Chapter 105 - Animal Models for Echinococcosis

Abstract

This chapter focuses on the animal models used for echinococcosis, which is caused by the four Echinococcus species. Due to the low host specificity of Echinococcus spp. in the metacestode stage, a wide range of mammal species are known to be natural intermediate hosts and, consequently, a long list of species has been used for experimental infections. Injection of protoscolices into the peritoneum is the most widely used technique to establish cystic echinococcosis in rodents. Various strains of mice (M. musculus) and Mongolian gerbils (Meriones unguiculatus) have been used as model hosts. Hydatid cysts usually develop free in the peritoneal cavity, but may be attached to or grow into neighboring organs. Several species of voles (Microtus spp.), cotton rats (Sigmodon hispidus), and various strains of mice (Mus musculus) have been used for oral infection of E. multilocularis. Since rodents are natural intermediate hosts for this cestode species, development of the metacestode, the primary location of which is invariably the liver, is usually rapid and leads to numerous protoscolices. However, due to difficulties in obtaining infective eggs, mostly from shot foxes, and the safety measures required for handling material infective to humans, few laboratories use oral infection as a routine method. Injection of homogenized metacestode material into the peritoneal cavity is the most widely used method to establish secondary alveolar echinococcosis in rodents. The most rapid growth occurs in Mongolian gerbils (Meriones unguiculatus), cotton rats (S. hispidus), and common voles (Microtus arvalis).