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Lung Apr 2022Strongyloidiasis has been estimated to affect over 600 million people worldwide. It is caused by Strongyloides stercoralis, a roundworm endemic to the tropics and... (Review)
Review
Strongyloidiasis has been estimated to affect over 600 million people worldwide. It is caused by Strongyloides stercoralis, a roundworm endemic to the tropics and subtropics, especially areas where sanitation is suboptimal Autochthonous transmission has been documented in rural areas of the USA and Europe. Humans are infected when larvae penetrate the skin or are ingested. Autoinfection, in which larvae generated in the host go on to re-infect the host, leads to a state of chronic asymptomatic infection often with eosinophilia. Hyperinfection syndrome may develop when patients develop immune suppression, due to medications such as corticosteroids or following solid-organ transplantation. Hyperinfection is characterized by exponential increase in parasitic burden, leading to tissue invasion and life-threatening disease and associated bloodstream infections due to enteric organisms. Cases following use of corticosteroids for COVID-19 pneumonia have been described. Strongyloidiasis can be diagnosed by direct visualization of larvae in stool or other body fluids, or by serology. Ivermectin is highly effective in treating the disease. Patients with exposure to endemic areas and those expected to become immune suppressed should be screened and treated before starting immune suppressive agents. Empiric treatment should be considered when timely testing is not readily available.
Topics: Animals; COVID-19; Eosinophilia; Humans; Sepsis; Strongyloides stercoralis; Strongyloidiasis
PubMed: 35396957
DOI: 10.1007/s00408-022-00528-z -
Clinical Transplantation Nov 2022We reviewed the scientific literature to gain insight on the epidemiology and outcome of Strongyloides stercoralis infections after transplantation. (Review)
Review
BACKGROUND
We reviewed the scientific literature to gain insight on the epidemiology and outcome of Strongyloides stercoralis infections after transplantation.
METHODS
CINAHL, PUBMED, and OVID/MEDLINE were reviewed from inception through March 31, 2022 using key words Strongyloides and transplantation.
RESULTS
Our review identified 108 episodes of Strongyloides infection among 91 solid organ transplant (SOT) and 15 hematopoietic cell transplant (HCT) recipients. Median time to infection was 10.8 (range, .14-417) and 8.8 (range, 0-208) weeks after SOT and HCT, respectively. Gastrointestinal symptoms were frequent (86/108 [79.6%]), while skin rash (22/108 [20.3%]) and fever (31/103 [30%]) were less common. Peripheral eosinophilia was observed in half of patients (41/77 [53.2%]). Bacteremia (31/59 [52.5%]) was frequently due to Gram-negative organisms (24/31 [77.4%]). Abnormal chest radiologic findings were reported in half (56/108 [51.9%]). The majority had hyperinfection syndrome (97/108 [89.8%]) while disseminated strongyloidiasis was less common (11/108 [10.2%]). Thirty-two cases were categorized as donor-derived infection (DDI), with donors (23/24 [95.8%]) who had traveled to or lived in endemic areas. Median time to DDI was 8 weeks (range .5-34.3 weeks) after transplantation. Treatment consisted of ivermectin (n = 26), a benzimidazole (n = 27), or both drugs (n = 28). There was high all-cause mortality (48/107, 44.9%) and a high Strongyloides-attributable mortality (32/49, 65.3%).
CONCLUSIONS
Strongyloidiasis should be strongly considered among recipients with epidemiologic risk factors for infection, even in the absence of eosinophilia or rash. A policy that provides guidance on pro-active screening is needed, to ensure preventive measures are provided to recipients at increased risk.
Topics: Animals; Humans; Hematopoietic Stem Cell Transplantation; Strongyloidiasis; Strongyloides stercoralis; Organ Transplantation; Transplant Recipients; Eosinophilia
PubMed: 35987856
DOI: 10.1111/ctr.14795 -
PLoS Neglected Tropical Diseases Feb 2022Strongyloidiasis and Chagas disease are endemic in northern Argentina. In this study we evaluate the association between S. stercoralis and T. cruzi infections in...
BACKGROUND
Strongyloidiasis and Chagas disease are endemic in northern Argentina. In this study we evaluate the association between S. stercoralis and T. cruzi infections in villages with diverse prevalence levels for these parasites. Further understanding in the relationship between these Neglected Tropical Diseases of South America is relevant for the design of integrated control measures as well as exploring potential biologic interactions.
