Case Report: Challenges for the Diagnosis and Treatment of Strongyloides stercoralis in Chronic Obstructive Pulmonary Disease Patients.

Strongyloidiasis, a neglected tropical disease (NTD), which is caused by Strongyloides stercoralis, can be fatal in immunocompromised patients. In most chronic cases, infections most frequently are asymptomatic, and eosinophilia might be the only clinical characteristic of this disease. The use of corticosteroids in some diseases like chronic obstructive pulmonary disease (COPD) may lead to the development of the life-threatening S. stercoralis hyperinfection syndrome. In the present research, we presented five cases of strongyloidiasis with a history of COPD and receiving corticosteroids from Abadan County, southwestern Iran. By performing the direct smear stool examinations, two cases were identified and the other three cases were diagnosed using the agar plate culture method. Despite reporting eosinophilia in previous patients' hospitalizations, the fecal examination was not performed for parasitic infections. Moreover, pulmonary symptoms were similar, but gastrointestinal symptoms were varied, including nausea, vomiting, abdominal pain, epigastric pain, constipation, and diarrhea. All the included patients were treated with albendazole, which is the second-line drug for S. stercoralis, and relapse of infection was observed in two patients by passing few months from the treatment. The increased blood eosinophil count was shown to play important roles in both the management of COPD and diagnosis of helminthic infections. In COPD patients who are receiving steroids, screening and follow-up for strongyloidiasis should be considered as priorities. In addition, ivermectin, which is the first-line drug for strongyloidiasis, should be available in the region.

Strongyloidiasis duodenum: A histopathological study.

Strongyloides stercoralis is an intestinal nematode that infects humans, percutaneously and has a complex life cycle. We report a case of a thirty year old male presenting with chief complaints of profuse watery diarrhoea, abdominal fullness, loss of appetite, creepy abdominal pain and low-grade fever for the last one month. He was on corticosteroids for systemic sclerosis. Endoscopy showed thickened and oedematous duodenal folds with pinpoint areas of bleeding and multiple ulcerations on the duodenal mucosa. Histopathologial examination of duodenal biopsy revealed infestation by Strongyloides stercoralis in the duodenum, the duodenal mucosal glands were occupied by various parts of parasite. The patient was successfully treated and had uneventful recovery.

Case Report: Disseminated Strongyloidiasis in a Patient with COVID-19.

The SARS-CoV-2 virus has emerged and rapidly evolved into a current global pandemic. Although bacterial and fungal coinfections have been associated with COVID-19, little is known about parasitic infection. We report a case of a COVID-19 patient who developed disseminated strongyloidiasis following treatment with high-dose corticosteroids and tocilizumab. Screening for Strongyloides infection should be pursued in individuals with COVID-19 who originate from endemic regions before initiating immunosuppressive therapy.

Chemosensory mechanisms of host seeking and infectivity in skin-penetrating nematodes.

Approximately 800 million people worldwide are infected with one or more species of skin-penetrating nematodes. These parasites persist in the environment as developmentally arrested third-stage infective larvae (iL3s) that navigate toward host-emitted cues, contact host skin, and penetrate the skin. iL3s then reinitiate development inside the host in response to sensory cues, a process called activation. Here, we investigate how chemosensation drives host seeking and activation in skin-penetrating nematodes. We show that the olfactory preferences of iL3s are categorically different from those of free-living adults, which may restrict host seeking to iL3s. The human-parasitic threadworm Strongyloides stercoralis and hookworm Ancylostoma ceylanicum have highly dissimilar olfactory preferences, suggesting that these two species may use distinct strategies to target humans. CRISPR/Cas9-mediated mutagenesis of the S. stercoralis tax-4 gene abolishes iL3 attraction to a host-emitted odorant and prevents activation. Our results suggest an important role for chemosensation in iL3 host seeking and infectivity and provide insight into the molecular mechanisms that underlie these processes.

The Strongyloides stercoralis-hookworms association as a path to the estimation of the global burden of strongyloidiasis: A systematic review.

