The term “viral shedding” has been thrown around in the media coverage of SARS-CoV-2 or its better known disease, COVID-19. Let’s take a step back and explore what it means.
As the name suggests, “viral shedding” is formally defined as the release/expulsion of viral progeny (after reproduction) from the host.
On a microscopic scale, the host could be a cell, a bacterium, etc. On a macroscopic scale, the “host” would be the human/person would could literally “shed” viruses: through droplets when coughing/sneezing (airborne droplets or aerosol spread); other body fluids/secretions; urine/feces; or using their hand to touch something (contact spread).
A person who is displaying symptoms (i.e. symptomatic) can shed, but so can people who are not showing symptoms (i.e. asymptomatic). When we think about asymptomatic individuals: they may never have been infected before; they may be silent carriers; and they may have been sick and recovered (asymptomatic) but still able to transmit the pathogen. Asymptomatic shedding and spread depends on the characteristics of the pathogen.
