Elimination of poliomyelitis in Europe: remaining problems to solve.

Global eradication of paralytic poliomyelitis is feasible since the causative agents, three serotypes of poliovirus, have no other natural host species and since the vaccines developed against poliomyelitis are highly effective. The WHO program for 'Global Eradication of Paralytic Poliomyelitis by the Year 2000' has made great progress during the last few years. Yet, more than 100,000 new cases of the disease still occur annually in the world. In Europe, paralytic poliomyelitis is a rare disease but appears to persist in restricted areas and occurs at a very low incidence in several European countries, mostly as an imported entity. Importation of wild polioviruses to Europe will continue as long as endemic circulation of the viruses is taking place somewhere in the world. Attention has to be paid to improve the surveillance of both suspected clinical cases and of putative wild poliovirus circulation in the population. In several Eastern European countries political and economic turbulence may endanger the maintenance of immunization programs. International collaboration is needed to prevent reestablishment of indigenous poliovirus circulation in these regions.