Inactivation of Human Norovirus Surrogates by Benzalkonium Chloride, Potassium Peroxymonosulfate, Tannic Acid, and Gallic Acid

Novel methods to effectively disinfect contact surfaces and prevent human norovirus transmission are essential. The effect of benzalkonium chloride (BAC), potassium peroxymonosulfate (KPMS), tannic acid (TA), and gallic acid (GA) on enteric virus surrogates, murine norovirus (MNV-1), feline calicivirus (FCV-F9), and bacteriophage MS2 was studied. Viruses at high (similar to 7 log(10) PFU/mL) or low (similar to 5 log(10) PFU/mL) titers were mixed with equal volumes of BAC (0.2, 0.5, and 1mg/mL), KPMS (5, 10, and 20mg/mL), TA (0.02 and 0.2mg/mL), GA (0.2, 0.4, and 0.8mg/mL), or water and incubated for 2 h at room temperature. Viral infectivity after triplicate treatments was evaluated using plaque assays in duplicate. Low titers of FCV-F9 and MNV-1 were completely reduced, while low-titer MS2 was reduced by 1.7-1.8 log(10) PFU/mL with BAC at all three concentrations. High-titer FCV-F9 was reduced by 2.87, 3.08, and 3.25 log(10) PFU/mL, and high-titer MNV-1 was reduced by 1.55, 2.32, and 2.75 log(10) PFU/mL with BAC at 0.1, 0.25, and 0.5mg/mL, respectively. High-titer MS2 was reduced by similar to 2 log(10) PFU/mL with BAC at all three concentrations. KPMS at all three concentrations reduced high and low titers of FCV-F9 and MS2 and low-titer MNV-1 to undetectable levels, while high-titer MNV-1 was reduced by 0.92 and 3.44 log(10) PFU/mL with KMPS at 2.5 and 5mg/mL, respectively. TA at 0.2mg/mL only reduced high-titer FCV-F9 by 0.98 log(10) PFU/mL and low-titer FCV-F9 by 1.95 log(10) PFU/mL. GA at 0.1, 0.2, and 0.4mg/mL reduced low-titer FCV-F9 by 2.50, 2.36, and 0.86 log(10) PFU/mL, respectively with negligible effects against high-titer FCV-F9. BAC and KPMS show promise to be used as broad-spectrum contact surface disinfectants for prevention of noroviral surrogate contamination.