How likely that 4 LFT’s could be wrong?

[bellsoflemon]

I do twice weekly LFTS’s Wednesday and Sunday.
I tested negative Wednesday.

As part of work I went to a lab on Thursday who required an LFT to be taken, which was negative.

Today i started with an awful cold, sore throat and feeling generally a bit run down.

I’m at a family bbq tomorrow so I did an LFT this morning which was negative, another one this evening which was also negative.

Have messaged in my family group to say I’m thinking of not going to BBQ and they’ve all told me the tests are negative and to still go.

covid.joinzoe.com/post/happy-birthday-i-got-you-covid-how-a-party-turned-into-a-super-spreader-event

Lateral flow tests can be wrong as can PCRs. This article on the Zoe Covid symptom tracker research page gives an example of a person with a sore throat and a negative lateral flow test attending a party. 17 out of 30 now have Covid.

A huge cold in our family currently. Negative lfts and pcrs. Literally a horrible cold. Having said that I read this week that Tim Spectre says the new variant presents as a cold and the anosmia side is barely happening now. Very interesting.

I just wouldn't go with a cold anyway.

Get a PCR. LFT were not designed and are no appropriate to use if you have symptoms. They are also not very accurate. As others have said, the actual list of COVID symptoms is far longer than the three "official" symptoms. I know people who have had COVID with only GI symptoms, just a sore throat, etc.

I wouldn't go to a family party either way. No one wants a big stinking cold, and as others have said even if not COVID it could cause symptoms that will require people to isolate etc.

I saw a colleague for lunch recently, out in the open, sandwich in a park. I was feeling under the weather with a headache and sore throat but negative lft. I just sent a message explaining and leaving it up to him - he was fine to meet, and in the end I had tonsillitis.

I should point out that this was pre delta variant though. And I had no fever. I wasn’t actively unwell at that point, just felt a bit ‘off’.

If I had an awful cold I wouldn't be going anyway. Irrespective of covid.

I don't usually have hayfever but the pollen's been awful this week, enough to feel in my throat and sinuses, try an anti-histamine just in case it makes you feel better.

Rather than all those LFTs, if you felt bad you should have had a PCR test, it's quick to do and more accurate. I'd be wary of passing on even a cold; nobody wants the extra isolation waiting for results, including your family's work colleagues, just tell your family no for this week and get the test. Family living nearby can just have another BBQ next week!

Regardless of COVID why would you go out and spread your germs when ill. It's totally selfish and irresponsible. Stay home, rest and get better

my daughter tested negative on lf's including the day she tested positive on a pcr.

They are reliable. You have a cold that is not covid.

It’s deeply shocking how many people on this thread totally misunderstand the function of lateral flow tests.

You don’t take a lateral flow test if you have any symptoms of anything.

And yes the symptoms you are displaying could well be indicative of covid.

The lateral flow test is useless at this point.

You need to self isolate and take a PCR test

The lateral flow tests are only to pick up covid BEFORE symptoms develop. And yes it is possible for 4 to be wrong. The are a very useful tool, but crude.

No wonder we are in such a mess with so few people apparently misunderstanding the basic fundamentals

LFTs shouid not be used when symptomatic because the false negative rate is so high

It's ok if you're trying to find otherwise undetected asymtomatic cases (because you're still finding some that would otherwise have been missed). Not ok to miss a proportion of symptomatic cases when there is a much more reliable test available,

I would not meet people until after a negative PCR in these circumstances. Which would be a blow if I had plans I was looking forward to, but these things happen

Colleague a few weeks ago was doing daily LFTs as we are required to do and developed symptoms which was then diagnosed as Covid within a few days. The LFTs did not pick up the Covid in the days before symptoms appeared, however a few days after testing positive by PCR she did a LFT to see if it showed and it did 🤷🏻‍♀️

Moral of the story is I would be hesitant to trust the LFTs if I wasn’t feeling great and didn’t have a PCR result.

@HareofEasttown

They are reliable. You have a cold that is not covid.

They aren’t reliable actually. They only really pick up cases with high viral load and give a high level of false negatives.

They’re a load of junk actually

I wouldn't go because you're going to give your cold to your family and they will then be obliged to get tested, even though they know it's your cold.

@0None0

It’s deeply shocking how many people on this thread totally misunderstand the function of lateral flow tests.

You don’t take a lateral flow test if you have any symptoms of anything.

And yes the symptoms you are displaying could well be indicative of covid.

The lateral flow test is useless at this point.

You need to self isolate and take a PCR test

The lateral flow tests are only to pick up covid BEFORE symptoms develop. And yes it is possible for 4 to be wrong. The are a very useful tool, but crude.

No wonder we are in such a mess with so few people apparently misunderstanding the basic fundamentals

Not helped by the fact that the government have not been crystal clear about them! People use them to test for covid just in case - why wouldn’t you? It’s too hard to get a PCR and the three “official” symptoms are not the only symptoms of covid. That’s why we are in a mess.

The lateral flow tests are worse than useless and only being pushed by the government because they bought so many of them at such vast cost.
If we all just stopped using them, most of the ridiculous unnecessary and damaging panic over one virus within the panoply of human illness would fade away.

If the probability of one test being wrong is 25% (I have seen 75% accuracy for LFT but don't know if this is a definite figure) then the probability of 4 negative tests being wrong would be 0.25×0.25×0.25×0.25 ie it is 99.6% likely that you are negative.

However you clearly do have a bug of some kind and it is ok to not go if you don't want to.

My son (lives with me)Tfelt rubbish on tuesday, sore throat, runny nose, headache, bloodshot eye etc. I got him to do a LFT as I have them at home due to work testing. It came up positive - we went and had a PCR test and again he was positive. We have both been self-isolating since. I have developed a sore throat, runny nose, tickly cough, achey and have been doing a LFT each day - they are all showing as negative, however I am fairly sure I have the same as him so will continue isolating for ten days from the onset of my symptoms. I have had both vaccines, maybe that is affecting it? Neither of us have had a high temperature or the taste/smell thing.

The FDA announced that the LFTs in use in the UK are fit only for the bin.

www.google.com/amp/s/amp.theguardian.com/world/2021/jun/11/us-health-agency-gives-innova-lateral-flow-covid-tests-scathing-review

Around the point you started to get symptoms you should have got a PCR test and stopped doing LFTs.

LFTs are only useful for people with no symptoms.

And yes Covid can look like a cold and a sore throat.

If the probability of one test being wrong is 25%

That's a bit optimistically high. And a major reason for inaccuracy is poor user technique. You've missed out the possibility that some people will always produce a negative for that reason

Also you miss out the nature of an incubating infectious disease. The earlier tests might be true negatives.

Professor Tim Spector, head of the Zoe covid symptom app, says the Delta (Indian) variant is presenting as a cold, with headache, sore throat and runny nose now the top 3 symptoms. He says this at around 5 mins 40 secs on his latest update video:

This video says the top symptom of new variant is fever, sore throat, runny nose and headache.
And even it's not covid, I think you shouldn't really go out and spreading whatever virus you may have.