Growth and spread of causative agent of Creutzfeldt-Jakob disease in intraperitoneally infected mice.

The progression of Creutzfeldt-Jakob disease (CJD) was studied in ddY mice infected intraperitoneally with the Fukuoka-1 strain, a transmissible agent isolated from a CJD patient in Japan. Infectivity became detectable simultaneously in the brain, the spleen and the liver, i.e. 19 weeks after inoculation. Infectivity titer ranged from 10(2) to 10(3) LD50/g in all three organs up to 35 weeks, in contrast to intracerebrally infected mice in which the content of infectious CJD agent is higher in the brain than in the liver and the spleen. Cuffs appeared in the brain roughly four times in the period from 3 to 37 weeks after inoculation. The observed infectivity was discussed in relation to the appearance of cuffs in the brain.