Even if you’re able to get tested for the coronavirus, it’ll still take about a week to get the results back — which means the U.S. still doesn’t have a real-time handle on the number of infected people.

Why it matters: We need to know where the virus is spreading in order to get a lid on those outbreaks before they become catastrophic.

Testing more people is part of that, and the U.S. is improving on that front. But we’re still working with outdated data, giving the virus a pretty big head start before we can even spot new problems.

What we’re hearing: An Arlington, Virginia, resident told Axios he got tested a week ago, but his results have now been delayed twice; he’ll likely end up waiting nine to 10 days for his results.

There are other anecdotal reports of test results taking about seven days.

Quest Diagnostics and LabCorp, the two private companies that have helped the U.S. ramp up its testing, both say they deliver results in an average of four to five days.

We saw this play out with Sen. Rand Paul. It took six days to get the results back from his coronavirus test, and he returned to work in the Senate during that time.

Paul turned out to be infected, which means he was putting other people at risk by adhering to his normal routine over the course of those six days. The same goes for anyone who doesn’t isolate themselves while waiting days for test results.

Delayed results also give us a distorted view of how bad the outbreak is.

We’re still not testing enough people, so we know the official count — more than 60,000 confirmed cases in the U.S. — is too low.

That tally of confirmed cases, in addition to being incomplete, is outdated.

Because it takes four to five days for test results to come back, today’s update in the number of confirmed cases doesn’t actually tell us how many people have coronavirus today. It tells us how many people had coronavirus four to five days ago.

days ago. And in four to five days, we’ll find out how many people had coronavirus today. And it will be spreading while we wait.

What’s next: The Food and Drug Administration signed off last week on a new test that can deliver results within about 45 minutes.

At least for now, that test will be somewhat limited. Hospitals will use it to quickly diagnose patients with severe symptoms who are likely to be admitted and need a fast, accurate diagnosis to begin treatment.

LabCorp and Quest didn’t answer questions about whether their average turnaround times are getting longer or shorter, though Quest says it “cannot accommodate everyone who wants testing and meet tight turnaround time expectations” because demand is growing faster than supply.

The bottom line: Testing is supposed to serve two purposes: getting individual patients a diagnosis and tracking the spread of the virus to help contain it.

The tests are only available to diagnose the sickest patients because we don’t have enough tests and the supplies needed for testing, the results take so long to come back, and the coronavirus has spread so widely while we’ve been playing catch-up.

And that means we’re not making the most of it as a tool to contain the outbreak and prevent more illnesses.

Go deeper: The problems with our coronavirus testing are worse than you think