Thank you, this is quite interesting! I did consider the possibility of some other virus being the cause of the positive tests, but it strikes me as somewhat odd to have 32 days in between positive tests. In any case, the explanation to this situation is probably something very unlikely, so this could be it. This situation is recent (my last positive antigen test was a few days ago), so I might wait for a few more weeks and do some tests again to see what happens.
[Update] Over the course of the past month (starting ~7 weeks after my last false positive), I’ve taken 8 rapid tests, 4 of which from Acon (the brand that is most correlated with my false positives). All of them were negative, and one of the Acon ones had a very faint test line (which I still interpret as being negative, though I didn’t confirm with a PCR). The only thing I noticed I did differently this time around was that I took most of these tests (6 of them) past 11am, and not right after I woke up, as I used to do before, and the one with a faint test line was among the two I took within 2 hours of waking up. I never eat or drink anything 30 minutes before testing, as the instructions recommend. My impression is that this is reasonably good evidence that whatever was triggering the false positives is now mostly gone, as per in gwillen’s comment about cross-reactivity. Besides the observation above I have no reason to think that the time of the day when I take it should make much of a difference to the test results; I might test that out in the coming months. As before, I’m happy to read any other possible explanations for this, and might also test them out in the future.
Thank you, this is quite interesting! I did consider the possibility of some other virus being the cause of the positive tests, but it strikes me as somewhat odd to have 32 days in between positive tests. In any case, the explanation to this situation is probably something very unlikely, so this could be it. This situation is recent (my last positive antigen test was a few days ago), so I might wait for a few more weeks and do some tests again to see what happens.
Would love an update if you do!
[Update]
Over the course of the past month (starting ~7 weeks after my last false positive), I’ve taken 8 rapid tests, 4 of which from Acon (the brand that is most correlated with my false positives). All of them were negative, and one of the Acon ones had a very faint test line (which I still interpret as being negative, though I didn’t confirm with a PCR).
The only thing I noticed I did differently this time around was that I took most of these tests (6 of them) past 11am, and not right after I woke up, as I used to do before, and the one with a faint test line was among the two I took within 2 hours of waking up. I never eat or drink anything 30 minutes before testing, as the instructions recommend.
My impression is that this is reasonably good evidence that whatever was triggering the false positives is now mostly gone, as per in gwillen’s comment about cross-reactivity. Besides the observation above I have no reason to think that the time of the day when I take it should make much of a difference to the test results; I might test that out in the coming months. As before, I’m happy to read any other possible explanations for this, and might also test them out in the future.
Thanks for the update! This is really interesting to follow along with.