The PCR test is being used in ways it shouldn’t be used, and it’s leading to a lot of panicked and wrong decisions on the Covid-19 response. From John Hunt, MD, at internationalman.com:
Editor’s Note: In the setting of COVID-19, almost every country in the world closed its borders, locked down its citizens, and forced businesses to close. Today, most governments still restrict travel, economic activity, and social gatherings.
The justification for these unprecedented measures has been a growing number of COVID-19 cases. This has unleashed an epidemic of COVID testing—with PCR and rapid antigen tests as the means of identifying positive COVID cases. Our very own Dr. John Hunt examines the science behind COVID testing, whether the testing paradigms are effective, and the rationality behind government response to the virus.
What COVID tests mean and don’t mean
RT-PCR tests can be designed to be highly sensitive to the presence of the original viral RNA in a clinical sample. But a highly sensitive test risks poor specificity for actual infectious disease.
Rapid antigen tests are different. They measure viral protein. They do so by reacting a clinical sample with one or two lab-created antibodies that are labeled with a measurable marker. These antigen tests are often poorly specific, meaning they can show as positive in the absence of any actual viral protein or any COVID disease.