Hand-washing, even without soap, is more effective at quickly killing influenza A virus than alcohol-based hand sanitizers, according to a study published Sept. 18 in mSphere.
If soap and water are not available, the CDC recommends clinicians use ethanol-based disinfectants for at least 15-30 seconds as an effective hand hygiene practice. However, researchers from the Kyoto (Japan) Profectural University of Medicine found that ethanol-based hand sanitizers must be in contact with influenza A for at least four minutes to completely kill the virus. They noted that mucus surrounding influenza A virus droplets protect it from the ethanol in sanitizers. Therefore, the virus cannot be deactivated by hand sanitizer until the mucus is completely dry. When mucus is dry, the virus is deactivated within 30 seconds.
This finding is significant, as many clinicians often use hand sanitizer quickly between patient interactions. To prevent the spread of influenza A, researchers recommended hand-washing instead of ethanol-based hand sanitizer, since hand-washing is effective against both dry and nondry mucus.
"In our study, the hand-washing was done without any soap," co-author Ryohei Hirose, MD, PhD, infectious disease researcher, told CIDRAP News. "Even hand-washing without soap is effective against influenza viruses. Of course, hand-washing with soap is also effective, and further increases in disinfection effects are expected."