SGCG and poliomyelitis: Between August 2011 and February 2012, type 2 VDPV (with 6–12 nucleotides substitution in capsid protein VP1 region) were isolated from three AFP cases who were diagnosed as clinically compatible polio cases by the provincial PEC and one contact in Ngawa County, Ngawa Tibetan and Qiang Autonomous Prefecture, Sichuan Province [22].