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Don’t Stop Now: Staying Home Is Reducing Coronavirus Spread

A Twitter friend turns me on to the Rt Covid-19 graph. Created by Instagram co-founders Kevin Systrom and Mike Krieger, Rt Covid-19 reports the effective reproduction rate of the coronavirus—i.e., the average number of people whom an infectious person infects.

Back in March, the Imperial College paper that helped me wrap my head around the full danger of this pandemic and the dire need for all of us to stay the heck home, the economy be darned, to save two million lives and our health care system spoke of the need to reduce the reproduction rate from an estimated 2.2 or 2.4 down to below 1.0. Imperial College’s R figure, R0, estimates the infectious power of coronavirus unchecked, among an unsuspecting population taking no countermeasures (or Schaunamaniacs letting nature run its course). For perspective, normal seasonal flu has an R0 of 1.3; SARS, 2 to 5; measles, 3.7 to 203.

Systrom and Krieger are trying to calculate effective spread rate day by day and location by location. Rt tries to capture that changing figure… that figure we can change. But we can read it the same way we read R0: if the value is greater than 1.0, there will be more sick people two weeks from now than there are now, and the pandemic will get worse. If the value is less than 1.0, we’ll still see new cases pop up for weeks, maybe months, but the pandemic is declining.

So how are we doing?

Four weeks ago, every state in the Union had an Rt greater than 1.0:

Rt Live, end of March coronavirus Rt figures for each state, screen cap 2020.04.28
Rt Live, end of March coronavirus Rt figures for each state, screen cap 2020.04.28.

As of April 27, 42 states and the District of Columbia had gotten their Rt below 1.0:

Rt Live, April 27 coronavirus Rt value by state, screen cap 2020.04.28.
Rt Live, April 27 coronavirus Rt value by state, screen cap 2020.04.28.

Now anyone who looks at these numbers and thinks we can go back to normal is going to get people killed. As Governor Kristi Noem wrote before Easter, fighting coronavirus is a marathon, not a sprint. If you look at your watch after just a couple miles into the marathon, see you’re running eight-minute miles, think, “Whoo-hoo! I’ve won!” and go back to your normal walking speed, pretty much everyone else will catch you. In this pandemic, go back to normal, and coronavirus will catch you and your local hospital.

More than a million Americans have caught covid-19. We’ve lost more Americans to this virus in less than three months than we lost in the Vietnam War across two decades. Declining Rt is important; sub-1.0 Rt is great, but it’s not victory, and it sure as heck isn’t an all-clear signal.

We’re headed in the right direction because we are social distancing. If we want to keep heading in the right direction—if we want to keep Rt below 1.0, if we want to keep another corps or army of Americans from dying—we have to make social distancing and canceled public gatherings and an overall slower economy our new normal. We have to accept, as Imperial College laid out over a month ago, that for the next year or two, previously normal economic and social activity will become the occasional brief exception amidst the normal rule of rolling shutdowns.

I know the metaphor is messy when the message is stay home. But keep up the pace: we have a long way to run against the coronavirus.

9 Comments

  1. Debbo 2020-04-28 21:01

    Look at the part of the country in the red. I hope that’s because the virus was last arriving in our neighborhood.

  2. ds 2020-04-28 21:39

    Unfortunately today Kristi Noem joined the ranks of governors opening up their states to business as usual, And list our family as ‘enablers’ because my wife and 22 year old son are both back at work as of today. Actually , they could have heeded Noem’s statement: if you don’t feel safe going out, you have the personal choice to stay sheltered at home. Well…yes and no. You see both were offered their job back by their boss, and i checked with the South Dakota DL&R and verified that if they decline to return to work they would loose their unemployment benefits anyway. So they did what they are expected to do, they went back to work and join the many others in the middle of random customers with you knows what….. do they have Corona virus or not?
    This ought to be OK for a few weeks since South Dakota Health Dept. claims that the virus is presently nearly nonexistent in Pennington County…but come Memorial Day and a bunch of tourists flocking to our uninfected county and i suspect the curve will spike up soon there after. Of course Noem and her Dept of Health state they will monitor the casualties and take action as needed…but too little too late. See what happened in Minnehaha County for two…three weeks after Noem pivoted from ‘should’ to shall’…Oops horses already out of the barn….

