Polio is a highly infectious, potentially fatal disease with serious complications including permanent respiratory damage, limb deformation, and paralysis. It has been eradicated in the United States since 1979, and in one of the most successful organized global-health efforts in history, it has been eradicated in most of the rest of the world as well: the total number of polio cases worldwide has been decreased by 99% since 1988. Much of this success can be attributed to the more than 2.5 billion polio vaccines that have been administered to children throughout the world.
Progress at eliminating polio worldwide as been ongoing since the vaccine was developed in 1955, along with the combined efforts of the World Health Organization, UNICEF, and the CDC; as recently as March 2014, Southeast Asia was declared polio-free. However, in several other countries it continues to be a problem: ten countries, including India, Pakistan, and Syria still have cases of polio, and the last three have had instances of the virus spreading beyond their borders. Polio anywhere is a threat to the population everywhere, because of the ease with which it spreads from person to person, along with the fact that many people go years without knowing they are infected and continue to spread the disease, due to the lack of visible symptoms.
In tumultuous, war-torn, or poverty-stricken nations like Syria, the continuation and spread of polio are difficult to fight since vaccines are harder to get and less of a priority to administer. Another problem occurs when refugees or other travelers leave these countries without having been vaccinated; they can infect people in other countries where polio hasn’t been seen in years. Even a single case of polio can lead to an epidemic as it spreads quickly and, often, silently.
It is possible for polio to reemerge, so continued efforts to get medical attention and vaccinations into countries where it still exists are vital. These nations have also been encouraged by the World Health Organization and others to provide vaccinations for their citizens traveling outside their borders to prevent the spread beyond its relative containment.
nationalgeographic.com/news/ 2014/05/140507-polio-health- disease-vaccination-war-world/