when large groups of animals were used for transmission experiments it became obvious that within one week after intranasal exposure , all the hamsters either died or became clinically affected , or did not show signs of disease but developed acute inflammatory brain lessions . tlater on , between 2-6 weeks following inoculations only 90 % of hamsters were affected with either overt signs of disease or subacute brain lesions , suggesting that in about 10 % of hamsters the initial infection did not progress further and that in these animals the early brain lesions disappeared .
C0012634
disease
C0009450
infection