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The CDC’s rocky effort to get Americans tested for coronavirus, explained

The US has done 2,000 coronavirus tests. South Korea has done more than 140,000. What gives?

Researchers Work On Developing Test For Coronavirus At Hackensack Meridian’s Center For Discovery and Innovation
 A researcher works in a lab that is developing testing for the Covid-19 coronavirus in Nutley, New Jersey.
Kena Betancur/Getty Images

Here’s a big, discomforting fact about the current coronavirus outbreak in the United States: We have no idea how large it is.

We don’t know because the US has been extremely slow to roll out diagnostic testing for the Covid-19 disease. It’s unclear if there’s a specific policy or decision to blame for the current situation. It arose from a combination of manufacturing problems, chronic underfunding, and an apparent lack of foresight. But no matter the specific reason, the testing challenges, scientists tell us, make us less prepared to deal with this unfolding public health crisis that will probably get worse before it gets better.

“I think that we could have probably controlled this, if we had effective testing,” Angela Rasmussen, a Columbia University virologist, says.

Accurate testing is critical to stopping an outbreak: When one person gets a confirmed diagnosis, they can be put in isolation where they won’t spread the disease further. Then their contacts can be identified and put into quarantine — so that they don’t spread the virus if they’ve become infected, too. That’s particularly important for a virus like this one, which seems able to spread before people show symptoms, or when their symptoms are mild.

Better testing, paired with aggressive public health actions — like social distancing, isolation of those who are sick, and tracing those who sick people made contact with — can still help save lives in the United States.

But it starts with testing. To date, per an investigation in the Atlantic, fewer than 2,000 people have been tested for Covid-19 in the US — a number far behind other developed countries. South Korea, for example, has tested more than 140,000 people and has even set up drive-though testing stations for people to access.

Evidence is mounting that early in the outbreak, in January and February, China bought the world time with its aggressive action to contain the viral outbreak in its borders. The testing fiasco in the US indicates we didn’t use that time well.

“There was clear lack of foresight,” Nathan Grubaugh, an epidemiologist at the Yale School of Public Health, says. “We were very slow to roll out testing capacity to individual places — wherever that came from, it was a very bad strategy.”

The testing has been really slow to start

There’s no one reason the testing effort has been so slow. There seem to be bureaucratic, scientific, and economic drivers for the debacle.

Here’s where the trouble started. The Centers for Disease Control and Prevention started sending out test kits to laboratories the first week of February, a month after China announced the outbreak. But the health agency quickly encountered a problem.

Some labs reported to the CDC that some of the test kits were delivering inconclusive results during verification. It’s believed that one of the chemicals used to conduct the test was not working properly and needed to be remanufactured.

“I’m very puzzled by what’s happened. The CDC did a really good job with H1N1 and Zika in exactly this thing: sending out huge quantities of test kits very rapidly to every state in the US and more than 100 countries around the world,” Tom Frieden, who led the CDC under President Barack Obama, told Vox. “The world came to rely on the CDC.”

The tests are conducted via mouth or throat swabs, through the testing of mucus that has been coughed up or fluid from a patient’s trachea. They’re designed to identify the virus’s specific genetic signature, and results have to be shipped to labs, where they take a day to process.

Also, at first, the testing was bottlenecked. Most states had to send their samples to the CDC until March 2, and so, to the frustration of state health officials, precious time was lost shipping materials to Atlanta in those critical first few weeks. What’s more, each test required lengthy phone calls with the CDC, Rachel Levine, who leads the Pennsylvania health department, told Vox. As of February 25, only 12 labs across the country — in just five states — had the ability to test.

Now that states can perform their own tests, they are able to turn them around in a matter of hours. “It’s a much more efficient mechanism,” Levine said, “but it took a long time for that to happen.”

In Seattle, currently the US city with the most Covid-19 cases, local researchers were so exasperated by the CDC’s initial faulty test that they came up with their own, as STAT’s Helen Branswell reported:

Frustrated by the lack of testing resulting from the problem with the CDC-developed kit, the Seattle Flu Study began using an in-house developed test to look for Covid-19 in samples from people who had flu-like symptoms but who had tested negative for flu.

That testing was vital for Washington state, as it led to more clues about how the disease was spreading there. Genetic detective work from Washington suggests the virus has been circulating there for at least six weeks. Modeling suggests there could be 500 to 600 cases of Covid-19 in the Seattle area, as STAT reports.

So there’s been human error. But it’s also important to know that the work of setting up testing for a new virus can be difficult. Laurie Garrett, the science journalist who won a Pulitzer Prize for her reporting on the Ebola outbreak in 1995, said China’s most-used tests have had false negatives nearly half the time.