    PS news flash President Donald Trump is under quarantine! Not for Corona Virus but for motormouth disease.

  3. jerry 2020-04-28 22:38

    ds, true that. As near as I can figure it, it goes like this. As long as NOem just opened up the state as a mandate, whether the employer opens or not, the employer cannot file for business interruption insurance since they are allowed to operate. This might get some traction from the Democrats, we can all hope for the bulldog in Nancy to deliver. https://www.clevescene.com/scene-and-heard/archives/2020/04/28/ohio-class-action-lawsuit-argues-that-business-interruption-insurance-should-cover-coronavirus-related-losses-for-restaurants

    Now the employer’s landlord can demand all monies because your business was allowed to open. Your furloughed staff, that is collecting unemployment, will have to come back to work or you, the employer, will have to let them go. Then the unemployment will go on the employer’s tab and if the virus blows up again, the employees are still on the employer’s tab since they would no longer be employed.

    It is right out of the Governor Rick Scott’s Florida right wing unemployment playbook. I’m sorry to hear about your wife and son, but as you can see, this is all about screwing the small business people and their employees for the benefit of the state’s coffers and the numbers game they are all playing. We are all collateral damage to the republican failure of governing.

  4. jerry 2020-04-28 22:45

    I see that there are 6 large cooling units at Camp Rapid, in a perfect line like formation, splendid efficiency. I’m gonna take a shot here and wonder out loud if those are so we don’t stink up the place as we pile up due to the casualty rate. There is nothing as vile as a decomposing body, but I digress. Anyway, we seem to be prepared for those days, lucky us.

  5. Debbo 2020-04-28 23:21

    Jerry is right about the plan working beautifully to screw the people and small businesses. In addition, Kruel Kristi has covered her hiney with both hands by not mandating anything, but “leaving it up to the people.” They can go back to work, catch the virus and/or starve. KK is not responsible for anything. Looks like ALEC has been in touch with their govs and legislatures to tell them what to do and they’re marching right along like good little girls and boys.

  6. Debbo 2020-04-29 01:33

    Utpal Dholakia Ph.D., has some thoughts about how our world will change due to this pandemic. It’s a brief essay. Do you think he’s correct?

    “Many of us will change our buying behaviors to support local enterprises, whether it is farms, mom-and-pop restaurants, or manufacturers. Large corporations that produce high-tech products, cutting-edge drugs, or provide standardized services will be tolerated, but they won’t gain consumers’ trust or loyalty easily. Foreign goods and brands will be treated with suspicion and be viewed as second choices in many categories, to be considered only when nothing local is available.”

    is.gd/KfUqLW

  7. Cory Allen Heidelberger Post author | 2020-04-29 07:11

    No reopening plan makes sense without criteria based on real data. Noem’s Normal plan says we can’t reopen until we see 14 days of downward trajectory of influenza-like illnesses and documented cases, but the plan (actually just two thin pages of bullet points) doesn’t give any hard methodology for those metrics. It doesn’t address how the state will weight numbers based on increased testing or sample bias in who gets tested. Systrom and Krieger are at least trying to do science with their Rt metric; Noem is just doing politics and self-cheerleading.

  8. Clyde 2020-04-30 06:41

    Debbo, I disagree with your ph.ds ideas. I’m thinking that this virus is going to be a huge boon for Jeff Bezos. Think small retail was in trouble before? In general the public is getting fed up with foreign everything anyway. Of course no PPE isn’t reassuring anyone that everything should be imported from the country willing to make it the cheapest.

  9. Debbo 2020-04-30 18:10

    Did you read the article Clyde?

    I think local support will increase as will a desire for increased domestic manufacturing. It’s hard to say how long that will last.

    Of course people with little $ will continue to have to buy whatever is cheapest.

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