Echinococcus Species: Tiny Tapeworms

Neotropical Echinococcosis: A Review

“…On the other hand, metacestodes of E. oligarthra 1 have been found in tissues of several intermediate hosts such as the agouties [1] ("picures" in Venezuela), spiny rats, pacas, opossums (Didelphis marsupialis), and in wild rabbits (Sylvilagus floridanus) [2] in tropical forests of Panama, Venezuela, Colombia, Chile, Brazil, and Argentina [3]. Proglotis and many eggs are shed from these tiny tapeworms into the gut lumen of their definitive hosts, passed out with the feces [4,5], and next, eggs are accidentally ingested by the intermediate hosts, which become infected; in the case of E. vogeli, once in the intestine, the oncospheres stages are freed, invading organs such as the liver, lungs, small intestine, spleen, where develop they as protoscoleces, which asexually proliferate forming the hydatid polycystic cyst stage, polycystic for E. vogeli. The unicyst for E. oligarthra appears to be less erratic, and in three out of four cases diagnosed were found retrorbital.…”