The FDA in the US recently announced that lateral flow tests should literally be thrown in the bin, and they wouldn't approve or support their use:
https://www.fda.gov/medical-devices/safety-communications/stop-using-innova-sars-cov-2-antigen-rapid-qualitative-test-fda-safety-communication
Part of the problem is with the self-testing of LF - if folks don't do their swab properly, or follow the instructions to the letter, it won't be accurate. Given that many folks find that sort of thing uncomfortable or distasteful at the best of times, and not wanting a positive result is invariably in most people's minds, the chances of a half-hearted negative result are very high. A friend of mine is a schoolteacher and they all have LF tests every three days, but they've still had positive cases come in via pupils or parents and staff had to self-isolate. I recently spent a week in hospital, and had three Covid tests when I was in, two days apart. The first was a pre-op test, 12 hours before, but I have no idea whether it was PCR or LF - ideally I was meant to be negative for the op, but a PCR can't be done that quickly - but they operated. Anyway,
I didn't see that first negative result on paper (or verbally) until four days later, the day before discharge. So if the other two tests were PCR, I wouldn't have got the results until last week. No-one's rung or texted me since, so I have to assume they were all negative. But I was very confident they'd done me properly as a nurse did all the swabbing, and she went
all the way in.
Unless you are on the point of vomiting you aint deep enough a little wipe around the external nostril doesn't cut it .
