The agency said early data suggests that antigen tests “do detect the omicron variant but may have reduced sensitivity,” meaning it’s possible such tests could miss an infection.
It looks like Santa may have given me Covid for Christmas, too. Won’t know for sure until I can tested, but I’ve got too many of the symptoms, so I am self-isolating.
Us too. The 5-year old started coughing a little on the 30th and tested faintly positive with a rapid test on the 31st just before we were going to go to a neighbor’s house for NYE. My wife has a very mild cough and I have a very slightly runny nose, but other than that we feel fine so far. 2-year old showing no symptoms.
Thankful that we were at least able to get him his first vaccine dose before Omicron hit.
Us too. My son had a positive rapid test: I have a test scheduled for Wednesday (they are so booked right now). I am on a 6 person group chat at work: one other person has it, and one thinks it’s likely (very mild symptoms, husband positive). So 3/6 people I associate with over break. I fully expect a quarter to a third of the adults to be out tomorrow. I feel like switching to remote instruction for a few weeks is inevitable. Not so much to stem Omnicron, but just because we won’t have enough adults to function.
This tweet from the Chair of the UCSF Hospital says that the asymptomatic test positivity rate for people coming into the hospital is in excess of 8%. People coming into the hospital for non-Covid reasons isn’t a random sample of the population, but it’s not far off. So 8% of people in SF without symptoms have Covid as of a few days ago. Probably higher now. It’s everywhere.
What does he have to say about the 800,000+ people who have died?
“Faintly positive”? I’ve never seen how the tests work. Is the result on a spectrum, not clearly positive or negative, like a pregnancy test?
A pet peeve of mine. Unless you are at zero Kelvin you have a temperature. If your temperature is “normal”, you do not have a fever, but you certainly have a temperature.
Get well soon.
I no longer bother trying to debate him on his stupid beliefs. But I’d guess he would say “the number of deaths is highly exaggerated by the liberal media. Hospitals report everyone who dies who has Covid as a Covid death, regardless of the actual cause of death.” Also he has an amazing ability to, all at the same time, complain about how sick he is, claim it’s no worse than the common cold, and also claim it’s a virus enginered in a Wuhan lab by the Chinese to bring down the west.
Fair enough-- so far, above room temp but below fever temp. Ranging 97.1 - 97.8 (I tend to run a bit cool).
Thanks.
Yes, it’s on a spectrum (sort of). There’s a chemical reaction that creates a line. The higher the viral load, the brighter the line. At some point, you go from no visible line to a visible line, and the line can be very faint. We were honestly not 100% sure it was really a positive and not a trick of the light (but we behaved as though it was positive and waited 2 days take another test which was clearly positive). Pdf of the directions for the test contains some photographs in the section “Positive Covid-19 Result”. The line on my son’s test was even fainter than the faintest one pictured.
I think a pregnancy test would work the same way, but I’m not sure. There’s a point when you have just enough of whatever biochemical the test is testing for to get a really faint line?
Do you know this to be true? Or do you have a source?
I understood that it’s really not a spectrum at all. A positive test is positive, and the relative faintness of the line is not relevant. Any line is a positive test. I had read (don’t remember where, or how reliable the source was) that a faint line is just a faint line; the way the test works means there’s some variability (based on a variety of random factors) in how the line appears.
So a high viral load could have a faint line or a low load could have a strong, bold line. Either way, if you see a line, you’ve got a load. It would take a much more sophisticated test to know how big a load it is,.
But I’m certainly no expert. Do you have more clear information on this? I’d love to know for sure how it works!
So do parvo tests.
We have a sick intern in our tech office whose cubicle is right next to mine, but he considerately contracted the disease after we went on winter break, so I dodged that bullet. He is actually sick from it and is currently quarantined at home. He will be back next week if he can test negative before next Monday.
I do not have a source that states it in so many words, but I understand in broad strokes how these tests work and I am extremely confident (99+%) that it is true. It is a chemical reaction with a protein that is part of the virus. More protein means more reaction and more virus. There are levels of virus that are too low to react enough to see a line at all, high levels that react a ton, and a continuous spectrum between them. Based on basic chemistry, it really can’t possibly be otherwise.
This is true, and not in conflict with what I wrote, which is that a brighter line indicates a higher viral load (in the sample, not necessarily in the patient). Any line that can be seen is a positive test in the sense that it is above the threshold that the test can measure. But a brighter line means more virus and a fainter one means less.
