switzerland, Australia and several African countries having been genotyped. Consequently, little is known about the global distribution of geographic sub-variants of these nematodes and the genetic diversity that exists within the genus Strongyloides generally. We extracted DNA from human, dog and primate feces containing Strongyloides, collected from several countries representing all inhabited continents. Using a genotyping assay adapted for deep amplicon sequencing on the Illumina MiSeq platform, we sequenced the hyper-variable I and hyper-variable IV regions of the Strongyloides 18S rRNA gene and a fragment of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene from these specimens. We report several novel findings including unique S. stercoralis and S. fuelleborni genotypes, and the first identifications of a previously unknown S. fuelleborni infecting humans within Australia. We expand on an existing Strongyloides genotyping scheme to accommodate S. fuelleborni and these novel genotypes. In doing so, we compare our data to all 18S and cox1 sequences of S. fuelleborni and S. stercoralis available in GenBank (to our knowledge), that overlap with the sequences generated using our approach. As this analysis represents more than 1,000 sequences collected from diverse hosts and locations, representing all inhabited continents, it allows a truly global understanding of the population genetic structure of the Strongyloides species infecting humans, non-human primates, and domestic dogs.
Topics: Animals; Cyclooxygenase 1; Dogs; Feces; Genetic Variation; Genotype; High-Throughput Nucleotide Sequencing; Humans; Neglected Diseases; Primates; RNA, Ribosomal, 18S; Sequence Analysis, DNA; Strongyloides; Strongyloides stercoralis; Strongyloidiasis
PubMed: 31525192
DOI: 10.1371/journal.pntd.0007609 -
Parasitology Research Jan 2019Strongyloides stercoralis is a worldwide-distributed intestinal nematode affecting mainly humans and dogs. Canine strongyloidosis is generally characterised by...
Strongyloides stercoralis is a worldwide-distributed intestinal nematode affecting mainly humans and dogs. Canine strongyloidosis is generally characterised by diarrhoea, malabsorption and bronchopneumonia, and may be fatal in cases of impaired immunity. In recent years, molecular and epidemiological studies suggested that host-adapted populations of S. stercoralis with different zoonotic potential may exist. Clinical and subclinical cases of S. stercoralis infection have been increasingly diagnosed in imported (France, Belgium, Bulgaria) and locally born dogs in Switzerland, showing that this parasite is currently circulating in Europe. Three of these clinical cases will be described here. All three dogs presented severe disease, characterised by harsh diarrhoea, dehydration, vomiting, respiratory and/or neurologic signs, and needed intensive care and hospitalisation. One of these dogs was related to a Swiss breeding kennel, in which the infection was subsequently diagnosed in several other dogs. Faeces were analysed by three coproscopical methods including (i) the Baermann technique, which consistently identified the typical S. stercoralis first-stage larvae in both clinical and subclinical infections, (ii) the sedimentation-zinc chloride flotation and (iii) sodium acetate-acetic acid-formalin concentration (SAFC) methods, which allowed the additional identification of parasitic females and/or eggs in two of the clinical cases. Interestingly, S. stercoralis isolated from all three independent clinical cases exhibited an identical genetic background on the nuclear 18S rDNA (fragment involving hypervariable regions I and IV) and the mitochondrial cytochrome oxidase subunit I (cox1) loci, similar to that of zoonotic isolates from other geographical regions, and not to that of dog-adapted variants. Due to the clinical relevance and zoonotic potential of this parasite, the awareness of both diagnosticians and clinicians is strongly required.
Topics: Animals; Belgium; Bulgaria; DNA, Ribosomal; Dog Diseases; Dogs; Europe; Feces; Female; France; Humans; Larva; Male; Strongyloides stercoralis; Strongyloidiasis; Switzerland; Travel
PubMed: 30552576
DOI: 10.1007/s00436-018-6173-3 -
PLoS Neglected Tropical Diseases Mar 2021There are no national prevalence studies of Strongyloides stercoralis infection in Australia, although it is known to be endemic in northern Australia and is reported in...
BACKGROUND
There are no national prevalence studies of Strongyloides stercoralis infection in Australia, although it is known to be endemic in northern Australia and is reported in high risk groups such as immigrants and returned travellers. We aimed to determine the seropositivity (number positive per 100,000 of population and percent positive of those tested) and geographical distribution of S. stercoralis by using data from pathology laboratories.
METHODOLOGY
We contacted all seven Australian laboratories that undertake Strongyloides serological (ELISA antibody) testing to request de-identified data from 2012-2016 inclusive. Six responded. One provided positive data only. The number of people positive, number negative and number tested per 100,000 of population (Australian Bureau of Statistics data) were calculated including for each state/territory, each Australian Bureau of Statistics Statistical Area Level 3 (region), and each suburb/town/community/locality. The data was summarized and expressed as maps of Australia and Greater Capital Cities.
