Basics: A viral infections that effects the gastrointestinal tract and can rarely spread to the central nervous system. Paralysis occurs in less than 1% of infections and the majority are unnoticed or feature a non-specific fever. The paralysis of polio is usually flaccid (weak) and aasymmetric (one side of the body). Legs are more commonly effected that arms. This infection is shed in the feces of infected persons and communicated to others in a fecal-oral route. The vast majority of cases occur in children less than 5 years of age.
Locations: Prior to widespread vaccination, polio was found world-wide. Wild type or naturally occurring polio is decreasing due to massive campaigns to vaccinate and as of 2002 was endemic in 7 countries: Afghanistan, Egypt, India, Niger, Nigeria, Pakistan and Somalia. During 2002 89% of wild type polio was found on the Indian sub-continent and 11% in West Africa. Although localized in geographic clusters, importation of disease to developed nations is still very possible. A large outbreak in 1992-1993 occurred in the Netherlands, among a specific religious group who refused the vaccine.
Recommendations for Adults: Most adults living in America, Europe and Australia have received their primary series in childhood and are immune to polio. The CDC discusses adults who travel to an area where wild type polio is know to be transmitted and their need for a single IPV vaccine, as a booster. This is a one time booster, for the life of the traveler. More can be read here: http://wwwn.cdc.gov/travel/yellowbook/2008/ch4/poliomyelitis.aspx