METHODOLOGY
Community based cross-sectional studies were carried in different villages of the Chaco and Yungas regions in Argentina. Individuals were diagnosed by serology for S. stercoralis and T. cruzi. The association between S. stercoralis and T. cruzi, and between anemia and the two parasites was evaluated using two approaches: marginal (Ma) and multilevel regression (Mu).
RESULTS
A total of 706 individuals from six villages of northern Argentina were included. A total of 37% were positive for S. stercoralis, 14% were positive for T. cruzi and 5% were positive for both. No association was found between infection with S. stercoralis and T. cruzi in any of the models, but we found a negative correlation between the prevalence of these species in the different villages (r = -0.91). Adults (> 15 years) presented association with S. stercoralis (Ma OR = 2.72; Mu OR = 2.84) and T. cruzi (Ma OR = 5.12; Mu OR = 5.48). Also, 12% and 2% of the variance of infection with S. stercoralis and T. cruzi, respectively, could be explained by differences among villages. On the other hand, anemia was associated with infection with S. stercoralis (Ma OR = 1.73; Mu OR = 1.78) and was more prevalent in adults (Ma OR = 2.59; Mu OR = 2.69).
CONCLUSION
We found that coinfection between S. stercoralis and T. cruzi is not more frequent than chance in endemic areas. However, the high prevalence for both parasites, raises the need for an integrated strategy for the control of STH and Chagas disease.
Topics: Adolescent; Adult; Animals; Argentina; Chagas Disease; Child; Child, Preschool; Coinfection; Cross-Sectional Studies; Emigrants and Immigrants; Endemic Diseases; Feces; Female; Humans; Male; Middle Aged; Prevalence; Strongyloides stercoralis; Strongyloidiasis; Trypanosoma cruzi; Young Adult
PubMed: 35120117
DOI: 10.1371/journal.pntd.0010179 -
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 -
PLoS Neglected Tropical Diseases 2013The soil-transmitted threadworm, Strongyloides stercoralis, is one of the most neglected among the so-called neglected tropical diseases (NTDs). We reviewed studies of... (Review)
Review
BACKGROUND
The soil-transmitted threadworm, Strongyloides stercoralis, is one of the most neglected among the so-called neglected tropical diseases (NTDs). We reviewed studies of the last 20 years on S. stercoralis's global prevalence in general populations and risk groups.
METHODS/PRINCIPAL FINDINGS
A literature search was performed in PubMed for articles published between January 1989 and October 2011. Articles presenting information on infection prevalence were included. A Bayesian meta-analysis was carried out to obtain country-specific prevalence estimates and to compare disease odds ratios in different risk groups taking into account the sensitivities of the diagnostic methods applied. A total of 354 studies from 78 countries were included for the prevalence calculations, 194 (62.4%) were community-based studies, 121 (34.2%) were hospital-based studies and 39 (11.0%) were studies on refugees and immigrants. World maps with country data are provided. In numerous African, Asian and South-American resource-poor countries, information on S. stercoralis is lacking. The meta-analysis showed an association between HIV-infection/alcoholism and S. stercoralis infection (OR: 2.17 BCI: 1.18-4.01; OR: 6.69; BCI: 1.47-33.8), respectively.
CONCLUSIONS
Our findings show high infection prevalence rates in the general population in selected countries and geographical regions. S. stercoralis infection is prominent in several risk groups. Adequate information on the prevalence is still lacking from many countries. However, current information underscore that S. stercoralis must not be neglected. Further assessments in socio-economic and ecological settings are needed and integration into global helminth control is warranted.
Topics: Animals; Global Health; Humans; Neglected Diseases; Prevalence; Risk Factors; Strongyloides stercoralis; Strongyloidiasis; Topography, Medical
PubMed: 23875033
DOI: 10.1371/journal.pntd.0002288 -
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 -
The Journal of Infectious Diseases May 2022Helminth infections may modulate the inflammatory response to Mycobacterium tuberculosis and influence disease presentation and outcome. Strongyloides stercoralis is...
BACKGROUND
Helminth infections may modulate the inflammatory response to Mycobacterium tuberculosis and influence disease presentation and outcome. Strongyloides stercoralis is common among populations with high tuberculosis prevalence. Our aim was to determine whether S. stercoralis coinfection influenced clinical presentation, cerebrospinal fluid (CSF) inflammation, and outcome from tuberculous meningitis (TBM).
