Fact-based Covid Missive, 7/11/20: Death Rates, Aerosols, and Gray Medicine

Hi, I'm back as Robin-Schoenthaler-the-Boston-cancer-doctor-who-writes-missives-about-Covid.

Today I’m talking about Death Rates and Aerosols and Medicine Being Gray.

Massachusetts continues to be stable. All the metrics we now measure (positive tests, death rates, hospitalizations) are good. It’s so awesome that I’ve been able to write the same sentence for several weeks now!

However, reopening is happening so we’ll get more cases — it’s inevitable if you put unmasked mouths and noses near other unmasked mouths and noses for any length of time. Witness much of the rest of the country.

What is happening in other states (on a huge scale) is that reopening seems to result in an uptick in young people getting Covid — they’re the ones who are out and about more, working in front-facing jobs, going out to eat, etc. It takes a couple weeks after that to see more hospitalizations since younger people tend to not get super dooper sick (they can; it happens, but at much lower frequency).

In the meantime, though, the infected young people go home to older mom and dad or help grandma out at the hardware store, or see Uncle Maskless at a family cook-out, and then they (often unwittingly) infect them. So a couple of weeks after that you start to see a real uptick in hospitalizations of the older people and then a few weeks later another tragic uptick in deaths.

So, Answer Number 1,2,3,4,5,6,7 as to why we’re seeing lower death rates in the sunbelt: Lag time, since it takes a solid six weeks to see an impact. This gives journalists a lot of time to write headlines like “Death Rates Fall!” but really the right response is unfortunately “Just You Wait.”

More widespread testing also has an impact. Why? Well, remember in March when you could only get a test if you were super sick or admitted to the hospital?

Flash forward to now when we’ve built this big testing infrastructure (41 million tests as of yesterday!) and are testing tons of asymptomatic people — people who want to travel, people who need a test for work, people who are just curious. This means we’re getting positive results in the “unsick” (the asymptomatic or barely ill who are never going to die of Covid) and the young (who are very unlikely to die).

So a lower death rate doesn’t mean things are better. It just means either we haven’t seen the real death rates yet or we’re being affected by age-shift but we all (especially >65) are still at real risk.

Same virus. Same susceptibility. Same need to be careful.

(Also it’s possible we’re getting better at treating this, but that’s another story which will take a little time to sort out.)

We just don’t know about death rates.

Yet.

But we will.

A lot of headlines this week about aerosols, too.

What the heck are aerosols? Essentially, they’re the mist of super tiny particles that comes out of your mouth when you breathe or speak and that can hang in the air after you’ve left. It’s super important to find out if they can transmit Covid since this will obviously matter in terms of indoor activities including schools.

(Speaking of which, people ask me about schools. At this point I am not going to weigh in on the school topic as it is an unbelievably involved question of psychosocial complexity that is way way way beyond my pay grade. I will, however, soon post several articles by super smart people that give helpful facts and frameworks.)

One thing about Covid is that it is keeping us all humble. Right now, what I can tell you is “we still don’t think” a lot of transmission is through aerosols, but “we still don’t know” a lot about the subject, but “aerobiologists” ( a field I didn’t even know existed) are all over this.

This is what we do know: we know respiratory droplets (the big wet droplets you cough and sneeze out of your mouth and potentially into my nose or throat) (but hopefully instead into your mask) can and do carry tons of real, live, healthy, intact, whole, and most importantly CONTAGIOUS corona viruses. We know this. And this is why we wear surgical and cloth masks — to stop somebody’s disgusting virus-laden respiratory droplets from shooting down our throats.

The big question is how often tiny little misty aerosol particles (very small, not as wet) can carry real, live, healthy, intact, whole, and most importantly CONTAGIOUS viruses. We also don’t know whether the virus can survive when the particles get drier (like on an AC vent) or older (like some hours later), etc.

My most esteemed colleague Dr Jennifer L. Kasten, MD, MSC, MSC (follow her on FB), wrote that there hasn’t yet been a study finding “viable living virus in random air samples.” The clinical evidence that aerosols make a huge impact is still limited, except in very special circumstances (like the famous choir practice where sixty older people sang their hearts out in one room for over two hours).

So even though your mist of aerosol particles can definitely float and hang hours after your breezy nose leaves Market Basket (which is a very scary thought), we don’t yet have absolute evidence that us later walking through your Eau d’YourGrodyNose can infect us the way that you sneezing directly down our unmasked throat in the check-out line certainly can. 

We just don’t know about aerosols.

Yet.

But we will.

You know, when you’re a kid, medicine is black and white.

You get a sore throat, you get a strep test, it’s positive, you get an antibiotic, you get better. Black and white. Or you fall down and bust your wrist, you get an x-ray, it’s broken, you get a cast, you get a follow-up x-ray showing it’s healed up, you get the cast off. Black and white.

Unfortunately, that was essentially the end of the black and white medicine in your life. After childhood, it gets gray.

When to treat high blood pressure can be gray. Who to give a cancer treatment to and who doesn’t need it can be gray. Even who needs their appendix out can be gray (now we often give antibiotics instead!). Most things in medicine are gray.

And Covid is showing us even more gray. The virus tests aren’t black and white — there’s a lot of false negatives (even now about 20%). The antibody tests aren’t black and white — the antibody response isn’t predictable in groups or even in any one individual. The role of aerosols isn’t close to black and white. It’s all still gray.

What is black and white is this:

Masks.

Physical distancing.

Hand washing.

Staying home when sick.

And in the meantime, scientists and researchers are studying all this like crazy — the death rates and droplets and 240 possible drug therapies and 160 potential vaccines, and out of the mist (including aerosols), maybe some black and white answers will emerge.

We don’t know yet.

But we will.