Hepatitis E virus resistant to alcohol-based disinfectants

Alcohol-based hand disinfectants might be insufficient to suppress hepatitis E virus (HEV) infectivity, a new study has found.

Using a robust HEV genotype 3 cell culture model, the researchers assessed the virucidal activity of various alcohols: 1-propanol, 2-propanol, and ethanol. The WHO-recommended disinfectant formulations, along with five different commercially available hand disinfectants, were also tested.

Standard suspension assays with 30-second incubation periods showed that 1-propanol, with concentrations ranging from 20% to 80%, had no clear impact on HEV infectivity. HEV also demonstrated strong resistance against various concentrations of 2-propanol.

In comparison, high concentrations of ethanol elicited a fivefold decrease in HEV infectivity, though such viral activity could still be detected at titres of 10⁵ FFU/mL.

Two WHO-recommended alcohol-based disinfectant formulations were then tested, one based on 2-propanol and the other on ethanol. Both likewise showed no substantial decrease in HEV infectivity.

Moreover, of the five tested commercial hand disinfectants, only one was able to achieve complete suppression of HEV infectivity. This disinfectant contained phosphoric acid, which may explain its virucidal properties. In contrast, HEV cultures continued to show activity even after exposure to the other four products.

“We provide evidence that HEV has strong stability against alcohols and alcohol-based hand disinfectants with the identification of one active product,” the researchers said. “These results will allow to improve hygiene measures for patients with an ongoing HEV infection as well as their environmental surroundings. In particular, in cases of an HEV outbreak all precautions should be made to reduce spread of the virus.”