When I first got that positive Covid test a week ago, I was so sure it must be correct that I canceled our much-planned-for flights without a second thought.
Then I learned a little more and became less sure.
Now, I’m at the point where I think it’s more likely than not that I never had Covid at all. And I’ll never know for sure at this point. But it’s looking more and more likely that I had a false positive last week.
Here’s what changed:
- I read that as the overall rate of Covid infection in a community decreases, the probability that any given positive test is false increases. In fact, in low-prevalence communities — which mine might be considered right now — there can be just as many false positives as true positives, or even MORE FALSE POSITIVES THAN TRUE POSITIVES.
- I took two BinaxNow OTC antigen Covid tests, about 18 hours apart. They both came up negative.
- Everyone in my household tested negative, then tested again five days after they’d last been exposed to me. They all tested negative again. Same with every other person who tested because they’d been near me.
- I interviewed Dr. Glenn Braunstein, the author of the paper I’d read. Not only did he explain all that wonky math to me, he listened to the details of my case and said my positive had likely been false.
Today, I drove to the Walgreens near my house and got a second PCR test. Unfortunately, they warned me that the results might not be in for two to four days. I only have three more days left in isolation at this point anyway. And my kids informed me that, no matter what the author of a peer-reviewed paper says, they won’t let me back in the regular house until my 10 days of isolation are up anyway.
So why did I test again? I’m still hunting for clarity. If this second PCR test comes up positive, I’ll believe that the one I took last week was also likely a true positive. If that happens, then I get to pat myself on the back for being so responsible for taking a screening test before a trip. I get to say, “Thank goodness I found out so I didn’t expose all the people on that airplane to Covid!”
But if the new test comes up negative, well, I still won’t really know if the first one was a true positive or not. I could have been positive last week, and just cleared all the Covid out of my system since then. But. Taken along with all the other evidence listed above, another negative test will be one more reason to doubt that first one.
And if the test I took last week was a false positive — as is looking more and more likely — I have to keep feeling like I naively ruined our trip for no good reason, by getting tested when I didn’t need to.
I now know what I should have done, all along. The author of the paper told me. And by the way, he said, this is what you should do too, if you get a positive test result that seems out of the blue:
Immediately retest. You can buy an OTC test like BinaxNow and take both. If they’re positive, forget it. Your first test was probably correct. Stay home.
But if they’re both negative? Immediately get a new PCR test. If that’s negative, that’s the tie breaker, and you don’t have to isolate. I mean, your local health department will probably tell you that you still have to. If your kids are like mine, they’ll tell you that you still have to. But according to Dr. Glenn Braunstein, no risk factors + no symptoms + multiple positive tests = safe to go.
If I had followed this protocol, I wouldn’t have gotten the PCR tests back enough to make my original flight. But I might have been able to make a later flight.
An even better idea would have been to not get that test at all. I had felt so extra-virtuous for testing before travel, but Dr. Braunstein also told me that there’s really no reason a vaccinated person with no symptoms who works from home, doesn’t go to crowded places, etc., needs to do screening tests. As I learned, testing comes with the risk of false positive, and in my situation, there just aren’t enough potential benefits to be worth that risk.
Now I know. And now you know, too.