Polycystic Echinococcosis (Polycystic Neotropical Echinococcus)

Abstract Polycystic neotropical echinococcosis (NE) is found in tropical areas of Central and South America. It is mainly caused by infection with the larval form of Echinococcus vogeli. The bush dog (Speothos venaticus) is the definitive host, and its prey the paca (Cuniculus paca) is the intermediate host. Similar to alveolar echinococcus, the liver is primarily affected, and patients often present in an advanced stage of disease when surgical cure is no longer an option. Diagnosis and staging are based on ultrasound and computed tomography (CT) scan. Treatment includes surgery and anti-parasitic drugs, depending on stage and extent of disease. Polycystic NE has similar features to malignancy, and similar principles of management should be applied. The second and rarer species causing NE in humans is E. oligarthrus. There are only four cases reported of NE caused by E. oligarthrus; they involved the eye and the heart.