 While a number of control and prevention strategies deal with cystic and alveolar echinococcosis, there are few methods to control and prevent polycystic echinococcosis.This is probably due to the fact that polycystic echinococcosis is restricted to Central and South America, and that the way that humans become accidental hosts of "E. oligarthrus" and "E. vogeli" is still not completely understood.Currently there are no human vaccines against any form of echinococcosis.