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The Brazilian Journal of Infectious... 2021Describe the diagnostic characteristics of a conventional multiplex PCR for the diagnosis of S. stercoralis, N. americanus and Ancylostomas spp.
OBJECTIVES
Describe the diagnostic characteristics of a conventional multiplex PCR for the diagnosis of S. stercoralis, N. americanus and Ancylostomas spp.
METHODS
Fecal samples were collected from a cross-sectional study in Orán department, Salta province, Argentina. The stool samples were analyzed using concentration-sedimentation, Harada Mori, McMaster, and Baermann techniques. DNA was extracted from 50 mg fecal sample using the FastPrep® Spin Kit for Soil. Three pairs of primers were used for the amplification of three products of 101, 330, and 577 base pairs (bp) for S. stercoralis, N. americanus and Ancylostoma spp, respectively. The sensitivity and analytical specificity of multiplex PCR were evaluated, as well as the sensitivity and diagnostic specificity, using a composite standard and Bayesian approach.
RESULTS AND CONCLUSIONS
Multiplex PCR did not present cross-reaction with other intestinal parasites, and the detection limit for multiplex PCR was between 2 and 20 pg of genomic DNA. In addition it presented a diagnostic sensitivity of 97.4% for S. stercoralis and 90.3% for hookworms with a specificity of 100% and 87.6%, respectively. PCR identified a higher proportion (p <0.01) of coinfections (15.3%) than microscopic techniques (3.5%). Also, multiplex PCR showed that there was a positive association between S. stercoralis and hookworms (odds ratio = 2.12). However, this association was due to N. americanus (odds ratio= 3.22), since no association was observed between S. stercoralis and Ancylostoma spp. Neither was an association observed between the two species of hookworms.
Topics: Ancylostomatoidea; Animals; Bayes Theorem; Cross-Sectional Studies; Feces; Humans; Intestinal Diseases, Parasitic; Multiplex Polymerase Chain Reaction; Sensitivity and Specificity; Strongyloides stercoralis; Strongyloidiasis
PubMed: 34774469
DOI: 10.1016/j.bjid.2021.101649 -
IDCases 2022Strongyloidiasis is endemic in tropical and sub-tropical regions however cases of strongyloidiasis have been reported in temperate climates. Corticosteroid use,...
Strongyloidiasis is endemic in tropical and sub-tropical regions however cases of strongyloidiasis have been reported in temperate climates. Corticosteroid use, immunosuppression, infection with human T-lymphotropic virus type 1 (HTLV1), and chronic alcohol use are the most common and well-established risk factors for strongyloidiasis. Due to characteristic features of hyperinfection and dissemination, it can potentially cause a lethal infection in an immunocompromised individual. Strongyloidiasis is predominantly asymptomatic, however some unusual manifestations of strongyloidiasis include duodenal obstruction, ileus, reactive arthritis, ascites, hepatic lesions, and pancreatitis. Here we present a case of a 47-year-old-St. Lucian female who was found to have duodenitis and pancreatitis secondary to in the setting of underlying HTLV-1 infection and chronic alcohol use.
PubMed: 35198385
DOI: 10.1016/j.idcr.2022.e01442 -
PLoS Neglected Tropical Diseases Jul 2022The prevalence of Strongyloides stercoralis infection is estimated to be 30-100 million worldwide, although this an underestimate. Most cases remain undiagnosed due to...
BACKGROUND
The prevalence of Strongyloides stercoralis infection is estimated to be 30-100 million worldwide, although this an underestimate. Most cases remain undiagnosed due to the asymptomatic nature of the infection. We wanted to estimate the seroprevalence of S. stercoralis infection in a South Indian adult population.
METHODS
To this end, we performed community-based screening of 2351 individuals (aged 18-65) in Kanchipuram District of Tamil Nadu between 2013 and 2020. Serological testing for S. stercoralis was performed using the NIE ELISA.
