Positive LFTs but negative PCR twice

[DaxtheDestroyer]

So confused! My DC tested positive on an LFT, we booked a PCR which was negative. When we got the result we checked with another LFT (completely different batch) which was even more strongly positive. Repeated PCR - negative again.
So what's going on? There must be something causing the positive LFTs, there are loads of cases at school at the moment. Anyone had this happen? Just so confused as to what's the right thing to do

Anecdotally, It's happening a lot in the SE too. I hope they get to the bottom of it soon so that we can adjust how or when we're testing & hopefully 'guidance' will be updated to
You MUST stay at home if you have symptoms & that the symptoms lust actually reflects current symptoms, not just those from 18 months ago

So we did a postal PCR just to double check...and it's come back positive. ☹️ Which makes me wonder if she's been positive since the first LFT over 2 weeks ago? What a nightmare.

@FWBNC

Anecdotally, It's happening a lot in the SE too. I hope they get to the bottom of it soon so that we can adjust how or when we're testing & hopefully 'guidance' will be updated to You MUST stay at home if you have symptoms & that the symptoms lust actually reflects current symptoms, not just those from 18 months ago

They cannot tell people to stay home if they have symptoms and a negative PCR.

@DaxtheDestroyer that’s crazy! We are waiting for our postal tests back abs I’m certain they will be positive - we’ve lost our smell and taste now so that’s pretty much a given! Worrying as all LFTs positive and all having one negative PCR each!

There must be an issue with the drive-in PCRs because there are SO many people at school in the same situation. Couldn't be worse timing and feel incredibly bad for any potential people unwittingly infected, urgh.

Bristol here and daughters classmate 2 postive lft but negative pcr.
Lots others saying same over the last week.

DaxtheDestroyer Definitely! How long did your postal results take or come back? I’m waiting impatiently 🤣

My dds came back neg yesterday, ordered a home test and it came today so sent it of.
Really strange all this because she has done 8 LFTs since Thursday all positive and these are some new LFTs and some old style ones.
The rest of the household is neg.

Several people where I work have had positive lateral flow followed by negative pcr. I’ve now got classic symptoms and tested positive on lateral flow this morning, am interested to find out what the pcr result is as I feel pretty unwell and have a fever which I would never have with a cold. Also literally just got over a cold and never have them back to back 🤨

I think the reason I’ve got it is because everyone else has come back into work with covid thinking they are negative!

I've messaged above but just recap husband had x3 positive lateral flow tests at home. He went to drive through for pcr this came back negative so he went to another centre in our county next day then a positive pcr result. I had positive lateral flows at home could only book pcr at 1st centre this was negative result I then lost taste and smell as with other symptoms so booked into another centre got positive pcr result late last night. This is so very worrying as imagine all the people with negative results 😕 when they are probably positive and now super spreading this virus its a huge mess and probably more common than we realise 🤷‍♀️

Postal result was back the day after it was sent off so very quick.
The woman I spoke to on test & trace said she'd never heard of anyone getting repeated positive LFTs and negative PCRs!
We've had 4 negative drive-in PCRs over the past couple of weeks, umpteen positive LFTs (and plenty of negative ones too) and finally a positive postal PCR.

The woman I spoke to on test & trace said she'd never heard of anyone getting repeated positive LFTs and negative PCRs!

I can understand a random member of the public not hearing about it, but unless she's only just started with test and trace then I don't see how she hasn't heard of it happening. It's been a problem for weeks now, so someone in daily contact with positive cases must have heard about it, whether first hand or through a colleague.

Agree, I was quite surprised. Don't think she was new, she said she'd dealt with hundreds of cases. It is a fairly recent thing though I guess.

As suspected ALL of our home PCRs have come back positive!! So glad we didn’t listen to the first ones and stayed in isolation!

@Peanut0583

As suspected ALL of our home PCRs have come back positive!! So glad we didn’t listen to the first ones and stayed in isolation!

How long did they take to come back?

@Karma1981 posted at 8am yesterday and got them back about 6.30 this evening x

[quote Peanut0583]@Karma1981 posted at 8am yesterday and got them back about 6.30 this evening x[/quote]
Thank you, hopefully get the results back tomorrow sometime then.
Hope your all doing ok.

There's some interesting maths about confirmatory PCRs. If you have a positive LFT there's about a 93% chance you have Covid. If you then get a PCR result most of the time you'll get a positive. But sometimes you'll get a negative. And in the specific situation of confirmatory PCRs there's a very high likelihood you have Covid. So that means that a much higher proportion of negatives in confirmatory PCRs are false negatives.

twitter.com/BristOliver/status/1439966843381460992?t=IKQxjUJWjSjXbs5IFXZpqw&s=19

This chap explains it better but it does mean potentially up to 40% of negative PCRs post positive LFT are false negatives I think.

www.theguardian.com/world/2021/oct/09/negative-pcr-test-covid-symptoms-self-isolate

I'm in the SW and have a similar dilemma, positive LFTs yesterday for my child (I did multiple tests, all positive) but the PCR yesterday was negative. Another LFT this morning was also positive. Presumably will need to be absent from school while showing symptoms, might get another PCR tomorrow if that LFT is positive. Difficult to know the right thing to do really.

Just to add we are in Gloucestershire and did drive-through PCR tests this weekend.

Yep this happened to my friend, also in the south west. She went to work as that's what her employer said to do. A few days later she did another pcr and that was positive. Now her work colleagues have covid !

It looks like The Guardian has picked up on anomalies in negative PCR results

Just got dds postal covid results back and yep positive.

@Karma1981 I’m not surprised! This is a massive issue and just the tip of the ice burg! How many people going around thinking they are fine and they aren’t!