CDC: After day 5, Covid patients with positive rapid tests can go out in public, if masked.
The agency’s new guidelines don’t provide real-world or modeling data to support this. Plus, other analyses.
The CDC released new Covid-19 recommendations today. The document, published in its journal Morbidity and Mortality Weekly Report is entitled, “Summary of Guidance for Minimizing the Impact of COVID-19 on Individual Persons, Communities, and Health Care Systems — United States, August 2022.”
I’m not certain the document stands to achieve this.
Some of the changes were expected and are sensible. For example, requiring quarantine for people merely exposed to Covid-19 no longer makes sense. Sunsetting the previous quarantine protocols is justified. Exposures are too frequent for routine quarantine to be workable. Instead, people with high-risk exposures are now told to wear masks when indoors and to take a Covid test at least 5 days after an exposure, regardless of vaccination status. This acknowledges where the science is and what the public can be reasonably asked to do.
One change that is confusing more than anything is the new guidance on routine testing (“screening testing of asymptomatic persons”), like testing everyone in schools or nursing homes on a weekly basis or more. Most observers are already interpreting the CDC’s new guidelines as downplaying the need to do routine screening in general community settings. As if anticipating pushback from the public health community, the CDC deployed soft language here, saying that officials “might consider prioritizing high-risk settings” [italics added] and that routine testing at places like schools “might not be cost-effective in general community settings, especially if COVID-19 prevalence is low.”
Here's the problem: The way the CDC has organized its document, one could easily conclude that the CDC thinks we live in a low Covid-prevalence world. We do not live in such a world. If criticized, the CDC will point to its many caveats. But those caveats read as afterthoughts (sometimes literally), rather than as representations of the world as it currently exists. It amounts to double-talk.
The most troubling part of the new document, in my view, is that the CDC has in effect revoked its prior “test to exit” protocol. Under its old guidance for those with access to at-home rapid antigen tests, Covid-19 patients feeling better after 5 days could return to public life provided they tested negative on at-home rapid tests. Now, the CDC says that even if a clinically improving Covid-19 patient tests positive on a rapid antigen test after day 6, they can still go back to public life, provided they wear a mask (of any kind—there is no mention of requiring N95s or other high-quality masks). Read that again before you go out.
If this is the case, why would anyone bother rapid testing if feeling better (other than, oh, not wanting to spread Covid-19 to others in the community)? Well, it seems that the CDC is now using rapid tests primarily as a carrot-and-stick for mask removal later in a Covid infection. Per the guidance, “Persons who choose to use testing to determine when to discontinue masking can end isolation after day 5 even if they receive a positive test result.”
That means that, starting now, people who are known to still be positive on a rapid antigen test—the best proxy for contagiousness the public has—can get on the bus with you. Now, if they’re wearing an N95 mask, and if they have a low enough viral load, and if the ventilation is good, and if others are masking, this all might just be safe. But those “ifs” are hardly guaranteed in most circumstances.
That means that, starting now, people who are known to still be positive on a rapid antigen test—the best proxy for contagiousness the public has—can get on the bus with you.
That said, the CDC has one thing right here. They allow that people who test negative on rapid tests no longer need to mask. I think that’s reasonable. If you are on the tail end of your Covid-19 illness and are no longer testing positive on a rapid test, you’re about as low risk to the community as you will ever be. In fact, someone 10 days out from their first positive test but who has been asymptomatic and testing negative on rapid tests for a few days is less of a public risk than a random person who might just becoming sick and is becoming more contagious by the minute. Assuming any notable prevalence of Covid in a community, you’d actually rather be in a room of people on day 10 of Covid who are asymptomatic and rapid antigen test negative that day, than a random group of people who haven’t been sick or tested (in the last day or so). During an outbreak like Omicron, a handful of the people in the second group might have just become infected and are on the cusp of becoming symptomatic. In short, during an outbreak of any size, in a random group, it isn’t unlikely that someone present is, unbeknownst to them, asymptomatically (or pre-symptomatically) contagious. But people 10 days out from a known illness and a couple of negative rapid tests to boot? They pose virtually zero risk. That is, unless they have rebound (i.e. either due to “Paxlovid rebound”, or the natural course of the virus), a situation in which a Covid patient who felt better and tested negative on rapid tests subsequently starts feeling worse again and tests positive on rapid tests again. (People with rebound are assumed to be contagious.)
Relatedly, the CDC states that people who choose to use rapid tests as the deciding factor on whether to keep masking in public (and at home) may have to mask longer than 10-days (the rule that applies to clinically resolving Covid patients who choose not to test/are unable to), if they keep testing positive. This could help pick up rebound cases, but it’s unlikely. Some rebound cases are asymptomatic. Why would an asymptomatic person test again after testing out of the mask requirement?
Indeed, the gaping hole in the CDC’s new document is the lack of acknowledgement that spread of Covid-19 may be happening among asymptomatic people after day 5 of illness. It almost certainly is. The question is, to what extent? The CDC offers, to my read, zero data or insight on this. If they have data or modeling to support their new approach, I’d like to see it. Instead, today’s guideline skips all of this, relegating rebound (Paxlovid or otherwise) to a footnote. This is bizarre when we know that a striking number of people are now experiencing rebound and are thus contagious for longer than we thought they might be, including some who did not even take Paxlovid. Meanwhile, when President Biden experienced rebound during his recent Covid illness, he did the right thing by resuming isolation until he was again negative on rapid testing. Apparently, the CDC thinks that was unnecessary. Again, if they have data to support that contention, we’d like to see it.
Ironically, there’s one way to interpret the new CDC flowchart that negates all of its baroque complexity and implicit permission for recovering patients to spread Covid more freely. Within its guidance for what Covid-positive people should do after day 6 of illness, the flowchart says to, “[A]void persons at high risk for severe illness.” Since people at high risk for severe illness are everywhere (and often impossible to identify), perhaps what they’re really trying to say—wink, wink—is that if you have Covid, stay home.
The CDC also says that anyone with a Covid-19 exposure should be tested. Again, since exposures are so frequent among people doing anything in public, one could interpret the CDC guidance as saying that, given current Covid prevalence in most places, for the purposes of screening to keep public accommodations open and safe, many people should still routinely get tested. Sure, when Covid is no longer very prevalent, routine screening will make less sense. However, as Covid remains rather prevalent, routine testing in many public settings (like schools) continues to make sense, both to decrease spread and to decrease the overall number of days people in a community have to stay home.
The CDC’s new guideline looks like a gamble to me. Note that I used the term gamble, as opposed to “calculated risk.” To make a calculated risk, one must do calculations. If that work has been done, nobody has shown their work, as far as I can determine. So, today’s guidelines leave me puzzled, curious, and uneasy, rather than impressed.
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