My Covid-19 Test Was First Positive, Then Negative: Why It Matters

After I tested positive on a rapid antigen Covid-19 test, I did a nasal swab test and got a negative result. Here's what it means and why it matters.

covid false positive testCourtesy Denise Mann

I had a positive Covid-19 test, and then I didn’t. Confused? I was, too, and in many ways, still am. But before I clear it up for you, let me share a little something about myself by way of background.

I am a health writer, hypochondriac, and career germophobe. It turns out this is not the ideal combination during a pandemic. I have been writing about Covid-19 for months and stressing about it for even longer.

I’ve covered pretty much every aspect of this novel coronavirus from the 11 signs you have already had Covid-19 and coronavirus quarantine constipation (it’s a thing) to depression during coronavirus quarantine and potential treatments such as convalescent plasma therapy and dexamethasone—the inexpensive drug that helps save the sickest people with Covid-19.

I’ve also interviewed doctors about what it’s like to be on the frontlines during coronavirus. Through my reporting, I have learned that reliable, accessible, affordable, and quick coronavirus testing is key to slowing its spread and reopening society.

What it’s like to take a rapid antigen Covid-19 test

I live in New York City, and when we were considered the epicenter of the pandemic, Covid-19 tests were hard to come by—reserved only for those who met certain criteria. And the results took forever. In recent months, however, tests—including so-called rapid point-of-care tests—have become more widely available.

I decided to get a Covid-19 test largely to better understand the process, as a first-person experience often adds a new dimension to my writing. I had no symptoms of Covid-19, which is not uncommon (many people are asymptomatic). I was not exposed to anyone with the virus as far as I knew.

I have been wearing a face covering since before the Centers for Disease Control and Prevention (CDC) first told us to do so, and I hopped on the social distancing bandwagon before most. (Confession: I turned 50 during the quarantine and may have been slightly less vigilant on my big day when friends surprised me with flowers, wine, and gifts.)

A family doctor told me about the rapid antigen test while we were discussing another matter. “Results take 15 minutes and it’s incredibly reliable. I did my research,” he told me. The price tag was hefty ($275), but this was more about my sanity than my finances so I scheduled an appointment for the following day. (Here are the 8 medical appointments to make during coronavirus.)

I could have (and perhaps should have) gone to a free testing center, but I had friends who were exposed who waited two weeks for results. I don’t have the mental fortitude for that.

What are point-of-care Covid-19 tests?

These point-of-care tests detect fragments of proteins (antigens) on or within the virus from samples collected from your nasal cavity. It’s quick, easy, and completely non-invasive. I didn’t feel a thing. The samples do not get sent off to a lab. Instead, your doctor applies a reagent to the sample and places it in a small machine to see if it reacts. A reagent is a compound that is added to see if it causes a chemical reaction. If it does, the machine will generate a positive—as in you have Covid-19—sign. This is similar to the way that the rapid flu or strep throat tests work.

The US Food and Drug Administration (FDA) has approved a few point-of-care tests under the emergency use authorization (EUA), which falls short of a full-on greenlight. The EUA aims to get things moving quickly due to the nature of this pandemic. As a result, things aren’t tested to the same degree of rigor. (The FDA has also authorized several at-home specimen collection kits for laboratory-based molecular testing.) The FDA recently reported that one point-of-care test may return false-negative results.

I made small talk with the doctor while waiting for my results. Fifteen minutes later, I glanced over and saw a positive sign. Shock is an understatement. My mind raced. Maybe I don’t feel fine. Maybe my stomach was upset from Covid-19 as opposed to a black bean burger and gigantic kale salad I had for lunch. The doctor seemed as thrown off as I did and quickly ushered me out the door. I was given no real information about what to do next except that I needed to get a more precise test to confirm these findings. (Also, here’s what you need to know about at-home Covid-19 tests.)

covid nasal swab test close upMario Tama/Getty Images

Undergoing a nasal swab Covid-19 test

Once I was able to form complete-ish sentences again, I had the same doctor test my husband and two sons. If they were positive, it would mean that we could quarantine together as opposed to me being locked in my room while I await results from the “more precise” test. (Someone at home has coronavirus? Here’s how you can manage a Covid-19 hot zone in your home.) All three tested negative. (The bill for this fact-finding mission was just shy of $2,000.)

As a health reporter, I have more contacts than most and I called Len Horovitz, MD, a pulmonary specialist at Lenox Hill Hospital in New York City. He has been on the front lines of the pandemic and is a straight shooter. He told me that he is not a believer in point-of-care testing yet, that false-positives are highly common and to just breathe.

