1887 Don’t Stop at the Colon! A Rare Case of Strongyloides Hyperinfection Diagnosed on Esophagogastroduodenoscopy

Abstract

INTRODUCTION: Strongyloides stercoralis (SS) endemic to the tropics, is uncommon in the US. Symptoms from SS infection can mimic Irritable Bowel Syndrome (IBS). Immunocompromised individuals may present with fatal systemic ‘hyperinfections’ where SS larvae enter the bloodstream and bring enteral bacteria with it. Current literature recommends the use of endoscopy with biopsy to confirm diagnosis and begin prompt treatment to prevent further complications. CASE DESCRIPTION/METHODS: A 46-year-old woman with Rheumatoid Arthritis managed with prednisone and Rituximab presented for chronic abdominal pain and diarrhea reportedly from IBS. Past medical history was significant for recurrent hospital admissions for gram negative meningitis attributed to her immunocompromised state. She was treated with Ceftriaxone empirically each time. As part of her IBS workup, she underwent out-patient diagnostic Esophagogastroduodenoscopy (EGD) and Colonoscopy. The Colonoscopy was unremarkable. The EGD showed diffuse white villi in the second part of the duodenum. Biopsy revealed inflammation with presence of many SS larvae and eosinophils. A unifying diagnosis of SS hyperinfection causing recurrent gram negative meningitis was thus made. The patient was treated with Ivermectin and Albendazole. Surveillance EGD and Colonoscopy with random biopsies showed absence of SS. She reported complete resolution of her symptoms. DISCUSSION: ‘Auto-infected’ SS larvae in the duodenum can transform into adult worms which reside in the colon and are known to mimic IBS. In immunocompromised hosts larvae can also enter bloodstream by transmural migration of the duodenum causing hyperinfection. Literature from regions endemic to SS suggest that enteral bacteria may accompany the larvae during this migration causing gram-negative septicemia and meningitis. Diagnosing SS can be challenging. Stool studies have poor diagnostic sensitivity. Endoscopy with biopsy confirming presence of SS larvae as seen in our patient continues to give the highest yield for diagnosis and prompt treatment to prevent fatal outcomes. A variety of endoscopic findings including duodenal white villi are documented but no pathognomonic finding is established for which more cases need to be reported. While a large burden of the adult worms reside in the colon causing IBS like symptoms, SS larvae reside in the crypts of duodenal mucosa. If SS hyperinfection is suspected, we strongly recommend to not stop the investigation at a diagnostic Colonoscopy but also perform an EGD.