Efficacy of Virucidal Treatments against Poliovirus Type 1 Deposited on Stainless-Steel Carriers

Safe containment of infectious poliovirus (PV) within Poliovirus-Essential Facilities (PEFs) will require the implementation of reliable PV-inactivation approaches for decontaminating work surfaces. Such approaches should be demonstrated empirically to display adequate efficacy at the use temperature, and the contact times required should be characterized to ensure efficacy. Such efficacy is judged by the ability of the inactivation approach to completely inactivate any PV deposited, with the demonstrated total log₁₀ reduction in PV titer being as high as empirically achievable. We screened several approaches for their efficacy in inactivating wild-type PV type 1 Chat strain experimentally deposited on stainless-steel carriers at room temperature. On the basis of the results, we selected two approaches (5000 ppm sodium hypochlorite in water and 95% <i>v</i>/<i>v</i> ethanol in water) for further characterization for repeatability of efficacy (log₁₀ reduction in PV titer) and time kinetics of inactivation. We now report that both PV-inactivation approaches, which should be readily available to all PEF laboratories globally, fulfill the expectations expressed above, with 5000 ppm sodium hypochlorite reproducibly causing ≥5.38 log₁₀ inactivation and 95% ethanol reproducibly causing ≥4.46 log₁₀ inactivation of PV on stainless-steel surfaces within a 5 min contact time at room temperature.