A Practical Approach to Screening for Strongyloides stercoralis

Strongyloides stercoralis, causative agent of a neglected tropical disease, is a soil-transmitted helminth which may cause lifelong persisting infection due to continuous autoinfection. In the case of immunosuppression, life-threatening hyperinfection and disseminated strongyloidiasis can develop. We propose a pragmatic screening algorithm for latent strongyloidiasis based on epidemiologic exposure and immunosuppression status that can be applied for any kind of immunosuppressive therapy. The algorithm allows the diagnosis of latent strongyloidiasis with optimal accuracy in a well-equipped setting, while for endemic settings where the complete testing array is unavailable, an empiric treatment is generally recommended. Accurate diagnosis and extensive empiric treatment will both contribute to decreasing the current neglect of strongyloidiasis.

Disseminated Strongyloides Stercoralis Hyperinfection in An Immunocompetent Patient First Diagnosed by Metagenomic Next-Generation Sequencing in Cerebrospinal Fluid: A Case Report

Background Disseminated Strongyloides stercoralis hyperinfection is rarely described in immunocompetent individuals and can lead to fatal outcomes if not recognized and diagnosed early. Non-specific clinical manifestations, such as pneumonia and gastroenteritis, pose a diagnostic dilemma. Case presentation: We report a case of a 67-year-old Chinese male who presented with two months of abdominal pain, fever, headache, vomiting, constipation, and slight cough with sputum. He had been in good health and had no history of glucocorticoid use. He was diagnosed with enterococcal meningitis and intestinal obstruction at a local hospital and improved after treatment with vancomycin, but symptoms of headache and abdominal pain soon recurred. The metagenomic next-generation sequencing (mNGS) of the cerebrospinal fluid using Illumina X10 sequencer revealed 7 sequence reads matching Strongyloides stercoralis. Disseminated strongyloidiasis was suspected. Next, microscopic examination of gastric fluid revealed Larvae of S. stercoralis. DNA extracted of larvae, the presence of both S. stercoralis ribosomal DNA gene and mitochondrial cytochrome c oxidase subunit 1 gene was identified. Disseminated strongyloidiasis was diagnosed. Albendazole (400 mg, twice daily) was used and the patient recovered gradually. Conclusions S. stercoralis hyperinfection can occur in immunocompetent individuals, imposing challenges for diagnosis. mNGS may be a useful tool for detecting rare infectious disease. The case would help clinicians to raise awareness of strongyloidiasis in non-endemic areas and reduce fatality.

Fatal Multiorgan Failure Syndrome in a Strongyloides-HTLV-1 Coinfected Patient, after Treatment with Ivermectin

Because of its characteristic features of autoinfection, the parasitic nematode Strongyloides stercoralis can infect patients for years. An acceleration of its autoinfective cycle can be triggered by human T-lymphotropic virus-1 (HTLV-1) infection, mainly by the deviation of the protective Th2- to Th1-type immune response and can lead to severe disease by dissemination of Strongyloides stercoralis larvae carrying intestinal bacteria to multiple organs. Meningitis caused by enteric Gram-negative bacteria is a potentially fatal complication of disseminated strongyloidiasis. Herein, we present the case of a Strongyloides-HTLV-1 coinfected patient, admitted for E. coli meningitis. One day after initiation of ivermectin, the patient developed significant S. stercoralis dissemination, complicated by multiorgan failure syndrome, and died from neurological failure. While the initial clinical scenario of our case has already been well described in the literature, its course after antihelminthic treatment initiation remains unclear and needs to be discussed.

Disseminated Strongyloides Stercoralis Hyperinfection in an Immunocompetent Patient First Diagnosed by Metagenomic Next-generation Sequencing in Cerebrospinal Fluid: a Case Report

Background: Disseminated Strongyloides stercoralis hyperinfection is rarely described in immunocompetent individuals and can lead to fatal outcomes if not recognized and diagnosed early. Non-specific clinical manifestations, such as pneumonia and gastroenteritis, pose a diagnostic dilemma. Case presentation: We report a case of a 67-year-old Chinese male who presented with two months of abdominal pain, fever, headache, vomiting, constipation, and slight cough with sputum. He had been in good health and had no history of glucocorticoid use. He was diagnosed with enterococcal meningitis and intestinal obstruction at a local hospital and improved after treatment with vancomycin, but symptoms of headache and abdominal pain soon recurred. The metagenomic next-generation sequencing (mNGS) of the cerebrospinal fluid using Illumina X10 sequencer revealed 7 sequence reads matching Strongyloides stercoralis. Disseminated strongyloidiasis was suspected. Next, microscopic examination of gastric fluid revealed Larvae of S. stercoralis. DNA extracted of larvae, the presence of both S. stercoralis ribosomal DNA gene and mitochondrial cytochrome c oxidase subunit 1 gene was identified. Disseminated strongyloidiasis was diagnosed. Albendazole (400 mg, twice daily) was used and the patient recovered gradually.Conclusions: S. stercoralis hyperinfection can occur in immunocompetent individuals, imposing challenges for diagnosis. mNGS may be a useful tool for detecting rare infectious disease. The case would help clinicians to raise awareness of strongyloidiasis in non-endemic areas and reduce fatality.

A fatal combination of disseminated strongyloidiasis with two bacterial infections in an immunocompromised host

Introduction. Strongyloides stercoralis is an intestinal nematode that is endemic in tropical countries. It can have a variable presentation ranging from asymptomatic eosinophilia in immunocompetent hosts to disseminated disease with sepsis in immunocompromised hosts. Case report. We report a case of chronic diarrhoea and decreased appetite in a 53-year-old man. He was a chronic alcoholic with diabetes, hypertension and dyslipidaemia and had earlier been treated for pulmonary tuberculosis. He was treated symptomatically for loose stools at a primary health care facility without relief. Following referral to our tertiary care centre, microscopic examination of the stool showed numerous larvae and a few eggs of Strongyloides stercoralis. Additionally, Aeromonas sobria was isolated from stool culture. The patient was discharged following improvement with a combination therapy of ivermectin, albendazole and ciprofloxacin. However, within 3 days, he was readmitted and succumbed to Escherichia coli sepsis. Conclusion. Strongyloidiasis can be diagnosed easily using a very simple but often neglected investigation, namely stool microscopy. This provides an early diagnosis, based on which prompt treatment with the appropriate antihelminthics can be started, thereby reducing the probability of disseminated infection. Disseminated strongyloidiasis is a medical emergency with a poor prognosis, especially in an immunocompromised state. Such patients should be treated aggressively with antihelminthics. They must be monitored for sufficient duration in the hospital for early signs of complication. Their discharge from hospital should be planned based on a negative stool microscopy report in addition to clinical improvement, so as to decrease the mortality reported for both untreated and treated individuals.