Positive LFT (negative pcr) which brand?

[NurseMumMe]

So my child used a flowflex (nose swab only) last night x2 and both show a clear positive although they line is not as dark as the control line.
We have been for PCR.
I have cold symptoms (1 week) negative LFT
We also out of curiosity tried an older brand of test - throat and nose- just now- negative.
My child has no symptoms except sneezing at times. They are a contact via school obviously as schools rife with it.

Do we think it could be the new lateral flow tests at fault?

2 of us here have multiple +LF and 2x negative PCRs.
We've done innova branded, xiamen biotime NHS boxes (sold by innova) and the new flowflex nose only. All positives.

My child just tested using 3 LFT across 3 brands - the positive one is floflex again the other two negative

It's quite normal to have a positive LFT followed by a negative PCR even if you are infected. My understanding is that LFT positives are almost always right. Specifically 3 out of 10,000 are wrong. But now this is where it gets tricky. PCR tests falsely give a negative 5% of the time. But if you have already tested positive with LFT and you get a PCR negative there is about a 50% chance the PCR is wrong. The easiest way I can think about it is that if everyone in the country had covid then all the PCR negatives would be false. So if you are already really likely to be positive because you had a positive LFT then there is a fair chance that a negative PCR is false.

But the official advice is to follow the PCR result isn’t it? 🤯

So Floflex are the more 'accurate', thank you. Maybe that explains why my oldest just had classic covid symptoms as did all her friends who tested positive while she tested negative. We've been using tests we were given last year....maybe they go off ?

I had 7 faint positives on flowflex last week.
Negative on all older throat and nose ones and one negative PCR.

Not done another since Saturday and that was a flowflex and that one was negative.

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

But the official advice is to follow the PCR result isn’t it?

If it is, I think it is wrong, sadly.

@loveandroses yes last week I was told the PCR out rules the 7 faint positives. God knows now if I'd had it without knowing and literally just because I'd got the flowflex and tested was at the end off it but flowflex now negative

One local Director of Public Health is asking people to make their own judgement…

It’s very interesting but makes it hard to know what to do about isolating etc

@NurseMumMe

It’s very interesting but makes it hard to know what to do about isolating etc

Exactly. It's easy to say make your own judgement but where I work (in healthcare), they will expect me back in work with a negative PCR.

Especially if asymptomatic, have mild symptoms or the less common symptoms.

Our school nurse said the nasal ones gave less false positives. Certainly true in my house where 2 lfts turned into 2 positive pcrs and we are seating the results of 4 more. 1 positive lft and 3 negative in that lot.

X4 positive flowflex on one of my children - negative pcr!
North east England !!

@NurseMumMe I'm north east too. I've now had another 2 faint positive flex ones. I've sent of a postal PCR this morning. Only me in the house this is happening too. Makes a total off 9 faint positives in a week. One negative PCR and negative on old ones but did have a negative flex on Saturday. I don't know what's going on 🤦🏻‍♀️

Your situation is pretty much the same as mine @frenchiemummy92

Except I'm faint positive on the old ones also. I'm Yorkshire area

@Bettyboopsboop what have you been advised to do? Isolate or not?

@Nahhh

But the official advice is to follow the PCR result isn’t it? 🤯

No, currently it is to follow the LFT result if it's positive.

@Nahhh

But the official advice is to follow the PCR result isn’t it? 🤯

"A director of public health is advising people to isolate if they have Covid-19 symptoms even if they subsequently receive a negative PCR test result."

www.bbc.co.uk/news/uk-england-58841259

@WhatMattersMost I don't have symptoms only the faint positives on the flex tests

I'm back at work. I don't have any official symptoms

Try a flowflex one but do your tonsils lile the old ones. It's slightly harder as they made the stick shorter but have seen online that people with a faint positive on those got a more definite positive if they did their throat too.

[quote frenchiemummy92]@WhatMattersMost I don't have symptoms only the faint positives on the flex tests [/quote]
Same at my house. Symptoms developed about 36 hours later.