TRIAL REGISTRATION: PROSPERO (registration code CRD42019131127).

Fatty acid and retinol-binding protein: A novel antigen for immunodiagnosis of human strongyloidiasis.

The tenacious human parasitic helminth Strongyloides stercoralis is a significant health problem worldwide. The current lack of a definitive diagnostic laboratory test to rule out this infection necessitates designing more specific diagnostic methods. Fatty acid and retinol-binding protein (FAR) plays a crucial role in the development and reproduction of nematodes. We generated a recombinant form of this protein and determined its applicability for immunodiagnosis of S. stercoralis. The L3 form of S. stercoralis was harvested and used for RNA extraction and cDNA synthesis. The coding sequence of S. stercoralis FAR (SsFAR) was cloned into pET28a(+) vector, expressed in E. coli BL21 and purified. ELISA and immunoblotting were employed to determine the specificity and sensitivity of rSsFAR using a set of defined sera. In addition, we analyzed the phylogenetic relationship of SsFAR with different FAR sequences from other nematodes. The cloned SsFAR had an open reading frame of 447 bp encoding 147 amino acids, with a deduced molecular mass of 19 kD. The SsFAR amino acid sequence was 93% identical to FAR of S. ratti. For differential immunodiagnosis of strongyloidiasis, rSsFAR exhibited 100% sensitivity and 97% specificity. However, cross-reactivity with FAR proteins of other parasites, namely Toxocara canis and Echinococcus granulosus, was noted. Our results provide a novel approach for immunodiagnosis of S. stercoralis infections using rSsFAR with reliable sensitivity and specificity.

Strongyloides spp. in cats: a review of the literature and the first report of zoonotic Strongyloides stercoralis in colonic epithelial nodular hyperplasia in cats.

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.

Microfilaria and Strongyloides larva diagnosed in cerebrospinal fluid and ascitic fluid, respectively: Approach to their morphology on cytology.

Filariasis and Strongyloidiasis are two endemic parasitic infections seen in any tropical country. Filariasis, commonly caused by Wuchereria bancrofti, Brugia malayi, and Brugia timori is seen often in peripheral blood and lymphoid tissue. But it can be isolated from wide variety of soft tissue sites in the body like soft tissue lumps, breast, thyroid, body fluids. Strongyloides stercoralis, a helminthic infection, usually affects the respiratory and gastrointestinal (GI) tract, and frequently picked up in GI biopsies. However, in cases of hyper infection and patients with altered immunity, it can be isolated from other rare sites like body fluid samples. Accurate morphological Identification and confirmation are important for specific management. We report a case of microfilaria isolated from cerebrospinal fluid and a case of Strongyloides larva isolated from ascitic fluid in clinically unsuspected cases of these two parasitic infestations. We have also added a brief discussion on morphological differences between the two larval forms.

[Strongyloides hyperinfection in patient from Patagonia with HTLV-1 co-infection]. / Hiperinfección por Strongyloides en paciente de la Patagonia con co-infección por HTLV-1.

Strongylodiasis is an unattended condition caused by the parasite Strongyloides stercoralis. The Strongyloides hyperinfection syndrome can develop in immunosuppressed hosts, mainly in those with depression of cellular immunity. Co-infection with human T-cell lymphotropic virus (HTLV) is a risk factor for the development of severe forms of strongyloidiasis. We present the case of a 50-year-old man with Strongyloides hyperinfection and coinfection with HTLV. The diagnosis was delayed owing to its unusual epidemiology and an initial suspicion of inflammatory bowel disease. Identification of the parasite in bronchioalveolar lavage and duodenal and colonic mucosa biopsies confirmed the diagnosis. Subcutaneous ivermectin was used as an anthelmintic treatment with an adequate therapeutic response.

