
PCR TESTS: People often test positive for weeks or even months after they recover

People often test positive for weeks or even months after they recover but have high CT values, suggesting the PCR has identified genetic material from noninfectious viral debris.
A test that registers a positive result after 12 rounds, for a CT value of 12, starts out with more than 10 million times as much viral genetic material as a sample with a CT value of 35.
A high viral load doesn’t necessarily lead to disease; some 40% of people who contract SARS-CoV-2 stay healthy even though they have a similar amount of virus to patients who fall ill.
READ THE FULL STORY: One number could help reveal how infectious a COVID-19 patient is. Should test results include it? | Science | AAAS