It is important to determine the source of the virus because for each reported case of paralytic polio caused by wild poliovirus, an estimated 200 to 3,000 other contagious asymptomatic carriers exist.
Considérase importante determinar a fonte do virus xa que para cada un dos casos rexistrados de polio paralizante provocados polo virus silvestre, estímase que existen entre uns 200 e 3000 portadores asintomáticos contaxiosos.