METHODS
From June 2017 to December 2019, 668 Vietnamese adults with TBM, enrolled in the ACT HIV or LAST ACT trials (NCT03092817 and NCT03100786), underwent pretreatment S. stercoralis testing by serology, stool microscopy, and/or stool polymerase chain reaction. Comparisons of pretreatment TBM severity, CSF inflammation (including cytokines), and 3-month clinical end points were performed in groups with or without active S. stercoralis infection.
RESULTS
Overall, 9.4% participants (63 of 668) tested positive for S. stercoralis. Active S. stercoralis infection was significantly associated with reduced pretreatment CSF neutrophil counts (median [interquartile range], 3/μL [0-25/μL] vs 14 /μL [1-83/μL]; P = .04), and with reduced CSF interferon ɣ, interleukin 2, and tumor necrosis factor α concentrations (11.4 vs 56.0 pg/mL [P = .01], 33.1 vs 54.5 pg/mL [P = .03], and 4.5 vs 11.9 pg/mL [P = .02], respectively), compared with uninfected participants. Neurological complications by 3 months were significantly reduced in participants with active S. stercoralis infection compared with uninfected participants (3.8% [1 of 26] vs 30.0% [33 of 110], respectively; P = .01).
CONCLUSIONS
S. stercoralis coinfection may modulate the intracerebral inflammatory response to M. tuberculosis and improve TBM clinical outcomes.
Topics: Adult; Animals; Coinfection; Humans; Inflammation; Mycobacterium tuberculosis; Strongyloides stercoralis; Tuberculosis, Meningeal
PubMed: 33104201
DOI: 10.1093/infdis/jiaa672 -
Parasites & Vectors May 2020Strongyloidiasis is a soil borne helminthiasis, which in most cases is caused by Strongyloides stercoralis. Human infections with S. fuelleborni fuelleborni and S....
BACKGROUND
Strongyloidiasis is a soil borne helminthiasis, which in most cases is caused by Strongyloides stercoralis. Human infections with S. fuelleborni fuelleborni and S. fuelleborni kellyi also occur. Although up to 370 million people are currently estimated to be infected with S. stercoralis, this parasite is frequently overlooked. Strongyloides stercoralis is prevalent among humans in Thailand; however, S. fuelleborni fuelleborni has also been reported. Three recent genomic studies of individual S. stercoralis worms found genetically diverse populations of S. stercoralis, with comparably low heterozygosity in Cambodia and Myanmar, and less diverse populations with high heterozygosity in Japan and southern China that presumably reproduce asexually.
METHODS
We isolated individual Strongyloides spp. from different localities in northern and western Thailand and determined their nuclear small ribosomal subunit rDNA (18S rDNA, SSU), in particular the hypervariable regions I and IV (HVR-I and HVR-IV), mitochondrial cytochrome c oxidase subunit 1 (cox1) and for a subset whole genome sequences. These sequences were then compared with each other and with published sequences from different geographical locations.
RESULTS
All 237 worms isolated from 16 different human hosts were S. stercoralis, no S. fuelleborni was found. All worms had the common S. stercoralis SSU HVR IV haplotype A. Two different SSU HVR I haplotypes (I and II), both previously described in S. stercoralis, were found. No animal heterozygous for the two haplotypes was identified. Among the twelve cox1 haplotypes found, five had not been previously described. Based upon the mitochondrial cox1 and the nuclear whole genome sequences, S. stercoralis in Thailand was phylogenetically intermixed with the samples from other Southeast Asian countries and did not form its own branch. The genomic heterozygosity was even slightly lower than in the samples from the neighboring countries.
CONCLUSIONS
In our sample from humans, all Strongyloides spp. were S. stercoralis. The S. stercoralis from northern and western Thailand appear to be part of a diverse, intermixing continental Southeast Asian population. No obvious indication for genetic sub-structuring of S. stercoralis within Thailand or within the Southeast Asian peninsula was detected.
Topics: Animals; DNA, Helminth; Feces; Female; Genetic Variation; Genome, Helminth; Genomics; Genotype; Humans; Male; Neglected Diseases; Phylogeny; RNA, Ribosomal, 18S; Strongyloides stercoralis; Strongyloidiasis; Thailand; Whole Genome Sequencing
PubMed: 32404172
DOI: 10.1186/s13071-020-04115-0 -
Strongyloides stercoralis prevalence and diagnostics in Vientiane, Lao People's Democratic Republic.Infectious Diseases of Poverty Sep 2020Despite the high prevalence of strongyloidiasis in the Laotian population, Laotian hospitals still lack diagnostic capacity to appropriately diagnose Strongyloides...
