Negative PCR after POS LFT. Lab error!

PurpleDaisies · 15/10/2021 09:10

That’s a lot of errors.

Ouchyhurt · 15/10/2021 09:12

I would bet money on further labs showing similar errors. I'm not a tin foil hat conspiracy nut but this seems all very odd, coupled with the news of how LFTs are accurate etc, I can see PCR testing being sidelined and the subsequent costs saved

ReturntoSpamfritters · 15/10/2021 09:13

Aha.

HelloNeighbour2021 · 15/10/2021 09:13

We got a false positive PCR due to cross tamination at the lab!! Happens often apparently

Whinge · 15/10/2021 09:14

Interesting that this states from September 8th, as earlier reports stated 3rd October - 12th October. It seems like this has been a problem for a while now, and I wonder how it's gone undetected for so long.

Ouchyhurt · 15/10/2021 09:14

@HelloNeighbour2021

We got a false positive PCR due to cross tamination at the lab!! Happens often apparently

How do you know? I guess at least false positives don't potentially spread it

Porcupineintherough · 15/10/2021 09:16

Im not surprised tbh. There have just been so many inexplicable positives followed by negatives across the sw recently. And now if course theyll be an uptick in cases as all those "negative" people have been sent out to get on with things.

Porcupineintherough · 15/10/2021 09:18

@HelloNeighbour2021

We got a false positive PCR due to cross tamination at the lab!! Happens often apparently

Did you retest? I had this last Christmas but they told me possible cross contamination and the second pcr was also positive (I was full of symptoms by then so it wasnt a surprise).

trumpisagit · 15/10/2021 09:33

So many people will have been carrying on as normal and spreading the virus (43000) mostly in SW.
Very worrying.

HelloNeighbour2021 · 15/10/2021 09:33

Sorry I'm new to NM so not sure how I tagged the people who's asked me questions!

We was all isolation due to my boy being a close contact at school and I'd been using LFT on us all during our isolation, on day 9 I started with a chest infection ( not unusual as I'm a smoker) but I thought I'd get tested anyways as I knew we wouldn't be going anywhere as 5 year old still had to isolate.

It gave me the option to test whole household so that's what we did.

Results me, partner and daughter all negative
Son was positve, we didn't think to question the results until track and trace said they believe he as had a false positive due to cross contamination ( he never had symptoms) they told us to re test him 24hr late he got negative results

I don't understand why they told us to re test him as we still all had to isolate due to the fact apparently unable to change system once a positive case as been logged so we lost 10days wage for nothing.

T&T told us that it happens often.

Iggly · 15/10/2021 09:34

Appalling and this will further damage the trust in testing.

LFTs are apparently more accurate - really - then why did initial reports suggest not and why were they not used earlier? Furthermore, not all covid cases are picked up by PCRs.

What an absolute shit show.

HelloNeighbour2021 · 15/10/2021 09:35

You should watch the BBC program
Panorama - undercover inside the covid testing lab

Iggly · 15/10/2021 09:43

@HelloNeighbour2021

You should watch the BBC program Panorama - undercover inside the covid testing lab

When was it aired? I’ll have a watch!

siestalady · 15/10/2021 09:47

@Whinge

Interesting that this states from September 8th, as earlier reports stated 3rd October - 12th October. It seems like this has been a problem for a while now, and I wonder how it's gone undetected for so long.

surely its good news if there has been a problem for that long - if the actual numbers of cases are higher, then we've not seen any impact on hospitalisations/deaths

Iggly · 15/10/2021 09:49

surely its good news if there has been a problem for that long - if the actual numbers of cases are higher, then we've not seen any impact on hospitalisations/deaths

It is a problem because what if some of these results were for people who’ve died with covid but it wasn’t picked up due to poor testing? My understanding is that postal PCRs were fine - it was the in person ones which were not. So some cases may have been missed.

siestalady · 15/10/2021 10:02

@Iggly

surely its good news if there has been a problem for that long - if the actual numbers of cases are higher, then we've not seen any impact on hospitalisations/deaths

It is a problem because what if some of these results were for people who’ve died with covid but it wasn’t picked up due to poor testing? My understanding is that postal PCRs were fine - it was the in person ones which were not. So some cases may have been missed.

