Case Report: Suspected intestinal helminthiasis on CT despite negative stool microscopy in a man experiencing homelessness

Soil-transmitted helminth infection is uncommon in high-income settings but may be considered in people with past residence in, or recent exposure to, areas where it occurs. We report a 41-year-old man experiencing homelessness, with previous residence in Puerto Rico, who presented with fever, leukocytosis, and abdominal symptoms and was treated for left buttock cellulitis with phlegmon. Computed tomography (CT) of the pelvis showed an equivocal small-bowel abnormality (internal hernia versus intussusception). CT of the abdomen and pelvis about 20 hours later showed that the intussusception had resolved and demonstrated multifocal tubular intraluminal filling defects within the small bowel and splenomegaly; the radiologist’s considerations were ingested material versus parasitic infection. A stool ova and parasite examination were reported as negative. Albendazole was given empirically while the patient was also receiving broad-spectrum antibiotics, and symptoms improved before discharge. No parasite was identified, no confirmatory or post-treatment testing was performed, and intestinal helminthiasis was not established. This case shows how non-specific CT findings can prompt empirical antiparasitic treatment, and why a structured differential diagnosis, confirmatory testing and follow-up are needed before such findings are attributed to helminths.