Exponential growth. It’s one of those terms that everyone has heard now and then, but until the last few weeks the meaning of that term hasn’t always been clear. Now it seems all too real as dozens of cases of COVID-19 turned rapidly into hundreds, and thousands, and tens of thousands. Today they’ll move past 100,000 in the United States alone.
That rate of growth in the United States shows that—so far at least—we haven’t done nearly enough to bring the growth of this disease under control. For all the jokes about binge watching, all the over-walked dogs, and a spate of bedroom concerts, the social distancing being practiced in the United States has proven utterly inadequate to bring down the rate of growth. In fact, COVID-19 in the United States appears to be growing faster than it did anywhere else in the world. And there’s a reason for that.
That reason is not that Americans are particularly susceptible (or tasty) to the SARS-CoV-2 virus. It’s also not that we’re spectacularly bad at social distancing compared with other countries. It’s certainly not that we’re simply larger. After all, COVID-19 got its start in a country four times the size of the United States, but even in China it didn’t grow nearly so fast.
China was at 24,000 cases on Feb. 5. Seven days later, it had 44,000—that was right in the heart of the fastest part of the disease’s growth curve in China. On March 14, Italy had 21,000 cases. Seven days later, it had 53,000. So it increased faster than China.
Now let’s look at the United States. On March 20, the U.S. had just 19,000 cases. Seven days later … we don’t know, because the numbers aren’t completely in. But it’s sure to top 100,000 before the end of the day. It took only seven days for the U.S. to go from 19,000 cases to 100,000. The United States added more cases—by far—in just seven days than either Italy or China did over the same period.
How is it even possible? Well, it’s not. Not in the sense of just those numbers. What’s really happening is you’re not where you think you are.
Here’s where things stood as of Thursday:
This is likely the last time I’ll make a chart showing total cases for either China or South Korea, because those values no longer have a lot of meaning. At this point, China has fewer than 4,000 active cases remaining and South Korea has fewer than 5,000. Both of them haven’t just flattened the curve—they’ve successfully isolated and controlled the spread of COVID-19 within their borders. From now on, their greatest task is protecting themselves from cases that enter the country from the United States.
But how is it that every other nation on the chart above has a curve that appears so similar, except for the United States? It’s because the United States doesn’t have that curve either. The problem with the United States, far more than any other country on the chart, is that the results are constrained by testing. The numbers we’re seeing aren’t a measure of the spread of COVID-19 in this country; they’re a measure of our ability to detect COVID-19.
If there was an arrow directed toward that dot on the upper right, the proper label for that position would be “You are not here.” Because the United States is not a week past the day when we had 19,000 cases. We’re more like 10 days. Maybe more. Take the curve being followed by Spain or Germany and project them several days into the future. Trace your finger far up into that land of 120,000 or 150,000 or even 200,000 cases. That’s where we are. That’s where you are.
We’ve known that something like this was the case from the moment the first community-transmission cases were discovered in Washington and California. Because it was clear right away that COVID-19 was never as constrained within the United States as Donald “just 15 cases” Trump or Larry “pretty much airtight” Kudlow insisted. It circulated, undetected, for weeks. We’re not really detecting new cases of COVID-19 in the United States, especially with the ridiculous restrictions still in place for most testing. We’re just discovering a landscape of disease that’s already out there.
However, this doesn’t mean what you think it may mean. It certainly does not mean that “everyone’s already had it” or that the cough you had back in January or February was a wave of COVID-19 sweeping past. Take a look at the hospitals in New York City: Had there been hundreds of thousands of cases around the nation, much less millions, we would know. We would know because they could be measured in mass graves.
But an exponential curve is exponential. It doesn’t take 100,000 cases hidden around the country back in January to put us where we are today. It only takes a few hundred, or even a few dozen, that were lurking out there, doing their regularly doubling thing, as the Trump White House fumbled, fumbled, and fumbled again with early testing.
Where the United States really is today isn’t on this chart, and the real number of cases almost certainly did not grow as steeply as the graph would indicate. However, this is not good news. Because right now it appears that the rate of growth of COVID-19 in this country is still exceeding the rate of growth in our ability to test. Until that’s no longer true, not only can we not tell the real extent of the problem—we have to have much more testing, much faster testing, much faster processing of testing, or we will keep stumbling forward in darkness, unsure whether what we’re doing is even having an effect.
To get a glimpse of how well we have not defined the edges of this national wound, check out the data available at The COVID Tracking Project. They’re not always as up to date as the sites that simply count the totals, but they’re a terrific source for links into state-level data, and (where available) statistics on testing. There are states that have done a lot of testing—like the 84,000 tests in New York—but the 37,000 positive results shows that the job is a long, long way from done. There are other states with only a few hundred positives, but also a few hundred negatives to pair with them.
Not only has no state reached a sufficient level of testing: the stories are still being told every day of nurses who can’t get tested after a known exposure, of symptomatic people who can’t get tested because they can’t prove exposure, of people who clearly meet both qualifications and are still either unable to get a test or waiting days for results. So long as this is the case, the numbers that we’re getting show that the situation is bad, but they can’t show how bad, or where we’re going, or how we find our way out.
Two months in, the one thing we’re still screwing up is the first and most important thing: testing.