Resistance of poliovirus 1 and enterovirus A71 against alcohol and other disinfectants

Abstract

Poliovirus 1 (PV 1) is the standard virus used in tests to support claims of virucidal property in commercial hand sanitizers and disinfectants in China. Classified within the same genus as poliovirus, enterovirus A71 (EV A71), which causes hand-foot-mouth disease among children, has caused numerous outbreaks in China and other countries. Hand hygiene and surface cleaning are critical to prevent and control this disease and many other infectious diseases. This study compared the efficacies of 17 self-made alcohol-based hand sanitizers and 10 commercially available disinfectants (4 high-level, 4 intermediate-level, 2 low-level) against these two viruses. The results showed that by itself, ethanol needed to reach a concentration of 75 % to meet the inactivation requirement of 4-log reduction in average TCID50 against PV 1. Nine out of 13 laboratory-formulated alcohol-based hand sanitizers reached the 4-log inactivation requirement against PV 1 after 4.5 min, while the remaining four sanitizers did not. Unexpectedly, none of the tested ethanol-based sanitizers inactivated EV A71 by 4-log. For the commercially available disinfectants, all four high-level and one intermediate-level disinfectants passed the inactivation requirements against both PV 1 and EV A71, while two intermediate-level disinfectants met the inactivation requirement against PV 1 but failed against EV A71. The last intermediate-level and both low-level disinfectants did not meet the requirement for either PV 1 or EV A71. Therefore, PV 1 is more susceptible to inactivation by many common alcohol-based and non-alcohol-based disinfectants than EV A71. Therefore, the adoption of EV A71 as the standard test virus would elevate the disinfectant requirement standard and provide better protection for the public. Based on these results, seven new alcohol-based hand sanitizer recipes were formulated and found to be effective against both PV 1 and EV A71, with two candidates reaching the required 4-log virus reduction efficacy within 1 min.

Keywords: Disinfectants; Enterovirus A71; Hand sanitizer; Poliovirus 1; Virus inactivation.