Thread by @sanjeevsanyal

A very interesting article on implications of the airborne nature of #COVID19. Ensuring ventilation in enclosed spaces may matter more than any other measure we are taking. 1/n

wired.com/story/the-teen…

This is why adding UV filters (incidentally very cheap) to central A/c systems and discouraging enclosed space congregation is important. May explain why Covid spiked in winter in cold countries and in summer here, and shows no seasonality on the equator (Brazil). 2/n

More research needed but this has important implications for what activities can be opened up quickly and what cannot. Also, how the high risk activities need to be redesigned. A/c of metro systems should be the single biggest focus in cities. 3/n

Also means that medical response to Covid shouldn't be concentrated in large hospitals but most be disaggregated as much as possible, even home care except extreme cases. Concentrated viral loads is the problem. All of this has been said before, but good to reiterate. 4/n

Incidentally, the article shows how the failure of recognise what may be obvious in retrospect is due to group-think in the public health fraternity - and this is turn is due to a old error that that became hardwired in protocols. Example of #Butterfly effect 5/n

A practical implication is that small, open local markets are relatively safe. We should keep them open LONGER to avoid concentration i.e. not impose curfews & restricted hours on them. 6/n

Here is another article in the same vein. It also shows why general spraying of disinfectants is a waste of time. Also, no amount of using toothpicks to press elevator buttons is effective if you are not wearing a mask 7/n

aarp.org/health/conditi…

A MIT study makes similar point. If you are in greater risk in an enclosed space even with all protocols than following some basic precautions in a park. This makes a hospitals particularly dangerous places (and their A/c systems need UV filters asap) 8/n
cnbc.com/2021/04/23/mit…

Some may think that this is common-sense that your grandma told you. However, Lancet article published just last month shows the issue is still hotly debated. If pandemic is all about airborne viral load, then indoors vs outdoors are totally different 9/n

thelancet.com/journals/lance…

Speculating here, but seems that medical staff in hospitals without HEPA or other filters may be safer opening the windows and using fans. It is hot, so perhaps give up full PPE kits and retain facemasks & shield. May be safer than full PPE kits plus A/c. Just thinking aloud.

Ok, a doctor friend says that is not a good idea in an active Covid ward as there will still be a lot of viral load even with open windows......full PPE kits evidently are unavoidable.