Serological Relationships within the Poliomyelitis Group of Viruses

A virus recovered from the feces of poliomyelitis patients pathogenic for suckling mice

A virus has been recovered from the feces of two children having symptoms similar to those of poliomyelitis. The virus is pathogenic for suckling mice and hamsters but not for rhesus monkeys. It induces striking lesions in the skeletal muscles of the experimental animal but not in the central nervous system. Other viruses inducing similar signs and lesions in suckling mice have been isolated from several other outbreaks of a poliomyelitis-like disease, including one large urban epidemic.

The susceptibility of the hamster to mouse encephalomyelitis virus

The OT strain of mouse encephalomyelitis virus induces an inapparent infection in suckling hamsters associated with lesions of the central nervous system and skeletal muscles. The virus increases in pathogenicity after alternating mouse-hamster transfers and then induces both paralysis and encephalitis. Pathogenicity is lost through serial hamster passages but is restored by a single mouse transfer.