Polio eradication efforts in Sudan started in 1994. The last endogenous wild poliovirus case was reported in 2001. An importation in 2004 led to an outbreak and spread of the virus to countries in the Horn of Africa, with the last case reported in June 2005. The country has subsequently had importations of wild poliovirus in 2007 and 2008, with one and two cases, respectively. The last wild poliovirus outbreak was in 2009, when an importation led to 5 cases in 2 states. The genomic sequencing indicated a link with wild poliovirus circulating in South Sudan. The country has been polio-free since then.

In 2014, routine oral polio vaccine type 3 coverage was high reaching 94.0% of children. Surveillance indicators are above certification standards. In 2014, the non-polio acute flaccid paralysis (AFP) rate was 2.7 per 100 000 population aged less than 15 years and stool adequacy rate was 97% (37). Although the surveillance system is sensitive and routine vaccination is high, the country faces 2 challenges: circulating vaccine-derived poliovirus

in South Sudan and the pool of susceptible children in inaccessible areas in South Kordofan (an estimated 180 000 unvaccinated children). The Federal Ministry of Health, supported by WHO, implemented two national and two subnational polio vaccination campaigns in 2014. Independent monitors reported 90.0% or greater coverage in all monitored districts.

In addition, checkpoint vaccination posts were established at the entry and exit points of insecure areas to mitigate the risk of low immunity among inaccessible children. The polio preparedness and response plan needs to be updated regularly and tested in the field for its appropriateness.