The rates and sites of accumulation of equine encephalomyelitis virus in tissues of young adult mice following infection by a peripheral route were studied. Virus was detected in circulating blood and in thymus 2 hours after inoculation with a small dose of virus (about 400 LD50). Virus could be recovered from all tissues examined at 6 hours, at which time definite increase in virus content could be demonstrated. The primary site of multiplication of virus could not be determined with certainty because of the rapid development of viremia. Maximum infectivity was attained in non-nervous tissues in 24 to 48 hours after inoculation. Concentration of infective virus decreased most rapidly after 4 days in blood and liver.
Virus accumulated more slowly in brain, but eventually reached the highest content found in any organ, then persisted at high titer throughout the course of the illness.
VEE virus was recovered from urine as well as from feces collected from mice 3 days after infection, prior to appearance of clinical signs of illness.
Present address: Department of Pathology and Bacteriology, New York State Veterinary College, Ithaca, N. Y.
Present address: Division of Geographic Pathology, Virology Branch, Armed Forces Institute of Pathology, Washington 25, D. C.