Positive LFT followed by negative PCR. Confused. Do I need to self isolate?

[SlateCoaster]

One of my colleagues had a positive lateral flow test on Thursday. As I'd been at work all week with her, I started self isolating. She took a PCR test on Friday and her result today is negative.

Very confusing!

Do I need to continue self isolating? I don't think I need to, but I'm confused because of her positive LFT the day before a negative PCR. How likely is a false-positive LFT?

Not unusual as far as I understand. Negative PCR means you don't need to isolate.

PCR is more accurate than LFT. Looks like you she had a false positive result on LFT. You don’t need to self isolate if her PCR was negative.

Does she have symptoms?

@Postdatedpandemic

Just a headache, but she's been putting that down to the extreme heat we'd been having.

If she had a negative pcr within 48 hours of the positive lft then you don’t need to isolate. Pcr trumps the lft.

Weirdly dp had this and within 48 hours and after 5 phone calls they said she didn't need to isolate. But the message to me to self isolate was never revoked.
Logically though if she doesn't need to isolate then neither do I.

LFT can false positives

You need to continue to self isolate IF you are a close contact of someone with COVID. A negative PCR doesn't currently get you out of self isolating if test and trace have told you to isolate

@powleda

I haven't been pinged by Test and Trace.
My colleague doesn't have COVID. Her PCR (within 48 hour of a positive LFT) was negative. She also doesn't have any symptoms. Therefore, I believe there is no need for me to continue self isolating.

That’s right. The law is that you must self isolate if you are symptomatic and have a positive PCR test or have been contacted by NHS Test and Trace. If you have been been exposed to someone who has had a posted PCR test, you may be contacted by NHS Test and Trace or pinged by the NHS app. If it is the latter, whilst it is recommended that you self isolate, and the guidance uses words such as must, it is not legally mandatory.

If someone you had close contact with, has had a negative PCR test, they and you, do not need to self isolate.