PCR Test Is Not Useful in Determining COVID Infectiousness – Dr. Joseph Mercola

One reason the CDC has changed its rules to not require retesting for COVID-19 infection after quarantine is that the PCR tests used to determine infectivity can stay positive for up to 12 weeks.

The rapid antigen tests also may be less sensitive to the Omicron variant, according to CDC director Dr. Rochelle Walensky, but even so, if you test negative on the rapid test and you have symptoms, you need to get the PCR test anyway.

Then, if you have symptoms and test positive on the PCR test, you just don’t have to retest after you’ve quarantined, as the long positivity rates for the PCR tests “would have people in isolation for a very long time if we were relying on PCRs,” she told ABC News.

SOURCE: ABC News December 29, 2021