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Ben Hammond09:09:07

my 5 year old daughter just PCR tested negative for covid-19 still got a hacking cough though 8-/

Ben Hammond09:09:22

what is the false -ve rate on those things

Ben Hammond09:09:35

or just failed to poke the swab in far enough...


poor thing... hopefully she gets better soon 😷


was it done professionally? ie. not an home test.

Ben Hammond09:09:05

I think its the top lip constantly bathed in snot and/or saliva that distressed her the most

Ben Hammond09:09:23

it was done in a car by my wife at a drive-through testing centre

Ben Hammond09:09:30

so not really professionally, no

Ben Hammond09:09:46

we don't seem to do professional swabbing in the uk

Ben Hammond09:09:57

thats a foreign concept

Ben Hammond09:09:21

my brother is in France, and he says the pharmacist alway does the swabbing


well, I assume if the virus is present you'd find it in all the snot as well.

Ben Hammond09:09:36

yeah I suppose so

Ben Hammond09:09:46

hard to know innit


here in NL you can do simple at home test and if they are positive you are supposed to get a proper test done by someone who knows what they are doing.


I read something that said the false positive and negative rates “should” be less than 5%, whatever that means.

Ben Hammond09:09:47

> someone who knows what they are doing seems to be anathema in the UK


not sure how 'professionally' that is though


well, if she has symptoms that could be attributed to covid I'd say you have waited long enough


All four of us had the same symptoms as each other. One tested positive, the rest tested negative. False positive rate is estimated at 0.8-4.3% (I couldn’t find anything that specific for false negatives), so I wonder if the positive one was wrong.


that is suspicious indeed


It’s possible that it’s a coincidence - that we all had a cold, and my son also had covid, with no extra symptoms (he coughed a little, so we got him tested just to be on the safe side), but with 30,000+ cases a day at the time, 1% false positives is >300/day 🤷

Ben Hammond09:09:03

cross contamination is surely an issue when it has been scaled up so far

Ben Hammond09:09:30

over and above laboratory condition uncertainty


My 4 year old kid has had that cough too for a while, and apparently a few other of his classmates too have it.


I think it's the normal "let's shove all the kids together, start of new school term, cough" type of thing


but, natch, given the situation, everyone is on tenderhooks if it is covid or not.

Ben Hammond10:09:54

given the new symptonms for delta, how could you possibly tell

Ben Hammond11:09:25

> If we agree that I definitely had something, then the chance I had Covid given that I had cold symptoms was (1.3/(1.3+6.1))*100, or about 17%. That’s high: almost exactly the chance of rolling a 1 on a six-sided die, something I do I’d be very nervous about, say, going to the pub with that chance of having the virus.

Yuriy Zaytsev11:09:29

I was making the test for my 7 years old son last week and I would say it is hard to make. I have no idea if I made it correctly. He had bad cough as well.


The impression that I got was that if you do it wrong it’s supposed to come back with no result, rather than negative.