At room temperature, hepatitis B virus (HBV) remains contagious for several weeks and can even withstand temperatures of four degrees centigrade over the span of nine months. When applied properly, disinfectants are effective – but only undiluted. These are the results obtained by a German-Korean research team in a study using a novel HBV infection system in human liver cells.

Due to the lack of human research models, research had been conducted in duck hepatitis B viruses. Professor Eike Steinmann from the Department for Molecular & Medical Virology at Ruhr-Universität Bochum (RUB) and RUB alumnus Professor Marc Windisch from the Institute Pasteur Korea in Seoul published their report in the Journal of Infectious Diseases

Hepatitis B is primarily transmitted through contact with blood. "Consequently, it should be easy to control," said Eike Steinmann. However, there are frequent cases of people contracting hepatitis B  virus in hospitals or in the workplace.

Attempting to find out why, researchers had hitherto been forced to make use of the duck hepatitis B virus, which is related to the human virus. "However, those studies have only ever rough estimates as far as the infectiousness of HBV is concerned," points out Steinmann.

HBV infection system

 For their analyses, he and his colleagues used an HBV infection system in human liver cells, recently developed at the Institute Pasteur Korea, in order to obtain more realistic results. "The new HBV infection system leads to studies on the human virus that had not been possible until recently," explains Marc Windisch.

Using this model, the researchers were able to demonstrate that the infectivity of HBV barely decreased at room temperature even after a few weeks and that it remains very stable at four degrees centigrade over a period of nine months. "Various alcohol and off-the-shelf hand sanitizers deactivate the viruses," says Eike Steinmann. "If the disinfectants are diluted, however, their deactivating properties are reduced."

Disinfectants 

Luckily, diluting disinfectants is not common practice. "weeks, and that it remains highly stable at four degrees centigrade over a period of nine months. "Various alcohols and off-the-shelf hand sanitizers deactivate the viruses," says Eike Steinmann. "If the disinfectants are diluted, however, their deactivating properties are reduced. Luckily, diluting disinfectants is not common practice."

The researchers compared the efficacy of two alcohol-based WHO-recommended hand sanitizers against different viruses that have an envelope, such as the HBV. The comparison viruses included the Ebola virus and the hepatitis C virus. "Among all tested viruses, HBV demonstrated the highest resilience against both disinfectants," stresses Marc Windisch.