Yes, testing is important

I have heard and read some people saying that testing for the coronavirus is not very important. They usually seem to have a physician friend who told them something like this: “I do not need to test anyone because the results are not actionable. We have no pharmaceuticals, and we are not going to intubate someone before they even have symptoms, so the test result would change nobody’s behavior. All it would do is provide some peace of mind, maybe.”

For most diseases this would be correct, of course. I want to explain why, for a pandemic, it could not be more wrong. Executive summary: Your test is not for you; it’s for everyone else.

South Korea appears to be getting their epidemic under control. They are doing it without welding apartments shut or arresting people for walking around without a mask.

What they have done, as of this writing, is to test over 250,000 people, and they are adding another 20,000 per day. For comparison, the U.S. has currently tested fewer than 5,000 total. Yes, this does imply the case numbers in the U.S. are utter fiction.

When someone tests positive, they usually self-isolate. Almost nobody wants to get others sick (notwithstanding the occasional apocalyptic death cult). Then the authorities track down their close contacts and encourage them to get tested, too.

Recall that this thing can spread without symptoms. So tell me, if you learned that a close colleague had tested positive, would you want to get tested? Would you change your behavior toward a live-in elderly relative?

South Korea is also publishing aggregate results. If there is an outbreak in a region, you do not need to cancel the concerts and soccer games there; people will do that for themselves. Almost nobody wants to get sick.

If you search the news for “South Korea” and “coronavirus”, you will find many articles about this.

Now let’s talk about the U.S. The public venue closures are too many to count now. But look up for a minute and think about the future. How does a county in rural Kansas decide when to close its schools? How does San Francisco decide when to reopen theirs? Most of these closures are nominally until March 31 or April 15. What then? It’s not going away any time soon.

Effective interventions are targeted. Targeted interventions are based on data. We are late starting this race, and at the moment, we are still running it blind. We need widespread testing to inform both personal and policy response. The test does not even need to be very accurate to let us gauge trends and focus efforts, assuming it is performed widely enough.

Exponential growth swings both ways. Small interventions early have outsized effects later. At this stage, testing is not just an important thing; it is the most important thing.

Leave a Reply