- New York has drastically ramped up its coronavirus testing in the last month: The state went from around 200 tests on March 11 to more than 300,000 on April 5.
- Other states with significant outbreaks, such as California and Washington, trail behind.
- On April 3, roughly 64% of California's coronavirus tests had yet to be processed.
- Washington Gov. Jay Inslee has said his state has a "desperate need" for more tests, as well as testing materials like swabs.
- For the latest news, see Business Insider's live updates here.
- Visit Business Insider's homepage for more stories.
As coronavirus testing capacity has ramped up in the US, the number of reported cases has also skyrocketed. As of Thursday, the US has completed more than 2.2 million tests, according to the COVID Tracking Project, which aggregates testing data from state and local public-health departments. That's a big jump from two weeks ago, when just 519,00 tests had been done.
But not all states are testing at the same rate. New York far surpasses the rest of the country in its quantity administered thus far.
The state had performed more than 365,000 tests as of Thursday.
Here's how six US states have increased testing over time, based on figures from the COVID Tracking Project.
By Thursday, California - the state with the second-highest testing capacity - had only performed around 159,000 tests. Florida trailed closely behind with around 144,000 tests.
Washington, the site of the nation's first coronavirus case and first death, had tested 92,000 people as of Thursday.
New York's testing strategy put it ahead of other states
Washington state reported the US's first coronavirus case in mid-January. The diagnosis was confirmed by a test from the Centers for Disease Control and Prevention, but the test had yet to be distributed to state labs. Another seven weeks would pass before public health labs in all 50 states were testing for COVID-19. By that time, certified private and academic labs were allowed to perform their own tests as well.
Soon after, New York enlisted the help of private labs to expand its testing capacity.
On March 11, Gov. Andrew Cuomo announced that the state was contracting with 28 private laboratories to administer more tests. The state also set up a satellite testing facility run by Northwell Health in the town of New Rochelle, where the outbreak began.
By that point, only 5,000 tests had been conducted nationwide, around 200 of which were in New York.
"We're not in a position where we can rely on the CDC or the FDA to manage this testing protocol," Gov. Andrew Cuomo said on March 11.
"The more tests we get, the more positives we will get," he added. "That's exactly what we are seeking."
On March 20, Cuomo announced that New York had processed 10,000 new coronavirus tests overnight, bringing the state's total to more than 32,000 tests.
In the days that followed, both New York's total cases and its testing capacity rose dramatically. The number of cases tripled from March 23 to March 30, from more than 20,000 to around 66,000. During the same time frame, testing more than doubled, from around 78,000 statewide tests to more than 186,000 on March 30.
To some extent, New York's high case count (more than 151,000) is a reflection of its high testing capacity. But the state is also the site of one of the US's biggest outbreaks, and New York City's density and extensive transit network have likely fueled the virus' spread.
Plus, even though it's done more tests than any other state, New York still can't test all prospective cases.
In New York City, hospitals are reserving tests for patients with severe illnesses. But research from the Chinese Center for Disease Control and Prevention indicates that most coronavirus cases are mild, suggesting that most infections in the city don't factor into the official case count.
California is seeing delays in processing tests
California's current case count - around 16,000 - suggests the state may not require as many tests as New York. The state issued a stay-at-home order several days before New York did, and counties in the San Francisco Bay Area acted even earlier. Some health experts believe these moves helped contain local outbreaks. Most parts of California are also less dense than the New York metro area, meaning there's less opportunity for the virus to spread.
"With the exception of major metropolitan areas, there's quite a dispersal of people that helps California have fewer infections," John Swartzberg, a clinical professor emeritus at UC Berkeley's School of Public Health, told Business Insider. "We know the further away you are from people, the less likely you are to get infected."
Still, as of April 3, roughly 64% of California's coronavirus tests had yet to be processed. A Vox analysis based on state testing data ranked California 39th out of 50 states for the number of tests conducted per capita.
"The reason in part why California doesn't report as many cases is because we haven't done as much testing as a state like New York," Swartzberg said.
Washington state's testing capacity is still limited
Washington state might also identify a larger outbreak as it ramps up testing.
"We have a desperate need for the testing kits," Gov. Jay Inslee told CNN on March 29. "We simply don't have the materials to take the test itself - some things as simple as the swabs."
Alex Greninger, assistant director of the University of Washington Medicine Clinical Virology Laboratory, told Business Insider on March 16 that his lab was administering up to 2,000 tests per day - about a fifth of the state's total at the time. But the lab's capacity is limited, he said, since it needs more researchers to process samples.
"That's actually one of the big choke points is just the physical processing of the samples to put them into tubes so that they can run on the automated machines," he said. "We have to sample every 40 seconds."
Still, Washington state has tested more people than Texas (a state with a similar case count) or Louisiana (which has double the number of confirmed cases).
"In the US, we've got a problem because we were slow to roll out testing and the epidemic is out of control, yet that doesn't mean we should give up," Steffanie Strathdee, associate dean of global health sciences at the University of California San Diego, previously told Business Insider. "In states or regions or countries that haven't seen a lot of cases yet, they could still get ahead by testing as many people as possible and isolating those folks."
Holly Secon and Tyler Sonnemaker contributed reporting.
Do you have a personal experience with the coronavirus you'd like to share? Or a tip on how your town or community is handling the pandemic? Please email covidtips@businessinsider.com and tell us your story.
Get the latest coronavirus business & economic impact analysis from Business Insider Intelligence on how COVID-19 is affecting industries.