A Brain Factor influencing the Viability of Neurotropic Rift Valley Fever

Abstract

DURING experiments on the viability of Rift Valley fever it was noticed that crude extracts of virus-infected brain tissue in 10 per cent rabbit, sheep or human serum were less stable than the virus partially purified by differential ultra-centrifugation and suspended in the same diluents. In Fig. 1 this difference in viabilities is shown. Curve (a) shows the survival at 37° C. of virus in a crude or unpurified suspension of four virus-infected adult mouse brains in 40 ml. of 10 per cent rabbit serum saline. Curve (b) shows the survival of partially purified virus stored under the same conditions. It will be noticed that the disappearance of the virus in the partially purified material followed the exponential law, whereas the unpurified material showed an increasing rate of inactivation with time.