BIOLOGICAL CHARACTERISTICS OF SOME OF THE ARBOR VIRUSES IN VIVO AND IN VITRO

Abstract

The effect of continous incubation at 37[degree]C on infectivity titers of Easter, Western and St. Louis encephalitis, Sindbis, West Nile, Ntaya and Bwamba viruses in cell-culture medium consisting of Morgan''s 199 solution supplemented with 5% inactivated calf serum was investigated. All viruses tested were found to be completely inactivated after an incubation period of 3 to 4 days. Differences in thermal stability were not related to the serologic groupings in the Casals'' classification of the ARBOR viruses.