Induced Latent Infection of Monkeys with Vacuolating SV-40 Papova Virus. Virus in Kidneys and Urine.

Abstract

A latent infection was induced by exposure of African primates by a variety of routes to the vacuolating SV-40 virus, the simian member of the papova virus group. Virus multiplied in the Cercopithecus (green) monkey more abundantly than in the baboon, without inducing an apparent illness in either species. Early in the infection SV-40 was found regularly in the urine. The titer of the urine was as high as 106-5 TCD50/ml. Later in the course of the infection when viruria was waning, neutralizing antibodies appeared in the urine (as well as in the blood). Three to 8 months after infection, when virus was no longer recoverable from the urine, kidney biopsies were obtained. Part of each biopsy was tested for virus by the conventional method of inoculating ground tissue fragments into susceptible green monkey cultures, but not a single positive was obtained in this way. However, a number of biopsies yielded virus when they were grown as ex-plants in tissue culture. Kidneys yielded virus by this method 3 months after infection was initiated, and this latent infection persisted. Later biopsies, 6 to 8 months after infection, yielded virus in the previously positive monkeys.