I dont mean to sound callous but if they've died with/from covid - presumably if its 'with' covid then its likely they would've been dying anyway from something else? and if its 'from' covid then presumably the patient will have gone into hospital with respiratory problems or whatever, and have been treated, regardless of the initial test result? Its not as though hospitals go "oh you're in respiratory distress but i see you had a negative covid result so you cant be treated"

I just dont really see how getting an incorrect test result will have made a difference to either scenario outcome.

Iggly · 15/10/2021 10:05

What I mean is that we wouldn’t know how many deaths were caused by covid if the tests aren’t working properly.

If the death rate from covid is higher than reported (unlikely, I hope), then it means there needs to be a bigger push for preventative measures eg masks and vaccine uptake (you can’t get a vaccine in my town, nearest centre is 6 miles away!). Otherwise the NHS is fucked.

poorbuthappy · 15/10/2021 10:09

I think the issues with the LFTs is that they are reliant on people logging their own results. Which people do if it's negative in order to access services / venues etc.

The PCR way of doing things meant all positive results were logged and people being contacted by T&T.
Now we are further down the path (not going to say out of the woods obv) they don't need the cost of the PCRs / T&T anymore so have changed the narrative.

trumpisagit · 15/10/2021 10:15

The problem is all those positive cases (40 000)who would have isolated have instead spread it much more widely. Our local schools are really struggling.

UnmentionedElephantDildo · 15/10/2021 10:15

LFTs have a high false negative rate - often down to user technique.

But I'd always thought false positives were rare, because a positive means that it has detected the virus (except for some cases of contamination if you've not followed the instructions and had certain foodstuffs just before the test).

So the high number of negative PCRs following positive LFT never made any sense to me.

Lab error on this scale makes a complete nonsense of the data, for as much as a month, it seems.

Porcupineintherough · 15/10/2021 10:19

The treatment of covid and non covid COVID respiratory distress can be quite different though @siestalady. I mean, youd hope the hospital woukd do a lung scan to check but dexamethasone is not normally given for pneumonia, you'd expect to be put on antibiotics. Nor eould anyone routinely check your clotting factors, kidney function etc. So actually getting the correct diagnosis can be crucial and the sicker you are the more crucial it becomes.

siestalady · 15/10/2021 10:28

@Porcupineintherough

The treatment of covid and non covid COVID respiratory distress can be quite different though *@siestalady*. I mean, youd hope the hospital woukd do a lung scan to check but dexamethasone is not normally given for pneumonia, you'd expect to be put on antibiotics. Nor eould anyone routinely check your clotting factors, kidney function etc. So actually getting the correct diagnosis can be crucial and the sicker you are the more crucial it becomes.

but surely they do a PCR when a patient gets to hospital as well though, especially if the treatment is different and they're presenting like they have covid but the original test they took is negative?

HarveySchlumpfenburger · 15/10/2021 10:29

@UnmentionedElephantDildo

LFTs have a high false negative rate - often down to user technique.

But I'd always thought false positives were rare, because a positive means that it has detected the virus (except for some cases of contamination if you've not followed the instructions and had certain foodstuffs just before the test).

So the high number of negative PCRs following positive LFT never made any sense to me.

Lab error on this scale makes a complete nonsense of the data, for as much as a month, it seems.

I’d also suggest that the fact that it’s taken so long for the ukhsa to notice it means there’s very little oversight going on.

It was fairly obvious that something odd was going on with the data at regional level and at more local levels even without knowing what testing centres were being used and that these places were using the same labs. Once they started looking into it, the ukhsa seem to have found the problem very quickly. But how on earth did they not notice that a new lab was throwing up obviously suspect results.

Sweetpeasaremadeforbees · 15/10/2021 10:53

I would bet money on further labs showing similar errors

This. And I wouldn't be surprised if the labs involved were private as opposed to NHS run ones. Unfortunately we'll never find out the extent of the problem because presumably a lot of the people with false negative PCRs are way past the time when self-isolation would have any benefit.

UnmentionedElephantDildo · 15/10/2021 11:15

because presumably a lot of the people with false negative PCRs are way past the time when self-isolation would have any benefit

Exactly - unless your test was within the last 10 days, there's no point in re-testing (arguably, allowing for processing time, that might be 8 days)