The Departments of Microbiology and Parasitology, Medical Microbiology, Pathology, and Medicine, University of Toronto, The Tropical Diseases Clinic and the Department of Pathology, Toronto General Hospital, Toronto, Canada
A fatal human infection with mesocercariae of Alaria americana is described. Several thousand mesocercariae were estimated to be present in the peritoneal cavity, bronchial aspirate, brain, heart, kidneys, liver, lungs, lymph nodes, pancreas, retroperitoneal adipose tissue, spinal cord, spleen, and stomach. Nine days from the onset of symptoms death resulted from asphyxiation due to extensive pulmonary hemorrhage probably caused by immune-mediated mechanisms. Circumstances suggest the victim probably ate inadequately cooked frog legs while hiking. Mesocercariae penetrated through the stomach wall and spread to the various organs both directly and via the circulatory system.