Asymptomatic Infection

The unknown true number of infected people — including untested asymptomatic cases — is expected to be much larger than the confirmed tested-case count, making early death-rate calculations highly uncertain. Asymptomatic and mildly symptomatic people largely do not appear in official confirmed-case statistics because they are not tested. People with no or mild symptoms can still spread the virus without knowing they are infected, which is a primary epidemiological reason for social isolation. Children and healthy adults may have a low personal risk of severe illness but can still participate in transmission chains that expose higher-risk people.