Ohio Governor Says His Flawed Virus Test Shouldn’t Undercut New, Rapid Methods



Gov. Mike DeWine of Ohio, who last week tested positive for the coronavirus, then negative and then negative again, said on CNN on Sunday that his roller-coaster ride should not be reason for people to think “that testing is not reliable or doesn’t work.”

His first test result was positive, when he was screened with a rapid testing method on Thursday before President Trump arrived in Ohio for campaign appearances.

Mr. DeWine was given an antigen test made by Quidel, one of two companies that have received emergency use authorization from the Food and Drug Administration for coronavirus antigen tests.

These tests, while fast and convenient, are known to be less accurate than PCR tests, which were used to retest Mr. DeWine twice on Thursday and once more on Saturday. All three PCR tests turned up negative, confirming that Mr. DeWine was not infected with the virus.

“I don’t think that DeWine’s results were surprising, per se,” said Andrea Prinzi, a clinical microbiologist and diagnostics researcher at the Anschutz Medical Campus in Colorado. “We know that the performance of antigen testing is not as accurate as PCR testing.”

The Ohio governor’s experience, however, may raise concerns about how much states will rely on antigen tests as they seek to augment the forms of testing, like PCR, that are in short supply or that are mired in laboratory backlogs, unable to generate results in a timely fashion to help assess caseloads and dole out treatments.

Mr. DeWine, a Republican, is one of seven governors who announced last week that they were banding together to buy 3.5 million rapid coronavirus tests, including antigen tests, to ramp up production.

Daniel Tierney, the press secretary for Mr. DeWine, noted in an email that the states involved were considering “multiple companies and multiple testing types,” but did not specify further.

On Sunday, Mr. DeWine said he had already been in touch with Gov. Larry Hogan of Maryland, a Republican, to talk about the states’ agreement to use their collective “purchasing power” for testing and other supplies.

Compared with PCR tests, antigen tests are more likely to return a false negative result, mistaking an infected person as virus-free. Quidel’s test, for instance, can miss up to 20 percent of the cases that PCR detects.

Notably, Mr. DeWine’s antigen test produced the opposite error: a false positive that incorrectly indicated he had been infected.

But Mr. DeWine might not have been have been the ideal candidate for an antigen test, said Karissa Culbreath, the scientific director of infectious disease, research and development at TriCore Reference Laboratories in New Mexico. Such tests usually perform better on samples that contain high levels of virus, which tend to come from sicker patients and people at higher risk of transmitting the infection. When given within the first five days after coronavirus symptoms start, Quidel’s false negative rate may drop below 5 percent, according to the company’s intended use statement.

Mr. DeWine, however, had not experienced symptoms, aside from a headache.

“If we’re testing outside of that intended use, we might expect false positives or false negatives,” Dr. Culbreath said, referring to the five-day window that follows the onset of symptoms.

Allocating tests to people who fit that criteria, she added, will also eliminate the need for scores of follow-up tests, especially while many suspected cases across the nation remain undiagnosed.

“Tests are not interchangeable in their usefulness,” Dr. Culbreath said. “We need to look at this as a tool belt and identify the right tool for the job.”

On Sunday, Mr. DeWine did note that antigen tests function especially well as “screening” tests, expediently delivering information to people while their results are confirmed — if necessary — by the more accurate PCR tests.



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