Anyone else prone to false LFT results? No idea what to think anymore!

[Whatinthe]

I'm just so utterly confused by it all now.

Last december my daughter had a positive LFT but PCR came back negative so carried on as normal (saw a lot of people and no one got covid so feels likely it really wasn't that for her).

Fast forward to this week, she took her first LFT since then and it again returned a very faint positive. Did a PCR which came back within 24hours as negative. That was Monday.
Tuesday - a stronger positive LFT (doing daily for school)
Wednesday - negative LFT
Today - back to positive

I'm going to take her for another PCR because everyone is confused by all the mixed results but somewhere along the line she's getting false results of one variety or another.

Just wondered whether anyone else has experienced anything like this before? It's just so strange.

FYI

My daughter also had this problem. Her doctor said the first time she tested positive might’ve been positive but got the wrong PCR result and ever since, she has tested positive as the virus can leave trails of it which are still being detected on the lateral flow tests.
I tend to agree but it’s the same as you, no one else caught covid from her when she first tested positive on the lateral flow!
Are you using flow flex by any chance? We did find that once we switched brands of LF, she no longer has this problem.

She’s had a positive LFT therefore has Covid. Is she symptomatic? If she’s not symptomatic you don’t need a PCR and rely on the LFT and isolate from that point as per current guidelines.

My daughter frequently gets faint second lines on the flow flex LFTs. Every follow PCR has been negative. ( she has had covid and that time she had a very obvious second line and symptoms).
I know a teacher at my son's primary has the same issue.

My DD11 had the same problem with the FlowFlex brand - false positives confirmed with negative PCRs.

My other daughter has a box of FlowFlex tests with QR codes so small/rubbish that they can't be scanned.

Maybe just stop testing then? And only go for PCR if ill?
Hopefully we’ll soon be done with all of his anyway.,

Quite a few threads on this if you take a look. I was loosing my mind with faint positive LFTs and negative PCRs. Apparently it's a fairly common issue with the flex flow! I was glad to read it wasn't just me having this issue xx

That's really interesting as we are also using the flowflex brand. She has a faint positive each time except yesterday. We have the older type so might do one of those on her to see.

@rengreen it's inconsistent though- if she had covid then she should also have tested positive yesterday. Also she had the same issue in December. My concern was that there won't come a point where she regularly tests negative because of some issue. PCR was appropriate because it was so unclear on Monday. PCR would be justified now as well because of the varying results.

@whattochoosenow they have to test daily at the moment because of covid in school.

@squirrelnutkins1 same, it's really reassuring to hear it's not just her!

For people saying stop testing it's not necessary that easy- my daughter is at high school and had to test twice a week, I work as a community nurse and have to test every working day at present- so having tests throwing up false positives is a real pain!

Yes me! I'd say about 1 in 3 look positive but also confirmed with negative pcr. So annoying.

Do children have to test or are they recommended to test?

@RenGreen

She’s had a positive LFT therefore has Covid. Is she symptomatic? If she’s not symptomatic you don’t need a PCR and rely on the LFT and isolate from that point as per current guidelines.

But I have been testing positive on LFTs since August. Never had a positive PCR.

I believe some of us have something in our biological make up that triggers a positive result when we don't have Covid. Kids were putting fruit juice on their tests to trigger a positive result.

Fruit juice can trigger a positive

So, is she eating/drinking before she takes the test, does she get reflux, are you reading the test after 15mins (for flowflex) might all be giving false positives.

Yes me. Constant faint positive on flow flex. I've managed to get hold of another brand of lfts and I'm negative on them (so they're the ones I use when I need to make sure I'm covid free). All my pcrs are negative.

I’m another flowflex faint positive person - went on for weeks but had several negative PCRs. Switched to other brands now and don’t get the faint positives on these.

@sushigo interesting you say that as she does have reflux, I didn't known that affected results. She never eats or drinks before and line is always up before 15 mins.

PCR booked, will never use flowflex on her again and maybe testing later in the day will help with the reflux. Sorry for everyone else going through it but it's a relief to know it's not abnormal.

@whattochoosenow I think it's just recommended but my children's classes have so much covid at the moment that everyone is testing daily. So many cases have been picked up through the LFTs.

There was a poster on another thread who was having this issue of faint positive LFTs . She also had a gastro condition that she was under consultant care for.

Her consultant had seen this issue with several of his patients. He suggested that if someone has acid reflux then they may get these false positives as the tests are looking for an acid-like substance and that wearing masks makes acid reflux worse and more concentrated in the nose/throat.

I’ve probably explained that badly but I think that was the gist.