Effect of Spraying Functional Water on Aerosolized Escherichia coli and Two Physicochemically Distinct Swine Viruses

Abstract

Abstract. Epidemic infectious diseases cause significant economic losses to the pork industry, and yet few control measures are currently available to reduce their airborne transmission. Therefore, the objective of this study was to determine whether spraying distilled water (DW), emulsified canola oil, didecyl dimethyl ammonium chloride, or slightly acidic diluted hypochlorite solution (SADH) could effectively reduce the concentration of mechanically aerosolized and two physicochemically distinct swine viruses, porcine sapelovirus (PSV) and porcine epidemic diarrhea virus (PEDV). Each functional water was sprayed in an enclosed room (4 m × 4 m × 4 m) at a Biosafety Level 2 experimental facility 15 min after aerosolization of a solution containing 10 log10 colony-forming units (cfu) of and 9 log10 50% tissue culture infectious dose (TCID50) of each of PSV and PEDV. Airborne and settling samples were collected before and after spraying, and the quantities of live and infectious virus were assessed. It was found that spraying treatment mitigated the bacteria concentration in the air and settling samples, with the airborne concentration decreasing by 1.5 log10 cfu m-3 following spraying with DW and immediately falling below the detection limit following spraying with SADH. Furthermore, the settling concentration fell below the detection limit 20 min after spraying with SADH. The airborne PSV concentration also decreased by 1.5 log10 TCID50 m-3 after spraying with DW and canola oil, while spraying with SADH caused both the airborne and settling PSV concentrations to immediately fall below the detection limit, where they remained 60 min later. Thus, spraying with functional water, particularly SADH, effectively reduced the airborne and settling concentrations of these bacteria and viruses. Keywords: Aerosols, Disease control, Misting, Sterilization.