Chemical inactivation of viruses

Doctor of PhilosophyDepartment of Diagnostic Medicine/PathobiologyRichard D. OberstViruses differ in their susceptibility and resistance to disinfectants and their ability to be inactivated based predominantly on structural and size differences. The virucidal methodology followed in this study was consistent with the U.S. Environmental Protection Agency guidelines for such efficacy testing. Various disinfectant chemistries were effective in rapid and complete inactivation of bovine coronavirus (BCV) including 25, 50, and 100% DF-200d, 10% bleach, 1% Virkon® S, and 70% ethanol following 10 min treatments. Efficacy was slightly reduced in the presence of organic challenge material (feces, soil). Treatment with 100% DF-200d or 10% bleach resulted in the degradation of BCV RNA. Treatment with 50 or 100% DF-200d, 10% bleach, or 1% Virkon® S resulted in the degradation of BCV proteins as detected by western blot analysis. Various disinfectants were effective in the complete inactivation of both mammalian and avian influenza test strains and included DF-200d, 10% bleach, 1% Virkon® S, and 70% ethanol following 10 min exposure but was reduced in the presence of organic challenge. Treatment with DF-200d or 10% bleach resulted in significant degradation of influenza RNA. Effective treatments against foot-and-mouth disease virus (FMDV) and bovine enterovirus-2 (BEV-2) included 10% bleach, 4% sodium carbonate, 2% sodium hydroxide, and Sandia DF-200. Treatment with 5% acetic acid was effective against FMDV, but not BEV-2. Treatment with 70% ethanol was not effective for inactivating FMDV or BEV. Additionally, 10 min treatment with 10% bleach, 2% sodium hydroxide, and Sandia DF-200 degraded FMDV and BEV-2 RNA. FMDV inoculated surfaces were exposed to 5% acetic acid, 10% bleach, 70% ethanol, 4% sodium carbonate, 2% sodium hydroxide, Sandia DF-200, 0.4% Oxy-Sept® 333, or 1% Virkon® S. All treatments except 70% ethanol were effective following 10 and 20 min contact on rubber and stainless steel. No treatments were shown to be effective for concrete, due to a low recovery of virus from this surface. Additionally, 10 and 20 min treatments with 10% bleach, 2% sodium hydroxide, and Sandia DF-200 degraded FMDV RNA on the surfaces evaluated