Sometime today or tomorrow, depending on your choice of tracker, we will cross the threshold of 100,000 reported deaths from COVID-19. Of course we passed 100,000 actual deaths some weeks ago. Excess mortality estimates put actual deaths 30-50% higher than reported deaths. That would have put us at 100,000 deaths sometime in the first week of May, just as we began reopening. Since that time, the US has gone from decreasing growth rates to flat growth rates. Deaths per day have continued to decline. However, they remain above 1,000 deaths per day on average. THe average time from diagnosis to death, for those cases that end in death, is 2-3 weeks, so I expect deaths to level off soon. Here’s a chart with a running 7 day average trend line showing the situation as of May 25th..
To be fair, growth rates in the US have come down considerably from the exponential growth we saw in March and April. Our growth factor (daily growth expressed as a percentage of total cases rather than as a set number of cases) is lower than the growth factor of the world overall. This is easiest to see on logarithmic graphs. Here are log graphs of the US and the World taken from the Johns Hopkins tracker.
Comparing the two graphs, you can see the World graph is rising more quickly at the end.
Additionally, steady growth is a lot easier to handle in terms of medical infrastructure than increasing growth as it allows us to reach an equilibrium of active cases. Each day, a certain number of existing cases resolve, either through recovery or death. It takes a certain amount of time for cases to resolve, somewhere around two to three weeks. So the number of cases that resolve today depends on the number of cases that were added two to three weeks ago. If we add the same number of cases each week, then the number of resolved cases each week will be the same as the number of new cases. So the active cases needing treatment will settle into a steady number. It’s a lot easier for the medical community to handle a steady caseload than rapidly changing caseloads, even if the steady caseload is higher than we might like.
The danger is that our currently steady growth may turn to increasing growth as we reopen. This is of special concern given some of the crowd scenes we’ve seen from Memorial Day weekend. In order for social distancing to be effective, it has to have high participation levels. If only half the people are wearing masks and keeping their distance, we’ll be back to exponential growth. It’s like walking under an umbrella with holes in it. If there’s just one or two small holes, you can still stay pretty dry. But once the umbrella has a certain number of holes, you’re just going to get wet.
I”m not going to run a projection today as the last one is still pretty accurate and I plan to run one in the morning. Watch for total deaths to cross the 100,000 mark and for the US to add about 20,000 new cases per day.
Thanks for reading, see you tomorrow.