A GLOBAL OVERVIEW AND HOPE FOR THE ERADICATION OF POLIOMYELITIS BY THE YEAR 2000

The path to disease eradication is littered with failures in which opt imism, usually based on the early success of a new intervention, outwe ighed realization of the problems involved. Only one disease, smallpox , has been eradicated. Not only did smallpox eradication remove foreve r the threat of an appalling disease, it also defined the requirements for disease eradication, showed that a soundly-based, well-coordinate d programme could achieve rapid results and that disease eradication, where possible, is highly cost effective. This is demonstrated by the fact that the largest donor to the smallpox eradication programme cont inues to recoup its full contribution once every 26 days. Smallpox era dication succeeded for five main reasons that have continuing relevanc e for other eradication initiatives: the causative organism was eradic able. It only affected humans, was antigenically stable and had limite d survival outside the body; the disease was seen as a major problem, being a threat to public health and could be readily diagnosed; the pr otective vaccine was stable, reliably effective and could be administe red easily by persons with minimal training; eradication strategies we re simple, epidemiologically appropriate, could be easily taught, but could be interpreted flexibly to meet local conditions; there was poli tical will to succeed, backed up by strong leadership directing the co mmitment of concerned health professionals and with sufficient resourc es to provide essential support. The table compares the attributes of the two diseases, smallpox and poliomyelitis and the programmes aimed at their eradication. All conditions essential for virus eradication a re shared by both programmes. Polio eradication faces greater difficul ties, particularly since most infections are subclinical but still inf ectious.