Farewell to polio in the Western Pacific.

Abstract

29 October 2000 will go down in history as the day on which the world celebrated the end of poliomyelitis in the Western Pacific Region -- a vast area stretching from the western borders of China to the eastern reaches of Polynesia, comprising 37 countries and areas and a quarter of the world's population. This matches the achievement announced on 20 August 1994 when the Pan American Health Organization declared the Americas to be polio-free. Now two of the World Health Organization's six regions have been declared polio free, meaning that in them the transmission of indigenous wild poliovirus has been totally stopped. In 1990 the independent International Commission for the Certification of Poliomyelitis Eradication in the Americas was established to provide an impartial and critical overview of the eradication process and its results. WHO set up the Global Commission for the Certification of Poliomyelitis Eradication in 1995. In its turn, the Western Pacific Regional Office of WHO (WPRO) established the Regional Commission for the Certification of Poliomyelitis Eradication(a) (RCC) and this body met for the first time in 1996 in Australia. Four years later, at its sixth meeting held in Japan, the RCC was able to conclude that the circulation of indigenous wild poliovirus had ceased throughout the Region. Since the last indigenous case had been detected in Cambodia, on 19 March 1997, a period of over three years had elapsed, during which conditions of high quality surveillance had been maintained throughout the region. The RCC met six times during those three years, and watched the number of cases of polio steadily drop in response to national, sub-national and targeted immunization activities conducted in endemic and recently endemic countries. WHO WPRO worked with national governments to work out special tactics to reach underserved populations in which wild poliovirus continued to circulate despite national immunization activities. In intensive operations targeting the last known areas of wild poliovirus circulation in several countries, mobile teams went from house to house and boat to boat to immunize mobile and difficult-access populations. As cases declined, the number of specimens from acute flaccid paralysis (AFP) cases subjected to virological examination rose dramatically, providing ever-increasing confidence in the surveillance system. The regional polio laboratory network, established by WHO as part of the global network, ensured that virological examination of samples from suspected polio cases was undertaken quickly and effectively. To give an idea of how dramatic the fall in the number of poliomyelitis cases has been, in 1990 nearly 6000 cases were reported in the region, and since the reporting system was incomplete the true number of new cases per year was estimated to be closer to 60 000. By 1993, with a complete and reliable surveillance system in place, this had dropped to 1147. For the remaining years of the 1990s the figures were: 744 in 1994, 481 in 1995, 198 in 1996 and, finally, 9 in 1997. The Global Commission has set criteria and guidelines for the certification process that have to be followed by the Regional Commissions. The Western Pacific RCC spelt out these criteria in detail in order to make our expectations as clear as possible to the National Certification Committees as they prepared their final documents. …