What is droplet transmission?
Droplet transmission occurs when bacteria or viruses travel on relatively large respiratory droplets that people sneeze, cough, drip, or exhale. They travel only short distances before settling, usually less than 3 feet. These droplets are loaded with infectious particles.
They can be spread directly if people are close enough to each other. More often, though, fomites are involved. The droplets land on hands, toys, tables, mats, or other surfaces, where they sometimes remain infectious for hours. Hands that come in contact with these surfaces (doorknobs, telephones, pens, etc.) become contagious. When the infectious hand touches the nose or eyes, the infection is able to enter the new person.
Many common infections can spread by droplet transmission in at least some cases, including: Common cold, Diphtheria, Fifth disease (erythema infectiosum), Influenza, Meningitis, Mycoplasma, Mumps, Pertussis (whooping cough), Plague, Rubella, Strep (strep throat, scarlet fever, pneumonia).
How can droplet transmission be prevented?
Frequent hand cleansing, especially with instant hand sanitizers, can help prevent droplet transmission. Hand cleansing is most important before eating and before touching the nose or eyes.
Covering the mouth or nose when coughing or sneezing decreases droplet spread—and can make hand cleansing even more important.
Using disposable towels and cups reduces the risk for infection. Cleaning or disinfecting commonly touched infected surfaces (doorknobs, faucet handles, shared toys, mats in daycare) can also help. Wearing a mask may help for brief, short exposures.
References and Resources
Jayaweera M, Perera H, Gunawardana B, Manatunge J. Transmission of COVID-19 virus by droplets and aerosols: A critical review on the unresolved dichotomy. Environ Res. 2020;188:109819. doi:10.1016/j.envres.2020.109819