La estrongiloidiasis es una afección desatendida causada por el parásito Strongyloides stercoralis. En los individuos inmunosuprimidos, fundamentalmente en los que tienen depresión de la inmunidad celular, puede desarrollarse el síndrome de hiperinfección por Strongyloides. La coinfección con virus linfotrópico de células T humanas (HTLV) es un factor de riesgo para el desarrollo de formas graves de estrongiloidiasis. Presentamos el caso de un hombre de 50 años con hiperinfección por Strongyloides y coinfección con HTLV. Se demoró el diagnóstico debido a su epidemiología inusual y a la sospecha inicial de enfermedad inflamatoria intestinal. El diagnóstico se confirmó mediante la identificación del parásito en muestras de lavado bronquio-alveolar y biopsias de mucosa duodenal y colónica. Se utilizó ivermectina subcutánea como tratamiento antihelmíntico con adecuada respuesta terapéutica.

Morbidity Associated with Chronic Strongyloides stercoralis Infection: A Systematic Review and Meta-Analysis.

Strongyloides stercoralis, a worldwide-distributed soil-transmitted helminth, causes chronic infection which may be life threatening. Limitations of diagnostic tests and nonspecificity of symptoms have hampered the estimation of the global morbidity due to strongyloidiasis. This work aimed at assessing S. stercoralis-associated morbidity through a systematic review and meta-analysis of the available literature. MEDLINE, Embase, CENTRAL, LILACS, and trial registries (WHO portal) were searched. The study quality was assessed using the Newcastle-Ottawa scale. Odds ratios (ORs) of the association between symptoms and infection status and frequency of infection-associated symptoms were calculated. Six articles from five countries, including 6,014 individuals, were included in the meta-analysis-three were of low quality, one of high quality, and two of very high quality. Abdominal pain (OR 1.74 [CI 1.07-2.94]), diarrhea (OR 1.66 [CI 1.09-2.55]), and urticaria (OR 1.73 [CI 1.22-2.44]) were associated with infection. In 17 eligible studies, these symptoms were reported by a large proportion of the individuals with strongyloidiasis-abdominal pain by 53.1% individuals, diarrhea by 41.6%, and urticaria by 27.8%. After removing the low-quality studies, urticaria remained the only symptom significantly associated with S. stercoralis infection (OR 1.42 [CI 1.24-1.61]). Limitations of evidence included the low number and quality of studies. Our findings especially highlight the appalling knowledge gap about clinical manifestations of this common yet neglected soil-transmitted helminthiasis. Further studies focusing on morbidity and risk factors for dissemination and mortality due to strongyloidiasis are absolutely needed to quantify the burden of S. stercoralis infection and inform public health policies.

Hiperinfección por Strongyloides en paciente de la Patagonia con co-infección por HTLV-1 / Strongyloides hyperinfection in patient from Patagonia with HTLV-1 co-infection

La estrongiloidiasis es una afección desatendida causada por el parásito Strongyloides stercoralis. En los individuos inmunosuprimidos, fundamentalmente en los que tienen depresión de la inmunidad celular, puede desarrollarse el síndrome de hiperinfección por Strongyloides. La coinfección con virus linfotrópico de células T humanas (HTLV) es un factor de riesgo para el desarrollo de formas graves de estrongiloidiasis. Presentamos el caso de un hombre de 50 años con hiperinfección por Strongyloides y coinfección con HTLV. Se demoró el diagnóstico debido a su epidemiología inusual y a la sospecha inicial de enfermedad inflamatoria intestinal. El diagnóstico se confirmó mediante la identificación del parásito en muestras de lavado bronquio-alveolar y biopsias de mucosa duodenal y colónica. Se utilizó ivermectina subcutánea como tratamiento antihelmíntico con adecuada respuesta terapéutica.

