A scenario for polio eradication.

Polio eradication has entered the phase operating in the Asian sub-continent and in sub-Saharan Africa, where polio is still endemic in 30 countries. These countries are apparently most resistant to the eradication effort. The WHO polio panel held in May, in Geneva, discussed a scenario to stop transmission by 2002 and thereafter three years for certification. This paper discusses the scenario based on experience with smallpox eradication from the viewpoint of impact of population density on immunisation. The programme in the Indian sub-continent, which has the world's highest population density, may require a more rigorous surveillance-containment type strategy than that in sub-Saharan Africa which, with its lower density of population in many countries, may be relatively susceptible to the eradication effort. However, countries with higher population density and/or with political trouble may pose substantial difficulties. Also briefly discussed are measures to be taken after interruption of polio transmission world-wide. These still require intensive studies. The goal is foreseeable and with intensified mobilisation of global resources.