Lateral flow tests getting darker

[IsabellesMissingSock]

Hi all - I had a positive LFT last Wed, confirmed by PCR same day. Symptoms started last Tuesday (mild only), am isolating until this coming Sat. I have done a few LFTs during isolation, the most recent being this morning and it came up very positive straight away. By contrast, my positive last week was a weak positive and took about 15 mins to come up.

Does this mean anything - eg am I getting worse? Or is it loads of dead virus cells (?!) confusing the issue? Could just be a better sample? Or is this continued testing during isolation utterly pointless? Should I just step away from the tests?

I was hoping for this morning's test to be negative, that would have been encouraging. But the fact that it's my most positive so far has concerned me.

I've had both jabs but the second one was only 3 days prior to the event at which I think I caught covid.

Is anyone knowledgeable on this topic and able to share information? I'd be very grateful

I don't really have symptoms, initial symptoms were mild and now I just feel like I am at the end of a cold. I have no intention of breaking my isolation even if I test negative - am just doing them out of curiosity and to try to make myself feel like the virus has exited the building (which it hasn't). Worried I am getting more contagious but I should be over the most contagious phase by now I think.

Thanks in advance for any thoughts!

Why are you —wasting— doing LFTs?

Covid can trigger on PCR tests for 3 months following infection. Of course it will show up on LFTs (which have no “strength” filter on them).

Like I said, out of curiosity. Thanks for the response. I am aware that PCRs can show up positive for 90 days. I wasn't aware that that same was true of LFTs.

I feel like lateral flow tests are becoming the new pregnancy test - is this a line? Is it getting darker?

I'd stop doing the LFTs and just follow the guidance based on your positive PCR.

Hope you feel better soon!

Thank you for the well wishes @stopknockingonmydoor and yes, I agree I should just stop it. Am isolating away from DH (it's just us two here and his PCR was negative) and I was hoping to get some sort of indication that my infection is waning. Not that I would then stop isolating from him, but I just wanted a bit of an encouraging sign I guess.

I know some people have to get a negative LFT after infection in order to return to work. Luckily I am not in that boat as I wfh.

I'll just stop with the tests, I know they are achieving nothing!

LFT and PCRs are different. The PCR is looking for the genetic material of the virus whereas the LFT is looking for proteins specific to the virus. So LFTs don’t remain positive in the long term like PCRs do. At least that’s my understanding.

My DH’s LFTs were positive until day 8 of isolation.

DP's lateral flow tests started off very dark and gradually got lighter until they were negative again around day 8.

Mine were the opposite, negative for 5 days (after positive PCR) then gradually got stronger up to day 8. I stopped then as no point worrying about it after day 10!

Thanks all! I am nearly there with the 10 days and won't be doing any more.

DH did one earlier and it was still showing negative. I am so relieved. Confining myself to one room and going through ridiculous cleaning performances in the kitchen and bathroom seem to have kept the covid away from him. No mean feat in a small flat with no outdoor space!

I was under the impression LFT react more strongly when you have higher levels of virus in the sample.
DH started weak positive, got stronger and then tested negative.
DS started strong positive, stayed strong positive and then weaker then clear over 5-6 days
I didnt test positive until after a positive pcr. Was showing weak positives until about day 8.
Used loads of lft but whoever was showing clear or weakest positive was the one doing most of the care for DD that day. System seemed to work as she never got it.

@IsabellesMissingSock I’m in the same boat atm! Symptoms started last week (isolation finishes tomo), all my LFTs were negative, negative PCR (although everyone at home was positive) and I started getting weak positive on LFTs recently (for two or so days now). I’m hoping I’m not contagious as my employers do want me back at work ASAP- did your LFT eventually show negative?

[quote pumpkin23g]@IsabellesMissingSock I’m in the same boat atm! Symptoms started last week (isolation finishes tomo), all my LFTs were negative, negative PCR (although everyone at home was positive) and I started getting weak positive on LFTs recently (for two or so days now). I’m hoping I’m not contagious as my employers do want me back at work ASAP- did your LFT eventually show negative?[/quote]
Yes they went negative after 2 weeks! Hang in there... I hope you are feeling well :)

Reading this thread is such a mind-blowing confirmation that if you give people things for free they will treat them like they're worthless. Have you seen how much single use plastic a lateral flow uses? Why are people using boxes full of them for no reason?!

@Hardbackwriter

Reading this thread is such a mind-blowing confirmation that if you give people things for free they will treat them like they're worthless. Have you seen how much single use plastic a lateral flow uses? Why are people using boxes full of them for no reason?!

I know. It beggars belief, doesn't it?

LFT - positive; PCR - positive. Isolate for ten days at least and until symptoms have gone. Don't test for 90 days thereafter.

What is so hard to understand about that?