RESULTS
Our data shows a seroprevalence of 33% (768/2351) for S. stercoralis infection which had a higher prevalence among males 36% (386/1069) than among females 29.8% (382/1282). Adults aged ≥55 (aOR = 1.65, 95% CI: 1.25-2.18) showed higher adjusted odds of association compared with other age groups. Eosinophil levels (39%) (aOR = 1.43, 95% CI: 1.19-1.74) and hemoglobin levels (24%) (aOR = 1.25, 95% CI: 1.11-1.53) were significantly associated with S. stercoralis infection. In contrast, low BMI (aOR = 1.15, 95% CI: 0.82-1.61) or the presence of diabetes mellitus (OR = 1.18, 95% CI: 0.83-1.69) was not associated with S. stercoralis seropositivity.
CONCLUSIONS
Our study provides evidence for a very high baseline prevalence of S. stercoralis infection in South Indian communities and this information could provide realistic and concrete planning of control measures.
Topics: Adult; Animals; Feces; Female; Humans; India; Male; Prevalence; Seroepidemiologic Studies; Strongyloides stercoralis; Strongyloidiasis
PubMed: 35857754
DOI: 10.1371/journal.pntd.0010561 -
Parasites & Vectors Jul 2019Four species of Strongyloides, Strongyloides felis, Strongyloides planiceps, Strongyloides stercoralis and Strongyloides tumefaciens, have been identified in cats based... (Review)
Review
BACKGROUND
Four species of Strongyloides, Strongyloides felis, Strongyloides planiceps, Strongyloides stercoralis and Strongyloides tumefaciens, have been identified in cats based on morphology and location in the host with limited data on the prevalence and disease potential of these different species. Strongyloides tumefaciens adults are located in colonic nodules while the other three species are in the small intestine. The literature on Strongyloides in cats is scattered and has never been compiled. The aim of this article is to provide a short review of the existing literature on Strongyloides spp. in cats, to describe the pathology of colonic nodules containing Strongyloides sp. seen at necropsies of cats in St. Kitts, West Indies, and to provide the first unequivocal report of zoonotic S. stercoralis in cats based on sequencing analysis of a portion of the cytochrome c oxidase subunit 1 (cox1) gene, and supported by phylogenetic analysis.
RESULTS
Colonic nodules containing sections of nematodes, histologically compatible with Strongyloides sp. were seen during necropsy in six cats in St. Kitts, West Indies. Sequencing of the cox1 gene of the mitochondrial DNA extracted from colonic nodules from two of these cats matched sequences of the zoonotic strain of S. stercoralis.
CONCLUSIONS
The morphological similarities between S. stercoralis-associated colonic nodules and previous reports of S. tumefaciens, together with the insufficient defining criteria for S. tumefaciens raises questions about the validity of the species. Further sampling and genetic characterization of isolates is needed to understand the species in cats and their zoonotic potential.
Topics: Animals; Cats; Colon; DNA, Mitochondrial; DNA, Ribosomal; Feces; Helminths; Hyperplasia; Phylogeny; RNA, Ribosomal, 18S; Strongyloides stercoralis; Strongyloidiasis; West Indies; Zoonoses
PubMed: 31300009
DOI: 10.1186/s13071-019-3592-7 -
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 -
Infection and Immunity Feb 2016Strongyloides stercoralis is a soil-transmitted helminth organism that infects ~50 to 100 million people worldwide. Despite its widespread prevalence, very little is...
