The yield of routine duodenal aspiration for Giardia lamblia during esophagogastroduodenoscopy

Giardia lamblia, the most common intestinal parasite in the United States, may present with nonspecific gastrointestinal symptoms when the infection is chronic. In order to determine how frequently the parasite could be detected in patients undergoing endoscopy for standard indications, duodenal aspirates were collected from 144 patients. Despite G. lamblia being endemic in the state (and therefore readily recognized in our laboratory), there was only one positive aspirate in the 144 specimens collected (0.7%) at this midwestern, tertiary care facility servicing a primarily middle class population. In the population sampled, routine duodenal aspiration for G. lamblia in patients not clinically suspected of having this parasitic infection is of very low yield.