At long last, we have a relatively unbiased random sample of the true infection rate of COVID-19 in New York City.

Last week, the New England Journal of Medicine reported the results of a screening that was conducted on 215 women admitted to New York City hospitals for delivery. About 15 percent tested positive for the COVID-19 virus.

We know that the test missed up to one third of those infected, either because of the low virus levels in patients in the asymptomatic and pre-symptomatic phase, or because of test failures. The true rate may be higher—as much as 20 percent.

If pregnant women are representative of the population as a whole, that means between 2.7 to 3.6 million of the 18.8 million people who live in the greater New York metropolitan area are infected.

That figure is a far cry from the 242,000 confirmed cases that were reported on Sunday. If the magnitude of the infection is really so much greater, New Yorkers aren’t the only ones who should be prepared to observe social distancing guidelines more closely in the months to come.

It’s in the best interest of residents of other hot spots like Chicago, Washington D.C., and New Orleans, as well as their respective state governments, to act under the assumption that reports of current caseloads greatly underestimate the extent of infection. The same goes for major cities that COVID-19 has yet to hit hard.

Otherwise, rates of infection may skyrocket nationwide, making the possibility of a smooth return “back to normal” ever more remote.