One of the abiding images of any virus outbreak is people in surgical masks.
Using them to prevent infection is popular in many countries around the world, most notably China during the current coronavirus outbreak where they are also worn to protect against high pollution levels.
Virologists are sceptical about their effectiveness against airborne viruses.
But there is some evidence to suggest the masks can help prevent hand-to-mouth transmissions.
Surgical masks were first introduced into hospitals in the late 18th Century but they did not make the transition into public use until the Spanish flu outbreak in 1919 that went on to kill over 50 million people.
Read more at BBC…