How Does Coronavirus Spread?
CORONAVIRUSES (COV)
COVID-19 infection can be transmitted through droplets of different sizes: larger droplet particles are referred to as respiratory droplets, while smaller ones are referred to as aerosolized. While it is still considered that the primary mode of transmission between people is through respiratory droplets and contact routes, more and more studies suggest that airborne spread is also highly likely, especially in crowded spaces, with poor natural or mechanical ventilation.
Droplet transmission occurs when a person is in close contact with someone who has respiratory symptoms (e.g. coughing or sneezing) and is therefore at risk of having his/her mouth, nose or eyes exposed to potentially infective respiratory droplets. Infective individuals expel droplets primarily through coughing and sneezing, but simple acts such as breathing, talking, singing or sighing heavily can also produce droplets of different sizes, which can spread onto nearby persons and surfaces, or remain suspended in the air. In addition to the direct person to person transmission through larger droplets, airborne transmission of the virus in air-suspended, microscopic respiratory droplets (micro-droplets) is also possible.
In addition to the airborne transmission, COVID-19 infection can also spread from person to person through handshakes, fist bumps or other close interactions. People are thought to be most contagious when they are symptomatic (when the symptoms have developed), but asymptomatic (not showing symptoms visibly) carriers can spread the disease as well. That is why the CDC recommends that suspected or confirmed patients be isolated until they are better and no longer pose a risk of infecting others.
When an infected individual coughs or sneezes, large droplets drop to the ground or onto surrounding surfaces before they evaporate, causing local contamination. Disease transmission through these large droplets is what we often refer to as “droplet/contact spread”, where disease transmission occurs because you touch a surface contaminated by these droplets. And while it is not thought to be the main way the virus spreads, it is possible to get COVID-19 by touching a surface or object that has the virus on it and then touching your mouth, nose, or eyes.