July 7, 2020
Airborne
I have been writing this blog for 4 months. Hard to believe how much has happened and that I would still enjoy writing it. I think it helps me process and truly consider what is going on. Weirdly, I sleep more soundly after writing. My brain turns off better. When I began, I admitted that the virus was so new that the data and recommendations would change as we learn more. That is happening. Amazing, really, how much has been learned so far.
We have learned more how to support people when they are critically ill so that more survive, we have learned more how to protect ourselves, learned more who is most at risk. But there is still so much to know. The virus has surprised many experts in its behavior in so many ways. Recommendations have changed and now many experts feel much more clearly that SARS-CoV-2, the virus that causes the disease COVID-19 is airborne.
Initially, they thought the virus spread through larger respiratory droplets which were more likely to fall quickly to the floor, but may contaminate surfaces. Likening it to influenza which is transmitted that way. They felt SARS-CoV-2 was not likely to hang in the air, like measles. Measles is very contagious for that reason- it can stay in the air in a room for 2 hours! That is why we hear about what locations people were at and what time they were there, prior to their diagnosis of measles. This can help people tell if they were exposed. The World Health Organization, the CDC, and other groups made initial. prevention recommendations based on the large droplet effect and less on the airborne effect. Hence, the emphasis on hand washing from the beginning and the confused messages about masks.
More and more evidence points towards the virus lingering in the air in smaller droplets, especially indoors. This knowledge matters. It explains why certain events have been super-spreading events, why household contacts or co-workers in indoor settings are more likely to catch COVID-19 from people infected around them, why asymptomatic transmission happens. Why the outdoors appears to be safer. Why masks seem to help and why distancing has been effective.
This knowledge can help you decide what places are safer to go to. Definitely smaller rooms, like conference rooms, not so much. Nor large indoor gatherings. Indoor dining? Probably not, but maybe outdoors on a breezy day? Going grocery shopping with a mask on while others are masked- pretty good, but don’t linger. Time of exposure matters too. The big considerations are schools and other places like day care. Good ventilation helps, as well as possibly ultraviolet light. Moving forward, planning can focus on these issues to lower transmission.
And beware air conditioning in the south. I wonder if it is one reason affecting the big increase in infections in places like Florida, Arizona, and Texas. Being outdoors is the best place to be around others, so save your energy about scolding people who are outdoors in places like the beach. Worry more about those going to bars or parties or groups who live together like the big Greek Row outbreak at UW. The outbreaks related to Spring Break, in other areas, are related more to sharing housing and partying, rather than being on the beach together. But I don’t really want you to worry about those things, just be aware of the risk that can be brought home from those situations.
I still recommend washing your hands, and definitely cover your nose and keep safe six. But enjoy being outdoors as much as you can.
And finally, my caveat is that this is my experience and my opinions, which are subject to change as more information is available, and not related to the organization I work for. Thanks for reading.
https://www.nytimes.com/2020/07/04/health/239-experts-with-one-big-claim-the-coronavirus-is-airborne.html
https://www.nytimes.com/2020/07/06/health/coronavirus-airborne-aerosols.html
https://news.harvard.edu/gazette/story/2020/06/air-conditioning-may-be-factor-in-covid-19-spread-in-the-south/
https://www.nytimes.com/2020/06/27/world/europe/coronavirus-spread-asymptomatic.html
https://www.theatlantic.com/health/archive/2020/07/it-okay-go-beach/613849/
https://www.washington.edu/news/2020/06/30/uw-public-health-seattle-king-county-responding-to-coronavirus-cases-in-greek-system/