 Monitoring for AFP aims at identifying outbreaks of polio by screening patients displaying symptoms consistent with but not exclusive to severe poliovirus infection.Stool samples are collected from children presenting with AFP and evaluated for the presence of poliovirus by accredited laboratories in the Global Polio Laboratory Network.Since rates of non-polio AFP are expected to be constant and large compared to polio cases, the frequency of non-polio AFP reported in a population is indicative of the effectiveness of surveillance, as is the proportion of AFP patients from whom high-quality stool samples are collected and tested, with a target of at least 80%.