Hydrogen Peroxide Gas and Ozone Gas Synergistically Inactivate Prion Infectivity on Stainless Steel Wire

Prions are infectious agents causing prion diseases, which include Creutzfeldt-Jacob disease (CJD) in humans. Several cases have been reported to be transmitted through medical instruments that were used for preclinical CJD patients, raising public health concerns on iatrogenic transmissions of the disease. Since preclinical CJD patients are currently difficult to identify, medical instruments need to be adequately sterilized not to transmit the disease. In this study, we investigated the sterilizing activity of two oxidizing gases, ozone gas and hydrogen peroxide gas, against prions fixed on stainless steel wires using a mouse bioassay. Mice intracerebrally implanted with prion-contaminated stainless steel wires treated with ozone gas or hydrogen peroxide gas developed prion disease later than those implanted with control prion-contaminated stainless steel wires, indicating that ozone gas and hydrogen peroxide gas could reduce prion infectivity on wires. Incubation times were further elongated in mice implanted with prion-contaminated stainless steel wires treated with ozone and hydrogen peroxide-mixed gas, indicating that ozone-mixed hydrogen peroxide gas inactivates prions on these wires more potently than ozone gas or hydrogen peroxide gas. Taken together, these results suggest that ozone-mixed hydrogen peroxide gas may be useful for prion sterilization of medical instruments.