Hanna Barczyk and Franziska Barczyk

Editor’s Note: The Atlantic is making vital coverage of the coronavirus available to all readers. Find the collection here.

An ongoing investigation co-founded by The Atlantic has tracked how many people are known to have the coronavirus in each state. You can explore our data by selecting a state in the chart below:

Data: The COVID Tracking Project, Census Bureau

Weeks into an outbreak that has hobbled the economy and rewritten the rhythms of daily life, more than 100,000 people have been tested for the coronavirus in the United States, we have found. The latest numbers represent a sharp increase in testing over the past week, but also underscore that the United States lags dramatically behind the testing response in many other countries.

In America, at least 12,000 people have tested positive for the virus, and 194 people have died as of Friday, March 20. Those confirmed positive cases represent only a fraction of the Americans who are infected with the virus.

The Atlantic reached its new estimate through an ongoing collaboration with a team of more than 100 volunteers recruited for their experience with data collection.

After weeks of debilitating delays and shortages, the country’s ability to test patients for COVID-19, the disease caused by the coronavirus, has started to rapidly increase, our investigation finds. The country’s 50 states, five territories, and the District of Columbia now report the results of roughly 25,000 tests a day, collectively. But even as testing has ramped up, its pace has fallen far short of what’s needed to capture the extent of the coronavirus’s spread nationwide.

This surge in testing capacity was slow in coming. In the 10 days after February 26—when the Centers for Disease Control and Prevention confirmed that the coronavirus was being transmitted through community spread in the United States—federal and state labs tested 2,806 Americans. Another week elapsed before the country had tested 20,000 people. In the few days since, the country has expanded its testing capacity to cover at least that many people every day.

Yet the national numbers are still distorted by massive testing operations in just a few states. New York, California, and Washington have conducted nearly half of all tests nationwide, even though those states contain, combined, about a fifth of the country’s population. Florida and Texas—each home to more than 20 million people—have tested only about 3,000 patients each.

Some state public-health departments aren’t reporting as much information as others. We’ve assigned every state a letter grade in the chart above to help readers understand how thorough each one is in its reporting. This grade is not assessing the quality of a state’s testing, but rather the transparency and regularity of its reporting.

All 50 states and Washington, D.C., regularly report their number of positive cases. Some states, such as Connecticut, disclose little additional information, so we’ve assigned them a grade of D. But others, such as Florida, publish not only their positive cases but also their negative cases and the results of tests conducted by private labs. Those states get an A grade. Having this full suite of figures at the state level allows for a far greater understanding of the size of both the outbreak and the response.

In the chart above, each state’s number of positive cases includes people who are currently ill with the disease, people who have recovered from it, and people who have died. We have also broken out the number of deaths in its own column.

Some states have used strict criteria to determine who can and cannot be tested for the coronavirus. While we haven’t factored these into a state’s grade, we think these rules—while perhaps necessary, given the shortage of tests available from the CDC—have led states to substantially undercount how many people had been infected in their communities, especially during the last week of February and the first two weeks of March. At least 18 states have enforced particularly stringent rules in some counties or hospitals: California, Hawaii, Indiana, Iowa, Kansas, Louisiana, Maine, Maryland, Massachusetts, Missouri, New Hampshire, New Jersey, Tennessee, Texas, Virginia, West Virginia, Wisconsin, and Wyoming. (Some of those states, such as Hawaii and Maryland, have since loosened their criteria.)

Yet even with the increase in capacity, our reporting shows that some people with a fever and a dry cough are still not being tested for COVID-19. In many places, the problem is no longer the supply of testing kits. Earlier this week, the Hospital of the University of Pennsylvania told its staff in an email that it had enough COVID-19 test kits to diagnose 250 people a day. But the testing kits require a crucial reagent that the hospital ran short on. Without that key ingredient, its testing capacity shrank to 20 people a day.

Such shortages—of important chemicals, N95 masks, and even medical swabs—continue to limit America’s ability to respond to this pandemic, just as the lack of basic information about how fast and far the virus spread hobbled the country’s fight against it.


Melissa DePuydt, Frankie Dintino, Tolulope Edionwe, Alexis C. Madrigal, Robinson Meyer, Gerald Rich, Quinn Ryan, and Jacob Stern contributed to this report.

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