Strongyloides stercoralis is a soil-transmitted helminth organism that infects ~50 to 100 million people worldwide. Despite its widespread prevalence, very little is known about the immune response that characterizes human S. stercoralis infection. To study the systemic cytokine profile characteristic of Strongyloides infection, we measured the circulating levels of a large panel of pro- and anti-inflammatory cytokines in asymptomatic, infected individuals (n = 32) and compared them to those in uninfected, controls (n = 24). Infected individuals exhibited significantly lower circulating levels of proinflammatory cytokines (gamma interferon [IFN-γ], tumor necrosis factor alpha [TNF-α], and interleukin-1β [IL-1β]) and significantly higher levels of anti-inflammatory cytokines (IL-4, IL-5, IL-9, IL-10, IL-13, IL-27, IL-37, and transforming growth factor β [TGF-β]). Moreover, treatment of Strongyloides infection resulted in a significant reversal of the cytokine profile, with increased levels of proinflammatory (IFN-γ, TNF-α, IL-2, IL-17A, IL-17F, IL-22, IL-23, and IL-1β) and decreased levels of anti-inflammatory (IL-4, IL-5, IL-9, IL-10, IL-13, IL-27, IL-37, and TGF-β) cytokines following treatment. Thus, S. stercoralis infection is characterized by alterations in the levels of systemic cytokines, reflecting major alterations in the underlying immune response to this chronic helminth infection.
Topics: Adolescent; Adult; Animals; Antinematodal Agents; Asymptomatic Diseases; Cytokines; Female; Humans; Interferon-gamma; Interleukin-5; Male; Middle Aged; Strongyloides stercoralis; Strongyloidiasis; Tumor Necrosis Factor-alpha; Young Adult
PubMed: 26597982
DOI: 10.1128/IAI.01354-15 -
European Journal of Case Reports in... 2020Patients with infections are usually asymptomatic but massive hyperinfection may occur in patients with diseases associated with abnormal cell-mediated immunity or...
UNLABELLED
Patients with infections are usually asymptomatic but massive hyperinfection may occur in patients with diseases associated with abnormal cell-mediated immunity or receiving immunosuppressive therapy. The authors present the clinical case of a 49-year-old man with a history of diarrhoea and cramping abdominal pain, generalized oedema, petechial rash, melanoderma, cough and dyspnoea. He presented hypokalaemia and arterial hypertension and was admitted with the diagnostic hypothesis of Cushing's syndrome or adrenocorticotropic hormone ectopic production. The patient developed respiratory failure associated with bilateral lung opacities and was admitted to the Intensive Care Unit. The abdominal computed tomography scan revealed liver and duodenal masses. The duodenal biopsy showed the presence of and the liver biopsy showed the presence of small cell neuroendocrine carcinoma. The patient died 50 days after hospital admission. The high level of endogenous cortisol observed in this patient may have facilitated the progression to severe fatal infection.
LEARNING POINTS
hyperinfection and disseminated disease can present as a multiorgan infection in immunocompromised patients with an appropriate clinical and epidemiological context. hyperinfection and disseminated disease can present with no eosinophilia and negative parasitological stool tests in more than 70% of cases.
PubMed: 32665921
DOI: 10.12890/2020_001509 -
Le Infezioni in Medicina 2022, a unique parasite, can cause mortal disease even years after the exposure. Iatrogenic use of steroids can complicate asymptomatic infections to a life-threatening...
BACKGROUND
, a unique parasite, can cause mortal disease even years after the exposure. Iatrogenic use of steroids can complicate asymptomatic infections to a life-threatening hyperinfection and/or disseminated infection. Data regarding seroprevalence of strongyloidiasis remains scarce and this knowledge gap needs due attention in many endemic countries including India.
AIM
The present study is aimed at assessing the seroprevalence of Strongyloides infection and the need for routine screening among individuals receiving steroid therapy.
METHODOLOGY
Eighty patients receiving steroid therapy and thirty healthy volunteers who had not received any immunosuppressive drugs and/or anthelminthic therapy in last six months were enrolled as cases and controls respectively and they were screened by Strongyloides IgG ELISA.
RESULTS
Among the 80 patients on steroids, the mean cumulative prednisolone equivalent dose received was 8.2 g (±11.2 g) for a mean duration of 184 days, 16 patients (20%, 95% CI 11.9-30) had a positive Strongyloides IgG serology. Only 4 controls (4/30, 13.3%, CI 3.8-30.7) tested positive (p=0.4).
