What I Learned, First-Hand, About Coronavirus Testing

In early August, my elderly relative went to the emergency department of NYU Langone Health due to problems, we thought, that related to her chronic health issues. While there she, coincidentally and surprisingly, tested positive for COVID-19. Thus, began my family’s personal journey into the frightening world of that dread disease. While doctors soon assessed that she was asymptomatic and not infectious, we faced several daunting days of decision-making amid much uncertainty. The clinical nuances we saw are not typically mentioned in the mountains of mass media articles on coronavirus experiences, while the frustrating confusion we encountered is not written up much in medical journals.

We were given: a frightening, bewildering diagnosis (since March, she had been living at home, in isolation except for carefully selected aides and visits from three family members, never leaving her apartment); sometimes conflicting instructions from healthcare providers; and an introduction to a new and extremely nuanced set of diagnostic parameters, which were the main basis for assessing her infectiousness and the next steps for caregivers. The situation was complicated by the presence, happily, of our elderly mother, who lives independently a few miles away, but is also fragile and would need some adjustment in visitation, given that our family visits both relatives frequently.

We were given a frightening, bewildering diagnosis, sometimes conflicting instructions from healthcare providers, and an introduction a a new and extremely nuanced set of diagnostic parameters.

 

As it turned out, my relative’s treatment would be straightforward, but the implications of the diagnostic workup are not. Although she tested positive, the ED staff didn’t act particularly alarmed–from the beginning, they seemed to suspect her condition was not caused by COVID-19. Her chest X-rays and quick, positive response to oxygen therapy looked more typical of chronic heart failure than COVID-19. Their educated guess was confirmed within days. The doctors considered my relative to be asymptomatic COVID-19 positive.

We did, however, have to grapple with ourselves: what to do about our own behavior and that of the aides? My relative is lucky enough to have four caring and kind aides, but they have intimate, ongoing exposure to her and are older themselves. They have families and need to work. What should they do? What about our family members, who regularly visit but do not have that same level of contact? What about those people? And there was a driver for the aides—hired to avoid mass transit during the worst of the outbreak—should she be worried? What about visits to our mom? No one was sick, and everyone had been exceedingly careful, knowing, as we all did, what had happened during the terrible months of March and April in New York City. Once my relative was out of immediate danger, this felt like a massive logistical morass. (See “Covid-19 Testing Strategies: Experts Weigh In,” MedTech Strategist, July 22, 2020.)

For answers to these questions, we turned to tests. Ah, the tests. We–the aides and myself—would all need to get tested. Which kind—PCR or antibody tests or both—and if the latter, would any test site do? Some of us did not know the difference. I did, but also had heard about the unreliability of antibody tests. Then again, that was weeks ago and maybe things were better. (See “Why is it so Hard to Develop a Serology Test for Covid-19?” MedTech Strategist, April 23, 2020 and “Everywhere Care for Covid-19 Diagnostics,” MedTech Strategist, July 22, 2020.)

Then, what to do with results? The ED staff warned us that we could not rely on negative results to dictate our behavior because of the generally accepted 30% false negative rate for PCR. The guidelines posted on the Centers for Disease Control and New York State websites still said two weeks of quarantine for people exposed to someone who is sick, regardless of PCR results. But the wonderful, cheery ED nurse at NYU Langone didn’t skip a beat—hospital staff who test positive now are asked to stay home for three days after symptoms subside, before returning to work, and several ER staffers suggested that would be appropriate for us, depending on our level of exposure. Some people, including lots of hospital staff, test PCR-positive for COVID for weeks, even months, after initial infection, but are no longer contagious, ED staffers said, pointing out that a positive PCR isn’t by itself grounds for long-term quarantine. In fact, while the hospital had initially asked employees who were diagnosed with COVID-19 to quarantine for 14 days, it had, very early on, called back those whose symptoms subsided after a week out of desperation. The earlier-than-expected return to work had not seemed to harm patient care or spread disease.

We wanted more clarity. They quickly put us in tele-touch via iPAD with a resident in the hospital infection control unit, who echoed what the ER nurse said. We argued it conflicted with CDC guidelines. We were as confused as ever. A physician’s assistant in the ED weighed in: the CDC timeline for quarantine was recently reduced from 14 to 10 days. We weren’t sure. When we looked it up, we didn’t see that change on the official CDC website. The full 14 days for the aides and myself seemed prudent, given our exposure to vulnerable populations, until we learned more.

Two days later, the antibody test results brought good news. The doctors insisted that, based on a variety of factors, including those tests, that our relative had likely been infected weeks or even months ago and was not contagious. Importantly, they wrote a letter to that effect.

But it wasn’t quite that clear-cut, at least to our family. We consulted with a cousin who is a neurologist in Sweden. He said he’d check with infectious disease experts there. The input wasn’t clear from that quarter, either.

Here’s what we learned: The CDC guidance on test interpretations is clear, but simplistic. The antibody test results in fact can be nuanced—and more informative than I thought. Putting questions of immunity aside—which no one yet has answers to—they can produce qualitative, simple positive or negative readouts, or more complex quantitative values. The latter seemed to me to add amazing fine-tuning. That is what happened in this case. My relative received what one doctor called in lay terms a “full” antibody test, including a breakdown of IgG and IgM results, as well as titers. IgM positive would indicate someone is early in the course of infection—and therefore likely infectious. IgG would indicate infection occurred a while ago and that the person is not infectious.

But it was a bit more complex. The results showed that, yes, she had antibodies, but at levels that were equivocal. Her readings were: IgG 6~ and IgM 1.3,with levels between 9 and 11 being equivocal, and levels of 11 units or above reliably positive. That meant to our untrained eyes, she could still be infectious—after all, her test results for both antibodies were officially negative. In that case, we wanted to know, how could doctors be so sure she was infected a while ago and was not contagious? And, yes, again and again, they were sure.

What I’ve learned is how knowledgeable about this disease we actually are. The quantitative results could paint a fuller picture of the status of infected patients to an extent I wasn’t aware of. The presence of both IgM and IgG indicated to doctors that her antibody levels were both trending down, something that could only occur if she had been infected a while ago. How long ago? They could not say. But it meant that if the small circle around her got tested, and those tests were negative, we would be free of quarantine.

My relative was admitted to the hospital and placed on a general medicine floor, albeit in an isolation room, with treatment supervised by the attendings on that floor, not a special COVID-19 infectious disease team. There was confusion among ED staff and even at the nurse’s station on the floor, about visitation rules, but ultimately, it turned out, the hospital’s rules on visitation of COVID-19 patients had recently changed and she could have PPE-attired visitors during certain hours.

All this took a bit of time to sort out, and we are now much more knowledgeable. It’s a reminder of how far we have come and how far we have to go.

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