Strongylodiasis is an unattended condition caused by the parasite Strongyloides stercoralis. The Strongyloides hyperinfection syndrome can develop in immunosuppressed hosts, mainly in those with depression of cellular immunity. Co-infection with human T-cell lymphotropic virus (HTLV) is a risk factor for the development of severe forms of strongyloidiasis. We present the case of a 50-year-old man with Strongyloides hyperinfection and coinfection with HTLV. The diagnosis was delayed owing to its unusual epidemiology and an initial suspicion of inflammatory bowel disease. Identification of the parasite in bronchioalveolar lavage and duodenal and colonic mucosa biopsies confirmed the diagnosis. Subcutaneous ivermectin was used as an anthelmintic treatment with an adequate therapeutic response.

Lethal strongyloidiasis - Diagnostic and forensic issues.

Strongyloidiasis is an infectious disease affecting approximately 30-100 million people globally. The main human pathogen is Strongyloides stercoralis which may cause a brief period of acute symptoms and signs after the initial infection, and then lapse into a chronic asymptomatic carrier state for decades due to the nematode's unique ability to autoinfect hosts. Immunosuppression from steroid therapy, T-lymphocytic viral (HTLV-1) infections, or a variety of underlying medical conditions may then result in dissemination and the highly lethal and infectious hyperinfection syndrome. Clinical suspicions for the condition are often not high in non-endemic areas, the diagnosis is difficult, and the incidence is increasing, particularly given recent mass population movements. Indications of infection at autopsy include gastrointestinal ulceration and haemorrhage, with pulmonary oedema, congestion, haemorrhage and diffuse alveolar damage.

A Cross-Sectional Study on Intestinal Parasitic Infections in Children in Suburban Public Primary Schools, Saraburi, the Central Region of Thailand.

Intestinal parasitic infection rate among school-aged children in Thailand has been decreasing. However, certain intestinal parasites remain problematic in some regions. This cross-sectional study was conducted between February and September 2016 in three suburban government primary schools (KK, BR, and HK), Saraburi, Thailand. Stool was collected from 263 asymptomatic subjects (4-15 years old), using simple direct smear, formalin-ether concentration, Boeck and Drbohlav's Locke-Egg-Serum (LES) medium culture, and agar plate culture. A self-administered questionnaire was used to collect data about lifestyle and socioeconomic status. The overall rate of intestinal parasites was 22.1% (15.6% single infection and 6.5% multiple infections). The helminths involving the digestive system found were Strongyloides stercoralis (1.5%) and Opisthorchis viverrini (0.4%). For protozoan infection, the major cause was Blastocystis hominis (17.5%). The other protozoa included Endolimax nana (4.6%), Entamoeba coli (3.4%), Entamoeba histolytica/Entamoeba dispar (1.1%), and Giardia intestinalis (0.8%). The sensitivity for the detection of B. hominis increased with the LES culture technique. The infection rate of each organism was not significantly different among the three schools except for B. hominis which showed the highest prevalence in the HK school (P = 0.001). This was correlated with the questionnaire results in which the HK school showed the highest risk of drinking contaminated water (P = 0.004). The present study emphasized the persistent problems of protozoan infections among suburban school-aged children. Lifestyle was still an important factor for intestinal parasitic infections among suburban school-aged Thai children in this study. Health education as well as routine surveillance was necessary to control the infections.

The relationship between treatment for Strongyloides stercoralis infection and type 2 diabetes mellitus in an Australian Aboriginal population: A three-year cohort study.

