Studies on entry and egress of poliomyelitic infection. VII. Early lesions in peripheral ganglia after simple feeding; with comments on the possible value of immunization in preventing neural entry.

At 56, 60, and 72 hours after simple feeding of poliomyelitis virus, typical, discrete lesions were found in the ganglia supplying the mouth and pharynx, which were most numerous and severe in the Gasserian ganglia. Lesions were also found in the nerve bundles adjacent to the infected ganglia. The character, localizations, and time of appearance of lesions point to nerve-conducted entry of infection from the mucosa of the mouth and pharynx. The possibility is suggested that under natural conditions of exposure, in which only small amounts of virus are involved, artificially induced immunity, active and probably passive, may block primary neural entry at the oropharyngeal portal by virtue of antibodies in the overlying mucus.