Thirteen confirmed cases of wild poliovirus type 1 have been reported to the World Health Organization (WHO).
The cases found in the Syrian Arab Republic hav been linked to a type of polio found in Egypt in December 2012.
Closely related strains have been found in Israel, West Bank and the Gaza Strip since February 2013.
As of 24 October 2013, large-scale immunisation programmes have been rolled out in the Syrian Arab Republic to vaccinate 1.6 million children against polio, measles, mumps and rubella.
A Health Protection Agency (HPA) report states: “Given the current situation in the Syrian Arab Republic, frequent population movements across the region and the immunization level in key areas, the risk of further international spread of wild poliovirus type 1 across the region is considered to be high.
“A surveillance alert has been issued for the region to actively search for additional potential cases.”
WHO's International Travel and Health recommends that all travellers to and from polio-infected areas be fully vaccinated against polio.