 During the ban the virus spread across Nigeria and into 12 neighboring countries that had previously been polio-free.By 2006, this ban would be blamed for 1,500 children being paralyzed and had cost $450million for emergency activities.In addition to the rumors of sterility and the ban by Nigeria's Kano state, civil war and internal strife in the Sudan and Côte d'Ivoire have complicated WHO's polio eradication goal.