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Clinical Infectious Diseases : An... Dec 2020Strongyloidiasis can cause devastating morbidity and death in immunosuppressed patients. Identification of reliable biomarkers for strongyloidiasis in immunosuppressed...
BACKGROUND
Strongyloidiasis can cause devastating morbidity and death in immunosuppressed patients. Identification of reliable biomarkers for strongyloidiasis in immunosuppressed patients is critical for the prevention of severe disease.
METHODS
In this cross-sectional study of solid organ transplant (SOT) candidates and recipients, we quantified Strongyloides-specific IgG to the recombinant NIE-Strongyloides antigen and/or to a soluble extract of S. stercoralis somatic antigens ("crude antigen") using enzyme-linked immunosorbent assays (ELISAs). We also measured peripheral eosinophilia, 4 different eosinophil granule proteins, and intestinal fatty acid-binding protein (IFABP).
RESULTS
We evaluated serum biomarkers in 149 individuals; 77 (52%) pre-SOT and 72 (48%) post-SOT. Four percent (6/149) tested positive by NIE ELISA and 9.6% (11/114) by crude antigen ELISA (overall seropositivity of 9.4% [14/149]). Seropositive patients had higher absolute eosinophil counts (AECs) than seronegative patients (P = .004). AEC was positively correlated to the levels of eosinophil granule proteins eosinophil cationic protein (ECP) and eosinophil peroxidase (EPO) (P < .05), while IFABP was positively related to the 2 other eosinophil granule proteins (major basic protein [MBP] and eosinophil-derived neurotoxin [EDN]; Spearman's r = 0.3090 and 0.3778, respectively; P < .05; multivariate analyses slopes = 0.70 and 2.83, respectively).
CONCLUSIONS
This study suggests that, in SOT patients, strongyloidiasis triggers both eosinophilia and eosinophil activation, the latter being associated with intestinal inflammation. These data provide insight into the pathogenesis of S. stercoralis infection in the immunocompromised population at high risk of severe strongyloidiasis syndromes.
Topics: Animals; Cross-Sectional Studies; Eosinophils; Humans; Inflammation; Organ Transplantation; Strongyloides stercoralis; Strongyloidiasis
PubMed: 32155244
DOI: 10.1093/cid/ciaa233 -
Medicine Sep 2022Strongyloidiasis is a parasitic disease caused by Strongyloides stercoralis. The clinical presentation varies according to the stage of infection. Diagnosing...
RATIONALE
Strongyloidiasis is a parasitic disease caused by Strongyloides stercoralis. The clinical presentation varies according to the stage of infection. Diagnosing strongyloidiasis is a challenge in clinical practice due to the inconsistency of eosinophilia and the low sensitivity of standard microscopic stool examination. Strongyloides infection presenting with shock is rare.
PATIENT CONCERNS
In this case, the condition of a 77-year-old immunocompromised patient with intermittent diarrhea progressed to shock and hypoalbuminemia. Reviewing her medical records, we learned that she had experienced intermittent peripheral eosinophilia during the past 10 months. Although a series of examinations were done, the disease progressed and the diagnosis remained uncertain.
DIAGNOSIS
Using standard microscopic stool examination and gastroduodenscopy with biopsy, a diagnosis of strongyloidiasis was made.
INTERVENTIONS
After the diagnosis of strongyloidiasis was made, 2 courses of ivermectin were administered.
OUTCOMES
The patient recovered uneventfully after treatment and there is no recurrence of eosinophilia in 1 year follow-up.
LESSONS
This report provides a brief review of the current modalities used for diagnosing strongyloidiasis. It emphasizes the low sensitivity of microscopic examination, and highlights the role of gastroduodenoscopy in the diagnosis of strongyloidiasis. This report also assures that patients with strongyloidiasis have a good prognosis when they are treated timely and appropriately.
Topics: Aged; Animals; Eosinophilia; Female; Humans; Immunocompromised Host; Ivermectin; Shock; Strongyloides stercoralis; Strongyloidiasis
PubMed: 36107578
DOI: 10.1097/MD.0000000000030490 -
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 -
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 -
Biomedica : Revista Del Instituto... Mar 2022Individuals infected with the human T-lymphotropic virus type 1 (HTLV-1) may present severe and disseminated forms of Strongyloides stercoralis infection with low...
INTRODUCTION
Individuals infected with the human T-lymphotropic virus type 1 (HTLV-1) may present severe and disseminated forms of Strongyloides stercoralis infection with low therapeutic response.
OBJECTIVE
To investigate the S. stercoralis infection and the seroprevalence of IgG anti-S. stercoralis antibodies in individuals infected with HTLV-1 attending the Reference Center for HTLV-1 (CHTLV) in Salvador, Bahia, Brazil.
MATERIALS AND METHODS
We conducted a cross-sectional study in 178 HTLV-1-infected individuals treated at the HTLV specialized center between January, 2014, and December, 2018. The parasitological diagnosis of S. stercoralis was performed using the Hoffman, Pons and Janer, agar plate culture, and Baermann-Morais methods. The IgG anti-S. stercoralis detection was performed using an in house enzyme-linked immunosorbent assay (ELISA). The HTLV-1 infection was diagnosed using a commercial ELISA and confirmed by Western blot.
RESULTS
The frequency of S. stercoralis infection was 3.4% (6/178). Individuals infected with S. stercoralis from rural areas (50.0%; 3/6) also showed S. stercoralis hyperinfection (>3,000 larvae/gram of feces). The frequency of circulating anti-S. stercoralis IgG antibodies was 20.8% (37/178).
