Next Winter, What If We Test for Even More Viruses?

Cough? Test. Stuffiness? Test. Scratchy throat? Test.

A nasal swab twisted into an infinity sign
Paul Spella / The Atlantic

In Emily Martin’s ideal version of next winter, no one in her family would get sick. In Emily Martin’s realistic version of next winter, someone probably will: There are simply too many viruses and bacteria bopping around in the chilly midwestern air. When that fate befalls her household, Martin has a plan, essentially the same one she rolls out every year—test, test, test, for everything she can.

“I was a very heavy tester, even before COVID,” Martin, an epidemiologist at the University of Michigan, told me. The diagnostic reflex kicks in every time she feels even the slightest bit sick. Cough? Test. Stuffiness? Test. Scratchy throat? Test. “Even with my daughter, a couple of sniffles and I try to see if she has the flu,” Martin told me. And why not? Tests yield knowledge; they clear a path to treatments. “I just think it’s helpful to know what you have,” she said.

For anyone schooled in a more common and casual approach to cold-and-flu season—stay home, drink fluids, Google your symptoms, and guess what’s wrong—the instinct to test first and test always might seem like overkill. But the past two years of trying to wrangle SARS-CoV-2 has made Americans more diagnostics-literate than ever before. “We have never tested for another respiratory pathogen like this,” says Roby Bhattacharyya, a microbiologist and infectious-disease physician at Massachusetts General Hospital. We now have the tools to diagnose a SARS-CoV-2 infection in minutes, in just about anyone, just about anywhere.

Right now, America’s fervor for testing is, like the virus, on the wane. Cases are falling; the threat feels more distant. Universities, businesses, and even entire states are winding down their screening, surveillance, and case-reporting programs. Pharmacies that couldn’t keep diagnostic products in stock now find themselves flush. Maybe, if the coronavirus’s danger continues to subside, many of us will return to our old ways, shrugging off most wintertime symptoms. Or maybe we just keep testing for this coronavirus, whenever we feel COVID-ish—and then do the same for a bunch of other respiratory pathogens too. Maybe, one winter sometime soon, we test for everything.

It’s a bold idea, and not everyone will be convinced it’s worth the effort. Martin, of course, is Team Test. So is Amesh Adalja, an infectious-disease physician and a senior scholar at the Johns Hopkins Center for Health Security. Like Martin, he thinks more aggressive respiratory-illness testing could fast-track people toward treatments, including antivirals that have to be taken within the first few days of infection to pack a proper punch. Flu is a prime example. “We underprescribe influenza antivirals,” Adalja said, even though “most people would benefit”—especially pregnant people, older individuals, the immunocompromised, and other flu-vulnerable groups. Flu viruses hospitalize tens of thousands of Americans annually; bolder test-and-treat protocols would almost certainly shave some cases off that toll. COVID might be an even better example: If Pfizer’s oral antiviral, Paxlovid, is given to high-risk individuals within the first five days of illness, it cuts the chances of hospitalization or death by nearly 90 percent. “That’s a big deal,” Bhattacharyya told me. That level of effectiveness is “better than anything does against flu, that I’m aware of.” And if scientists discover that the antiviral curbs infectiousness, or battles long COVID, more people should probably be taking it.

Other microbes could eventually join SARS-CoV-2 and flu viruses in the self-testing arena. Adalja envisions a future in which most American homes have a single device that can detect a glut of respiratory pathogens—among them SARS-CoV-2, RSV, rhinovirus, strep-throat-causing bacteria, and a couple of types of flu. Team Test’s dreams get bigger, too: Positive results could, in this universe, directly notify health-care providers, who’d then dole out advice or prescriptions from afar.

Besides the advantages for individuals, more testing would have rippling benefits. Results could reduce transmission and guide public-health decision making. That’s not just important mid-outbreak, Martin said. Americans too often go into work when they’re sick, shrugging off their symptoms or chalking them up to allergies or the weather. A bona fide positive test result adds the oomph of evidence: Actually, you do have COVID; don’t go in. Data from diagnostic devices could be funneled to local public-health officials, helping them pinpoint a rise in cases of a particular pathogen. IDing a bug might seem mostly unnecessary for someone who’s young, healthy, and hardly ill. But if a test nudges that person to stay home, it could keep a microbe away from someone who might not bear contagion so well.

