Strategies for the certification of the eradication of wild poliovirus transmission in the Americas. Expanded Program on Immunization, Pan American Health Organization

Because it appears that the last case of poliomyelitis caused by transmission of indigenous wild poliovirus occurred 2 years ago on 23 August 1991 in Peru, the challenge for PAHO is to develop a methodology of certification that will convince the rest of the world that the eradication of poliomyelitis in the Americas has been achieved. To that end, the guidelines set forth here allow for a rigorous and standardized evaluation of the certification process by objective experts. As it was during the campaign to eradicate smallpox, epidemiologic surveillance (of acute flaccid paralysis [AFP] in the case of polio) will be the most important component of the certification process. It must be demonstrated that when cases of AFP occur, they will be identified, reported, and investigated in a timely manner to insure that if wild poliovirus is present, it will be identified.

Published by Bulletin of the Pan American Health Organization, 1993. The guideline itself is at the source linked here.

pubmed.ncbi.nlm.nih.gov/8220524/