This egregious misunderstanding about masks is the kind of thing that happens when a 'scientific' conclusion is drawn from the evidence without a thorough investigation of the underlying facts. The practice of mask wearing by medical staff during surgery in particular and care of the ill in general in clinical settings does indeed reduce the rate of infection - but nobody who studied it ever really investigated how or why this happens; they all just take it on faith that the mask acts as a filter to stop the germs. Recent very simple testing demonstrates that aerosol sprays, cigarette smoke, moisture droplets, and a host of other contaminants all far larger and easier to trap than a virus or bacterium all penetrate these masks. The masks cannot filter out the infectious agents from the wearer's breath, yet somehow they do indeed reduce the rate of infection during surgery. Why?

Most people have an unsanitary habit so deeply ingrained in them from childhood that they do not even observe themselves doing it. How many of you can read a newspaper, count money, or open a paper or plastic bag without first licking your finger? Try it sometime. The surgeon's point of contact with the patient's open wounds is the tip of his finger; the germs are harbored inside his mouth. The mask keeps the fingertips out of the mouth. Mask-wearing in any other context is pure hogwash.