While hand hygiene (disinfection and hand washing) is important for effective prevention of contact infections with the new coronavirus and influenza virus, there is no preventive measure in the blank time between hand hygiene.It has been suggested that some disinfectants have a disinfecting effect (residual disinfecting effect) that remains even after being applied and dried, but accurate evaluation has not been performed so far.
Therefore, this time, the team of Kyoto Prefectural University of Medicine built a model for accurate evaluation of the residual disinfection effect.On this model skin, it is possible to obtain almost the same data as the evaluation results on the subject skin obtained in clinical studies, and the survival time of the virus on the model skin after applying and drying various disinfectants. The change was investigated and the residual disinfection effect was evaluated.
As a result, when a disinfectant such as povidone iodine, chlorhexidine gluconate, or benzalkonium chloride was applied, the survival time of the virus was significantly shortened, and a residual disinfectant effect was observed.With 0.2% benzalconium chloride, which showed a particularly strong residual disinfection effect, the survival time of the new coronavirus, human coronavirus, and influenza virus was shortened from 665 minutes to 5 minutes, from 1285 minutes to 12 minutes, and from 121 minutes to 4 minutes, respectively. That is.It was also confirmed that the effect was maintained for about 4 hours after being applied to the skin.
On the other hand, it was found that alcohol-based disinfectants such as ethanol and isopropanol, which are known to have a strong disinfecting effect, have almost no residual disinfecting effect.However, the addition of 0.2% benzalkonium chloride was able to produce a mixture that had both a strong disinfecting effect and a strong residual disinfecting effect.By using such a mixture for hand hygiene, it is expected that "appropriate disinfection of fingers" and "creation of a skin surface on which viruses do not easily survive" can be achieved at the same time.
The results of this research are expected to greatly contribute to the development of infection protection in the future as an innovative contact infection prevention method.