Platform news, 5th August, 2020, Wednesday
Dr. Pritom Das
We are seeing emerging evidence for better efficacy of face masks in comparison to surgical and N95 masks than previously thought. By most evidence the virus can be ‘airborne’ (the quotation mark b/c its different from other typical measles and flu airborne transmission) and microdroplets formation can occur particularly in 3 ‘C’- confined, crowded and close-contact settings. Risk presumed to be lesser in outdoor spaces.
Few pointers on what we are doing wrong, what we know better than before and simple solutions we can afford
1. Masks are for preventing dissemination of droplets from WEARERS to protect others from getting infected as opposed to preventing the already aerosolized viruses from getting in (it does that too-next point), by the CDC protocol- till now.
2. Masks can not only PREVENT infection (by not letting any particle at all- this is less), but also can reduce the SEVERITY by limiting the viral dose (by stopping the larger droplets- more common). I.e. you still might get infected but won’t need hospitalization/ won’t die.
3. Cloth masks work better when in multiple layers i.e. 2/3 layers than single layer. This also depends on the material type.
4. Efficacy reduces as droplet size drops i.e. works lesser for aerosols than droplets. Places where viral load is higher like in hospitals doctors need to wear N95 mask which gives better protection against aerosols.
5. You can (and definitely should) try to improve ventilation in either isolation/ quarantine settings by opening window, keeping the fan on, can try to install exhaust fan (expensive), ACs need to change filter (merv 13 or more- way expensive).
6. Remember that masks lose efficacy not by losing their capacity to filter particles (rather evidence claims they get better with time) than getting dirty and worn-down i.e. getting unbreathable.
7. Reusing masks- the problems with fomite transmission (droplets setting upon mask surfaces) thought to be less severe than before. Can still remain cautious by using it at 48 hours interval (both cloth and N95).
8. N95 masks are more durable than you think- by some claims can be used for 20 times at least. If you keep the mask clean that is, problem is not with particle filtration as previously said.
9. Masks (clean) DON’T CAUSE HYPOXIA. There are some additional myths that should be challenged too.
10. N95 masks reusing- there are some methods that have been proposed- soapy water, hydrogen peroxide, alcohol, microwave steam, UV lights. All have some problems and advantages on their own- better have 2/3 masks at hand.
11. Problem with our country- people are TOLD to wear masks- many are complying but only few know the proper ways to use masks (don’t wear it down when talking/ sneezing, when need to remove it completely, don’t touch the outer surface, keep distance on regardless of masks use). They need to be EXPLAINED how to wear one, how to remove along with other basic hygiene measures like hand-washing. Public health communication needs to improve, but let’s not get into those now.
Few basic improvements we can afford right now-
1. Advocate for multiple layer cloth masks instead of surgical/ single layer/ face- shields/ head cap/ coverall/ disinfection kits/ fever checks.
2. Even if single layer, methods to wear PROPERLY should be reinstated
3. Masks have greater importance in 3 ‘C’s than in outdoors, that’s where risk communication should be strengthened.
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