A single coronavirus case exposes a bigger problem: The scope of undetected U.S. spread is unknown

The discovery that a California woman was likely infected with the novel coronavirus by a previously unrecognized case in her community is proof of an enormous problem the country is facing at the moment, according to public health experts. It’s clear that the virus is spreading undetected in the United States — but how broadly it’s spreading is an utter mystery.

Before Thursday, a perfect storm of problems in the Centers for Disease Control and Prevention’s development of test kits — and the agency’s reluctance to expand its recommendation of who should be tested given the limited availability of kits — meant very little testing has been done in the country. As of Wednesday, the CDC said that 445 people had been tested — a fraction of the number of tests that other countries have run.

The new case in California makes it clear the virus is spreading undetected in at least one area of one state. The woman is not believed to have traveled outside the country and had no contact with a known case. As her condition worsened — she is on a ventilator — health officials in California asked the CDC to test her for the virus. Because she had not been to China and had not been a contact of a known case, the agency said no.

Eventually, more than 10 days after she went into hospital, the CDC agreed she could be tested. Dozens of health workers who may have come into contact with her at NorthBay VacaValley Hospital, in Vacaville, Calif., are now being monitored.

California Gov. Gavin Newsom was critical of the testing debacle in a press conference on Thursday. His state has only 200 kits to test for the new coronavirus, he said.

“Testing protocols have been a point of frustration for many of us,” Newsom said. He added that, based on conversations with the CDC, states have been informed new protocols are coming and they have been promised an “exponentially” increased capacity to test.

Indeed, on Thursday the CDC announced a new testing protocol that will greatly expand the number of people who should be tested.

Requests for comment from the CDC on Thursday went unanswered. The New York Times reported that the Trump administration has ordered that all statements on the coronavirus be funneled through the office of Vice President Mike Pence, who was named to head the administration’s coronavirus response on Wednesday by President Trump.

Experts said it has been long past time to broaden the testing protocol beyond people who traveled to China. Outbreaks are gathering speed in Italy, Iran, and South Korea, and dozens of other countries are reporting cases.

On Thursday afternoon the agency did just that in new guidelines for the medical community on who to test for Covid-19, the disease caused by the virus. People with symptoms compatible with Covid-19 and who have recently traveled to China, Iran, Italy, Japan, or South Korea should be tested for the virus, the new guidance says.

The CDC’s own advice to travelers warns Americans not to travel to South Korea because of the coronavirus risk and urges people with medical conditions to avoid traveling to Italy, Iran, and Japan at this time.

“It is accurate to say that we have recognized 60 cases in the U.S. from returning travelers and one now unexplained by travel in California. But it’s not accurate to say that we have 60 cases,” said Tom Inglesby, director of the Center for Health Security at Johns Hopkins School of Public Health. “We don’t know how many cases we have. We can’t estimate that until we’ve done clinical testing and surveillance testing.”

The new guidance also frees up hospitals to test patients with ARDS — acute respiratory distress syndrome — for which there isn’t a diagnosed cause to see if they are infected with the new virus, a move Inglesby had also called for.

The CDC developed and sent test kits to state and local labs in early February. Even then, those labs were clamoring for the ability to test and questioning why it was taking so long to develop assays for the new coronavirus.

Because the federal government declared the coronavirus outbreak an emergency, state and local laboratories are prohibited from using tests developed in-house. They could only use tests that had received an emergency use authorization from the Food and Drug Administration. In this context, that means the CDC test.

When laboratories start to use a new CDC-designed test, they have to first assess their own ability to run the tests accurately, and report back to the CDC if they are having problem getting the tests to work in their hands. It quickly became apparent that a lot of the state and local laboratories were having trouble with one part of the test, Health and Human Services Secretary Alex Azar told the House Ways and Means Committee on Thursday, adding that the CDC “probably, in retrospect, maybe over-engineered [the test] a bit.”

The CDC told the few states that weren’t having a problem to continue testing and pulled back the kits from the others, which meant that any time those states had a patient who needed to be tested, they had to send the sample to the CDC.

The organization that represents state and local labs — the Association of Public Health Laboratories — was so concerned that on Monday it asked the FDA in a letter if local labs could begin to use in-house tests, executive director Scott Becker said.

“That’s really what led us to reach out to the FDA in really a very public way saying: ‘What else can we do? Because we’re hamstrung here. We’re between a rock and a hard place,’” he told STAT.

Becker said state and local labs have now been told that those that can run all three parts of the test should do so; those that can’t get the third part to work properly can now drop that part. Meanwhile, a next-generation test is being readied.

“I expect it to go very quickly in the next few days,” Becker said. “I really feel like yesterday” — Wednesday — “was a pivotal point and there’s some positive movement.”

Having more laboratories able to test will only solve part of the problem, however. Giving doctors and hospitals more leeway to test more patients who look like they might have Covid-19, regardless of whether they’ve traveled or not, will help further define the level of transmission in this country, experts said.

Inglesby called for a surveillance effort — designating certain hospitals or cities to test more broadly for the virus to try to assess whether there is undetected spread.

The CDC said several weeks ago such a program would be launched in six cities. But the testing problems have delayed the rollout.

Megan Thielking contributed reporting.