3 ms·

if there is a reason for the mass testing, because it doesn't really let you know anything except whether or not you have COVID If you test positive, you're su

if there is a reason for the mass testing, because it doesn't really let you know anything except whether or not you have COVID If you test positive, you're supposed to stay home and isolate so you don't spread COVID. Tests aren't perfect, since as you said, there seems to be a significant false-negative rate with Omicron, and you can be contagious before you show symptoms, but the tests help prevent people from spreading confirmed cases, and can be helpful to pre-test before you spend time with someone who is at high risk for COVID.

dragontamer 5y ago
> Tests aren't perfect, since as you said, there seems to be a significant false-negative rate with Omicron Its not even Omicron. Rapid tests always had something like a 40% false-negative rate or something stupidly high. ------ That's why you're supposed to take two tests if you're asymptomatic, to reduce the chances of a false-negative. Fortunately, the false-positive rate is less than 5% IIRC, and fairly reliable. EDIT: Sensitivity and Selectivity isn't really false-negatives or false-positives. But for the purposes of this discussion, its probably good enough. Besides, I'm just an ignorant programmer who doesn't know the difference between them.
- Johnny555 5y ago
  I'm just going by what the FDA said: https://www.bizpacreview.com/2021/12/29/fda-says-rapid-at-home-tests-not-as-sensitive-to-omicron-variant-causing-false-negative-results-1181524/ https://www.bizpacreview.com/2021/12/29/fda-says-rapid-at-ho... “RADx recently performed preliminary studies evaluating the performance of some antigen tests using patient samples containing live virus, which represents the best way to evaluate true test performance in the short-term. Early data suggests that antigen tests do detect the omicron variant but may have reduced sensitivity,” according to the FDA.
  - dragontamer 5y ago
    I'm sure. But the sensitivity of rapid tests were always much much worse than the sensitivity of PCR tests. The original sensitivity of rapid tests were like 60%. Frankly, going from 60% to 40% doesn't change my viewpoint on rapid tests. Its all "unreliable false negative" to me (I don't know what it is for Omicron, I'm just pulling 40% out of nowhere). But whatever it was, the sensitivty was always so low that you never could rely upon a negative-reading, due to the high chance of false-negatives. ---------- Rapid tests remain useful, but you _MUST_ always be mindful of their high false negative rate. The fact that their "unreliable stat got even more unreliable" isn't really news, because you shouldn't have been relying upon it anyway.
xanaxagoras 5y ago
The most recent guidance says isolate for 5 days, then go back to work if you want to, or optionally take another rapid test and if it's still positive, isolate for another 5 days. The CDC also acknowledges that the virus is transmissible for 10 days after symptom onset. These "shoulds" and "supposed tos" are being thrown out the window. Health care workers in CA can go back to work immediately following a positive test if their symptoms aren't severe and in many cases they're being asked to.

dragontamer 5y ago

> Tests aren't perfect, since as you said, there seems to be a significant false-negative rate with Omicron Its not even Omicron. Rapid tests always had something like a 40% false-negative rate or something stupidly high. ------ That's why you're supposed to take two tests if you're asymptomatic, to reduce the chances of a false-negative. Fortunately, the false-positive rate is less than 5% IIRC, and fairly reliable. EDIT: Sensitivity and Selectivity isn't really false-negatives or false-positives. But for the purposes of this discussion, its probably good enough. Besides, I'm just an ignorant programmer who doesn't know the difference between them.

Johnny555 5y ago
I'm just going by what the FDA said: https://www.bizpacreview.com/2021/12/29/fda-says-rapid-at-home-tests-not-as-sensitive-to-omicron-variant-causing-false-negative-results-1181524/ https://www.bizpacreview.com/2021/12/29/fda-says-rapid-at-ho... “RADx recently performed preliminary studies evaluating the performance of some antigen tests using patient samples containing live virus, which represents the best way to evaluate true test performance in the short-term. Early data suggests that antigen tests do detect the omicron variant but may have reduced sensitivity,” according to the FDA.
- dragontamer 5y ago
  I'm sure. But the sensitivity of rapid tests were always much much worse than the sensitivity of PCR tests. The original sensitivity of rapid tests were like 60%. Frankly, going from 60% to 40% doesn't change my viewpoint on rapid tests. Its all "unreliable false negative" to me (I don't know what it is for Omicron, I'm just pulling 40% out of nowhere). But whatever it was, the sensitivty was always so low that you never could rely upon a negative-reading, due to the high chance of false-negatives. ---------- Rapid tests remain useful, but you _MUST_ always be mindful of their high false negative rate. The fact that their "unreliable stat got even more unreliable" isn't really news, because you shouldn't have been relying upon it anyway.

xanaxagoras 5y ago

The most recent guidance says isolate for 5 days, then go back to work if you want to, or optionally take another rapid test and if it's still positive, isolate for another 5 days. The CDC also acknowledges that the virus is transmissible for 10 days after symptom onset. These "shoulds" and "supposed tos" are being thrown out the window. Health care workers in CA can go back to work immediately following a positive test if their symptoms aren't severe and in many cases they're being asked to.