Hepatitis E virus is highly resistant to alcohol-based disinfectants

P Behrendt, M Friesland, JE Wißmann, V Kinast, Y Stahl, D Praditya, L Hueffner, PM Nörenberg, B Bremer, B Maasoumy, J Steinmann, B Becker, D Paulmann, FHH Brill, J Steinmann, RG Ulruch, Y Brüggemann, H Wedemeyer, D Todt, E Steinmann

J Hepatol. 2022 Jan 24;S0168-8278(22)00019-8. doi: 10.1016/j.jhep.2022.01.006. Online ahead of print.

Background: The Hepatitis E virus (HEV) is the most common cause of acute viral hepatitis worldwide and mainly transmitted via the fecal-oral route or consumption of contaminated food products. Due to the lack of efficient cell culture systems for the propagation of HEV, limited data regarding HEV sensitivity to chemical disinfectants are available. Consequently, preventive and evidence-based hygienic guidelines on HEV disinfection are lacking.

Methods: We used a robust HEV genotype 3 cell culture model which allows quantification of viral infection of quasi-enveloped and naked HEV particles. For HEV genotype 1 infections the primary isolate Sar55 in a faecal suspension was applied. Standardized quantitative suspension tests using end point dilution and large-volume-plating were performed for the determination of virucidal activity of alcohols (1-propanol, 2-propanol, ethanol), WHO disinfectant formulations and five different commercial hand disinfectants against HEV. Iodixanol gradients were conducted to elucidate the influence of ethanol on quasi-enveloped viral particles.

Results: Naked and quasi-enveloped HEV was resistant to alcohols as well as alcohol-based formulations recommended by WHO. Of the tested commercial hand disinfectants only one product displayed a virucidal activity against HEV. This activity could be linked to phosphoric acid as essential ingredient. Finally, we observed that ethanol and possibly non-active alcohol-based disinfectants disrupt the quasi-envelope structure of HEV particles, while leaving the highly transmissible and infectious naked virions intact.

Conclusions: Different alcohols and alcohol-based hand disinfectants were insufficient to eliminate HEV infectivity with the exception of one commercial ethanol-based product including phosphoric acid. These findings have strong implications for the efficient prevention measures to reduce viral transmission in clinical practice.

Lay summary: Hepatitis E virus (HEV) showed a strong stability against alcohols and alcohol-based hand disinfectants. With phosphoric acid one essential substance could be identified to active ethanol in its virucidal activity against HEV, which allows to improve hygiene measures for the prevention of HEV transmissions.