Epidemiology of poliomyelitis--options and update.

Poliomyelitis is a disease of major public health importance. Since the launch of the Global Poliomyelitis Eradication Initiative in 1988, considerable progress has been achieved globally. At present, the causative agent for the disease--poliovirus--remains endemic in only four countries (Afghanistan, India, Nigeria and Pakistan). The poliovirus eradication plan, as outlined in the WHO strategic plan for 2004--2008, incorporates priority activities for each phase of the plan: (i) polio eradication certification for regions, (ii) oral poliovirus vaccine (OPV) cessation phase, and (iii) post-OPV phase. The ultimate goal to eventually stop all vaccination is, however, jeopardized by the emergence of vaccine-derived polioviruses and the risk of bioterrorism. In the post-eradication era, individual countries will be presented with guidelines on OPV cessation and inactivated poliovirus vaccine (IPV) usage. This paper, presented during the Asian Pacific Pediatric Association (APPA) meeting in Pattaya, Thailand from 20 to 22 July 2006, provides an update on the current global situation, focusing on the progress and challenges faced by different countries in their quest for poliovirus eradication.