Poliomyelitis eradication in Africa--update on importations.
D000349:Africa / Q000453:epidemiology; D004196:Disease Outbreaks; D006801:Humans; D011051:Poliomyelitis / Q000453:epidemiology / Q000517:prevention & control*; D017955:Poliovirus / Q000302:isolation & purification; D011159:Population Surveillance