Lateral flow tests consistently positive

[alwaysonadiet1]

A friend has tested positive on lateral flow tests, twice a week, every week, since February. For the first few results he took a follow up PCR test which has always been negative. Does anyone have insights on what might be happening here?

I know two people this has happened to who hadn’t had covid. Nobody seems to know what keeps causing it.

Is it always the same brand test or different brands of tests? If always same brand, can they get a different one to test out?

That's so weird.

Different brands

I'm wondering if his PCR result was a false negative (they're not 100% accurate)? But you can test positive for 90 days after contracting covid as the covid cells are in your system for a long time after the contagious period. It seems unlikely that you would have that many false positives.

Odd

Could the LFT be positive for 90 days or just the PCR?

Could be what he eats and drinks before taking the test? Full fat Coke and kiwi are supposed to give false positives.

Wine?

Did they test regularly with LFT before February? Was there a period when they consistently tested negative? If yes, then the PCR must have been a false negative. Was there just one PCR done?

He started lateral flow tests late February. No test before that. No symptoms.

DH had confirmed covid early March. He was told that LFT could pick up a positive for up to 90days afterwards. He's taken quite a lot of LFT since (he's a teacher) and originally they all came back positive for a while but now they are finally showing negative.

It would be very very rare for LFT to consistently pick up + if your friend had not had covid before. Far more likely that they did in fact have Covid a while ago and it's still being picked up now.

He's had covid in February with a false negative on the PCR test, though it's not worth worrying about being infectious after all this time. Has he been isolating since February then or repeating the PCR tests every week?

@EnoughnowIthink

Could be what he eats and drinks before taking the test? Full fat Coke and kiwi are supposed to give false positives.

This isn't true. The acid in some food items can break the tests when used on their own, and as demonstrated by covid deniers in videos. The tests are not designed to be shoved in coke though and there isn't evidence that they will give a false positive when used as expected based on food. You'd need a lot of acid remaining in the throat to break the test like that. Try shoving a pregnancy test in a coke can and you'll get a positive pregnancy result on that too, that doesn't mean pregnancy tests don't work if you drink coke.

I was wondering this too.

This happens - it's not covid.

Unfortunately LF tests are just not going to be useful for him.

Ok thanks all, I think the 90 days is the answer, he must have had in in Jan/Feb and been asymptomatic at the time.