I’m Fine, Thank You. But I’m Stuck.

I have no symptoms and the C.D.C. says I can go out. But I keep testing positive, so I might be infectious. What’s the responsible thing to do?

I’ve been in isolation for seven days now, meaning the C.D.C.’s new guidelines say I could have left two days ago. But I’ve tested positive on my Day 6 and Day 7 rapid tests, making me I worry that I might still be slightly infectious. So now I’m hanging on till Day 10.

This is a perfect illustration of both the usefulness and the fallibility of testing, despite the blind faith we place in it. And of the difficulty of writing coherent public health policy under economic and political pressure. Even science is not an exact science. And government science gets flimsier when the airline and cruise industries are screaming about their lost profits. (Almost 100 cruise ships are having outbreaks — who thought it was a bright idea to let them weigh anchor?)

To recap: on December 27, I woke up with a scratchy throat. Since I knew that, in the vaccinated, Covid often shows the symptoms of a regular cold, I took a rapid test. It was just barely positive, a faint pink line, but that’s enough. As quickly as I safely could, I left my girlfriend’s house, went home and started shunning human contact.

Later that same day, the C.D.C. announced its new guidelines: Anyone infected could leave isolation after just five days as long as their fever was over and they could mask up for five more.

I felt that was just too loosey-goosey. For hospital staff, for fire and police, sure, of course. You can’t lose too many of them or society falls apart. (It was clear two years ago that hospitals would ultimately be forced to ask their staffs to work while sick.)

But not all of us non-essential workers need to be out prowling around. (And what could be less essential than a retired journalist?)

So I decided to follow the British protocol: hole up for seven days, and come out if I tested negative on Days 6 and Day 7. I noticed that a lot of medical experts also felt that at least one test was warranted.

Now it sounds as if the C.D.C. may be rethinking its decision.

I think I’m doing the right thing — even though the tests mean I’m stuck a bit longer.

The first few days of isolation were fun. It was cold and rainy outside. I had end-of-year paperwork to do. No big deal.

And since my email list includes some of the nation’s top doctors, I got many moving expressions of concern. And lots of free high-level medical advice.

Most of which was contradictory.

Dr. P advised using a fingertip monitor to watch for “happy hypoxemia,” which is feeling perky while your blood oxygen drops dangerously low. And also an Apple Watch to detect atrial fibrillation.

I did have the fingertip doohickey; I do not have an Apple Watch.

Dr. H said my Day 2 early morning blood-oxygen level of 93 was “of concern.” In a hospital, I’d be on oxygen, he said, so I should go to an ER and demand monoclonal antibodies. I said the GSK monoclonals, the only ones believed to work against Omicron, were in short supply, and I’d feel wrong getting them, since I felt pretty good, despite the opinion of a $20 piece of technology. He said go anyway and maybe I’d get remdesivir.

I didn’t want remdesivir; I decided to wait.

Dr. K, on the other hand, told me to avoid monoclonals unless I got bad. He had a patient who had an anaphylactic reaction to them.

I noticed that two cups of coffee gave my oxygen level a kick in the butt. So to reassure Dr. H. that I was no happy hypoxic, I put on my sneakers and did two rapid circuits of my block while watching my finger.

That popped my oxygen right up to 95–98, dead normal. (Just the fact that I could fast-walk eight blocks told me I was OK. I had walking pneumonia five years ago, and I could not have done that.)

But others are not doing as well in this “mild” wave. Children’s hospitals are filling up.

Day 6 rapid test

By Day 3, I was symptom-free and just trying to run out the clock. My girlfriend and I made in-home dinner plans for Day 6, assuming I was negative that morning.

But I wasn’t, that day or the next. In fact, the “positive” lines on the tests — of two different brands — were much darker than they had been a week earlier.

That’s the problem: everybody’s immune system is different.

I’m not the only one caught in this confusion. I hear of both people like me who are asymptomatic but test positive and people who feel ill but test negative.

Day 7 rapid test

For my girlfriend’s son, the tests are working: he probably got infected a day before I did. He too is getting better but testing positive longer than expected, though his lines do get paler each day. In his case, the passage of time does threaten his job: he’s supposed to be shooting a movie. But he can’t be on a set of 100 people until he’s cleared by movie industry standards — which are tougher than the C.D.C.’s.

Friends have suggested: “Why don’t you take a PCR?” That, however, would be meaningless. If you have enough virus in your nose to turn a rapid test positive, you might get positive PCR tests for weeks, long after you’re out of the danger zone. The whole point of a PCR machine is to amplify even the tiniest speck of virus in a sample. It doesn’t mean there was enough in your nose to infect anybody; even dead viral fragments can turn a PCR test positive.

I probably am non-infectious. But I can’t take the chance of giving my girlfriend a breakthrough case.

Not that she’s worried for herself. She has the immune system of an alligator, whose blood kills anything. In two weeks, she was unwittingly exposed to three positives — me, her son and a friend of hers — but two Modernas and a Pfizer booster have apparently turned her into a Louisiana swamp monster. She has stayed negative on test after test.

However, she volunteers in a cancer hospital with immunocompromised patients and also visits her mother. She can’t risk being a carrier.

So now I’m going to do what the C.D.C. used to recommend: isolate for 10 days. At that point, it’s safe to come out, test or no test.

That protocol was developed before rapid tests existed and was based on a simple epidemiological observation: virtually no one transmits Covid after 10 days of recovery. By that time, one’s antibodies and T-cells have suppressed the virus.

Just to make sure, I checked with one of the doctors I know — a certain Dr. F, who despite what the far right thinks, knows what he’s talking about, and has for the 20 years I’ve known him.

He wrote back: “You are absolutely doing the right thing.”

An earlier version of this article said one of my childhood babysitters had died in this wave of Covid. I misunderstood what my sister had said; our former babysitter died in 2020, before vaccines were available.