Infectious diseases can be transmitted through surfaces (see figure below). Surfaces can include a range of commonly touched objects such as tabletops, doorknobs, toys, light switches, and other objects. Generally speaking, the likelihood of disease transmission through surfaces depends on the following factors:
Amount of pathogen (virus) shed by infected individuals
Virus survival on surfaces
Rate of transfer from surfaces to hands and mouth/nose/eyes
Number of viruses required to cause disease (infectious dose)
Resistance of the virus to disinfection
This review provides a synthesis of the mechanisms involved in surface-mediated virus transmission, including evidence related to SARS-CoV-2 .
While SARS-CoV-2 transmission via surfaces is possible, the scientific evidence available to date suggests that the primary transmission route for SARS-CoV-2 is airborne (as outlined in this Lancet comment) and that contaminated surfaces present a low risk (as noted in this Science Brief by the US CDC).
Surface-mediated transmission. Adapted from: Julian, 2010.