The overall rate is 1.26, and outside of New York it is 1.32
Look at Aaron Lindsey’s spreadsheet. The 3DDRR starts to turn down around March 27. The steepest drop is during the first week of April. Since then, the decline has been agonizingly slow.
If you assume that the trend in deaths lags the trend in infections by about three weeks, this says that we started to turn the corner on infections at the end of the first week in March, which I think is before most people were changing behavior (am I right about that?). Then the steepest drop in infections took place between about March 10 and March 17, when people were changing behavior but no lockdowns were in place. Since then, the infection rate as declined further, but more slowly.
Here’s a good post with a good ‘patterns and stories’ model: My Covid-19 Thinking: 4/17 | Don’t Worry About the Vase
There’s a general linearish down trend with a shape remarkably like a sine wave with a period of one week composed together. And that’s just eyeballing it.
The open table data indicates that people started changing behavior right around March 1st. Pretty much everywhere in the US.
https://www.opentable.com/state-of-industry
Here’s, my likely wrong and “dangerous” theory.
I’d love someone to tell me where I’m wrong, so I can get these nasty thoughts out of my head and think of something else.
1. COVID-19 has been in 5-10% of the population since late Jan/early Feb.
2. It’s spread rate is slightly higher than typical virus, but mainly from indoor, close contact. But, I think it’s rolling through the pop at 5-10% at a time in most places, with some growth in that % in areas like NYC with lots of elevators, mass transit and small abodes.
3. When we ramped up testing, we mistook the growth in positive cases as an indication of the spread rate, when it was really the growth in testing as the testing discovered (depending on locale) the 5-10% that had it. This one bugs me. I’m sure we didn’t because that seems like such a rookie mistake. But, I have yet to find anything compelling on how we did estimate the spread rate. It seems like this mistake was repeated in almost every country, except ones like S. Korea that had enough tests available to not be so restrictive on testing.
4. We panicked from #3, and started staying home more (whether ordered or not) and going to hospitals to get tested.
4a. Staying come condensed about 2-3 weeks worth of inter familial infections into 3-4 days because we increased the chances of an infected person spreading to family members. This one doesn’t increase total infections, just changes the timing.
4b. Having infected show up in hospitals that were ill-prepared for this virus, caused hospitals to become outbreak. Not sure how much of this is a timing shift vs. incremental.
4a & 4b helped cause the peaks we saw in early April.
5. Steady-state after the peak will be where we were before the panic around mid-to-late Feb, but didn’t know it because we didn’t have the testing to see it.
6. That will have some ups and downs, depending on how well we manage key outbreak scenarios (big family events with lots of touching, nursing homes, hospitals), but will gradually trail off as larger % of the population develop antibodies.
7. Social distancing may have had impacts, both positive and negative (e.g. 4a), but given that some places without extreme social distancing have fared better than places with it…the jury is still out for me. It seems places that did it, saw similar results, peaks 2-3 weeks after settling back to a steady state (that may have existed before testing was available). Open to counterexamples.
8. Somewhere between 10 and 40% of population has already had it (depending on geography).
Here’s a blog post with a couple charts (log chart of number of tests and positive tests by day & % positive tests by day for US) that helped me form this theory: https://ourdinnertable.wordpress.com/2020/04/17/the-big-question-when-we-open-will-cases-grow-exponentially/
A. The growth in positive cases closely follows the growth in testing. Once # of tests/day levels off so does number of positive cases. We don’t know what the red line really looked like prior to having wider testing available, but to me it looks like could extend back into Feb at late March levels.
B. The % positive hit steady state around March 10. Could just mean that selection criteria for remained consistent from that point forward, but I would think as they worked through higher risk cases, they would have opened testing up to more folks and I would have expected to see some change. These feeds my delusion that the persistence in the population is relatively steady.
Unknowns:
What the growth rate looked like to get to 5-10% of the population.
Why just 5-10% of the population.
True impact of extreme social distancing and what happens after.
What % of population has had it
How many truly has it now