According to the International Committee on Taxonomy ofViruses (ICTV), HEV has four classical genotypes (1, 2, 3 and 4)belonging to the Orthohepevirus genus, and it includes a diversearray of viral variants that can infect different hosts (primarilymammalian and avian). Genotypes 1 and 2 are strictly human,whereas strains corresponding to genotypes 3 and 4 are zoonotic,with pigs being the primary host (Kamar et al., 2014).