Echinococcosis (Hydatid Disease) By Chelsea Marie, PhD, University of Virginia; William A Petri, Jr, MD, PhD, University of Virginia School of Medicine Reviewed / Revised Dec 2021 | Modified Sep 2022 View Patient Education Pathophysiology Symptoms and Signs Diagnosis Treatment Key Points Topic Resources Echinococcus Life Cycle Echinococcosis is infection with larvae of the tapeworm Echinococcus granulosus (cystic echinococcosis, hydatid disease) or Echinococcus multilocularis (alveolar disease).