Inactivation of transmissible degenerative encephalopathy agents: A review

The unconventional agents that cause transmissible degenerative encephalopathies, such as bovine spongiform encephalopathy, scrapie, and Creutzfeldt-Jakob disease (CJD), are relatively resistant to inactivation by standard decontamination procedures. The only methods that appear to be completely effective under worst-case conditions are strong sodium hypochlorite solutions or hot solutions of sodium hydroxide. Other procedures that result in significant degrees of inactivation are described. The infectivity levels in histologically-fixed tissue can be reduced substantially by treatment with concentrated formic acid without adversely affecting the microscopic quality of the tissue.