Asymptomatic Strongyliodes Found in a Colonic Polyp

Abstract

Strongyloidiasis, caused by Strongyloides stercoralis, is a worldwide parasitic disease endemic to tropic and sub-tropical regions. Typically the infection remains asymptomatic, however life-threatening hyperinfection may occur in immunocompromised hosts. We present a 73 year-old asymptomatic female with well-controlled HIV who was found to have strongyloides induced colitis on surveillance colonoscopy. A 73 year-old female with HIV on HAART (CD4 - 749) presented for surveillance colonoscopy. Lab work revealed chronic anemia with a hemoglobin between 10-11g/dL and an absolute eosinophil count greater than 10%. She denied any diarrhea or other gastrointestinal (GI) symptoms. History was notable for immigration from Puerto Rico many years ago. Colonoscopy five years prior showed two hyperplastic polyps. Repeat colonoscopy showed two 3-4 mm sessile polyps, which were removed with jumbo forceps. Pathology revealed eosinophilic rich mucosa and nematode (Figures 1,2) consistent with strongyloides induced colitis. The patient was treated with Ivermectin.Figure 1Figure 2Strongyloidiasis is a worldwide parasitic disease. The complex life cycle of the parasite promotes a prolonged auto-infection in hosts. Strongyloidiasis is asymptomatic in up to 30% of infected individuals, however GI symptoms including abdominal pain, watery diarrhea, weight loss, nausea and vomiting are common. The infection may occur in both healthy and immunocompromised hosts. However, in immunocompromised individuals, autoinfection may progress to disseminated infection with a mortality rate of approximately 60%. Many of the reported cases of colonic involvement in strongyloidiasis were associated with hyperinfection or disseminated strongyloidiasis. Colonoscopic features in strongyloidiasis include loss of vascular pattern, aphthous ulcers, erosions and yellowish-white nodules. Yellowish-white nodules may be a characteristic finding of colonic lesions in strongyloidiasis. The clinical diagnosis of S. stercoralis is confirmed by detection of larvae in the stool. However, single stool microscopy has a sensitivity of only 30% when there is low parasite burden, underscoring the need for stool aspirate microscopy or endoscopic biopsy for diagnosis. Due to its non-specific presentation and the risk of hyperinfection, gastroenterologists must maintain a high index of suspicion for strongyloidiasis especially in the immunocompromised population presenting with non-specific GI symptoms and/or unexplained peripheral eosinophilia.Figure 3