"A flu" at the US Open? Hmm! And: Why I still mask in some, but not all, public situations.

I attended the US Open over the weekend in New York. Apparently, there’s “something going around” the Open; it has been reported that a handful of tennis players have experienced a variety of viral symptoms.

The thing is, nobody knows whether it’s Covid. Players are no longer required to test for it. That said, TV commentator John McEnroe said he’d tested positive for the coronavirus after being on the premises all tournament long. It’s a bit conspicuous that the one famous person who doesn’t have tons of money riding on how far he goes into the tournament decided to get tested for Covid—to reveal the results to the public. I’d wager that at least some of the players with illnesses that some are calling "a flu,” really have Covid. The better players who got sick early in the competition were probably hoping that they could power their way through the initial rounds and be on the mend in time for the later rounds of the tournament when the matches get a lot tougher.

A few thoughts:

“A flu” may or may not be “the flu.”

I couldn’t help but notice a turn of phrase being used. Check it out:

"I think I got a flu or something.”

“I’m a zombie because I have a flu.”

Notice something here?

“A flu” as opposed to “the flu.” There’s long been a misunderstanding here. Not every flu-like illness is influenza. Many viruses share the same symptoms as influenza, but are less dangerous and last for shorter periods. Influenza A and Influenza B can cause some pretty serious suffering, albeit so can other viruses whose names you’ve likely never heard of.

But in 2023, I think we should be a little more specific. If you have a cold or a flu-like illness, you probably should not be around vulnerable people—or at least wear a good mask and be very careful with hand hygiene. If you have lab-confirmed influenza A or B (the “real” flu) or Covid, you definitely should not be around vulnerable people.

Now, a bunch of world-class athletes are probably not the highest-risk group. But there are coaches, and families, and tennis-legend-turned-TV commentators like John McEnroe to consider. My feeling is that if players are sick, they should take some precautions—perhaps masking at press conferences or skipping indoor events. This is both good public health citizenship and, in the year 2023, also just polite common sense.

Is “I’m not contagious” good enough?

If the Covid-19 pandemic taught us anything, it’s that asymptomatic transmission is probably more common than we previously appreciated. At-home antigen tests have shown us that many people remain at least somewhat contagious for 7-14 days, even if feeling better.

People used to throw around terms like “I’m not contagious,” based on vague misunderstandings (if not misinformation) about communicable diseases. A lot of people internalized the notion that if you got sick but you haven’t had a fever for a day or two, they’re no longer contagious. That’s pretty dubious. It might be true. It might not be. We know it’s not true for Covid. And it’s probably not true for influenza either.

I was speaking with my colleague Dr. Michael Mina about this today. We agree that we know more about Covid than almost any other pathogen humans have ever encountered. It’s likely that other pathogens are contagious to some degree for far longer than commonly appreciated. There haven’t been millions of people who have taken rapid antigen tests for influenza every couple of days for two weeks the way many have done for Covid. If enough people did that (i.e., if such tests were commonly available) we’d probably find out the the CDC guidance on influenza isolation is basically useful, if not airtight. That is, isolating for 4-5 days after flu symptom onset reduces most transmission. But I bet it’s nowhere near all, and immunocompromised people might shed these viruses longer and be more susceptible to falling ill in the face of less intense exposures (i.e., getting infected despite encountering less virus for less time). We should be studying these questions not just for Covid but for all major respiratory illnesses we routinely encounter.

How I handle traveling—and life—in 2023.

I flew down to New York entirely for recreational purposes this time. I had not attended the US Open in many years (a result of the pandemic and having moved to Boston full-time. Oh, and having kids—which tends to curb such extravagances). But I love going to the Open and I’d been wanting to get back to attending. So, some colleagues and I made plans to make the trip.

To answer the big question: yes, I still wear a mask in high-risk settings when I travel (and at home). It may seem like a contradiction to wear a mask for 95% of a plane ride (taking it off for 5% of the time to sip come coffee), or to put one on in the subway, only to then dine indoors for two hours (which I did do for one meal while in New York) with no mask in sight. And I didn’t wear a mask in my tennis stadium seats (outdoors, not that crowded). But I did put one on when I used the restroom there (indoors, crowded, and kinda gross, right?)

Putting on a mask in some crowded settings but not others is not a contradiction, nor is it virtue signaling, nor an exercise in futility; It is harm reduction. Taking this measure (and upping my hand hygiene game) continues to help me avoid the sheer inconvenience of getting sick, to say nothing of any misery or health risks I may face. As I told Slate Magazine recently, “I have stuff I want to do next week.”

So for me, it’s all about choices. If I get Covid because of a wonderful late-night dinner in a fairly uncrowded restaurant in New York with three excellent friends, I won’t feel cheated by the universe. It would be a consequence of a conscious choice I made. But if I got Covid from the subway, that wouldn’t feel like a good bargain.

Bottom line: I still have never gotten Covid—though I’m not sure how long that will last. For all I know, I just got it in New York and I’ll be reporting back to you in a few days on that. But I believe that at least some of my track record reflects having been careful in high-risk places, picking my battles, and throwing on mask when doing so literally costs me nothing. I’m not trying to get sick, and I’m not trying to spread viruses of any kind to my family, friends, and patients. The pandemic made me more attuned to this. That’s a good thing.