There has been some recent discussion about routes of transmission of SARS-CoV-2, the virus that causes COVID-19.
While it has long been acknowledged that this coronavirus spreads through person-to-person contact, it has also been suspected by scientists that the virus may spread through what is known as airborne transmission. Ultimately, it really should not significantly affect how people reduce the risk of spread of the virus.
Many respiratory viruses, including the common cold or the flu, spread through what are known as respiratory droplets. These are larger-sized droplets that fall quickly to the ground because of gravity. They are produced during coughing, sneezing or talking loudly. Respiratory droplets are transmitted from person to person in close proximity to one another, usually 6 feet in distance (two arm-lengths) or less.
Airborne transmission of a respiratory virus or bacteria is much less common. Examples include measles or pertussis, also known as whopping cough. Airborne transmission is more efficient and involves tiny droplets that remain suspended in the air for longer periods of time, known as aerosols. They can travel distances longer than 6 feet, such as in restaurants or other public places. Aerosols are produced both by activities such as coughing or sneezing and also by singing, regular talking or even just breathing.
It is well understood that COVID-19 spreads easily from person to person. The risk of spread increases when people are in closer proximity for longer periods of time, especially in enclosed spaces.
Measures to reduce spread are now widely known and known to be effective. They include practicing “the three W’s” – wash your hands, watch your distance and wear a mask.
Using the hands to touch the face, coughing or sneezing into the hands, or even touching potentially contaminated objects can result in contamination of the hands with the virus. Frequent hand-washing or use of hand sanitizer can minimize this means of transmission.
Maintaining at least a 6-foot distance between people, also known as physical or social distancing, can reduce easy spread through respiratory droplets. Routine and universal mask use can reduce viral spread by blocking both respiratory droplets and aerosols.
Also important is avoiding “the three C’s” – closed spaces, crowded places and close-contact settings. Closed spaces indoors, especially those with poor ventilation can promote the persistence of aerosols. Indoor spaces can be made safer through use of air purifiers and regular decontamination of surfaces. When possible, outdoor interaction can reduce spread.
Crowded places such as festivals or other gatherings promote proximity and therefore risk of spread of the virus, while close-contact settings such as close-range conversations also increase risk.
As we head into the fall and winter, practicing the three W’s and avoiding the three C’s can stem the tide of the coronavirus and help to prevent a surge in cases in our community.
Dr. Matthew A. Clark is a board-certified physician in internal medicine and pediatrics practicing at the Ute Mountain Ute Health Center in Towaoc.