Here’s the coronavirus growth rate through Wednesday. The US is now slightly above the Italian trendline, possibly because we’ve picked up the pace of testing.
A couple of notes. First, a friend emails to warn me against calling the spread of coronavirus “exponential.” Technically, that’s true. At the beginning of a viral outbreak the growth rate is pretty much exponential, but it slows down later. This article suggests that it then follows a power law, and eventually it flattens out and then declines. When all’s said and done, the outbreak will follow a Gaussian path that looks like a familiar bell curve. For example, here is the growth curve of the Spanish flu in 1918, skyrocketing from nothing to massive death tolls over the course of only four weeks:
Second, a couple of readers have emailed to tell me that Sweden’s flattening rate of coronavirus growth has nothing to do with great case management. They just aren’t bothering to test for it. Here is one comment:
I’m an American living in Sweden, where they have not been taking coronavirus seriously and have an almost nonexistent testing regime. It is much more likely that this flattening has to do with the unavailability of tests than anything else. You can see English-language coverage here, which confirms that not only is Sweden not tracking contacts of infected people, but it is also only testing people who “have severe respiratory symptoms or who belong to a risk group.” From what I hear from contacts in the hospital system, this does not even include all healthcare workers, much less anybody else; the rest of us have just been advised to stay home, with no real quarantine measures, lockdowns, or closures (except for, starting this week, higher education). I have been profoundly underwhelmed by the Swedish response and have no confidence in their management of this going forward.
As always, the raw data from Johns Hopkins is here.
