Testing for the coronavirus might have stopped it. Now it’s too late.

But the United States has lagged far behind the rest of the world in testing for the new coronavirus. As a result, outbreaks here are likely to be more numerous and more difficult to control than they would have been otherwise. I research infectious disease and how to fight it, so I know how important it is to detect outbreaks early. The covid-19 outbreak is the largest acute infectious-disease emergency most of us have experienced. And we may have let it go undetected here for too long.

For countries that are lucky enough so far to have been spared large covid-19 outbreaks, the way to handle the virus is simple: Strangle it at birth. If you detect it while there are still just a handful of cases, it is comparatively easy to chase down the contacts of the people who have it, isolate them quickly and halt transmission. If that fails, stopping transmission might take measures like the draconian restrictions imposed in China, which — while apparently successful — we should wish to avoid…

Explanations for this shortfall in basic outbreak response in the United States range from the bureaucratic (confusion among federal and state agencies) to the scientific (which test is the best?) and the economic (who pays?). While U.S. officials talk about how to fix things, South Korea has drive-through testing facilities. On Wednesday, the Centers for Disease Control and Prevention announced that coronavirus testing is now available for anyone, with a doctor’s approval, which is great news. But making test kits is one thing. Using them on patients requires trained professionalsto deploy them. And even those professionals aren’t getting tested quickly enough to help slow the virus’s spread; I know of people right now, some of them front-line health-care workers (a group at particular risk for covid-19) who are sick and struggling to get tested.