Disclaimer: The views and opinions expressed by this author are their own and do not represent the official position of the Barbados Today Inc.
There are various statistical models that have calculated the risk of COVID-19 transmission. If someone who has COVID-19 (on the left in the picture above), not wearing a face mask, coughs or sneezes in close proximity (< 6 feet) to someone not wearing a mask, the risk of transmission is as high as 90 per cent. If the second person wears a mask, the risk drops to 30 per cent.
The best scenario (apart from the one in which neither person has COIVD-19), where everyone wears a mask, and maintains social distancing (6 feet), there is an almost zero chance of disease transmission.
The type of mask may also be important. While two types of professional masks, the N95 and the surgical masks, have been around for many years and have undergone scientific scrutiny, this new pandemic has generated a band of new entrepreneurs who offer home-made masks for sale. Some research coming out of Australia suggests that a three-layer mask was the most effective at limiting droplet spread. A two-layer cloth cotton mask was more effective during coughing and sneezing than one made from a single layer, but even the single-layer mask was better than no mask. Since COVID-19 does not seem to want to leave us anytime soon, continued focus on personal and community safety will always be needed in the future, and investing in a proper set of masks will help keep everyone healthy.
At the start of the pandemic, when there was a worldwide shortage of face masks and other personal protective equipment (PPE), health officials advised the general public to reserve the masks for health officials. Now, that advice has evolved into everyone should wear masks at all times when in public.
Another study by the World Health Organization (WHO) found that if people wear masks whenever they are in public, it is twice as effective at reducing the R value than if masks are only worn after symptoms appear. The R value measures the average number of people that one infected person will pass the disease on to. An R value above 1 can lead to exponential growth, such as seems to be happening in many parts of the world not named Barbados. Putting this into the picture above, it may not be known if the person on the left is COVID-19 positive, or has any symptoms of the disease, but viral transmission is still possible. At this point, some seven months after the disease first appeared, the virus still has the upper hand in very many parts of the world.
In the absence of a vaccine which we may or may not have access to, for a variety of reasons, the maintaining the 3W’s: wash your hands, wear your face mask, and watch your (social) distance is still a very effective way of preventing viral spread.
Dr. C.V. Alert, MB, BS, DM.