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CDC Revises COVID-19 Test Criteria, Director Tells House Panel

<ѻý class="mpt-content-deck">— Mere suspicion of infection now enough to warrant testing
MedpageToday
A pipette transferring a specimen to a vial labeled COVID-19

WASHINGTON -- Criteria determining who's tested for the COVID-19 coronavirus has been expanded following the first possible case of community transmission in the U.S., CDC Director Robert Redfield, MD, told lawmakers during a House Foreign Affairs subcommittee hearing on Thursday.

But subcommittee members expressed concern over healthcare providers' access to the tests and the time it takes to deliver results.

After a patient with no known exposure to the virus tested positive for it, the CDC quickly began reconsidering its current criteria, Redfield said.

Subcommittee Chairman Ami Bera, MD (D-Calif.), pointed out that testing had been delayed because that patient didn't meet the CDC's criteria when seen by doctors on Wednesday, Feb. 19. The patient was tested the following Sunday only after Bera's former colleagues at the University of California Davis insisted on it. Another 3 days elapsed before the positive result came back.

Ideas around how the virus is transmitted have been evolving, Redfield said. Initially, experts thought the only individuals who contracted the virus were those exposed at a seafood market in Wuhan, China. Then others with flu-like illness tested positive.

After learning of the new California case, senior CDC officials met immediately to revise the case definition of "persons under investigation," Redfield said.

The new recommendation posted Thursday is "when a clinician or public health individual suspects coronavirus, then they should be able to get the test for coronavirus," Redfield said.

Speaking more broadly, in his opening remarks, Redfield noted that the U.S.'s containment strategy has been successful thus far, but "we must be prepared to move to a blended containment-mitigation approach," and "get ready for broader community spread."

In addition to the specific challenges with testing criteria, Bera also asked about the "rapidity and availability" of such tests. Bera noted that in South Korea 15,000 people are being tested each day.

Redfield noted that there are currently 40 jurisdictions with the ability to perform the test for COVID-19.

The difference between the U.S. and other countries is that here, -- tests created and used within the same lab -- must go through a regulatory process before they can be deployed.

Bera recommended agencies consider ways of "speeding up that regulatory process."

Redfield, towards the end of the hearing, noted that while his agency worked with the FDA and found its sister agency to be "very supportive" he suggested that "the loss of laboratory development tests to be used when ... responding to emergencies, I think, is something that should be re-looked at."

Improved surveillance

In addition to exploring more rapid and accessible testing, Redfield also spoke about surveillance. He noted that the agency is stepping up its efforts on surveillance and plans to implement broad surveillance for coronavirus modelled off other respiratory disease surveillance systems, including flu.

He said he hopes to have a national coronavirus surveillance system in place within 8-12 weeks.

During the hearing, Redfield also tried to clear up what Rep. Andy Levin (D-Mich.) described as "mixed messages" from administration officials and the president regarding the risk posed by COVID-19.

Levin pointed to the words of Nancy Messonnier, MD, director of the CDC's National Center for Immunization and Respiratory Diseases, who on a media call Tuesday suggested that community spread of the coronavirus in the U.S. was inevitable.

and how many people in this country will have severe illness," Levin said, paraphrasing Messonnier.

He contrasted her statement to that of Larry Kudlow, the president's chief economic adviser, who said, ", I won't say it's airtight but its pretty close to airtight."

And, on top of that, President Trump is telling the public the virus is "under control" and "going to go away."

"That's all on the same day," Levin said.

Redfield stressed that the current risk to the American public is "low" and that the U.S.'s "aggressive containment strategy really has worked up to this time." Before the new case in Sacramento there hadn't been any other new cases for 2 weeks, Redfield said.

But also conceded that there will be more new cases and said "we do believe now there may be a ... cluster or occurrence of community acquisition."

Redfield noted while the disease is spreading rapidly in some countries such as South Korea, others -- particularly Singapore and Hong Kong -- have limited the spread through blended containment-mitigation strategies.

"We're of the point of view that we're still in aggressive containment mode, which is dependent on early case recognition, isolation, and contact tracing," he said.

What Messonnier was trying to explain on the call Tuesday, Redfield said -- which "could have been done much more articulately than what the American public heard" -- was "it's also a good time for us to prepare if we have to go with more mitigation."

Treatment and recovery

Asked what factors impact patients' chances of recovery, Redfield suggested that age and comorbidities are clearly significant in COVID-19 lethality.

But, he added, "we believe the integrity of the health system is the major factor," and the U.S. is in a "strong position" with its own "effective healthcare system."

Countries with less sound public health infrastructure will see more challenges.

For instance, in Wuhan, mortality rates are over 4% because the health system there is "beyond strained."

While Wuhan expanded the number of available isolation beds from 132 to 20,000, there aren't enough healthcare providers to meet the demand, he said.

"If you don't have access to oxygen, mortality's going to be a lot higher," he added -- one reason experts are particularly concerned about areas like Pakistan, Afghanistan, and North Africa.