Certification of smallpox eradication.

The world's last known case of smallpox resulting from human-to-human transmission in an endemic focus occurred in Somalia in October 1977, and there remains the task of documenting the global eradication of the disease and establishing the safety of vaccination. Those countries as yet uncertified have been grouped into four categories according to the procedures recommended for their certification. An important criterion for deciding the type of procedure is how recently smallpox was endemic in a particular country. This paper is concerned with those countries in which the disease has been nonendemic for some years but which have not yet received certification of eradication. One such country is Burma, which was certified free of smallpox in 1977, some 8 years after its last reported case but 2 years after the last case in Bangladesh, with which it shares a long frontier. The procedures used in Burma and the lessons that were learnt therefrom are described.