Hand sanitizer may not be enough to stop the spread of flu

Hand sanitizer may not be enough to stop the spread of flu. According to new research from the Kyoto Prefectural University of Medicine, using ethanol-based hand sanitizers is not enough to prevent the spread of flu viruses. This includes influenza A virus (IAV), which remains infectious in wet mucus of those infected, even after ethanol-based disinfectant (EBD) is introduced.

The researchers found that in order to fully deactivate the virus, one would need a whopping four minutes of exposure to the EBD.

“The physical properties of mucus protect the virus from inactivation,” said study leader, Ryohei Hirose, Ph.D, MD., a physician and molecular gastroenterologist at the University of Medicine. “Until the mucus has completely dried, infectious IAV can remain on the hands and fingers, even after appropriate antiseptic hand rubbing.”

Ethanol spreads more slowly through the viscous mucus than it does through saline, the researchers saw. After analyzing the sputum that had been collected from IAV-infected patients, and then dabbed on human fingers and introduced to an EBD, the virus remained active even after two minutes of EBD exposure. Four minutes of exposure was the minimum amount of time needed to deactivate the virus.

The researchers believe misinformation has been spread about the effectiveness of EBDs on reducing the spread of IAV due to the fact that most studies are conducted on dry mucus, in which IAV can be deactivated by EBDs in about 30 seconds.

Luckily, the researchers did identify a hand-hygiene strategy that works to reduce the spread of IAV. We should wash our hands with antiseptic soap as often as possible, rather than relying on EBDs. Antiseptic soap, they found, deactivated the virus within 30 seconds, whether the mucus was wet or dry.

This study is published in mSphere.

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By Olivia Harvey, Earth.com Staff Writer

Image Credit: Shutterstock/yurakrasil