BACKGROUND
Despite the high prevalence of strongyloidiasis in the Laotian population, Laotian hospitals still lack diagnostic capacity to appropriately diagnose Strongyloides stercoralis infections. This cross-sectional hospital-based study was conducted to assess the prevalence of Strongyloides stercoralis infection among hospitalized patients treated at Mahosot Hospital, the primary reference hospital of Lao People's Democratic Republic (Lao PDR), and to validate feasible methods for diagnosing S. stercoralis infection at hospital's laboratory.
METHODS
Between September and December 2018, stool samples of 104 inpatients were investigated for S. stercoralis infection by wet smear, Baermann technique, Koga Agar plate culture (KAPC), and real-time detection polymerase chain reaction (RTD-PCR) at the Infectious Diseases Ward of the Mahosot Hospital in Vientiane. The sensitivity, the specificity, the negative predictive value (NPV) of each diagnostic test, as well as their combination(s) was calculated using a composite reference standard (CRS). The correlation of the different test methods was assessed by chi-square or Fisher's exact test. Cohen's kappa coefficient was used to assess the diagnostic agreement of the different test methods.
RESULTS
The overall prevalence of S. stercoralis infections among the study population was 33.4%. The cumulative infection prevalence statistically significantly increased from the lowest age group of 40 years and below (22.4%), to the medium (40.0%) and to the oldest age group of 61 year and above (72.7%)(P = 0.003). The cumulative infection prevalence of CRS was considerably higher in male (40.4%) compared to female patients (28.1%), but not statistically different (P = 0.184). The diagnostic sensitivity of Baermann technique, KAPC, RTD-PCR, and the combination of Baermann technique and KAPC were 60.0, 60.0, 74.3, and 77.1%, respectively. Only 13 patients (37.1%) of the total 35 S. stercoralis patients diagnosed with any technique had a simultaneously positive diagnostic test with Baermann, KAPC and RTD-PCR.
CONCLUSIONS
We identified Baermann technique and KAPC to be currently the most feasible and implementable standard methods for diagnosing S. stercoralis at a hospital setting such as Mahosot Hospital and provincial and district hospitals in Lao PDR and other low- and middle income countries in Southeast Asia.
TRIAL REGISTRATION
This study was approved by the National Ethics Committee for Health Research in Lao PDR (reference no. 083/NECHR) and by the Ethics Committee Northwest and Central Switzerland (reference no. 2018-00594).
Topics: Adult; Aged; Aged, 80 and over; Animals; Cross-Sectional Studies; DNA, Helminth; Feasibility Studies; Feces; Female; Humans; Inpatients; Laos; Male; Middle Aged; Prevalence; Reagent Kits, Diagnostic; Real-Time Polymerase Chain Reaction; Strongyloides stercoralis; Strongyloidiasis; Young Adult
PubMed: 32958071
DOI: 10.1186/s40249-020-00750-y -
Tropical Medicine & International... Mar 2023Strongyloidiasis is a nematode infection caused by Strongyloides stercoralis. Previous studies have addressed the possibility of the parasite to establish a complex... (Observational Study)
Observational Study
OBJECTIVES
Strongyloidiasis is a nematode infection caused by Strongyloides stercoralis. Previous studies have addressed the possibility of the parasite to establish a complex relationship with the host that could affect the risk of developing diabetes mellitus or modify its presentation. This study aims to evaluate the potential impact of strongyloidiasis in diabetes mellitus and other metabolic diseases.
METHODS
Case-control observational retrospective study that included 95 S. stercoralis-infected patients and 83 non-infected individuals. Epidemiological and clinical variables were retrieved from medical records, and a statistical analysis was carried out to explore any association between strongyloidiasis and diabetes mellitus and other metabolic diseases.
RESULTS
Most of the patients were men (99, 55.60%) with a mean age of 42.53 ± SD 14 years. Twelve (6.70%) patients were diabetic; 30 (16.90%) presented arterial hypertension; 28 (15.70%) had dyslipidaemia; and 10 (5.60%) had thyroid pathology. When comparing patients with strongyloidiasis and uninfected patients, no differences were found regarding diabetes mellitus or other metabolic diseases.
CONCLUSIONS
The results obtained in the present study do not confirm any type of association between strongyloidiasis and diabetes mellitus or other metabolic diseases.
Topics: Adult; Animals; Female; Humans; Male; Case-Control Studies; Diabetes Mellitus; Retrospective Studies; Strongyloides stercoralis; Strongyloidiasis
PubMed: 36651761
DOI: 10.1111/tmi.13853