Positive LTF 3 weeks after positive PCR

[WindUpBird]

DD had a positive LTF & PCR & mild symptoms between 26.8. & 30.8. All negative LTF after that. Close friends at school have now got covid symptoms & positive LTF & PCR. DD’s LTF now showing a VERY light positive result. Surely it’s not possible to get covid again 3 weeks later?!

You're not supposed to test again for covid for three months after a positive PCR, as you can still test positive from the initial infection.

Why are you continuing to test? No testing required within 90 days of a positive

Only retest if showing symptoms

It's picking up her past infection. This is why you're not meant to LFT within. 90 days of confirmed infection.

Ah ok, I thought it was just PCRs which picked up past infections. Her school & extra-curricular clubs ask to test twice a week. It was weird that this LFT showed positive when all the others since infection have been negative.
She’s already had a missed call from Test & Trace so I’m sure they’ll call back & hopefully confirm what you’ve all said!

I thought it was just PCRs which picked up past infections
Why? Why would you think this? They're looking for the same thing. One identifies it well but has to go to a lab, the other is a bit crap but can be done at home. But they're both looking for Covid. Neither can distinguish between old and new Covid.

It was weird that this LFT showed positive when all the others since infection have been negative.
Not that weird. LFTs are unreliable. It's entirely predictable that a bunch would miss traces of existing infection then one would randomly pick it up. That's very indicative of their accuracy.

She shouldn't have to isolate again, but she needs to stop doing tests. A test is only recommended within 90 days if new symptoms develop