Decontamination studies with the agents of bovine spongiform encephalopathy and scrapie

Macerates of bovine brain infected with bovine spongiform encephalopathy (BSE) agent, and rodent brain infected with the 263K or ME7 strains of scrapie agent, were subjected to porous-load autoclaving at temperatures between 134 and 138 degrees C for < 60 min. Bioassay in rodents showed that none of the regimes produced complete inactivation. Homogenates Of BSE-infected bovine brain were exposed for < 120 min to solutions of sodium hypochlorite or sodium dichloroisocyanurate containing < 16,500 ppm available chlorine. There was no detectable survival of infectivity after the hypochlorite treatments but none of the dichloroisocyanurate solutions produced complete inactivation. Homogenates of BSE-infected bovine brain, and rodent brain infected with the 263K and ME7 strains of scrapie agent, were exposed for < 120 min to 1 M or 2 M sodium hydroxide but no procedure produced complete inactivation of all agents tested.