Positive LFT yesterday, negative LFT today

[Downtonbabby]

Hi,

My oldest son is currently off school and had a positive LFT and PCR test last Wednesday / Thursday. I kept my younger two children off school Wednesday to Friday last week whilst we waited the results and to give it time incase they started to show symptoms and we’ve all been doing daily LFTs.
Anyway we all did lateral flow tests yesterday before returning school and my second son had a light but positive LFT, so they younger two stayed off school again yesterday and we took them and ourselves for a PCR test this morning. However before we went for our PCR test today we all did our daily lateral flow and my son who was positive yesterday was negative on the LFT today. I don’t know what to think? We had let him go back to sharing his bedroom with my oldest who is positive after his positive LFT as we just presumed he was positive after this test. So they were ok to be mixing more together as they were both positive. I know the PCR will clear it up for us, but I wondered if anyone had ever had this before, only tested positive once on a LFT and actually positive?

Also anyone who has had a child with Covid at home, did you all get Covid and how long did it take to become positive? We are currently at 6 days since my oldest got a positive test.

You arent supposed to retest for 90 days after a positive test. LFTs aren't accurate enough to say for certain that you don't have covid so you can get false negatives

I didn't check mine again once they got positive lft as they both got positive pcr's same day. DD1 is on day 9 (although i think she may have had it longer) and DD2 on day 8 and I am still testing negative on lfts and no symptoms.

Ds had symptoms and got positive lft. Next morning we repeated lft and it was negative. His pcr was negative.

I thought a positive LFT was extremely rare? Far rarer than a false negative.

I think if it’s positive they probably have Covid

A false positive LFT is unlikely
More likely to have been a false negative PCR

I don’t know why I tested again. I just thought my oldest had such a strong positive on his LFT, I thought my younger sons would have got stronger on todays one as we had caught it a bit quicker, not that it would be gone! It’s made me wonder if it was actually a false positive! However he has been around my oldest and shares a room with him (we moved him into his sisters room though once my oldest had a positive test) so I know he’s definitely been in contact with it! I just hate the waiting!

I tested negative on LFT the entire time I had Covid. I really wouldn't have that much faith in them, they're shite.

I just wrote about my son but I also got faint positive followed by clear negative lft next morning. Pcr was negative. I just did lft again and it was faint positive again. I don't have any symptoms. Can some of the lfts be malfunctioning?

That interesting guineapigs, I wonder if it will be the same for my son.
I’ve been testing for work since the start of the year and I’ve never got a false positive, which is why I was so confused by the positive yesterday then negative today. Hopefully the PCR results will come back soon!

Not me but a family member just has exactly the same - their DS had a positive LFT followed by a negative one.

Whole family was symptomatic, several colleagues in close contact now positive, extended family who joined half term holiday also positive, it’s rife in DC’s school. It MUST be Covid, right…..nope PCR tests were negative. Second PCR done to be sure was also negative. Personally, I’m sure they do have Covid but for whatever reason the tests are falsely negative.

I think it must be covid he just may not have a strong viral load for it to be picked up.
I tested lft every day out of curiosity when I have covid. I was ill but didn't get a positive lft until a few days in then positive lft for a few days then a faint positive then a negative.

Similar here. DD positive LFT. We all went for PCR. I'm symptomatic now (DC not) and feel bloody awful. But PCR came back negative overnight. I'm a teacher and DD is a student at same school. We are in contact with multiple positive cases daily it seems. There is no way work will not expect us both in today. We spent ages collecting the PCR sample too so I doubt it's wrong from that respect iyswim.

I'm so bloody sick of it all now.

The new government tests, the rapid nasal swab only seem to be throwing out weak positives ime. So many PCRs say negative.

With the older NHS throat swab LFTs I would have said a positive is a positive, but I don't agree anymore.

@Whataday21 the new ones are supposed to be much more accurate! Which is quite concerning.

pointless to do a lft if you have just had a positive pcr really

It's weird. I've had a few faint lines and PCRd a lot off the back of them and all negative (not part of the Wolverhampton scandal). A month apart and a faint line again. I've recently done an antibody test and I've not had covid.

It ended up coming back negative on the PCR test! Who knows what the positive was about on Monday. So he will be back at school tomorrow. It has made me loose a bit of faith in the lateral flows though.

I was really surprised that ours came negative too. I have not had covid and all the other lfts(and pcr) have been clear.

I would prob do pcr again to be sure as positive case in house and positive lft the other day