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Acta Tropica Sep 2020Strongyloides stercoralis is a parasitic worm that is of considerable clinical relevance. Indeed, it may persist asymptomatically for many years, but can lead to...
Strongyloides stercoralis is a parasitic worm that is of considerable clinical relevance. Indeed, it may persist asymptomatically for many years, but can lead to potentially fatal dissemination when the host's immune status is impaired. As commonly employed stool microscopy techniques (e.g. Kato-Katz thick smear) fail to detect S. stercoralis, the epidemiology is poorly understood. In 2013, we conducted a cross-sectional household survey in the district of Mimika in Papua, Indonesia. A total of 331 individuals, aged 1 month to 44 years, had a single stool sample subjected to real-time polymerase chain reaction (PCR) for S. stercoralis diagnosis. The prevalence of S. stercoralis infection was 32.0% (106/331 individuals); higher than any of the three main soil-transmitted helminths (Ascaris lumbricoides, 23.9%; Trichuris trichiura, 18.4%; and hookworm, 17.2%). Amongst the S. stercoralis-infected individuals, 73.6% were concurrently infected with another helminth, with hookworm being the most frequent co-infection (27.4%). Fourteen percent of the S. stercoralis infections had low cycle threshold values on real-time PCR, which may indicate a higher infection intensity. Multivariate logistic regression analysis revealed that age ≥5 years (adjusted odds ratio (OR) 5.8, 95% confidence interval (CI): 3.1-10.8) was significantly associated with S. stercoralis infection. There is a need for in-depth clinical and diagnostic studies to elucidate the public health impact of S. stercoralis infection in Indonesia.
Topics: Adolescent; Adult; Animals; Child; Child, Preschool; Coinfection; Cross-Sectional Studies; Female; Humans; Indonesia; Infant; Male; Molecular Diagnostic Techniques; Risk Factors; Strongyloides stercoralis; Strongyloidiasis; Young Adult
PubMed: 32505594
DOI: 10.1016/j.actatropica.2020.105575 -
Emerging Infectious Diseases Jul 2022Widespread use of corticosteroids for COVID-19 treatment has led to Strongyloides reactivation and severe disease in patients from endemic areas. We describe a US...
Widespread use of corticosteroids for COVID-19 treatment has led to Strongyloides reactivation and severe disease in patients from endemic areas. We describe a US patient with COVID-19 and Strongyloides hyperinfection syndrome and review other reported cases. Our findings highlight the need for Strongyloides screening and treatment in high-risk populations.
Topics: Adrenal Cortex Hormones; Animals; Humans; Strongyloides stercoralis; Strongyloidiasis; Syndrome; COVID-19 Drug Treatment
PubMed: 35731220
DOI: 10.3201/eid2807.220198 -
Scientific Reports Mar 2023We explored the impact of chronic Strongyloides stercoralis infection on the gut microbiome and microbial activity in a longitudinal study. At baseline (time-point T0),...
We explored the impact of chronic Strongyloides stercoralis infection on the gut microbiome and microbial activity in a longitudinal study. At baseline (time-point T0), 42 fecal samples from matched individuals (21 positive for strongyloidiasis and 21 negative) were subjected to microbiome 16S-rRNA sequencing. Those positive at T0 (untreated then because of COVID19 lockdowns) were retested one year later (T1). Persistent infection in these individuals indicated chronic strongyloidiasis: they were treated with ivermectin and retested four months later (T2). Fecal samples at T1 and T2 were subjected to 16S-rRNA sequencing and LC-MS/MS to determine microbial diversity and proteomes. No significant alteration of indices of gut microbial diversity was found in chronic strongyloidiasis. However, the Ruminococcus torques group was highly over-represented in chronic infection. Metaproteome data revealed enrichment of Ruminococcus torques mucin-degrader enzymes in infection, possibly influencing the ability of the host to expel parasites. Metaproteomics indicated an increase in carbohydrate metabolism and Bacteroidaceae accounted for this change in chronic infection. STITCH interaction networks explored highly expressed microbial proteins before treatment and short-chain fatty acids involved in the synthesis of acetate. In conclusion, our data indicate that chronic S. stercoralis infection increases Ruminococcus torques group and alters the microbial proteome.
