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Original poster

Multiple positive LFT, negative PCR

21 replies

LemonMuffins · 18/12/2021 00:53

DSS... He was at a weekend away and tested negative on lateral flow tests on Thurs, Fri, Sat and Sun. Monday he had two immediate and strong positive lateral flows. Did PCR on Tuesday, took until Friday morning to be told his results couldn't be read. Have continued daily LF testing and he has been very positive each day. Did another pcr this morning and have just had very speedy negative result.

We now don't know what to do. He did feel mildly unwell on the first day or two (light-headed, scratchy throat, tired), so he wasn't asymptomatic.

LF have been from various boxes and four of us have been testing at the same time. The rest of us are negative every time.

I'm now feeling very dubious about the pcr processing...

Which test would you follow in this instance? I'm inclined to ignore the PCR or book him in for a third?

OP posts:
Original poster
LemonMuffins · 18/12/2021 00:55

We're in Berkshire in case anyone has experienced similar as a regional quirk...

OP posts:
HelloCovid · 18/12/2021 02:26

Sounds as though he may have Covid, but were they FlexFlow? Other posters have had problems if you search, including me.

Lokdok · 18/12/2021 03:20

Lateral flows are very accurate, he definitely has it and his timeline/symptoms sound similar to mine. I would do another PCR. Keep isolating for ten days from first symptom and tell contacts yourself so they can be tested. They don’t need to isolate (as long as they’re not anti-vac idiots).

TurkeyRoastvBubbleandSqueek · 18/12/2021 03:44

Is it possible that he did have Covid, but by the time of his 2nd pcr the viral load had dropped so much that it either didn't register, or that he just recovered from it?

Butterfly44 · 18/12/2021 03:58

Take another pcr

frenchiemummy92 · 18/12/2021 05:43

As @HelloCovid said, where they flowflex? I always showed a faint positive with them but clearly there. Now the brand has changed again and don't have that issue. I would of thought a PCR would of picked it up if he was positive.

Original poster
LemonMuffins · 18/12/2021 10:29

They are flowflex as that's all we have. We've been using them regularly for a while and he's never been positive before. Positives are from multiple boxes. Will try another from a fresh box today.

His lateral flows were negative from Thursday to Sunday and from Monday extremely positive - he gets a line immediately and it goes very dark, so I'm not sure how he could have recovered from it to the point of being undetectable on pcr? His close friend had tested positive on the Friday so we do have a potential source. It's just a bit Hmm

We told contacts and he's been isolating since Monday afternoon. He'll jump at the chance of being released but I'm certainly not comfortable with it. Also surprised none of the rest of us have picked it up as we haven't been particularly careful inside the house.

Inclined to continue with isolation until he gets a negative lft.

OP posts:
WhatMattersMost · 18/12/2021 10:33

30% failure to detect positive cases with PCRs.

A positive LFT, on the other hand, is rarely wrong.

MilkBread · 18/12/2021 10:36

@WhatMattersMost

30% failure to detect positive cases with PCRs.

A positive LFT, on the other hand, is rarely wrong.

Great summary. I wish the general population understood this!
loosinggame · 18/12/2021 10:37

@Lokdok

Lateral flows are very accurate, he definitely has it and his timeline/symptoms sound similar to mine. I would do another PCR. Keep isolating for ten days from first symptom and tell contacts yourself so they can be tested. They don’t need to isolate (as long as they’re not anti-vac idiots).

Not true, a lot of posters on here have had positive lateral flows and been negative, especially with the flex flow LFT

ScarlettSunset · 18/12/2021 10:46

I'd be inclined to believe the LFTs, especially as they are only consistently positive for him and not anyone else. It's not unheard of to get false negative PCRs. After the testing fiasco earlier in the year, the LFTs wee generally shown to have been correct.

Original poster
LemonMuffins · 18/12/2021 10:51

Not true, a lot of posters on here have had positive lateral flows and been negative, especially with the flex flow LFT

But what are they picking up then? It's not that he's getting rogue positives between negatives. He is consistently positive when he never has been before Confused

I don't want to jeopardise anyone else's Christmas by sending him out into the wilds...

If the tests are dodgy why is only he getting the positives and the rest of us are getting negatives? I've attached a photo to show that they're undeniable.

Multiple positive LFT, negative PCR
OP posts:
shreddednips · 18/12/2021 11:02

@LemonMuffins

Not true, a lot of posters on here have had positive lateral flows and been negative, especially with the flex flow LFT

But what are they picking up then? It's not that he's getting rogue positives between negatives. He is consistently positive when he never has been before Confused

I don't want to jeopardise anyone else's Christmas by sending him out into the wilds...

If the tests are dodgy why is only he getting the positives and the rest of us are getting negatives? I've attached a photo to show that they're undeniable.

I've had numerous false positive flowflex tests- only one in my family to get them, only if I take them first thing in the morning. But that line is MUCH darker than mine were, I'd get a second PCR.
loosinggame · 18/12/2021 11:05

@LemonMuffins
There is a thread on here about certain people
Constantly restring positive on them lateral flow tests despite being negative on PCR, seems it happens a lot

YukoandHiro · 18/12/2021 11:14

Do another PCR

Neolara · 18/12/2021 11:17

I would assume the PCR was wrong and get a second one done asap.

FruitToast · 18/12/2021 11:21

My DH has false negative flex flows quite a lot but they are all extremely light lines. He's either getting constant repeat exposure but not infection (he's a secondary school teacher) or he's got reflux which means his LFTs are acidic and go positive. However, if the lines are that strong over consecutive days then he's got covid (or SARS but guessing that's not very likely). It's more likely that the PCRs are wrong rather than multiple LFTs with those lines, especially if the first one was inconclusive.

PotteringAlong · 18/12/2021 11:24

When I had a false positive LFT my line was barely there. That’s a massive positive! I would get another PCR

fruitpastille · 18/12/2021 13:06

I wouldn't bother with another pcr, just do the isolation.

Frazzled2207 · 18/12/2021 13:14

@fruitpastille

I wouldn't bother with another pcr, just do the isolation.
Me too i would just assume he had it from the first day of his symptoms. You’ve done the right thing and got him a pcr, it would appear it was probably wrong. Similarly my friend and her husband and son who’ve tested positive then other son gets exactly the same symptoms, positive lft and yet his pcr is negative too.
Original poster
LemonMuffins · 19/12/2021 12:00

We did end up taking him for another pcr yesterday and it has come back positive.

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