To be baffled at the void PCR after 5 positive LFTs

[Laughingstock91]

My DS 14 has had 5 positive LFTs in the last 48 hours. We took him for a PCR Friday morning & the results have only just come back now and are void so we have to go again.

The LFTs (which aren’t supposed to be that accurate) have been turning positive before we even finish putting the drops on them. He’s virtually completely asymptomatic too.

AIBU to be baffled by the PCR result given the number of positive LFTs we have had. It’s actually given me more faith in the accuracy of the LFTs to be honest. He’s tested positive every day since Thursday so I am assuming he has it/ has had it on that basis.

The whole thing is just SO frustrating as he has hardly any symptoms so we have no idea where we are at with it all. We are just counting the 10 days isolation from his first positive LFT

Void doesn’t mean negative it means the test didn’t work right & needs done again.

I know - it’s just really annoying- I just can’t believe it’s inconclusive after all these extremely conclusive LFTs

LFT are not that inaccurate. He has COVID. Ideally though confirm with a pcr for his medical records. FWIW I think counting his isolation period from the first positive lateral flow is absolutely fine.

Why baffled?

For whatever reason the test didn't work. Doesn't mean negative, doesn't mean positive. Just means it has to be repeated.

My db had 3 positive lft’s and a negative pcr last week. My dsis couldn’t visit my dm because db had been in her house the day before.
It’s so frustrating my poor dm was really upset as it was the only time dsis could go before Christmas.

@Porcupineintherough thanks, yes, we are all isolating just to be sure although the rest of our LFTs tests are currently negative. All our PCR results came thru void 🙄

I dont think you understand what a void pcr is.

It's nothing to do with the fact that he may or may not be positive. Its that the sample has been compromised in some way.

So maybe while doing the swab there was too much contact with cheeks/tongue, or that something went wrong in the processing system. Or could have just been a fault with the swab/equipment.

It doesnt mean the sample was 'weaker'. The odds of him havibg covid are not aby lower or higher after getting a void pcr. Its different to a negative result.

@MLMshouldbeillegal because his lateral flows have been so conclusive. It implies they couldnt get a sample but his LFTs have literally been turning immediately positive and we have done 5 over 48 hours.

@ChatterMonkey yes, I guess I am just frustrated as all 3 came back void.

If all the PCRs were void then something perhaps happened to spoil the batch / spoil the process for all of those tests.

[quote Laughingstock91]@Porcupineintherough thanks, yes, we are all isolating just to be sure although the rest of our LFTs tests are currently negative. All our PCR results came thru void 🙄[/quote]
Did you go to a testing centre that does the swab for you?

If not, and theyve all come back void then it may be that you did it wrong. Or that the processing centre had an issue with a batch and theyve all come back void.

The tests were obviously faulty or handled incorrectly etc OP. They may even just have been dropped on the floor or something for all we know. Nothing at all the infer a result either way.
It's a minor inconvenience, these things happen.
Hope your son is OK.

My friend had positive lft but pcr was negative they them rang 2 days later and told her she's actually positive. Luckily she wasn't up for going anywhere. Nearly came into work though. Her 2nd pcr results are still negative though they've said she's still positive. No clue what's going on atm.

Apparently unreadable can mean that a very weak amount of the virus was detected, but not enough to be positive. It can also mean a failure with how the test was processed.

The advice is the same, repeat test.

It sounds like there is a problem with the batch that your tests came from, rather than them being inconclusive. If another person had used those tests they also would have had the same result.

I think it’s as simple as that really.

I'd redo the PCR and I would stop doing the lateral flows. He doesn't need anymore right now!

@MostNamesAreTaken which is why I thought it was weird as assumed that his viral load must be quite high if he’s had so many positive LFTs. But as someone said, maybe they just dropped our tests on the floor

I had repeat void tests (before positive), which indicated inconclusive rather than dropped. Some one else in my household also got a void (at a different time to mine). Anecdotally void ("unreadable ") seems more common at the moment, I wonder if there will be an explanation in due course eg

• machines at lab need maintenance
• due to viral load being less due to repeat infections/ vaccinations the tests are less accurate, and maybe need recalibration

Or maybe a lab worker is dropping a lot of batches!

It’s not necessarily anything to do with the viral load, could honestly just mean someone fucked up processing the test in the lab. (I’m a molecular microbiologist and have done thousands of PCRs).
But from what you are saying about the LFT your son does have covid, it just needs to be confirmed for medical records, and also monitoring the variant type etc which is all done with PCR. PCR is much much more sensitive and informative than LFT.

They might have had a really snotty one being processed in the same batch that contaminated them all. Or they were left too late to process. Or someone spilt coffee on them.

I had a positive LFT - did 3 from 3 different boxes in my panic and all were positive.

Went for a PCR the next day which was negative. DH and DC all tested positive.

Spoke to GP who said either PCR error or I was right at the end of the virus. Recommended I isolate regardless (which I have done).

GP and all medic friends have said getting multiple false positive LFTs is basically impossible.

Well, just been back to the test centre and we were the 4th family this morning called back with void results so it’s clearly the test centre/faulty batch. Another family came in with same issue as we were leaving too with same issue—all from Friday too! So frustrating!

Sounds like someone in the lab dropped a tray as PP said or some other mistake was made. These things happen occasionally, frustrating to be the one it happened to but it's very likely your son has Covid, false positive LFTs are very unlikely