and other countries in the Western hemisphere must take into account the possibility of importation from areas where polio disease has not been eradicated. The global eradication of polio means the documentation that no cases of polio caused by wild-type poliovirus have occurred, that wild-type poliovirus transmission has ceased, and that no wild-type poliovirus has been found, despite intensive efforts to do so. This has been accomplished in the Americas, and the World Health Organization (WHO) goal for global eradication is the year 2000. The basic strategies for global eradication are similar to those demonstrated to be effective in the Americas, as described above. OPV has been the vaccine of choice for use in global eradication programs.
The benefits (both direct and indirect) of polio eradication efforts include (1) reductions in disease and disability; (2) financial benefits (the estimated potential savings of the cost of vaccine and its administration are at least $230 million per year in the United States and $1 billion globally); (3) improved primary health care in general, including better control of measles and neonatal tetanus, especially by using NIDs; (4) development of a laboratory network as the basis for tackling other diseases of public health importance; and (5) better disease surveillance and the consequent improved ability to identify and address other public health problems.
The global level of routine immunization with three doses of OPV in children by 1 year of age increased from about 10 percent in the early 1980s to a peak of 85 percent in 1990 and has been sustained at about 80 percent since then. The number of reported cases of polio declined from 35,000 in 1988 to an estimate of less than 7,000 in 1994. On the basis of data from 1994, the Americas have been polio-free for 3 years; emerging polio-free zones elsewhere around the world include western and central Europe, China, parts of north Africa and southern Africa, and the Arabian Peninsula. The highest proportion of reported cases of polio (67 percent) in 1994 was in the WHO's southeast Asia region, which comprises the Indian subcontinent and Indonesia; India and Bangladesh account for almost all of this, with more than 60 percent of the cases reported worldwide in 1994 being in India.
A substantial proportion of the estimated costs of polio eradication are paid by countries where polio is endemic, rather than by external donor organizations. Thus, it takes a high level of commitment and political will on the part of countries where polio is endemic to implement polio eradication strategies. The estimated external need is about $500 million over the next 5 years, or about $100 million per year in external donor support. About 80 percent of this is for the purchase of OPV. The main obstacles to polio eradication are the lack of funds for vaccine and technical support; insufficient political commitment in several countries where polio is still endemic; falling levels of routine immunization in a number of countries in sub-Saharan Africa;