CNN News: When you should take a PCR vs. a rapid antigen test

PCR tests are considered to be the gold standard for detecting coronavirus infections. They are able to detect even the smallest amounts of the coronavirus genetic material in a specimen. Even though this sensitivity can be advantageous for detecting coronavirus after recent exposure, it also means that PCR tests might be positive even after you are no longer contagious. According to Dr. Leana Wen, an emergency physician and visiting professor of health policy and management at the George Washington University Milken Institute School of Public Health, a PCR test might show up as positive even after three or four weeks after you have recovered. Therefore, according to her, after seven to ten days the PCR test is no longer appropriate and one should opt for a rapid test. This is also an important differentiation between the terms “infected” and “infectious” comes about: an “infected” individual is someone who still has the virus inside of them, but an “infectious” individual is someone who is shedding virus and transmitting it to others. In accordance with the latest CDC recommendations, the best approach is to take a rapid test toward the end of a five-day isolation period. Those who will continue to test positive at that point should continue until they reach the ten-day mark after their symptoms began and continue to wear a mask. Unfortunately, as of now, there is not an FDA-cleared test that can tell us exactly how much virus is needed to be infectious to other people. Read the full article here