Limited in vivo susceptibility of the South American monkey -Cebus apella- to type 1 poliovirus: physical and histopathological observations after intraspinal inoculation.

Type 1 polioviruses (an attenuated strain, Sabin 1 LSc 2ab and a virulent strain, Mahoney) were inoculated intraspinally into the South American Cebus monkey Cebus apella. Neither physical symptoms nor histological changes in the central nervous system were observed after inoculation of attenuated Sabin strain. But the virulent Mahoney strain caused flaccid paralysis in two of three monkeys. In these two paralyzed monkeys, definite specific histological changes were observed with spreading of the lesions to places far from the inoculation site, i.e., the cervical cord and brain. These results suggest that Cebus apella has limited susceptibility to type 1 poliovirus.