RT Book, Section A1 Langston, Shannon M. A1 Bales, Brian D. A2 Knoop, Kevin J. A2 Stack, Lawrence B. A2 Storrow, Alan B. A2 Thurman, R. Jason SR Print(0) ID 1177130344 T1 Hydatid Cyst T2 The Atlas of Emergency Medicine, 5e YR 2021 FD 2021 PB McGraw-Hill PP New York, NY SN 9781260134940 LK accessmedicine.mhmedical.com/content.aspx?aid=1177130344 RD 2021/04/15 AB Hydatid cysts are formed by the larval stage of Echinococcus granulosus tapeworms. The life cycle is maintained between canines and various farm animals (usually sheep or cattle). Adult worms inhabit the canine small intestine, and eggs are passed in the stool. Farm animals become infected when they feed upon stool-contaminated material. The life cycle is completed when dogs or other canines ingest larval cysts formed in infected farm animals. Humans are infected from inadvertent ingestion of canine fecal material and are considered accidental hosts.