CONCLUSIONS
HTLV-1-infected people living in precarious sanitary conditions are more prone to develop severe forms of S. stercoralis infection. Considering the high susceptibility and unfavorable outcome of the infection in these individuals, the serological diagnosis for S. stercoralis should be considered when providing treatment.
Topics: Animals; Cross-Sectional Studies; Human T-lymphotropic virus 1; Humans; Immunoglobulin G; Seroepidemiologic Studies; Strongyloides stercoralis; Strongyloidiasis
PubMed: 35471168
DOI: 10.7705/biomedica.5888 -
World Journal of Gastroenterology Sep 2017Animal models and clinical studies have shown that helminth infections exert immunomodulatory activity, altering intestinal permeability and providing a potential...
Animal models and clinical studies have shown that helminth infections exert immunomodulatory activity, altering intestinal permeability and providing a potential beneficial action on autoimmune and inflammatory disorders in human beings, such as inflammatory bowel disease (IBD) and celiac disease. This is consistent with the theory that intestinal microbiota is responsible for shaping human immunological responses. With the arrival of the immunobiologic era and the use of antibodies, we propose a distinctive pathway for treating patients with IBD and celiac disease. We have some evidence about the safety and tolerability of helminth use, but evidence about their impact on disease activity is lacking. Using worms to treat diseases could be a possible way to lower treatment costs, since the era of immunobiologic agents is responsible for a significant rise in expenses. Some questions remain to be investigated regarding the use of helminths in intestinal disease, such as the importance of the specific species of helminths used, appropriate dosing regimens, optimal timing of treatment, the role of host genetics, diet, environment, and the elucidation of the exact mechanisms of action. One promising approach is the use of helminth-derived anti-inflammatory molecules as drugs. Yet there are still many challenges with this method, especially with regard to safety. Studies on intestinal permeability point to as a useful nematode for these purposes.
Topics: Animals; Biological Products; Biological Therapy; Celiac Disease; Clinical Trials as Topic; Complementary Therapies; Humans; Hygiene Hypothesis; Immunotherapy; Inflammatory Bowel Diseases; Intestinal Mucosa; Permeability; Strongyloides stercoralis; Treatment Outcome
PubMed: 28970717
DOI: 10.3748/wjg.v23.i33.6009 -
Parasite Immunology 2004Strongyloides stercoralis is the most common human parasitic nematode that is able to complete a life cycle and proliferate within its host. The majority of patients... (Review)
Review
Strongyloides stercoralis is the most common human parasitic nematode that is able to complete a life cycle and proliferate within its host. The majority of patients with strongyloidiasis have an asymptomatic infection or mild disease. However, when autoinfection occurs, a high number of infecting larvae can gain access to the bloodstream by penetrating the colonic mucosa leading to a severe hyperinfection and the development of disseminated strongyloidiasis. The human T cell lymphotropic virus type 1 (HTLV-1) predominantly infects T cells and induces spontaneous lymphocyte proliferation and secretion of high levels of type 1 cytokines. Strongyloides stercoralis patients with HTLV-1 co-infection have a modified immunological responses against parasite antigens and co-infection has clinical implications for strongyloidiasis. The high production of IFN-gamma observed in patients co-infected with HTLV-1 and Strongyloides stercoralis decreases the production of IL-4, IL-5, IL-13 and IgE, molecules that participate in the host defence mechanism against helminths. Moreover, there is a decrease in the efficacy of treatment of Strongyloides stercoralis in patients co-infected with HTLV-1. Alterations in the immune response against Strongyloides stercoralis and the decrease in the efficacy of anti-parasitic drugs are responsible for the increased prevalence of Strongyloides stercoralis among HTLV-1 infected subjects and make HTLV-1 infection the most important risk factor for disseminated strongyloidiasis.
Topics: Animals; HTLV-I Infections; Human T-lymphotropic virus 1; Humans; Strongyloides stercoralis; Strongyloidiasis
PubMed: 15771684
DOI: 10.1111/j.0141-9838.2004.00726.x -
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 -
The American Journal of Tropical... Oct 2017is widely distributed in the tropics and subtropics. The aim of this study was to determine the prevalence of and other intestinal parasites and identify the risk...
is widely distributed in the tropics and subtropics. The aim of this study was to determine the prevalence of and other intestinal parasites and identify the risk factors for infection with in a rural area of Angola. A cross-sectional study was conducted in school-age children (SAC) in Cubal, Angola. A questionnaire collecting clinical and epidemiological variables was used, and two stool samples were collected. A concentration technique (Ritchie) and a technique for detection of larvae migration (Baermann) were performed. Of 230 SAC, 56.1% were female and the mean age was 9.3 years (SD 2.45). Severe malnutrition, according to body mass index (BMI)-for-age, was observed in 20.4% of the SAC, and anemia was found in 59.6%. was observed in 28 of the 230 (12.8%) SAC. Eggs of other helminths were observed in 51 (22.2%) students: spp. in 27 students (11.7%), hookworm in 14 (6.1%), four (1.7%), in four (1.7%), in three (1.3%), spp. in two (0.9%), and one (0.4%). Protozoa were observed in 17 (7.4%) students. Detection of was higher using the Baermann technique versus using formol-ether (11.3 vs. 3%). Overall prevalence of in the school population of 16 studied schools in the municipal area of Cubal was greater than 10%. This fact must be considered when designing deworming mass campaigns. The use of specific tests in larvae detection is needed to avoid overlooking this parasite.
Topics: Angola; Animals; Child; Cross-Sectional Studies; Feces; Female; Humans; Intestinal Diseases, Parasitic; Male; Parasite Egg Count; Prevalence; Risk Factors; Rural Population; Strongyloides stercoralis; Strongyloidiasis
PubMed: 28820707
DOI: 10.4269/ajtmh.17-0159 -
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