Should we all be wearing face masks during the pandemic?
Current World Health Organisation (WHO) recommendations are that face masks are of use in clinical situations and may also prevent the spread of disease if worn when someone has a cough or coronavirus symptoms.
In short, members of the public are advised not to wear one unless they are sick with coronavirus or caring for someone who is. This is based on there being no specific evidence to suggest the mass wearing of masks has any potential benefit. There are anxieties about incorrect fits and false reassurance for individuals wearing them, not to mention the global shortage of masks for those at the healthcare front line.
Is there a shift to advising everybody to wear masks in public?
Two factors are prompting some re-evaluation by the WHO – new unpublished evidence from Hong Kong on viral spread, and the US Centres for Disease Control and Prevention (CDC) – arguably the world's second most influential public health agency – flagging a need for change.
US case numbers are doubling every two to three days and CDC concerns have been heightened by “a significant amount of asymptomatic spread” – people with no obvious symptoms infecting others.
Put simply, one or two days before symptoms develop, a person may be contagious and spreading the virus. CDC data shows high rates of transmission by people who are infected but do not know it yet.
An infected person may not develop any symptoms at all and masks could reduce transmissions from this cohort.
Is asking billions of people to wear face masks an impossible ask?
The CDC has been quick to underline it’s not going to be advising everybody to get their hands on high-grade “N95” medical masks, an essential piece of personal protection equipment (PPE) for front-line workers that is already scarce.
For this purpose, ordinary surgical masks and even home-made masks will do as a last resort. They will help slow transmission in the community, though they don’t ensure complete protection for wearers.
There’s a side benefit, wearing any kind of mask, even a scarf, makes you less likely to touch your face – an important infection control measure.
What level of protection can home-made masks offer?
Understandably, home-made masks are not as effective as medical-grade ones. Wearing a home-made mask will not guarantee protection against coronavirus, also known as Covid-19. Their effectiveness is better when combined with regular hand-washing, physical distancing, self-isolation and cocooning.
Researchers have evaluated a range of household materials that in the event of a pandemic serves as a DIY guide. They found T-shirts and pillowcases made into a mask can act as a barrier against influenza, or help limit spread by a person with symptoms. There are many online guides to making masks. It can be as simple as using a folded piece of cotton and two elastic bands. But infectivity risk demands that masks are put on and taken off correctly.
What will the WHO be factoring in as it weighs up its advice?
The WHO is facing into an arduous evaluation of latest evidence, logistics and the risk that altering its stance may shift focus in the wrong way in the Covid-19 battle.
Masks themselves can become a virus spreader when they become saturated with breath condensation, and they don’t protect against coronavirus getting into the eye.
The WHO will also have to factor in cultural differences. In countries like China and Singapore masks are a norm for those with respiratory disease symptoms and at times of epidemics. The current emergency has exacerbated discriminatory behaviour towards those who wear masks as a precaution from people who associate masks with infection.
The most telling factor prompting change, however, is likely to be indication that droplets may be projected much farther into the air than previously thought – 6m (20ft) for a cough and up to 8m (26ft) for a sneeze.
