Viral load - high enough to transmit, but not detect on a LFT

[zafferana]

My family have Covid at the moment and it has got me thinking.

• DS was infected at school last week.
• He infected me over the weekend (I know this because he's a weekly boarder), yet he tested negative on Sun eve.
• He returned to school Mon morning and tested positive on Mon eve.
• I had symptoms on Tues morning, tested negative, but by 6pm that evening I tested positive.
• DH has consistently tested negative (daily tests since Tues), yet he has mild Covid symptoms (runny nose, occasional coughing, sneezing).

All of this suggests that you can be infectious before you have sufficient viral load to show up on a test and quite possibly you can have Covid, but never test positive. Is this common knowledge and I've only just figured it out?

Common. That's how I caught Covid, work colleague was a close contact on a Sunday, she did not test positive on LFT until Friday by which point she'd passed it on to me and another colleague. I never tested positive on LFT at all, only PCR picked up my infection.

Yes of course.

It took me 2 days of symptoms to get a positive.

I had awful symptoms for two days and was negative. Finally I tested positive on the third day.

I've never had a positive LFT. I have Covid and I've had it pretty badly. On the mend now but never showed up on an LFT. Presume I've been contagious as I likely managed to pass it on to MIL.

I feel like my Dd2 9 has had it all week but is testing negative. Horrible cold last week, sore throat on Monday. Lots of her class have it so I did a PCR on her which came back negative. She's had a temperature and headache last 2 days but is still negative. Maybe it's something else but since 9 people in her class are off with covid, it seems unlikely. She did have it last term though (asymptomatic) so maybe has antibodies.

I got my first positive LTF on day 2 of bad symptoms - had to swab throat too. I'm day 4 now and got a strong positive on LTF with just nose only. I'm sure I caught it from my DC who were sneezing and had a headache last week - no positive for them though.