Purpose: To test the efficacy of a novel portable device for delivery of aerosolized hydrogen peroxide against GI.6 and GII.4 HuNoV, as well as bacteriophage MS2, Feline Calicivirus (FCV), and Tulane Virus (TV).
Methods: Sterile stainless steel strips (1 x 5 cm) were inoculated with 25 μl of either fecal stocks (HuNoV) or viral stocks (surrogates). Inoculated strips were allowed to dry and placed throughout a 1,040-ft3 BSL3 containment lab. The air handler unit was turned off, and an 8% aerosolized hydrogen peroxide (aHP) solution was delivered into the room using the RDS3110 portable unit (Aeroclave LLC, Winter Park, FL) until the target concentration of aHP was met (ranging from 0.2 to 0.35 ml/ft3). The target concentration was held for 5 min, and the air handler unit was then turned back on to reduce aHP levels to below 2 ppm. Exposed virus was eluted in PBS and stored at -80°C prior to analysis. Impact of aHP on viral fitness was determined using RT-qPCR for HuNoV samples, and plaque assays for surrogate viruses. All experiments were performed in triplicate.
Results: The amount of aHP injected was significantly associated with the degree of virus inactivation (P < 0.05). Exposure to 0.35 ml-aHP/ft3 achieved a 2.5-log reduction in RT-qPCR units for both GI.6 and GII.4 HuNoV, and a 5.5, 4.3, and 3.4-log reduction in PFU for MS2, FCV, and TV, respectively.
Significance: FCV and MS2 were more sensitive than HuNoV or TV to aHP. TV may be a better surrogate than FCV for future disinfection studies. The RDS3110, using an 8% H2O2 solution, is a portable and effective means for HuNoV disinfection for users concerned with hazards associated with higher concentrations of H2O2.