… in active infection testing? By that I mean, is that the main source of the errors (or much of one at all) I’m sure there’s some handling/procedure produced errors. What else?
Yes, viral load is one. Degraded specimen, especially if it’s testing for an RNA virus. RT-PCR tests are looking for the RNA. I suppose bad test reagents but that should be picked up with the positive control.
But with the current better tests, is that the major reason? I’m just curious bcause that would also imply false negatives were less contagious.
I suppose that depends. If someone tests because they think they were exposed but are several days before they start showing symptoms, their viral load is low and they may not be that contagious. Also, viral load slowly drops a little over a week after symptoms start. Sometimes the tests will come out negative and it’s harder to culture live virus. So they may be less contagious but if they’re coughing a lot, they’re spewing particles all over.
Well, what I’m thinking about is nursing home negative test “passports” for family visitors. Some might say that’s a bad idea because of the high false negative rate. If the vast majority of false negatives were still likely not contagious at test time, it would make those passports a safer idea.
I definitely think it’s a bad idea.
They’ve already been doing it up here for around a month. These residents have been basically locked in a room for months with no visitors.
Oh, I forgot you’re in Canada. I wouldn’t worry about it. The tests are an extra precaution, but you all don’t have nearly the number of cases. What’s the probability of having a presymptomatic person where cases are already low?
Yes but we botched our nursing care covid response so extra precautions are good. I’m not really worried about it – I’m curious about whether a false negative probably means “not very contagious”