For both forms of transmission of COVID-19 disease, by close contact and by air, it is respiratory droplets containing the virus that spread the disease. Everyone produces respiratory droplets, which are small, moist particles that are expelled through the nose or mouth when coughing, sneezing, talking, screaming, singing, or exhaling deeply. Current evidence suggests that the virus spreads mainly between people who are in close contact with each other, for example, at a conversational distance. The virus can spread from the mouth or nose of an infected person in small liquid particles when he coughs, sneezes, talks, sings, or breathes.
Then, another person can get the virus when infectious particles that pass through the air are inhaled over a short distance (this is often called a short-range aerosol or short-range airborne transmission) or if the infectious particles come into direct contact with the eyes, nose, or mouth (droplet transmission). The spread of COVID-19 occurs through airborne particles and droplets. People who are infected with COVID can release particles and droplets of respiratory fluids containing the SARS CoV-2 virus into the air when they exhale (for example, droplets or aerosol particles vary in a wide range of sizes, from visible to microscopic). Once the infectious droplets and particles are exhaled, they move out of the person (the source).
These droplets carry the virus and transmit the infection. Indoors, very fine droplets and particles will continue to spread through the air in the room or space and may accumulate.