Topics: Humans; Animals; Strongyloides stercoralis; Strongyloidiasis; Proteome; Persistent Infection; Longitudinal Studies; Ruminococcus; Chromatography, Liquid; COVID-19; Communicable Disease Control; Tandem Mass Spectrometry; Feces
PubMed: 36918707
DOI: 10.1038/s41598-023-31118-5 -
Nefrologia 2023
Topics: Animals; Humans; Strongyloides stercoralis; Kidney Transplantation; Strongyloidiasis; Tissue Donors
PubMed: 36437204
DOI: 10.1016/j.nefroe.2022.11.017 -
Parasites & Vectors Dec 2014Strongyloides stercoralis can undergo an alternative autoinfective life cycle in the host, which, in some individuals can lead to a lethal infection. However, due to a...
BACKGROUND
Strongyloides stercoralis can undergo an alternative autoinfective life cycle in the host, which, in some individuals can lead to a lethal infection. However, due to a number of factors, such as, the majority of those infected are from low-income backgrounds and the limitation in experimental models for studying human S. stercoralis, strongyloidiasis remains neglected. Improved knowledge of animal models that are susceptible to this parasite is needed in order to investigate the immunological mechanisms involved during infection and in particular to further understand the natural history of the autoinfective cycle.
METHODS
Callithrix penicillata were inoculated subcutaneously with 100 (n = 2), 300 (n = 4) or 500 (n = 9) third-stage infective larvae (L3i) of S. stercoralis of human origin. Three marmosets received smaller inocula (i.e., one received 100 and two received 300 L3i) to ensure a greater capacity to withstand the infection after immunosuppression, which was triggered by administration of dexamethasone during early patency. Qualitative faecal analyses began at 7 days post-infection (DPI), and semi-quantitative tests were also performed for the dexamethasone-treated primates and the three matched controls. During the necropsies, specimens of S. stercoralis were recovered and tissue fragments were processed for histopathology.
RESULTS
The mean prepatency and patency periods were 16.1 ± 3.0 and 161.1 ± 72.2 DPI, respectively. The marmosets typically tolerated the infection well, but immunosuppressed individuals exhibited higher numbers of larvae in the faeces and progressive clinical deterioration with late disseminated infection. In these cases, the number of females recovered was significantly higher than the number of inoculated L3i. Large quantities of larvae were observed migrating through the host tissues, and histopathology revealed pulmonary and intestinal injuries consistent with those observed in human strongyloidiasis.
CONCLUSIONS
Both complicated and uncomplicated strongyloidiasis occur in C. penicillata that is described as a susceptible small non-human primate model for S. stercoralis. This host permits the maintenance of a human strain of the parasite in the laboratory and can be useful for experimental investigations of strongyloidiasis. In parallel, we discuss data related to the autoinfective cycle that provides new insights into the biology of S. stercoralis.
