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.
“If anyone needed a wake-up call with antigens, how careful you have to be, we certainly saw that with my test,” Mr. DeWine said. “And we’re going to be very careful in how we use it.”
A spokesman for Mr. Hogan, Michael Ricci, echoed that sentiment: “We are taking this one step at a time.”
Accurate test results are crucial for curbing the spread of disease. False positives, like the one Mr. DeWine received, can set off an unnecessary period of self-isolation, depriving people of access to their workplaces or their own families. False negatives, on the other hand, can hasten the spread of disease from unwittingly infected people.
PCR tests, like the ones used to determine Mr. DeWine’s health status, are often the best bet for avoiding incorrect results. But these tests are in short supply nationwide as manufacturers and laboratories struggle to meet the increase in demand that has accompanied recent surges in infections. Turnaround times for results have stretched past two weeks in some parts of the country, rendering the information useless for anxious people who need to know their status immediately so they can self-isolate as needed and stop the virus from spreading further.
“Honestly, PCR tests were not designed for this type of mass screening/testing,” Ms. Prinzi said. PCR tests, she added, function best in laboratory environments that are well stocked with chemicals, high-tech machines and specially trained personnel. Their high-maintenance ingredient lists and relatively hefty price tags aren’t terribly compatible with quickly getting answers to large numbers of people.
Rapid tests, on the other hand, can catch a majority of active infections if administered frequently, even if they’re less accurate, many experts have argued.
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.
The Coronavirus Outbreak ›
Frequently Asked Questions
Updated August 6, 2020
Why are bars linked to outbreaks?
- Think about a bar. Alcohol is flowing. It can be loud, but it’s definitely intimate, and you often need to lean in close to hear your friend. And strangers have way, way fewer reservations about coming up to people in a bar. That’s sort of the point of a bar. Feeling good and close to strangers. It’s no surprise, then, that bars have been linked to outbreaks in several states. Louisiana health officials have tied at least 100 coronavirus cases to bars in the Tigerland nightlife district in Baton Rouge. Minnesota has traced 328 recent cases to bars across the state. In Idaho, health officials shut down bars in Ada County after reporting clusters of infections among young adults who had visited several bars in downtown Boise. Governors in California, Texas and Arizona, where coronavirus cases are soaring, have ordered hundreds of newly reopened bars to shut down. Less than two weeks after Colorado’s bars reopened at limited capacity, Gov. Jared Polis ordered them to close.
I have antibodies. Am I now immune?
- As of right now, that seems likely, for at least several months. There have been frightening accounts of people suffering what seems to be a second bout of Covid-19. But experts say these patients may have a drawn-out course of infection, with the virus taking a slow toll weeks to months after initial exposure. People infected with the coronavirus typically produce immune molecules called antibodies, which are protective proteins made in response to an infection. These antibodies may last in the body only two to three months, which may seem worrisome, but that’s perfectly normal after an acute infection subsides, said Dr. Michael Mina, an immunologist at Harvard University. It may be possible to get the coronavirus again, but it’s highly unlikely that it would be possible in a short window of time from initial infection or make people sicker the second time.
I’m a small-business owner. Can I get relief?
- The stimulus bills enacted in March offer help for the millions of American small businesses. Those eligible for aid are businesses and nonprofit organizations with fewer than 500 workers, including sole proprietorships, independent contractors and freelancers. Some larger companies in some industries are also eligible. The help being offered, which is being managed by the Small Business Administration, includes the Paycheck Protection Program and the Economic Injury Disaster Loan program. But lots of folks have not yet seen payouts. Even those who have received help are confused: The rules are draconian, and some are stuck sitting on money they don’t know how to use. Many small-business owners are getting less than they expected or not hearing anything at all.
What are my rights if I am worried about going back to work?
- Employers have to provide a safe workplace with policies that protect everyone equally. And if one of your co-workers tests positive for the coronavirus, the C.D.C. has said that employers should tell their employees — without giving you the sick employee’s name — that they may have been exposed to the virus.
What is school going to look like in September?
- It is unlikely that many schools will return to a normal schedule this fall, requiring the grind of online learning, makeshift child care and stunted workdays to continue. California’s two largest public school districts — Los Angeles and San Diego — said on July 13, that instruction will be remote-only in the fall, citing concerns that surging coronavirus infections in their areas pose too dire a risk for students and teachers. Together, the two districts enroll some 825,000 students. They are the largest in the country so far to abandon plans for even a partial physical return to classrooms when they reopen in August. For other districts, the solution won’t be an all-or-nothing approach. Many systems, including the nation’s largest, New York City, are devising hybrid plans that involve spending some days in classrooms and other days online. There’s no national policy on this yet, so check with your municipal school system regularly to see what is happening in your community.
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.
He added that it was incumbent upon the companies developing the tests to demonstrate their accuracy, and that the experience would not deter him from expanding testing in his state.
“We could use additional money for testing,” Mr. DeWine said. “We have doubled our testing the last four weeks. We need to double it, and then double it again.”
Ohio was among the first states to reopen in May, but as cases ticked up in mid-June and July, Mr. DeWine signed a statewide mandatory mask mandate and asked several counties to limit gatherings of any size. There have been at least 99,969 cases and 3,668 deaths in Ohio since the beginning of the pandemic, according to a New York Times database.
The status of testing in the United States is far from ideal, Ms. Prinzi said. But for now, it’s time to make do with the materials we have, she said. “We can argue about diagnostic accuracy all day, but this is a huge public health crisis right now,” she added.
Flaws and all, antigen tests are “a necessary part of our management of the pandemic,” Dr. Culbreath said. “But we have to be very intentional about how we use these tests.”