CONCLUSIONS
Our study demonstrated a Strongyloides seroprevalence of 20% in the study population emphasizing the need for screening for Strongyloides infection prior to immunosuppressive therapy in order to prevent hyperinfection or possible dissemination.
PubMed: 36482946
DOI: 10.53854/liim-3004-15 -
Proceedings of the National Academy of... Jan 2018hyperinfection causes high mortality rates in humans, and, while hyperinfection can be induced by immunosuppressive glucocorticoids, the pathogenesis remains unknown....
hyperinfection causes high mortality rates in humans, and, while hyperinfection can be induced by immunosuppressive glucocorticoids, the pathogenesis remains unknown. Since immunocompetent mice are resistant to infection with , we hypothesized that NSG mice, which have a reduced innate immune response and lack adaptive immunity, would be susceptible to the infection and develop hyperinfection. Interestingly, despite the presence of large numbers of adult and first-stage larvae in -infected NSG mice, no hyperinfection was observed even when the mice were treated with a monoclonal antibody to eliminate residual granulocyte activity. NSG mice were then infected with third-stage larvae and treated for 6 wk with methylprednisolone acetate (MPA), a synthetic glucocorticoid. MPA treatment of infected mice resulted in 50% mortality and caused a significant >10-fold increase in the number of parasitic female worms compared with infected untreated mice. In addition, autoinfective third-stage larvae, which initiate hyperinfection, were found in high numbers in MPA-treated, but not untreated, mice. Remarkably, treatment with Δ7-dafachronic acid, an agonist of the parasite nuclear receptor -DAF-12, significantly reduced the worm burden in MPA-treated mice undergoing hyperinfection with Overall, this study provides a useful mouse model for autoinfection and suggests a therapeutic strategy for treating lethal hyperinfection.
Topics: Animals; Cholestenes; Female; Methylprednisolone; Methylprednisolone Acetate; Mice; Strongyloides stercoralis; Strongyloidiasis
PubMed: 29203662
DOI: 10.1073/pnas.1712235114 -
Parasitology Research Dec 2023Strongyloidiasis is a clinical issue both in humans and in dogs. Moreover, there are concerns about its zoonotic potential. We aimed to explore Strongyloides stercoralis... (Observational Study)
Observational Study
Strongyloidiasis is a clinical issue both in humans and in dogs. Moreover, there are concerns about its zoonotic potential. We aimed to explore Strongyloides stercoralis epidemiology in Southern Italy in humans and dogs sharing the same environment in three different settings: (1) kennels (group K); (2) livestock farms (group L) and (3) agricultural farms (group A). For humans, a commercial ELISA test was used for screening. RT-PCR on faecal samples was done for people testing positive or equivocal at serology. On dog's faecal samples, Baermann test and RT-PCR were performed. A total of 145 dogs and 139 persons were tested. Based on faecal tests in dogs and serology in humans, a S. stercoralis positivity of 4.1% and 6.5% was revealed, respectively. The sites where cases were found were different for animals and humans. In dogs the highest positivity was in group K (6.7% against 2% and 0% in L and A). Differently, in humans the proportion of positive results was similar between the groups (p = 0.883). Fifty percent (3/6) of positive dogs were healthy; the other dogs presented weight loss and/or diarrhoea. ELISA-positive persons (n=9) were all in health, but abdominal pain (37.5%), urticaria (22.2%) and asthma (22.2%) were reported, resolving after treatment with oral ivermectin 200 μg/kg. RT-PCR performed on 13 human faecal samples resulted negative. These findings suggest that strongyloidiasis is present in humans and dogs in Southern Italy, and screening in larger cohorts would be needed for more accurate estimates.
Topics: Animals; Dogs; Humans; Feces; Italy; Ivermectin; Strongyloides stercoralis; Strongyloidiasis
PubMed: 37735273
DOI: 10.1007/s00436-023-07978-1