AIM: To determine the effect of treatment for Strongyloides stercoralis infection on type 2 diabetes mellitus in an Australian Aboriginal population. METHODS: A three-year cohort study of 259 Aboriginal adults living in northern Australia. Subjects were tested for S. stercoralis infection, diabetic status and HbA1c at recruitment. 92 subjects were ELISA positive for S. stercoralis and 91 were treated with two doses of ivermectin 0.2mg/kg. Serological cure was assessed after 6months and those who remained positive were retreated. All subjects then underwent the same testing at 3years follow up. RESULTS: Follow up was successful in 80% of subjects. Eight new cases of T2DM were recorded, 7 in the treatment group and 1 in the non-treatment group (Unadjusted RR 7.71, CI 0.98-60.48, p=0.052. Adjusted RR 5.45, CI 075-35.92, p=0.093). In addition, worsening glycemic control (T2DM or newly diagnosed glucose intolerance) was recorded in 13 cases (10 treatment group, 3 non treatment. Adjusted RR 3.74, CI 1.06-13.20, p=0.04). There was a significant improvement in glycemic control in the patients with pre-existing T2DM when treated for S. stercoralis compared to the non-treatment group (Diff. -1.03, p=0.009). CONCLUSION: This study demonstrated a differential effect of treatment for S. stercoralis on glucose metabolism in patients with and without T2DM. It showed a significant effect on the development of T2DM and glucose intolerance in those without T2DM, while improving glycemic control in subjects with pre-existing T2DM. Although numbers in this study are small, it suggests that larger studies may be of interest.

Strongyloides stercoralis in solid organ transplantation: early diagnosis gets the worm.

PURPOSE OF REVIEW: Strongyloidiasis is a parasitic infection affecting millions of people worldwide. Complications of infection are strongly associated with alcoholism, immunosuppression, and organ transplantation. Delayed diagnosis results in hyperinfection syndrome and disseminated strongyloidiasis leading to mortality rates approaching 80%. Early detection, and prevention of infection and transmission are key to diminish this illness. RECENT FINDINGS: In this review, we cover the basic concepts in immunity, immunosuppression, and disorder necessary for understanding the infectious syndromes associated with Strongyloides stercoralis infection. Focused discussion on donor-derived transmission and recipient risk in solid organ transplantation is presented. Current methodology for diagnosis, screening algorithms, and treatment are also reviewed. SUMMARY: Strongyloidiasis complicated by hyperinfection and dissemination remains associated with a poor outcome. The poor outcome pleads for a high level of suspicion and aggressive treatment in at-risk patients. As the population of transplant patients continues to increase, the risk of infection also increases, compelling us to address this highly fatal infectious complication in solid organ transplantation (SOT). Here we review the pathology, immunology, diagnosis, and treatment of strongyloides infection in the immunosuppressed SOT population.

Pulmonary strongyloidiasis: assessment between manifestation and radiological findings in 16 severe strongyloidiasis cases.

BACKGROUND: Strongyloidiasis is a chronic parasitic infection caused by Strongyloides stercoralis. Severe cases such as, hyperinfection syndrome (HS) and disseminated strongyloidiasis (DS), can involve pulmonary manifestations. These manifestations frequently aid the diagnosis of strongyloidiasis. Here, we present the pulmonary manifestations and radiological findings of severe strongyloidiasis. METHODS: From January 2004 to December 2014, all patients diagnosed with severe strongyloidiasis at the University of the Ryukyus Hospital or affiliated hospitals in Okinawa, Japan, were included in this retrospective study. All diagnoses were confirmed by the microscopic or histopathological identification of larvae. Severe strongyloidiasis was defined by the presence of any of the following: 1) the identification of S. stercoralis from extra gastrointestinal specimens, 2) sepsis, 3) meningitis, 4) acute respiratory failure, or 5) respiratory tract hemorrhage. Patients were assigned to either HS or DS. Medical records were further reviewed to extract related clinical features and radiological findings. RESULTS: Sixteen severe strongyloidiasis cases were included. Of those, fifteen cases had pulmonary manifestations, eight had acute respiratory distress syndrome (ARDS) (53%), seven had enteric bacterial pneumonia (46%) and five had pulmonary hemorrhage (33%). Acute respiratory failure was a common indicator for pulmonary manifestation (87%). Chest X-ray findings frequently showed diffuse shadows (71%). Additionally, ileum gas was detected for ten of the sixteen cases in the upper abdomen during assessment with chest X-ray. While, chest CT findings frequently showed ground-glass opacity (GGO) in 89% of patients. Interlobular septal thickening was also frequently shown (67%), always accompanying GGO in upper lobes. CONCLUSIONS: In summary, our study described HS/DS cases with pulmonary manifestations including, ARDS, bacterial pneumonia and pulmonary hemorrhage. Chest X-ray findings in HS/DS cases frequently showed diffuse shadows, and the combination of GGO and interlobular septal thickening in chest CT was common in HS/DS, regardless of accompanying pulmonary manifestations. This CT finding suggests alveolar hemorrhage could be used as a potential marker indicating the transition from latent to symptomatic state. Respiratory specimens are especially useful for detecting larvae in cases of HS/DS.

