Polioviruses belong to the family Picornaviridae and are classified as human enterovirus C (HEV-C) species in the genus Enterovirus according to the current taxonomy [15, 16] . Polioviruses can be divided into three different genotypes: 1, 2 and 3. The genome of each genotypes contains a single positive-stranded RNA with a size of approximately 6 kb consisting of a single large open reading frame (ORF) flanked by 5' and 3' untranslated region [17] .