Where is this piece of information coming from?

[Liziz]

Ok, so after hearing a poster here comment recently on how her DC's pediatrician told her "you can test positive on an antigen test for long time after you're no longer contagious" I've now heard this from two other unrelated people -- both of whom claimed it was "based on official articles they read" claiming sources like the CDC, and in conjunction with discussion/confirmation from (family member/friend) doctors.

I have always heard that it's possible to test positive on a PCR test for loooong after you are no longer contagious, but that rapid/antigen tests are a fairly good indicator that you are *currently* positive and likely infectious. I just spent way too much time trying to find some credible source that comments on false-positive rates in antigen tests, and/or has any evidence-based proof of whether a positive antigen tests means someone is likely contagious. I can not find a thing. I found a few random news articles with a quote from some "expert" -- but they quotes don't even all agree, and none point to any formal guidance, studies, or evidence.

Does something exist? Does anyone know where these people are coming up with this "you'll test positive on a home test for a long time" thing? At first I just thought someone was mixing up the difference between PCR and antigen tests, but it's so odd to me I'm hearing this from multiple unrelated places all of a sudden.

[essnce629]

Well, what's their definition for "a long time?" Many of my friends who had Covid this month tested positive on their antigen tests till day 10. I haven't personally heard of anyone testing positive on a rapid after that.

Sent from my SM-A526U1 using Tapatalk

[AnnieW625]

I haven’t heard that before about RAT tests, but have read on posts here and probably read online or on a mainstream media site (don’t recall which one but it made sense when o heard it) that you can still test positive on a PCR a few months after infection. TBH I had a mild head cold, a slight fever, congestion in early October and then DD1 had something similar at the very beginning of December or late November (so both before the omicron variant really started to travel) and so when DH tested positive a few weeks ago, and we all had PCR tests done I was afraid they would show up as positive even though for me it had been 3 months since I had been sick even though at the time I had no Covid related symptoms. Both DD1 had no symptoms when we tested. My rapid test was negative but from what I understand rapids clear the virus quicker. DH who tested positive on day 4 of symptoms via RAT and PCR tested negative via an at home rapid test on day 14 since symptoms started. He told his doctor and the doctor didn’t request that he take a PCR test then and he had been symptom free since around day 8 of first symptoms so no need to do the PCR test.


Sent from my iPhone using Tapatalk

[echoesofspring]

I wonder if people are assuming this b/c of the reduced CDC guidelines (of not needing a test to leave quarantine) despite many many people test positive on RAT's after day 5.

FWIW TWIV touched a bit on this 2 weeks ago in reviewing a paper on the sensitively of the RATs, commenting that it might be nice if we had different tests for different situations b/c they may be picking up positives that are no longer infectious. But again they are talking about the time immediately following a test, not months out like PCRs. You can listen to that part of the episode starting at 15:29 and going to about 22. https://www.microbe.tv/twiv/twiv-853/, the specific comments about positive RATs but no longer infectious start at around 19:20. But I kind of doubt all the people you are encountering are listening to TWIV

[Liziz]

Well, what's their definition for "a long time?" Many of my friends who had Covid this month tested positive on their antigen tests till day 10. I haven't personally heard of anyone testing positive on a rapid after that.

Sent from my SM-A526U1 using Tapatalk

Well, one of the two was stating they'd been told "by a doctor" that they could test positive on a rapid for up to 90 days, so they didn't need to bother taking tests again or worrying that they got re-infected within the first three months, and that a new positive test would be a false positive. I responded with "it sounds like they're talking about PCR tests, not the antigen testing" and explained that the reasoning was likely coming from historic (now questionable, with omicron) data showing that antibodies from a COVID infection were usually protective for the first three months after infection. They swore up and down that the discussion of long-term positive testing was about rapid tests, and that they read articles to prove it. This conversation was a couple days ago, then I had an almost identical conversation with a totally unrelated person today, also swearing they'd read it from reputable sources. It was just so weird to hear it twice so close together, so I've been trying to track down what these people must be reading to say that (because I don't think it's actually accurate, and if someone had COVID 2 months ago, and now was testing positive on a RAT, I personally would *absolutely* assume it's a new infection, not a "residual false positive".

[dogmom]

I have not idea. I know from patient experience PCR they can be positive for over a month, even after symptoms are abating. Antigen tests can be positive for up to a week afterwards in some cases. BUT..

