Fig. 4

There are two types of SARS-CoV-2-infected individuals: those that develop symptoms at some point (symptomatic in a broad sense, ~75%–84%) and those that never develop symptoms (asymptomatic, ~16%–25%). The former individuals undergo three stages of infection: presymptomatic (where viral RNA is detectable but there are no symptoms), symptomatic (in a strict sense), and postsymptomatic (symptoms are gone but viral RNA is still detectable). They are often referred to as presymptomatic, symptomatic, or postsymptomatic individuals. These stages have distinct implications for transmission. Since all SARS-CoV-2-infected individuals are initially symptomless, testing, follow-up, and a thorough symptom assessment are required to truly differentiate asymptomatic from presymptomatic, paucisymptomatic (individuals experiencing mild or few symptoms), and postsymptomatic infection