The polio virus is an obligate human parasite. Therefore, it can be eradicated from the population by mass vaccination of all susceptible individuals. Campaigns to accomplish this have been successful in the Americas, Europe, Australasia, and in most countries in Africa and Asia. In 2002, only seven countries (Afghanistan, Egypt, India, Niger, Nigeria, Pakistan, and Somalia) reported indigenous cases. Unfortunately, political factors disrupted the polio vaccination campaign in Nigeria after 2002 and led to return of paralytic poliomyelitis in 18 countries (Yemen, Indonesia, and 16 African nations). A WHO/UNICEF/CDC initiative aims to eradicate polio worldwide. See http://www.polioeradication.org/.
Subjects: Public Health and Epidemiology.