It usually takes a few days after infection to become contagious. So if someone waa exposed several days before, they could suddenly become contagious at any time.
It usually takes a few days after infection to become contagious. So if someone waa exposed several days before, they could suddenly become contagious at any time.
No. As Guttermouth said, the virus has to replicate enough to be detectable. Usually thatтАЩs when symptoms begin, though you can have an asymptomatic infection too. Taking tests every day or 2x a week is more reliable тАж though not 100% reliable either. Lots of medical tests miss stuff or give false positives, itтАЩs not just Covid tests.
Confirming a тАЬcaseтАЭ (meaning the disease Covid-19, not just the presence of the virus SARS Cov-2) is partly clinical and requires symptoms.
An asymptomatuc infection isnтАЩt a тАЬcaseтАЭ but itтАЩs believed to be potentially contagious anywayтАФnot sure if this is definitely confirmed to be true but itтАЩs believed to beтАФbut you can be contagious in the presymptomatic (prodromal) stage, same happens with a cold, as well as low symptomatic, which may be very mild.
The false positivity rate increases in direct proportion to the number of PCR cycles.
It is extremely unlikely to show positivity "immediately" after infection as there is no population in the body yet (unless you happen to swab right over the exposure point, but even then, you're simply proving exposure, not infection).
It usually takes a few days after infection to become contagious. So if someone waa exposed several days before, they could suddenly become contagious at any time.
Thanks, I had absolutely no idea how this biological action works.
But does the test show positivity immediate after infection? Do we know for sure? What is the false positivity rate? I am confident of nothing.
No. As Guttermouth said, the virus has to replicate enough to be detectable. Usually thatтАЩs when symptoms begin, though you can have an asymptomatic infection too. Taking tests every day or 2x a week is more reliable тАж though not 100% reliable either. Lots of medical tests miss stuff or give false positives, itтАЩs not just Covid tests.
Confirming a тАЬcaseтАЭ (meaning the disease Covid-19, not just the presence of the virus SARS Cov-2) is partly clinical and requires symptoms.
An asymptomatuc infection isnтАЩt a тАЬcaseтАЭ but itтАЩs believed to be potentially contagious anywayтАФnot sure if this is definitely confirmed to be true but itтАЩs believed to beтАФbut you can be contagious in the presymptomatic (prodromal) stage, same happens with a cold, as well as low symptomatic, which may be very mild.
The false positivity rate increases in direct proportion to the number of PCR cycles.
It is extremely unlikely to show positivity "immediately" after infection as there is no population in the body yet (unless you happen to swab right over the exposure point, but even then, you're simply proving exposure, not infection).