From the Centers for Disease Control and Prevention. Imported wild poliovirus causing poliomyelitis--Bulgaria, 2001.
D002031:Bulgaria / Q000453:epidemiology; D002675:Child, Preschool; D004196:Disease Outbreaks / Q000517:prevention & control; D005260:Female; D006801:Humans; D017589:Immunization Programs; D007223:Infant; D008297:Male; D011051:Poliomyelitis / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control; D017955:Poliovirus / Q000302:isolation & purification*; D016036:Seroepidemiologic Studies