Here is a tweet from an epidemiologist with a diagram. Note that the first day that a rapid test shows positive the graphic is faint red, the next days are brighter as the viral load increases, then the following days it is fainter again.
ETA: Since people are probably fairly bad at performing the test the same, even following the instructions, you probably can’t compare tests that different people took, but if the same person did the test and followed the procedure the same, I’d expect that fainter = lower viral load, and brigher = higher.
The PCR test I took came up negative, but I think it still maybe wrong, unless I really just did have a bad cold. Curious if a PCR test would still be “too early” at T+4 days after exposure. I ask because the doctor at the urgent care place advised me to take it again if it did show a negative result. Of course, with 4-day lag in the test results, I’m now 8 days past exposure and feeling great, with just a very minor cough remaining. Not sure I want to wait 4 hours for another PCR test, especially with the shortage and delays, since others have more of an immediate need.
My dearest friend got Covid for Christmas, she just didn’t know it until after Christmas. She went to a family + friends (ho boy) party a day or two before the holiday. Very unusual not to hear back from her over the holidays and now I understand why. I worry about her because when she gets sick, she gets SICK (in the lungs really bad). I don’t think she has been boostered yet (hope I’m wrong). She feels awful, no taste or smell, and is quarantined at her parents’ home. Her dad is not in amazing health, so I hope she really stays isolated. And takes it easy until she is truly feeling better. She joked that it was “worth it”- I just don’t know how to respond to that. She’s a major foodie- I hope she fully recovers.
(We, on the other hand, canceled travel AND hosting this year at the last minute and stayed. home. And it was a big fat bummer, but we made do, imperfect as it was. And today thankfully I feel great. Was it worth it? I think so- doesn’t have to feel ideal to be worth it, I guess.)
Note that this is actually a result of the different tests. The PCR test reveals the presence of the spike proteins, so indicates the presence of the virus in your body, and will test positive soon after the virus appears, and for a while at the end of your illness as the destroyed virus remnants are being disposed of. The rapid antigen test (RAT) reveals the presence of virus antigens as your immune system ramps up in reaction to the virus, so won’t be positive for the first few days and for the tail end.
The medical advice I’ve seen says this pretty much matches the entire virus cycle for the PCR and the infectious period for the RAT. This is how you can test negative for the RAT and positive for the PCR. If you’re negative for the RAT, then you’re very likely not currently infectious, but better test again every day if this is critical (nursing homes here test staff daily for this reason).
As neither test is looking for variant-dependant factors, they should work as well for Omicron as for earlier variants. I suspect that the poorer results for the RAT test with Omicron may indicate that a fully vaccinated immune system is already primed to handle the less severe form without triggering major antibody production. YMMV
Weird illness.The progression seems to have no rhyme or reason. My nasal congestion, sneezing and coughing, and watery eyes abated, I felt ok and put in a full day of working from home yesterday. Thought I was over the worst of it. Then I started feeling crappy and getting chills as the afternoon wore on, took my temp, and for the first time it was elevated at 99.5-- which for me is kind of high because I tend to run a bit cool, around 97.1-97.5.
Still no sense of smell what. so. ever. Absolutely nothing. Popped a mentholyptus cough drop, and other than detecting the cool sensation if I inhaled through my mouth, it might as well have been a sugar pill. Getting a little concerned about that. I’ve heard a lot of scary stories about people with Covid losing their sense of smell for months, or even permanently.
Son says he’s on the mend, though he still has a hacking cough and says he can’t smell anything either.
Thanks! This makes sense to me (with my extremely limited understanding of chemistry). Appreciate the more complete explanation.
When I had covid, the red line was bold and strong. My main hope is not to see it again, faint or bold!
This implies that the PCR is detecting the virus and RAT is detecting an immune response, but that’s not correct. Both are detecting parts of the virus in your body. PCR is more sensitive to small amounts of virus because PCR goes through several cycles of amplification, while the RAT tests have to detect whatever amount of virus protein is on the sample swab.
PCR is more sensitive, so it will go positive earlier and stay positive longer, but RAT is arguably a much better test for most purposes because you get the results very quickly (compared to a PCR test where sometimes you have to wait a day or more) and the period in which you are positive maps very closely to the period in which you are infectious.
When we went to Hawaii, unvaccinated people had to get a PCR test within 72 hours of flight departure. Which, even with the higher sensitivity of PCR is likely significantly less useful than a rapid antigen test 30 minutes before the flight boards.
Just to add, the PCR amplifies the genetic material of the virus that codes for a protein part of the virus.