The high prevalence of EITB antibody bands in pigs from T. solium-endemic areas may arise from pigs with viable infections but may also represent transient responses in pigs exposed but not developing cysts, pigs with degenerated or past infections [26], pigs with maternal antibodies transferred by passive immunity [27], and pigs infected with T. hydatigena metacestodes (due to cross reactivity of the GP50 band) [28]. This evidence concerns the gene ERVW-1 and infection.