INTRODUCTION:Strongyloidiasis is a parasitic infection caused by the intestinal nematode Strongyloides stercolaris. We report a case of Strongyloides –related septic shock.
CASE PRESENTATION:A 75 year old man with hypertension, diagnosed with dermatomyositis five months prior to the onset of his present illness, using prednisone 20 mg daily since then. The patient presented dysphagia, productive cough, general malaise, lethargy, anorexia and weight loss one week prior to visiting our institution. When seen in emergency he was obtunded, tachypneic and hypotensive with an oxygen saturation by pulse oximetry of 87% while breathing 100% oxygen by face mask. His condition deteriorated requiring mechanical ventilation for imminent hypoxemic respiratory failure. Physical examination revealed diffuse bilateral rhonchi on auscultation and palpable purpurae over the periumbilical area, flanks and buttocks; rest of abdominal examination was unremarkable. Hypotension persisted despite fluid loading, requiring norepinephrine infusion. The initial chest x-ray showed diffuse bilateral airspace disease (Figure 1); initial laboratories included a white blood cell count of 10,800 (40% neutrophils, 37% bands, and 0% eosinophils), hemoglobin of 7.1 g/dL, and platelet count of 265,000 and normal coagulation times. After intubated PIF ratio was 334 mmHg.The patient was admitted to the ICU and empiric treatment with ceftriaxone and azithromycin were started. Because of persistent hypotension he was treated with low doses of hydrocortisone and fludrocortisone. A diagnostic fiberoptic bronchoscopy with bronchoalveolar lavage (BAL) was performed within 24 hours of admission; findings included a friable and erythematous mucosa at the right upper lobe. Gram stains of the BAL fluid reported Strongyloides larvae (Figure 2). Treatment with ivermectin was started. Stool samples for ova and parasites which were initially positive for Strongyloides stercolaris, after 10 days therapy were reported negative for parasites.The patient responded well to treatment. He was extubated on the 16th day of ICU stay and was transferred to internal medicine ward.
DISCUSSIONS:Strongyloides infection begins with skin contact with filariform larvae which migrate hematogenously to the pulmonary circulation. They ascend through the tracheobronchial tree and are swallowed into the gastrointestinal tract. They mature into adult worms and burrow into the intestinal mucosa, where they live for many years. The adult female produces rhabditiform larvae within the lumen of the GI tract which are passed in the feces. This cycle requires approximately several weeks. The parasitic burden may increase during autoinfection, when the rhabditiform larvae mature into the filariform larvae within the gastrointestinal tract. In patients with impaired cell-mediated immunity autoinfection may give rise to the potentially fatal hyperinfection syndrome (HS). Massive dissemination of filariform larvae induces inflammation that may result in multiorgan dysfunction and septic shock.Our patient’s clinical presentation is consistent with the HS, without eosinophilia on presentation despite extensive disease. Eosinophilia may be absent in patients using corticosteroids. Strongyloides HS may mimic ARDS, pulmonary hemorrhage, pulmonary embolism and exacerbated bronchial asthma.Strongyloides larvae are capable of carrying enteric Gram-negative bacilli when they migrate hematogenously. In patients with hyperinfection , Gram-negative bacteremia should be suspected and treated empirically.The drug of choice for the treatment of strongyloidiasis is ivermectin; however, there are no clearly established therapeutic guidelines for HS. It is recommended that patient be followed with serial stool for ova and parasite to guide length of treatment. In endemic regions patients should be routinely screened for Strongyloides stercolaris prior to immunosuppressant therapy.
CONCLUSION:Strongyloides HS should be recognized by the clinician in order to institute appropriate diagnostic and therapeutic interventions. In our case, early bronchoscopy was fundamental in the diagnosis, treatment and successful outcome.
DISCLOSURE:Jose Adorno-Fontanez, No Financial Disclosure Information; No Product/Research Disclosure Information