The certification of smallpox eradication and implications for guinea worm, poliomyelitis, and other diseases: confirming and maintaining a negative.

Rigorous, independent, confirmation of disease eradication is necessary to assure credibility of the claimed accomplishment. The criteria and procedures for formal certification of global disease freedom are based on the biological and epidemiological features of the pathogen and its manifestations. Certification activities by previously endemic and at-risk countries include comprehensive documentation focusing on surveillance, reports of national independent review groups, and special field surveys. National and regional results are reviewed by authoritative International Commissions (ICs) which verify the findings by field visits. The ICs present their results to an independent WHO-convened group ("Global Commission" for smallpox), members of which participate in field visits. When fully satisfied, the Global Commission makes conclusions and recommendations to the World Health Assembly (WHA). Smallpox was confirmed eradicated in 1980 by the WHA less than three years after the last naturally occurring case was detected. Dracunculiasis (guinea worm) freedom has been certified in 187 countries. Regional commissions have certified the Americas, Asia, and Europe polio-free; however, re-establishment of endemic foci in countries previously declared disease-free has created special challenges for completing this program. Post-eradication activities require attention to surveillance, maximum security of the microbial agent, and essential research to assure maintenance of disease freedom.