How We Misunderstand COVID Testing
COVID testing sites are currently seeing long lines. There is a troubling surge in cases during the past couple of weeks but the present rush to COVID testing is largely due to a huge misconception. COVID testing is not a pass to celebrate Thanksgiving indoors with family and friends. The rate at which the coronavirus multiplies and therefore becomes detectable needs to be considered. A negative COVID testing result tells us that an individual does not carry enough viral load to be detected only at the time of testing. "At the time of testing" is key to using correctly the result of a COVID test. During the past summer, some tourist destinations resorted to a COVID test as a requirement for travel, which probably added to the misconception that a negative COVID result was enough proof for safety. Georgetown University remained open during the current semester to a few students and researchers but these individuals had been required to be tested twice a week. Without a vaccine, regular monitoring is necessary if spending hours indoors with other people is expected. This is only monitoring. It does not stop the spread of the coronavirus. What curbs the spread of the virus is wearing masks, social distancing, and self-quarantine for fourteen days after a suspected exposure.
A recent study published in Science Advances suggests that for COVID testing, it is not the accuracy or reliability that is of prime importance. What apparently counts more is the frequency of testing and the speed at which results are obtained.
Of course, only a daily test can avoid missing an infection but this is obviously costly prohibitive. Data indicate, however, that twice a week is able to stop almost 90 percent of infections even with a "not-so-sensitive" test.
Testing is not a substitute for the necessary nonpharmaceutical interventions such as wearing a mask, social distancing, and self-quarantine after exposure. These measures still need to be taken. These measures work. Indoor dining and bars cannot adhere to these measures for obvious reasons. Georgetown University apparently can, but with much reduced occupancy. The university is not only testing individuals twice a week but also practicing all of these measures: wearing masks, social distancing, contact tracing and self-isolation after exposure. There are no short-cuts.