Long-term persistence of scrapie infection in mouse spleens in the absence of clinical disease

Studies were made of the 87V strain of scrapie in IM mice (Sincp7) to discover why the intracerebral route of injection of a 1% brain inoculum produced clinical scrapie but the intraperitoneal route did not. It was found that the intraperitoneal route rapidly established a persistent infection in spleen (and presumably other extraneural tissues) without there being any significant spread of infection to the brain during the 1.5 year period of observation.