How accurate is the test? Coronavirus symptoms but negative test?

[AnotherEmma]

Two flatmates. One has coronavirus symptoms. They both get tested and both come back negative.

The NHS website is not completely clear but I think it says that the negative tests mean they no longer need to self-isolate:
www.nhs.uk/conditions/coronavirus-covid-19/testing-and-tracing/what-your-test-result-means/

However, I've read that the coronavirus test is only 70% accurate, so there is a chance of false negatives.

They could be incubating the virus and not testing positive yet.

Am I right?

The flat mate with no symptoms wants to meet at a socially distanced gathering, which I would usually be ok with, but some of the people attending are in the vulnerable category (nb just vulnerable, not extremely vulnerable and shielding) and one is a 3yo who is unlikely to stick to the 1m rule!

If anyone has any links to reliable sources about the efficacy of the test I'd be very grateful.

isn't the NHS site reliable?

Well yes! But it doesn't give detail about the accuracy of the tests.

I was in hospital this past week and the nurses said the Covid test is only 70% accurate. It’s why they want people to isolate for 14 days before surgery as the test isn’t that great.

I think this was covered in a recent episode of Radio 4's More or Less.

Yes 70% to be safe i would isolate anyway- testing also really has to be within 5 days

@girlofthenorth do you mean testing in the first 5 days of symptoms starting?

I’m also interested in this as DH had a 72 hour fever / sickness, and has had some sort of post viral fatigue and nausea since then (6 weeks) but tested negative for CV. I would have preferred it to come back positive as then at least we would know what it was.

Right, I've done some googling.

BMJ:
"A single negative covid-19 test should not be used as a rule-out in patients with strongly suggestive symptoms"
www.bmj.com/content/bmj/369/bmj.m1808.full.pdf

Medical News Today:
"A team from Johns Hopkins Medicine has found that PCR-based tests for SARS-CoV-2 have a false negative rate of at least 20%, depending on the time of testing."
www.medicalnewstoday.com/articles/tests-may-miss-more-than-1-in-5-covid-19-cases

I had a false negative test at a drive thru centre. I had all the symptoms. When I was still unwell several weeks later my GP did a blood test, and I was sent to the hospital due to the abnormal results.
The swab in the hospital was positive. They did appear to go much further up my nose at the hospital, so maybe the first one wasn't done properly.

I've just had a positive antibody test done 6 weeks later.

You can have the test come back negative and then the next day it would be positive. Hence why they do them a few times in this situation for hospital patients.
I think they should skip the gathering and order some more tests

@MeanMrMustardSeed yes the test is more reliable if it's done within the first 5 days. I had symptoms at the start of lockdown - I'm an HCP so I'm pretty sure it was covid and so was GP. I was tested on day 9 and negative. Many colleagues with similar story to your DH also tested negative , one several times!

I bet its quite high false negative. Not just from the reliability of the test but also by people having to administer their own test through home tests and at some testing centres

Well I’d not even think to isolate if the test came back negative.. I doubt the majority of the population would either to be honest.. it’s not exactly common knowledge they might not be accurate! 🤨 We can’t live life based on ‘might be wrong’ surely?! Especially in winter when similar symptomed bugs are flying round!

"We can’t live life based on ‘might be wrong’ surely?!"

Well we've all been forced to live extremely restricted lives for the last 3 months based on the possibility of catching coronavirus.

What the fuck was the point of that if people with SYMPTOMS OF CORONAVIRUS have been told to carry on as normal on the basis of taking one unreliable test?!

I have disagreed with a LOT of the rules and measures under lockdown. However, I think that people with symptoms should self-isolate. I don't think a negative test should make them exempt if the test isn't reliable and there is a high risk of false negatives.

@AnotherEmma that might be okay if you do not have to go to work. Most employers will want people back after a negative test. If we went by that principle we would go back to the original crap plan of no need to test, just isolate. As we go into winter isolating with symptoms would be unmanageable

Yes but the person who tested negative is not going back to work, they want to attend a social gathering with vulnerable people. That's the point.

In terms of the risk/benefit analysis, someone who tested negative probably should go to work, especially if they're a key worker. But of course there's a small risk they could infect vulnerable people at work.

It's a personal decision as everyone will weigh up risks and benefits differently.

I just find this particular situation very frustrating!

"As we go into winter isolating with symptoms would be unmanageable"

Indeed, but it's not winter yet - it's June!

Your last comment was not specific to yoit friend. You said anyone with symptoms should isolate.

they want to attend a social gathering with vulnerable people

Irrelevant of the test results they should only do this if they can socially distance and the vulnerable people the same.

The vast majority of people who have Covid have no symptoms.

You are right though, it is a frustrating situation with no correct answer. I would think it unlikely they would both get a false negative though

If I had symptoms and then a negative test result I'd judge it on my circumstances as to whether I continued to self isolate.
If I knew I'd been in contact with someone who had tested positive, I probably assume a false negative. If I had lost my sense of smell and taste I might also assume false negative as I've never had that with any other illness.
If me, DH and DD all got a fever and all tested negative, I'd assume we all had the same non-CV bug, rather than assume three false negatives.

I work in the NHS. Tested negative twice. Self swab at a drive through testing centre.

My GP signed me off sick with Covid as I had symptoms, clearly had a nasty virus that has laid me low for 6 weeks now and he says the tests are giving 1/3 false negatives. He's had patients hospitalised with Covid who took three tests (in hospital) to show up as positive.

Thank you all. We decided not to go and I think it was the right decision. We told everyone to meet without us (didn't want to spoil their fun) but they decided to postpone instead and I'm relieved tbh, for the sake of the vulnerable people in the group.