One number could help reveal how infectious a COVID-19 patient is. Should test results include it?

This article explains that PCR tests detect SARS-CoV-2 by amplifying viral RNA through multiple cycles, and the cycle threshold (CT) value represents the number of cycles needed to detect the virus. A lower CT value indicates a higher starting amount of viral genetic material, with, for example, a CT of 12 corresponding to over 10 million times more virus than a sample with a CT of 35. In a study of 3,790 positive samples, researchers found that 70% of samples with CT values of 25 or below contained viable virus, whereas fewer than 3% of samples with CT values above 35 did.