PRINCIPAL FINDINGS
We obtained data for 81,777 people who underwent serological testing for Strongyloides infection, 631 of whom were from a laboratory that provided positive data only. Overall, 32 (95% CI: 31, 33) people per 100,000 of population were seropositive, ranging between 23/100,000 (95% CI: 19, 29) (Tasmania) and 489/100,000 population (95%CI: 462, 517) (Northern Territory). Positive cases were detected across all states and territories, with the highest (260-996/100,000 and 17-40% of those tested) in regions across northern Australia, north-east New South Wales and north-west South Australia. Some regions in Greater Capital Cities also had a high seropositivity (112-188/100,000 and 17-20% of those tested). Relatively more males than females tested positive. Relatively more adults than children tested positive. Children were under-represented in the data.
CONCLUSIONS/SIGNIFICANCE
The study confirms that substantial numbers of S. stercoralis infections occur in Australia and provides data to inform public health planning.
Topics: Adolescent; Adult; Aged; Animals; Antibodies, Helminth; Australia; Child; Child, Preschool; Enzyme-Linked Immunosorbent Assay; Female; Humans; Infant; Male; Middle Aged; Prevalence; Seroepidemiologic Studies; Strongyloides stercoralis; Strongyloidiasis
PubMed: 33690623
DOI: 10.1371/journal.pntd.0009160 -
Current Opinion in Infectious Diseases Aug 2012This review discusses the latest approaches to the diagnosis and treatment of patients with strongyloidiasis, with an emphasis on infection in the immunocompromised host... (Review)
Review
PURPOSE OF REVIEW
This review discusses the latest approaches to the diagnosis and treatment of patients with strongyloidiasis, with an emphasis on infection in the immunocompromised host and the risk for disseminated strongyloidiasis.
RECENT FINDINGS
The differences in acute, chronic, accelerated autoinfection, and disseminated disease in Strongyloides stercoralis infection are explored with particular emphasis on early diagnosis, treatment, and prevention. The goals of treatment are investigated for the different infection states. Predisposing risks for dissemination are delineated, and the roles played for newer diagnostics in the identification of at-risk individuals are detailed.
SUMMARY
The use of newer diagnostic tests and broader screening of immunocompromised patients from Strongyloides-endemic areas is of paramount importance, particularly if prevention of life-threatening dissemination is the goal.
Topics: Acute Disease; Animals; Antinematodal Agents; Chronic Disease; Early Diagnosis; Humans; Immunocompromised Host; Immunosuppressive Agents; Risk Factors; Strongyloides stercoralis; Strongyloidiasis
PubMed: 22691685
DOI: 10.1097/QCO.0b013e3283551dbd -
Scientific Reports Oct 2018Strongyloides stercoralis is not hyperendemic in European countries but has been increasing in prevalence due to migration and travel. The infection is characterized by...
Strongyloides stercoralis is not hyperendemic in European countries but has been increasing in prevalence due to migration and travel. The infection is characterized by a mostly asymptomatic course or nonspecific symptoms in healthy subjects. However, immunosuppression or chemotherapy have been described as leading triggers for Strongyloides stercoralis hyperinfection syndrome and may have a fatal course. A post hoc analysis was performed among renal transplant patients during a 5-year period. Plasma samples of two hundred kidney allograft recipients were retrospectively analyzed for Strongyloides stercoralis seropositivity by established ELISA testing. Positive Strongyloides stercoralis serology was found in 3% of allograft recipients. One patient developed a life-threatening hyperinfection syndrome. His Strongyloides IgG signal had been elevated for years before the outbreak of the disease. Stronglyoides infections in transplant recipients are an important issue that physicians also in Central Europe should be aware of, given the risk of hyperinfection syndrome and the challenges in clinical diagnosis. Our study suggests that recipient and donor screening should be recommended in kidney transplantation programs in Central Europe as Strongyloides infection rates increase and its prevalence may be underestimated. Further research is needed to understand why some Strongyloides stercoralis seropositive individuals develop hyperinfection syndrome and others do not.
Topics: Adult; Aged; Animals; Case-Control Studies; Europe; Humans; Immunosuppression Therapy; Kidney Transplantation; Middle Aged; Prevalence; Retrospective Studies; Seroepidemiologic Studies; Strongyloides stercoralis; Strongyloidiasis; Systemic Inflammatory Response Syndrome; Transplant Recipients; Transplantation, Homologous
PubMed: 30337607
DOI: 10.1038/s41598-018-33775-3