( CNN ) -- Additional polio cases have been confirmed in two new areas in Syria : near the capital of Damascus and in northern Aleppo , near Turkey , the World Health Organization said Tuesday . In Syria 's first outbreak of the disease since 1999 , 10 cases of polio were initially confirmed among children last month . That number has now risen to 17 , the WHO said . In addition to 15 cases confirmed in Deir Ezzor province , `` two additional cases have been confirmed , one each in rural Damascus and Aleppo , confirming widespread circulation of the virus , '' the WHO said in a statement . It said the risk of further spread of the disease was considered high given the fighting , large-scale movement of refugees and number of children who have not been fully immunized in the country . Last month , health officials launched a program to immunize 1.6 million Syrian children against polio , measles , mumps and rubella -- in government- and rebel-held areas . The response , which also includes neighboring countries , is expected to last at least six months , the WHO has said . `` A surveillance alert has been issued for the region to actively search for additional potential cases in addition to implementing the recommended supplementary immunization activities with oral polio vaccine , '' the WHO said . About 22 million children under the age of 5 are being targeted in mass polio vaccination campaigns in the region , it said . According to UNICEF , 500,000 children in Syria have not been vaccinated against polio . The highly infectious viral disease , which spreads via fecal-oral transmission and contaminated food and water , primarily affects young children . Initial symptoms can include fever , fatigue , headache , vomiting , neck stiffness , limb pain and , in a small number of cases , paralysis and death . It can be prevented through immunization , but there is no cure . The incidence of the disease has dropped by more than 99 % since 1988 . It remains endemic in three countries -- Pakistan , Nigeria and Afghanistan -- down from more than 125 countries in 1988 . Public health can be among the first casualties of war , as resources are diverted from ensuring clean water supplies and intact sewer lines . According to the United Nations , more than 100,000 people have died in the Syrian conflict , which began in March 2011 when government forces cracked down on peaceful protesters . Vaccination campaign against polio , other diseases , begins in Mideast . CNN 's Per Nyberg contributed to this report .
WHO Polio cases have spread to Damascus and rural Aleppo . It says a total of more than 125 polio cases have been confirmed . The risk of further spread is high , the World Health Organization : says .