Progress towards the global eradication of poliomyelitis

Abstract

Poliomyelitis has been virtually eliminated from the industrialized countries by mass campaigns conducted with oral polio vaccine (OPV). In 1988, the World Health Assembly set the goal of global eradication of poliomyelitis by the year 2000. The current WHO strategy for eradication uses three primary activities beyond routine immunization with OPV. They are: (i) improved disease surveillance, (ii) building a global network of laboratories, and (iii) supplemental immunization strategies which include mass immunization campaigns with OPV at the national level, and targeted campaigns at the local level. Eradication of polio from the Region of the Americas is close and may have already been achieved. In other regions, the number of reported polio cases has declined, largely as a result of high immunization coverage. As more countries implement polio eradication strategies, the number of polio cases will continue to fall until eradication is achieved.

PIP: The current status of poliomyelitis in the world is outlined. In May 1988, the World Health Assembly committed the World Health Organization (WHO) to the global eradication of poliomyelitis by the year 2000. Polio eradication cannot be achieved through routine immunization alone using the primary strategy of expanded program of immunization (EPI). Additional strategies recommended by WHO are: 1) Improving the surveillance systems to detect all cases of paralysis which might be polio. 2) Building a global network of laboratories to reliably identify polio virus from specimens. 3) Conducting national vaccination days, outbreak response immunization, targeted mass vaccination campaigns in high-risk areas. An increasing number of countries are adopting these strategies. In 1990, 16,435 cases of polio were reported globally, a 39% decrease from 1989 when 26,916 cases were reported. For 1990, 171 (88%) of 184 countries had reported polio case counts to WHO on October 1 of the following year, compared to 166 (85%) for 1989. Improvements in both timeliness and completeness of reporting at the national level have occurred as more countries improve surveillance for polio as well as for other EPI target diseases. There has been a dramatic decrease in the number of reported polio cases and the eradication of wild polio viruses is imminent in the Americas. WHO estimates that in 1990, approximately 150,000 cases of paralytic poliomyelitis occurred in the world. Although improved immunization coverage with 3 doses of oral polio vaccine given by routine administration can reduce the number of polio cases, polio eradication will require supplemental immunization activities.