WHat do LFTs detect?

[Thingsthatgo]

I’m on day 8 of asymptotic isolation, and I am incredibly bored. My LFTs have been blazing positives throughout, and I don’t hold any hope of getting out before my 10 days are up. I’ve been isolating in my room so my DH and DCs don’t catch it from me.
I am interested to know what is causing these strong positives, is it possible that I am still contagious?
In Denmark, for example, people are allowed out after 48hours of being symptom free. If I lived there I would’ve been out days ago!
I don’t have any intention of braking the rules, I promise. I’m just interested to know.

I think it’s very likely I will still have positive LFTs after 10 days. Will I still be contagious then?

They detect the nucleocapsid protein - one of the proteins in the centre of the virus. Yes, if you're having blazing LFTs, then the likelyhood is you're infectious.

@Motorina thank you, that’s interesting. Do you know what happens at 10 days? Why are people allowed to go out then, even with a positive LFT?

I'm still getting positives on day 10.

The medical advisor at work said that any positive line, no matter how faint, means you are still infectious (admittedly less so than with a strong line, but infectious none the less).

Bonkers that you can head off to the shops/work/pub etc at that point just because you're on Day 10 regardless of the test result.

@Thingsthatgo trade off. The longer the isolation, the greater the economic harm, both societally and to the individual. The longer the isolation, the lower the compliance.

When it was dropped from 14 days to 10, it was acknowledged that some infectious people would be released early, but it was felt that there would be low numbers, and that the advantages of reducing disruption outweighed that.

Now we have ubiquitous LFTs I think there's an argument medically for increasing the isolation period to until you have two negatives, no matter how long that takes. But I can't see people complying, and the political will for increased restrictiosn isn't there.

@Motorina thank you for the information, that’s really helpful. I am desperate to get out and about, but I definitely won’t until day 11, and I will stay away from people until I’m testing negative.

I tested positive on lfd tests until day 12, two of my kids until day 11. Dp got a negative on day 10. Only my DD got negatives earlier, on day 5 and 6, but I suspect she actually had covid before her day zero, despite a negative LFD at that point.

I'd be skeptical of anyone (particularly an adult) getting negative results by day 5.

Someone said on here the other day that NHS staff have to stay off work until they get two negatives, regardless of the number of days. Apparently 12-14 is not uncommon. I guess most people are going to have zero to low infectiousness by day 10, but advisible to keep your distance from anyone who might be vulnerable for a while longer.

My trust says two negative LFTs, or 14 days, whichever is longer.

Interesting to see what rules other countries have around isolation.

I'm in Victoria, Australia and if you test positive you're allowed out of iso at day 7 if you have no symptoms (mild cough is fine as that can linger).
We're also advised NOT to test again to get a negative as the antibodies can remain in your system for a month or so and you will test positive even if you have no symptoms.

So 7 days iso and that's it, you're free to go!

What happened to the advice of not testing after Covid for 90 days as results would be unreliable - surely that’s still relevant for those testing positive by day 10?

I’m on day 8, still strong positive up to yesterday, not done today’s yet.

@Feenie I think that 90 days refers to PCRs which detect something different in the sample.

Nope.

Eek, wrong screenshot, sorry!

I thought the idea was that you are very unlikely to get reinfected within ninety days so irrespective of how likely a lingering positive, any positive would be a false positive and tests would do more harm than good. That was before omicron.

Interesting that Victoria, having been so locked down in the past, is releasing people from isolation 4 days earlier than England! ( If I read it right ON day 7. Englandnis AFTER 10 full days so day 11. (Some people leave earlier qith 2 negative tests but thats not the case in our house 🙄. Very cabin fevery here!)

@Feenie ah sorry. I didn’t know that. I guess at least now that people are testing so much more they will know if it’s a new infection or not.
I’m finding waiting for the two lines to come up really triggering because I spent years doing pregnancy tests (with many miscarriages.)

@QueBarbaridad

I thought the idea was that you are very unlikely to get reinfected within ninety days so irrespective of how likely a lingering positive, any positive would be a false positive and tests would do more harm than good. That was before omicron.

That was the case before Omicron, but previous strains don't give any meaningful immunity to that. Lots of people have been catching Omicron within 90 days of having delta.

What's weird here is I have had covid (possibly twice as thought to have it in March 2020 - trouble breathing but not hospitalized) and I'm only negative one in a house of 3 positives. Kids all over me so maybe previous cases have offered some immunity? My body isn't brilliantly well/healthy so amazed it isnt gettig omnicron!

@ChildHeadache

What's weird here is I have had covid (possibly twice as thought to have it in March 2020 - trouble breathing but not hospitalized) and I'm only negative one in a house of 3 positives. Kids all over me so maybe previous cases have offered some immunity? My body isn't brilliantly well/healthy so amazed it isnt gettig omnicron!

There was a study showing recovery from infection followed by a primary immunisation course (2 shots) gave better immunity than primary course and booster, of course based on limited and evolving data.

I had covid in April2020, then immunised, then booster, I work in a health care setting and I'm still concerned about catching omicron, or, any new variants that may emerge...

I'd be skeptical of anyone (particularly an adult) getting negative results by day 5.

I’m currently on day 5 since my positive pcr. I’ve never had a positive lateral flow so far. Although I’m probably not contagious I’ve stuck to isolating just in case but will head back out if it’s negative again tomorrow. Only very slight symptoms for a very short while.

My son had blazing positives like you describe, the strongest I’ve ever seen. Then one day there was nothing, it was so stranger.

Blazing positive days 1-7, day 8 completely negative! We tested a few times afterwards and all negative too, so there is hope!