The Family Relationship of Encephalomyocarditis, Columbia-SK, M. M., and Mengo Encephalomyelitis Viruses

By means of neutralization, complement-fixation, and cross-immunity tests, the viruses known as encephalomyocarditis, Columbia-SK, M. M., and Mengo encephalomyelitis have been found to be identical. Analysis of their known physical and pathogenic properties further indicates that they are probably different strains of a single virus. We have been unable to demonstrate any relationship between the four strains of this virus and the Lansing, Yale-SK and Brunhilde strains of poliomyelitis or a murine encephalomyelitis virus.