I visited his office the following day and underwent a nasal swab test that detects the genetic information of the virus or RNA. This test is referred to as the genetic, RNA or PCR test. It is considered the “gold standard” for diagnosing Covid-19 today. The nasal swab goes much deeper than it did during my first test. It actually felt like he tickled my brain.

What it’s like to be in isolation at home

For two days, I stayed in my room in our apartment, waiting. My husband slept on the couch, my kids communicated with me by texts only and I ate all meals at my desk. These two days were long, and the nights were longer. Could I be asymptomatic (no symptoms ever)? Or is that fullness in my ears a sign of something brewing? Maybe I was pre-symptomatic (symptoms are on their way). I was clearly unraveling fast. (Here’s what you need to know about the difference between self-isolation and quarantine.)

A close friend of mine is a contact tracer. She held my hand during these two days (virtually, of course). She told me what to expect when the result is confirmed, including what I would be asked to do and who I would need to notify. In a nutshell, I would be asked to self-isolate from my first symptom (which I hadn’t experienced yet) and those who I came into contact with for longer than 15 minutes would need to be tested and quarantine until they get their results.

And then I got this text: “Negative. Rapid Test was Wrong.” Just like that, I was Covid-19 free. (I have no idea of the cost as it was submitted through my insurance, which I believe covers this type of testing. The family doctor does not take insurance, so while I will submit a claim, I am not hopeful.)

Two Covid-19 tests, two different diagnosis

When it comes to testing, two components are important: sensitivity and specificity.

Sensitivity tells you how often a test correctly generates a positive result for people who have the condition, while specificity measures a test’s ability to correctly generate a negative result for people who don’t have it. The bottom line is that point-of-care tests are not as sensitive or specific as molecular PCR tests. This is why the results must be confirmed before acting. (Here’s what happened when one health writer thought she had coronavirus.)

There’s more to it as well. “Labs have better reagents,” Dr. Horovitz says. The PCR test also amplifies the genetic information of the virus (RNA), making it easier to get a more accurate result. And then there is the nature of the sample. “The swab has to get all the way up there—that’s how it’s done,” he says. Put another way, these rapid tests grab whatever they can get, which may not be as fruitful as a sample that is taken from higher up in your nasal passage. “We need to get close to where the Covid virus tends to replicate, and that is high up in the nasal passage,” Dr. Horovitz says.

The nature of the test is also a little dicey. “Yes, there are some proteins or antigens in Covid-19, but antigens they are calling positive may not be a protein of this virus,” he explains. By contrast, the genetic code of the virus is in the RNA and that is telling, he explains. “We all want a rapid test on the spot but we aren’t there yet, “Dr. Horovitz says.

Why my story matters

Thinking you have Covid-19 does a number on your psyche, but thinking you are in the clear when you’re not is likely worse. Yes, testing is getting better, but it is far from perfect, and unless and until we get this right, reopening society and rolling back restrictions is a dangerous game. You’ve been warned. (Next, learn what SARS, MERS, and Covid-19 have in common.)

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Denise Mann, MS
Denise Mann is a freelance health writer whose articles regularly appear in WebMD, HealthDay, and other consumer health portals. She has received numerous awards, including the Arthritis Foundation's Northeast Region Prize for Online Journalism; the Excellence in Women's Health Research Journalism Award; the Journalistic Achievement Award from the American Society for Aesthetic Plastic Surgery; National Newsmaker of the Year by the Community Anti-Drug Coalitions of America; the Gold Award for Best Service Journalism from the Magazine Association of the Southeast; a Bronze Award from The American Society of Healthcare Publication Editors (for a cover story she wrote in Plastic Surgery Practice magazine); and an honorable mention in the International Osteoporosis Foundation Journalism Awards. She was part of the writing team awarded a 2008 Sigma Delta Chi award for her part in a WebMD series on autism. Her first foray into health reporting was with the Medical Tribune News Service, where her articles appeared regularly in such newspapers as the Detroit Free Press, Chicago Sun-Times, Dallas Morning News, and Los Angeles Daily News. Mann received a graduate degree from the Medill School of Journalism at Northwestern University in Evanston, Ill., and her undergraduate degree from Lehigh University in Bethlehem, Pa. She lives in New York with her husband David; sons Teddy and Evan; and their miniature schnauzer, Perri Winkle Blu.