Topics: Animals; Callithrix; Disease Models, Animal; Feces; Female; Humans; Larva; Male; Strongyloides stercoralis; Strongyloidiasis
PubMed: 25499310
DOI: 10.1186/s13071-014-0579-2 -
Molecular and Biochemical Parasitology Jul 2022Mechanisms governing morphogenesis and development of infectious third-stage larvae (L3i) of parasitic nematodes have been likened to those regulating dauer development... (Review)
Review
Mechanisms governing morphogenesis and development of infectious third-stage larvae (L3i) of parasitic nematodes have been likened to those regulating dauer development in Caenorhabditis elegans. Dauer regulatory signal transduction comprises initial G protein-coupled receptor (GPCR) signaling in chemosensory neurons of the amphidial complex that regulates parallel insulin- and TGFβ-like signaling in the tissues. Insulin- and TGFβ-like signals converge to co-regulate steroid signaling through the nuclear receptor (NR) DAF-12. Discovery of the steroid ligands of DAF-12 opened a new avenue of small molecule physiology in C. elegans. These signaling pathways are conserved in parasitic nematodes and an increasing body of evidence supports their function in formation and developmental regulation of L3i during the infectious process in soil transmitted species. This review presents these lines of evidence for G protein-coupled receptor (GPCR), insulin- and TGFβ-like signaling in brief and focuses primarily on signaling through parasite orthologs of DAF-12. We discuss in some depth the deployment of sensitive analytical techniques to identify Δ7-dafachronic acid as the natural ligand of DAF-12 homologs in Strongyloides stercoralis and Haemonchus contortus and of targeted mutagenesis by CRISPR/Cas9 to assign dauer-like regulatory function to the NR Ss-DAF-12, its coactivator Ss-DIP-1 and the key ligand biosynthetic enzyme Ss-CYP-22a9. Finally, we present published evidence of the potential of Ss-DAF-12 signaling as a chemotherapeutic target in human strongyloidiasis.
Topics: Animals; Caenorhabditis elegans; Caenorhabditis elegans Proteins; Helminth Proteins; Humans; Insulins; Larva; Ligands; Parasites; Receptors, Cytoplasmic and Nuclear; Steroids; Strongyloides stercoralis; Strongyloidiasis; Transforming Growth Factor beta
PubMed: 35697206
DOI: 10.1016/j.molbiopara.2022.111490 -
BMC Infectious Diseases Aug 2021Strongyloidiasis is a disease of great public health significance, caused by the parasitic nematodes Strongyloides stercoralis, Strongyloides fuelleborni, and... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Strongyloidiasis is a disease of great public health significance, caused by the parasitic nematodes Strongyloides stercoralis, Strongyloides fuelleborni, and Strongyloides fuelleborni subsp. kellyi. This systematic review and meta-analysis aimed to assess the prevalence of Strongyloides stercoralis infection in Peru.
METHODS
The review was based on a literature search in PubMed, SciELO and Google Scholar using the key words or root words "strongyl*" AND "Peru" on 15 July 2020. Eligible studies were published from 1 January 1981 to 15 July 2020 and written in English, Spanish, Italian, or French.
RESULTS
We included 21 papers in the analysis. Studies were heterogeneous in terms of study population and diagnostic methods (e.g. Baermann technique, agar, Dancescu or charcoal cultures, serology, string capsule). Prevalence of S. stercoralis ranged from 0.3 to 45%. The pooled proportion of Strongyloides in the general population was 7.34% (95% CI 4.97 to 10.13%). Half the studies were designed to detect parasites in general. In studies designed to detect S. stercoralis, the most widely used diagnostic method was the Baermann technique.
CONCLUSION
Prevalence of S. stercoralis in Peru was high but varied by geographic area, techniques for stool examination, and participant characteristics.
Topics: Animals; Feces; Humans; Peru; Prevalence; Strongyloides stercoralis; Strongyloidiasis
PubMed: 34348671
DOI: 10.1186/s12879-021-06441-9 -
Parasites & Vectors Jan 2018Human infections by the gastrointestinal helminth Strongyloides stercoralis and the enteric protozoans Giardia duodenalis, Cryptosporidium spp. and Blastocystis spp. are...
Prevalence and molecular characterization of Strongyloides stercoralis, Giardia duodenalis, Cryptosporidium spp., and Blastocystis spp. isolates in school children in Cubal, Western Angola.
BACKGROUND
Human infections by the gastrointestinal helminth Strongyloides stercoralis and the enteric protozoans Giardia duodenalis, Cryptosporidium spp. and Blastocystis spp. are not formally included in the list of 20 neglected tropical diseases prioritised by the World Health Organization. Although largely underdiagnosed and considered of lower public health relevance, these infections have been increasingly demonstrated to cause significant morbidity and even mortality globally, particularly among children living in resource-poor settings.
