Polio

Polio is a viral disease that has caused considerable suffering for much of human history. The oldest clearly identifiable reference to paralytic poliomyelitis is an Egyptian stone engraving from 14th century BCE. Prior to the introduction of effective vaccines in the 1950s, polio was a common infection of childhood, with a small proportion of infections resulting in death or lifelong paralysis. Control began in 1955 after the first inactivated poliovirus vaccine (IPV) and subsequently several years later an oral polio vaccine (OPV) was also introduced. In most developed countries, a good level of control was achieved by the mid 1960s. In 1985, the Pan American Health Organization (PAHO) launched an initiative to eradicate polio in the Americas by 1990. Based on the success of the PAHO program, in May 1988, the 41st World Health Assembly committed the Member States of the World Health Organization (WHO) to the global eradication of poliomyelitis by the year 2000 (resolution WHA41.28). Despite great progress, by the end of 2006, there were still four countries in which polio was endemic (Nigeria, India, Pakistan, and Afghanistan), with another eight countries experiencing importations (Angola, Cameroon, Ethiopia, Indonesia, Nepal, Niger, Somalia, and Yemen).