We have had cases of kids getting Covid, testing positive on PCR, recovering, testing negative, all on PCR, they getting symptoms and testing positive on PCR again with what looks like a second infection within in 30 day time frame. We have dropped our Covid recovered time frame (when we don’t test people before procedures) from the previous 90 days to 45 days now.

I think this message is coming out because SO MANY people are testing positive, and they are getting told this. (That and some surgeons offices ar quoting the 90 vs 45 day rule.) I would urge people to be cautious. We have people coming in pre-op and not get tested for Covid because they had a positive rapid antigen test at homemade but never got a PCR Test, so they can’t prove to us they had Covid, so they should still get tested per our policies. (I would love to believe them, but this is a tactic used by people who don’t want to get tested.) So the decision needs to be made whether to go through the procedure or not. This is a huge issue now because so many people have gotten Covid in the last 45 days and so many have done so on home tests.

[nfceagles]

I’ve picked up on this recently too, but my impression is that we are talking about days maybe two weeks when we say “longer” on rapid tests. But still the idea that it could be after you are no longer infectious. First a cabinet maker working on a project for me had to delay the job because he and his wife tested positive at the start of the month. We were in a holding pattern waiting for him to test negative. At one point he texted me that he was still testing positive at day 12 and so was his wife on day 15 for her. I thought that odd and even slightly wondered if he was just procrastinating the job, but I didn’t want him in my house with COVID so I wasn’t about to challenge it. Then I was listening to some sort of podcast where the guest mentioned almost in passing that rapids can still pick up virus for a little while after you are no longer contagious. But again, I don’t think he meant MONTHS. I don’t remember exactly where I heard it but it was either TWIV or Andy Slavitt’s podcast.

It’s had me worried a little bit because DH needs to travel to London mid March and he needs to be home at least 12 days after his intended return in order for me to head on a long anticipated trip to Germany at the end of March. Then I need to be able to fly back to the US in time to join my family for our spring break trip. I’ve been mentally prepared for 5-10 day delays if we test positive upon return, but getting stuck out of country for 12-15+ days is a whole different story.


Sent from my iPhone using Tapatalk

[Liziz]

Then I was listening to some sort of podcast where the guest mentioned almost in passing that rapids can still pick up virus for a little while after you are no longer contagious. But again, I don’t think he meant MONTHS.

Sent from my iPhone using Tapatalk

Yes, I think this part is kind of why I'm a bit confused myself, and was trying to track down something reliable based on my own current knowledge vs. what I'm hearing others tell me lately. It strikes me as confusing that (apparently?) the CDC is both saying "antigen tests are a good indicator of current infection, test yourself on day 5 and you can leave isolation if it's negative, but stay in isolation if you're positive because that's a good indication you're still contagious" ... but then all of a sudden on day 10 a positive isn't a good indication of being contagious anymore?

ncfeagles, sending P&PT that everything works out just fine for all the travel coming up!!!

[essnce629]

My best friend's 15 year old DD (fully vaccinated but not boosted) still has a super super faint line (like hold sideways and squint) on her rapid today on day 10. She's supposed to go back to school tomorrow. My friend plans to test her again in the morning but I'd agree that such an extremely faint line at day 10, while still positive, is probably indicative that she's barely (if at all) infectious at this point. Which is what I think TWIV was talking about from the period of day 6-10. I'd be fine with her returning to school tomorrow as she's at a school with mandatory masks and has had zero symptoms for days. Now if she still had a blaring positive at day 10 I wouldn't send her, but I've yet to have anyone experience that. She did have a blaring positive on day 6 however and my other friend's DD still had a blaring positive at day 8, but because of the 3 day weekend she ended up not going back to school till day 13.

DS2's friend (fully vaccinated and boosted) who came down with symptoms and tested positive last Friday tested negative yesterday on day 5 and returned to school today on day 6. It seems like being boosted possibly helped him to clear the virus quicker. His only symptoms were the sniffles.

Sent from my SM-A526U1 using Tapatalk

[georgiegirl]

My mom is still testing positive on a rapid test and it’s been THREE WEEKS!!!!! However, she’s immunocompromised (blood cancer and recent treatment with immunosuppressive therapies) and she’s still mildly symptomatic. DH mentioned that one of his colleagues had a lymphoma patient with the same issue. They just can’t seem to clear the virus.

My dad tested positive for about 9 days. It was light by the end. He was only symptomatic for maybe 4 days at the start.

It’s total bull that you stop being contagious after 5 days.