Diagnosis of Strongyloidiasis Identification of larvae by microscopic examination of samples, including stool or duodenal aspirate and, in patients with hyperinfection syndrome and disseminated strongyloidiasis, bronchial washings, sputum, or other body fluids Enzyme immunoassay for antibodies Microscopic examination of a single stool sample detects larvae in about 25% of uncomplicated Strongyloides infections.