EN
Non-parasitic vermiform organisms can circumstantially be associated with humans and theiridentification can be challenging for medical professionals. The present report describes the finding of a vermiformorganism in the toilet bowl by a patient from Brazil, who thought he had expelled it in his faeces. The gross analyses ina clinical laboratory reveal the worm was different from other macroscopic organisms routinely identified, and thelaboratory staff requested assistance in an academic laboratory specialized in helminthology. After preliminary analysisin a stereomicroscope, the supposed human worm was identified as an oligochaete annelid (earthworm). The patient wascontacted to investigate a possible case of pseudoparasitism. However, we were informed that the organism had beencollected in a toilet bowl from a rural environment where the untreated water comes from a cistern indicating our findingwas circumstantial. The methodology revisited herein allowed a quick microscopic analysis of easy-to-viewmorphological structures, which are useful to separate oligochaete annelids from helminths and can preventmisdiagnosis in similar situations. We discuss the overly restricted view on human parasites by health professionals incollecting clinical history and laboratory analysis, providing some epistemological insights on the necessaryinterdisciplinarity between parasitology and other basic knowledge with health practice.