METHODS
In this cross-sectional survey the prevalence, frequency and molecular diversity of S. stercoralis, G. duodenalis, Cryptosporidium spp. and Blastocystis spp. were investigated in a school children population in the province of Benguela (Angola). A total of 351 stool samples were collected during January to June 2015. The presence of S. stercoralis and G. duodenalis was confirmed by qPCR methods. Giardia duodenalis assemblages and sub-assemblages were determined by multilocus sequence-based genotyping of the glutamate dehydrogenase and β-giardin genes of the parasite. Detection and identification of Cryptosporidium and Blastocystis species and subtypes was carried out by amplification and sequencing of a partial fragment of the small-subunit ribosomal RNA gene of both protozoan. Analyses of risk factors potentially associated with the transmission of these pathogens were also conducted.
RESULTS
Prevalences of S. stercoralis, G. duodenalis, Cryptosporidium spp., and Blastocystis spp. were estimated at 21.4% (95% CI: 17.1-25.7%), 37.9% (95% CI: 32.8-43.0%), 2.9% (95% CI: 1.1-4.5%) and 25.6% (95% CI: 21.18-30.2%), respectively. Overall, 64.1% (225/351) of the children were infected by at least one of the pathogens investigated. Sequence analyses of the 28 G. duodenalis isolates that were successfully genotyped allowed the identification of sub-assemblages AI (14.3%), AII (14.3%), BIII (7.1%) and BIV (25.0%). Discordant typing results AII/AIII and BIII/BIV were identified in 7.1% and 14.3% of the isolates, respectively. A total of five additional isolates (17.9%) were identified as assemblage B. Three Cryptosporidium species including C. hominis (70%), C. parvum (20%) and C. canis (10%) were found circulating in the children population under study. A total of 75 Blastocystis isolates were assigned to the subtypes ST1 (30.7%), ST2 (30.7%), ST3 (36.0%), ST5 (1.3%) and ST7 (1.3%), respectively. Children younger than seven years of age had significantly higher risk of infections by protozoan enteropathogens (PRR: 1.35, P < 0.01), whereas being underweight seemed to have a protective effect against these infections (PRR: 0.74, P = 0.005).
CONCLUSIONS
The burden of disease attributable to human strongyloidiasis, giardiosis, cryptosporidiosis and blastocystosis in Angola is considerably higher than initially estimated in previous surveys. Surveillance and control of these infections should be jointly tackled with formally considered neglected tropical diseases in order to maximize effort and available resources. Our data also demonstrate the added value of using molecular diagnostic methods in high transmission areas.
Topics: Adolescent; Animals; Blastocystis; Blastocystis Infections; Child; Child, Preschool; Cross-Sectional Studies; Cryptosporidiosis; Cryptosporidium; Feces; Female; Genetic Variation; Genotype; Giardia lamblia; Giardiasis; Humans; Male; Parasitic Diseases; Prevalence; Real-Time Polymerase Chain Reaction; Risk Factors; Schools; Strongyloides stercoralis; Strongyloidiasis
PubMed: 29378626
DOI: 10.1186/s13071-018-2640-z -
Revista Espanola de Enfermedades... Feb 2023We herein report a case of ulcerative colitis (UC) exacerbated by strongyloidiasis. Parasites including Strongyloides stercoralis and Entamoeba histolytica can cause...
We herein report a case of ulcerative colitis (UC) exacerbated by strongyloidiasis. Parasites including Strongyloides stercoralis and Entamoeba histolytica can cause chronic gastrointestinal inflammation and long-lasting symptoms resembling UC. On the other hand, it is not well-known that such organisms can trigger the exacerbation of pre-existing UC. We would like to highlight the importance of recognition of strongyloidiasis in the management of UC patients who have lived in or migrated from endemic regions, such as Asia, Africa, and South America.
Topics: Animals; Humans; Strongyloidiasis; Colitis, Ulcerative; Strongyloides stercoralis; Inflammation
PubMed: 35815784
DOI: 10.17235/reed.2022.9044/2022 -
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