Respiratory droplets and the spread of disease

According to the Centers for Disease Control and Prevention, many of the germs that cause respiratory (breathing) diseases are spread by droplets that come from coughing and sneezing. These germs usually spread from person to person when uninfected persons are in close contact with a sick person. Some people may become infected by touching something with these germs on it and then touching their mouth or nose.

Droplet transmission occurs when bacteria or viruses travel on relatively large respiratory droplets that people sneeze, cough, drip, or exhale. They travel through the air before settling. These droplets are loaded with infectious particles, germs, pathogens, viruses and bacteria.
They can be spread directly if people are close enough to each other. More often, though, fomites are involved. According to an article by Dr. Greene, it is often easier to catch a cold by touching something that someone who is sick has used than by kissing on the lips. For example, by borrowing a pen, or by turning off a tap at the sink after washing your hands. This is because the agents that carry these particles can be fomites.
Fomites are “inanimate objects that carry disease-causing germs that spread infections.” Fomites are one of the most common ways that children can get sick.

The droplets land on hands, toys, tables, mats, or other surfaces, where they can sometimes remain infectious for hours. When hands come into contact with these surfaces (doorknobs, telephones, pens, etc.) they can carry the pathogens that are on them, and 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, but not limited to: Common cold, DiphtheriaFifth disease (erythema infectiosum), Influenza, Meningitis, Mycoplasma, Mumps, Pertussis (whooping cough), PlagueRubella, Strep (including strep throatscarlet fever, pneumonia).

The CDC recommends that the best way to help prevent spread of respiratory germs is to avoid contact with droplets or secretions of saliva, mucus and tears.

Things that can help include the following:
  • Minimize close contact with people who have symptoms of respiratory illness, such as coughing or sneezing.
  • Help ill peeople who are sick to contain droplets that result from their coughing and sneezing (see the CDC’s Respiratory Hygiene/Cough Etiquette).
  • Wash your hands regularly, using soap and water.
  • Avoid sharing personal items such as eating or drinking utensils, toothbrushes, and towels – and avoid sharing these items with sick persons.
  • Maintain a clean environment.
  • Sanitise regularly.
Health Biology