Genome-Wide Analyses of Individual Strongyloides stercoralis (Nematoda: Rhabditoidea) Provide Insights into Population Structure and Reproductive Life Cycles.

The helminth Strongyloides stercoralis, which is transmitted through soil, infects 30-100 million people worldwide. S. stercoralis reproduces sexually outside the host as well as asexually within the host, which causes a life-long infection. To understand the population structure and transmission patterns of this parasite, we re-sequenced the genomes of 33 individual S. stercoralis nematodes collected in Myanmar (prevalent region) and Japan (non-prevalent region). We utilised a method combining whole genome amplification and next-generation sequencing techniques to detect 298,202 variant positions (0.6% of the genome) compared with the reference genome. Phylogenetic analyses of SNP data revealed an unambiguous geographical separation and sub-populations that correlated with the host geographical origin, particularly for the Myanmar samples. The relatively higher heterozygosity in the genomes of the Japanese samples can possibly be explained by the independent evolution of two haplotypes of diploid genomes through asexual reproduction during the auto-infection cycle, suggesting that analysing heterozygosity is useful and necessary to infer infection history and geographical prevalence.

Estrongiloidiasis crónica y uso prolongado de corticoides / Chronic strongyloidiasis and extended use of corticoids

La infección causada por Strongyloides stercoralis puede permanecer asintomática o con síntomas ligeros en humanos por varios años. Sin embargo, algunos individuos inmunodeprimidos, entre ellos los pacientes tratados con esteroides por tiempo prolongado, pueden presentar hiperinfección con altas tasas de mortalidad. El objetivo es reportar por primera vez en Cuba el caso de una paciente con síntomas de estrongiloidiasis crónica asociada al uso de esteroides orales. Se trata de una paciente de 63 años, asmática con síntomas de estrongiloidiasis crónica y riesgo de hiperinfección por el uso de esteroides orales por tiempo prolongado. Se describen las manifestaciones clínicas y los análisis complementarios. Se discuten los factores predisponentes para la adquisición inicial y el desarrollo de la enfermedad. El laboratorio confirmó la presencia de larvas rabditoides de Strongyloides stercoralis en las heces de la paciente. Aunque existen evidencias de casos fatales de pacientes con strongiloidiasis asociada al uso prolongado de esteroides en la literatura internacional, hay escasez de esos reportes en Cuba. Adicionalmente, es probable que el diagnóstico y el tratamiento oportunos, hayan contribuido a evitar complicaciones fatales en esta paciente(AU)

The infection caused by Strongyloides stercoralis may remain asymptomatic or with slight symptoms in humans for decades. However, immunocompromised patients, particulary those receiving long-term steroid therapy, may face hyperinfection resulting in high mortality rates. The objective was to present the first report in Cuba about a patient with chronic strongyloidiasis associated to use of oral steroids. Here is a 63 years-old asthmatic woman, who showed chronic strongyloidiasis symptoms and hyperinfection risk due to the long-term use of oral steroids. The symptoms and physical examination were described as well as various diagnostic tests. Predisposing factors for the onset and development of the disease were discussed. Laboratory diagnosis confirmed the presence of Strongyloides stercoralis rabditoid larvae in the patient's feces. Although there has been evidence of fatal cases with chronic strongyloidiasis associated with long-term use of steroids in the international literature, such reports are rare in Cuba. Additionally, it is likely that timely diagnosis and treatment have contributed to avoid fatal complications in this patient(AU)