Do you have four minutes? That's how long researchers say it'll take a man to rub his hands with a sanitizer before flu-A can be deactivated.
KYOTO, Japan – The influenza season is fast approaching, meaning that millions will use hand sanitizers more often in an effort to protect themselves from the flu. Most people, including healthcare professionals, believe that flu viruses are quickly neutralized after coming into contact with an ethanol-based disinfectant, but a new study finds that this is not the case for at least one flu strain.
Professional Kyoto researchers at the University of Medicine in Japan found that influenza A virus (IAV) remained active and infectious in infected wet mucus even after being exposed to ethanol-based disinfectant for two full minutes. According to their studies, it took almost four minutes to expose the desinsectant to completely deactivate the virus.
Needless to say, most people do not rub their hands with a disinfectant for four minutes. [1
So, imagine that someone with influenza A coughs on your hand and then shakes your hand a few minutes later. You will need to rub your hands with a disinfectant for four minutes to disable the virus if even the slightest trace of wet, infected mucus breaks into your hand.
"The physical properties of mucus protect the virus from inactivation," says doctor and molecular gastroenterologist Dr. Rhehei Hirose in a message from the American Society of Microbiology. "Until the mucus is completely dry, the infectious IAV can remain on the hands and fingers, even after proper antiseptic rubbing of the hands." we are cutting against this flu virus. The research team says that doctors and other healthcare professionals need to be extra careful; if they do not properly deactivate the virus between seeing different patients, they can quickly spread the flu to many people.
Click here to subscribe to our weekly newsletters and receive the latest STUDYFINDS.ORG surveys by email!  First, the study authors analyzed the physical properties of mucus, and just as they expected, they noted that ethanol was much more difficult to pass through mucus than through saline. Next, the phlegm collected from patients with IAV is smeared on human fingers and analyzed. The aim of the researchers during this phase was to try and simulate a situation in which medical personnel transmit the virus as best as possible.
After being exposed to ethanol for hand disinfection for two minutes, the IAV virus was still active in the mucus of the fingertips. After four minutes, the virus was completely deactivated.
This study is particularly noteworthy because it challenges previous studies that have found ethanol to be effective against IAV. However, Dr. Heights believes that he knows why his study came to such different conclusions: previous studies have analyzed mucus that is already dry, while this study analyzes mucus that is still wet. In fact, when Dr. Hearrows and his team repeated the experiment using dry mucus, the virus was completely deactivated by the disinfectant within 30 seconds.
It is also worth noting that the finger test used for this study may not be accurate mimicking typical hand rubbing movements that may be a little more effective at spreading a disinfectant all over the hand.
Currently, both the Centers for Disease Control and Prevention and the World Health Organization formally recommend the use of regular disinfectant for 15-30 seconds to ensure optimal hand hygiene. Unfortunately, this is simply not enough friction to stop the IAV, according to Dr. Heights.
On the bright side, researchers have identified a strategy for cleaning hands that is even more effective than disinfectants. Washing the hands with antibiotic soap has been shown to deactivate the IAV virus within 30 seconds, even when the mucus was still wet.
The study was published in the scientific journal mSphere.