AFP and poliomyelitis: Poliovirus surveillance evolved substantially with the polio eradication endgame, from a system that distinguished polio cases from non-polio cases, then to also characterize the specific type of poliovirus that caused cases, then to also distinguish both the type and strain of poliovirus, and finally to provide genetic sequencing of the VP1 region of the poliovirus genome for positive AFP and ES samples, and now increasingly to provide whole genome sequencing data.