SARS-CoV-2 is Transmitted by Exposure to Infectious Respiratory Fluids

The U.S. CDC confirmed on May 7, 2021, the principal mode by which people are infected with the SARS-CoV-2 beta coronavirus that causes COVID-19 is through exposure to respiratory fluids carrying infectious virus.

Exposure occurs in three principal ways: (1) inhalation of very fine respiratory droplets and aerosol particles, (2) deposition of respiratory droplets and particles on exposed mucous membranes in the mouth, nose, or eye by direct splashes and sprays, and (3) touching mucous membranes with hands that have been soiled either directly by virus-containing respiratory fluids or indirectly by touching surfaces with the coronavirus on them.

People release respiratory fluids during exhalation, such as quiet breathing, speaking, singing, exercise, coughing, sneezing in the form of droplets across a spectrum of sizes. These droplets carry viruses and transmit infection.

Once infectious droplets and particles are exhaled, they move outward from the source. The risk for infection decreases with increasing distance from the source and increasing time after exhalation, says the CDC.