Infectious agents spread from the respiratory tract when coughing and sneezing are an example of droplet transmission. This means that infectious droplets containing pathogens are expelled from an infected person's respiratory tract and can directly reach the mucosal surfaces (mouth, nose, eyes) of others nearby or contaminate surfaces that others may touch, leading to infection. These droplets are relatively large and typically travel short distances (about 1 meter) before falling to the ground, distinguishing them from smaller aerosols that remain airborne longer and travel farther.
Explanation of Droplet Transmission
- Droplet transmission occurs primarily when a person is in close contact with someone who is coughing or sneezing, as these actions generate virus-laden droplets.
- A cough can produce approximately 3,000 droplets, and a sneeze can release around 40,000 droplets.
- These droplets vary in size, with larger droplets settling quickly and smaller ones sometimes traveling several feet in the air before settling.
- Infection spreads when these droplets land on or are inhaled by a susceptible host's mucosal surfaces or contaminate hands/surfaces that then come into contact with the face.
Therefore, coughing and sneezing spreading infectious agents from the respiratory tract exemplify droplet transmission as a means of spreading infectious diseases. This mode is one of the primary ways respiratory viruses, including influenza and COVID-19, spread between people.