To be clear, we’re … nowhere near achieving this ideal of maximalist testing. “I don’t know if I can envision that future,” says Emily Pond, a staff researcher at the Johns Hopkins Center for Health Security—so many logistical, cultural, and policy hurdles stand in the way. For starters, there’s a technological gap. Huge, multi-pathogen tests exist in health-care settings, but we’re just now getting SARS-CoV-2/flu/RSV tests off the ground and into homes—forget about scanning for a dozen bugs at once. We’ve battled flu for years, and at-home tests for those viruses still aren’t widespread; even clinicians don’t always deploy the fairly simple, rapid tests they have on hand, according to Martin. And as fast and convenient as rapid tests can be, their accuracy can be wanting, or their interpretability murky. Rapid flu tests, for instance, have struggled to detect certain viral strains in some years. Plus, if we tested for everything we knew could trouble our airways, sometimes the results wouldn’t yield medically actionable information: We still lack specific treatments for many airway pathogens. And some of the ones that do exist—Paxlovid among them—aren’t widely available, and may not work in certain high-risk individuals, such as people with severe liver or kidney disease. (Adalja argues that more testing could create more demand for treatments, though, and spur pharmaceutical companies to invest in designing more and better drugs.)

Solve those initial technical issues, and still others would persist. Pond points to the cost and supply problems that have bedeviled America’s diagnostic approach to SARS-CoV-2. Capacity for wide-scale testing has been sorely lacking, or at the very least inconsistent; we’re still largely operating on a market-based approach, meaning that Americans have too often had to either queue up for hours to access a swab, or scramble to buy a super-pricey product off a pharmacy shelf. Only recently has the government offered to send the products out for free, and only in tiny quantities, hardly enough for a typical family through a single sneezy month. Long-term government subsidization of testing might help address some of these issues; so would bulking up free testing capacity at urgent-care clinics, schools, nursing homes, correctional centers, and even mobile sites like vans—places with health liaisons who could help ensure that infected individuals’ needs are met.

Even if excellent, easy tests somehow became free and ubiquitous, the right people would still need to take them, then act on their results, neither of which is a guarantee. Many of the consequences of testing during the pandemic have felt negative: days-long isolations, missed work, day-care and school closures, even stigma or guilt. For certain individuals, “there is almost a fear of getting a diagnosis” of COVID-19, says Stefan Baral, an infectious-disease physician and epidemiologist at Johns Hopkins. “And the disincentives to test were always the greatest among the people who most need to test.” That won’t change, Baral told me, without systems that offer support for the ill—paid sick leave, child care, food assistance, dedicated isolation spaces (when appropriate), and more. But as things stand, many individuals simply cannot afford to test, or deal with the repercussions that come with the results.

And if more testing means more treatment, it’s worth considering the costs there, too, Bhattacharyya said. All interventions come with price tags, and resources are limited; that’s part of why we prioritize antivirals for the populations that stand to benefit from them the most. Antivirals can also cause side effects. Paxlovid’s include diarrhea, and the tablets can interfere with other drugs. Bhattacharyya also raised the question of whether we’ll see antiviral resistance crop up with more frequent use—an area researchers are still delving into with SARS-CoV-2.

So maybe a total testing revolution won’t happen overnight. But we do have precedent for something more ambitious than our status quo—with HIV, to date the only other virus for which we’ve built the infrastructure to diagnose large numbers of people at home. In the past decade, companies have even debuted simple oral-swab-based tests that are available over the counter, and can deliver results in 20 minutes. People appreciate the convenience, privacy, and ease of use, and it’s a way to “detect infections in people who might not otherwise have come in,” says Kathryn Macapagal, a clinical-health psychologist at Northwestern. For respiratory pathogens, we don’t yet have that capacity. But even if test for everything will take some time to come to pass, test for more of everything is still plausible, and very much within reach.