( CNN ) -- The spread of polio constitutes an international public health emergency , the World Health Organization declared Monday . `` If unchecked , this situation could result in failure to eradicate globally one of the world 's most serious vaccine preventable diseases , '' the WHO said in a statement . At the end of 2013 , 60 % of polio cases resulted from the international spread of the virus , and `` there was increasing evidence that adult travelers contributed to the spread , '' according to the statement . Polio mainly affects children under the age of 5 , according to the WHO . One in 200 infections leads to irreversible paralysis ; 5 to 10 % of patients die when their breathing muscles become immobilized . It can only be prevented by vaccination . Of the 10 countries currently infected with polio , three -- Pakistan , Syria and Cameroon -- have allowed the virus to spread internationally , according to an emergency committee convened by the organization , which met late last month . Polio has spread from Pakistan to Afghanistan , from Syria to Iraq and from Cameroon to Equatorial Guinea , according to the WHO . The concern is that the spread comes during the low transmission season for polio , typically January through April , said WHO spokeswoman Christine Feig . This is a `` red flag , '' she said , as `` it has been years '' since the virus was spread to three countries during low season . Polio re-emerged in Syria in October 2013 after a 15-year absence . The ongoing civil war in Syria has hampered immunization rates `` due to the severe interruption of public health services and to the conditions in which the people are living , '' according to a WHO report . There have been 74 cases of polio so far this year , Dr. Bruce Aylward , WHO assistant director-general for polio , emergencies and country collaboration , said Monday . Of those , 59 were in Pakistan . No other country has reported more than four cases , and the only country with four was Afghanistan , he said . The committee 's decision to declare an international public health emergency means that Pakistan , Syria and Cameroon are urged to declare national public health emergencies regarding polio and ensure all residents and long-term visitors are vaccinated . In addition , the WHO said , citizens of those countries traveling internationally should be vaccinated before their departure and carry proof in the form of an International Certificate of Vaccination or Prophylaxis . Meet India 's last polio patient . `` A coordinated international response is deemed essential to stop this international spread of wild poliovirus and to prevent new spread with the onset of the high transmission season in May/June 2014 , '' according to the organization . Nations infected with polio , but not spreading the disease internationally now include Afghanistan , Equatorial Guinea , Ethiopia , Iraq , Israel , Somalia and Nigeria , the WHO said . Those nations were also encouraged to take similar measures to ensure high levels of vaccination in residents and travelers . While the recommendations are not legally binding , they are in the context of the International Health Regulations , which are binding on member states , Aylward said . `` These recommendations are not legally binding in the strict sense ... but they do carry substantial weight because , of course , they are in the context of a legally binding international treaty , '' Aylward said Monday . No cases of polio have been detected in Israel , but the WHO previously reported the virus was found in sewage samples , as well as in stool samples from children who had been immunized . In all , 417 cases of polio were reported worldwide in 2013 , said Aylward . Further spread of the virus could put at risk countries that are currently polio-free but are `` conflict-torn and fragile '' with compromised routine immunization services , the WHO said . The current situation is `` in stark contrast '' to the `` near-cessation '' of the spread of polio from January 2012 through April 2013 , according to the statement . In March , Southeast Asia , including India , was declared polio-free . India , the world 's second most populous country , was able to achieve the goal by deploying immunization efforts to reach those most vulnerable , according to UNICEF . Polio was eradicated in the United States in 1979 , according to the U.S. Centers for Disease Control and Prevention . Vaccination campaign against polio , other diseases begins in Mideast . Pakistan grapples with polio fight . India beats the odds , beats polio .
It has spread to many countries this year . It 's typically the low season for transmission of the disease . Pakistan , Nigeria and Cameroon are urged to put measures into place . No cases of polio were reported worldwide in 2014 , WHO says .