“Everybody is having trouble with the sensitivity/specificity issues” with the coronavirus, Garrett said. But the slow start to testing in America, compounded by the problematic test kits that were first sent out into the field, has set back the US response.

“I have no criticisms for the scientists at the CDC who developed the test because sometimes tests just don’t work,” Rasmussen says. But she does mention it’s problematic that the CDC has removed data about the number of people tested in the United States from its website, saying it didn’t want there to be discrepancies with state testing numbers. “In my view, the biggest scandal is that sort of response.”

Now that we have a functional test, it’s still not reaching enough people

Vice President Mike Pence and other top Trump administration officials have been promising to ramp up the country’s capacity to test for coronavirus, but they have failed to meet their goals.

As Bloomberg reported this week, senators were told in a CDC briefing that the Trump administration would not be ready to roll out the 1.5 million kits it had promised by the end of this week. The number would be fewer than 500,000, it appeared.

The Atlantic has provided the best accounting of how many tests have actually been conducted in the United States so far: fewer than 2,000, according to its survey of state health officials and other sources. That puts the US far behind some of its economic peers with much smaller populations:

The figures we gathered suggest that the American response to the coronavirus and the disease it causes, COVID-19, has been shockingly sluggish, especially compared with that of other developed countries. The CDC confirmed eight days ago that the virus was in community transmission in the United States—that it was infecting Americans who had neither traveled abroad nor were in contact with others who had. In South Korea, more than 66,650 people were tested within a week of its first case of community transmission, and it quickly became able to test 10,000 people a day. The United Kingdom, which has only 115 positive cases, has so far tested 18,083 people for the virus.

Making matters worse, some people who have sought tests in the past few weeks have been turned away. And these shortcomings make it harder for the public health community to react to a virus that spreads quickly and easily.

Many people don’t really show symptoms of Covid-19, or their symptoms are very mild, but you want them to be tested anyway if there is an opportunity. To do that, doctors need to be able to order the test, which the CDC is only now permitting them to do. Commercial labs only recently started processing the coronavirus test, too, a step health care providers had been urging the administration to take.

“The issue is with asymptomatic transmission. You don’t know who is infected, and symptoms aren’t going to help if the patient doesn’t have any,” Abraar Karan, a Harvard physician, said. “A rapid test would help because you can then do mass testing at scale.”

Another is the criteria for who qualified to be tested. Originally, that was limited only to people who traveled to China or who had been in close contact with someone known to have Covid-19.

Then the tests expanded to include anyone who traveled to any affected country, as well as people with unexplained flu-like symptoms. Now, anyone with a physician’s authorization can be tested for Covid-19 — that is, if they can access a test.

Meanwhile, the federal government has decreased some regulatory roadblocks for more testing labs to come online. Labs can now start testing if they are pursuing an emergency authorization to test, and don’t have to wait for the Food and Drug Administration to give them final approval.

What needs to happen

As cases of Covid-19 in China were increasing dramatically in January and February, a lot of the US response was focused on travel restrictions and travel-focused testing. In retrospect, there should have been more planning for a pandemic.

“Once it was established this virus was spreading efficiently between people by the respiratory route, [we] immediately should’ve realized that this was not going to be containable,” Amesh Adalja, a senior scholar at Johns Hopkins Center for Health Security, writes in an email. “At that point every country in the world should [have begun] pandemic preparation. This would include scaling up diagnostic testing, preparing hospitals, and crafting public health messages.”

Instead, the response may have even made the US more vulnerable. “The focus on keeping the virus out of the US, rather than turning to preparedness and mitigation of US outbreaks, may have delayed really critical efforts to keep vulnerable populations safe, like nursing home residents,” said Crystal Watson, senior scholar for the Center for Health Security at Johns Hopkins.

We don’t need testing just to diagnose sick people coming into doctor’s offices and hospitals. We also need testing to do surveillance out in communities. “You actually have to go out like now in many places in the US and start taking samples from people,” Grubaugh says.

Those surveillance studies will help us understand how prevalent milder cases are in populations. And the addition of those milder cases into data sets will help researchers determine, more accurately, how deadly this virus is, whom it tends to infect, and how often people spread it before showing symptoms. As testing ramps up, be prepared to hear about a lot more cases of Covid-19 in the US.

All that information can then be used to better halt the spread of the illness.

Again, without testing, we’re in the dark. And while we’re in the dark, the virus can spread. “We don’t know what the prevalence actually is,” Rasmussen says. “So in the short term, I think that we’re going to start seeing community spread in a number of places other than Seattle.”

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Correction: This post originally referred to Abraar Karan as a Harvard epidemiologist. He is a Harvard physician.