Overview of Current Information on COVID-19 Airborne Transmission

During the early weeks of what has become known as the COVID-19 pandemic (or coronavirus pandemic), there has been a considerable amount of confusion about the virus, including in regard to the manner of transmission. COVID-19 is a new virus strain. As is the case with nearly any new-found virus, there is at least some uncertainty regarding the manner of transmission. 

A primary focus of confusion regarding the means of transmission of COVID-19 centers on how it actually can infect people through an airborne spread. Researchers at the University of Minnesota published one of the most exhaustive analysis of the confusion surrounding the potential for airborne transmission of COVID-19 at this juncture in time. Before digging deeper into our overview of information about COVID-19 airborne transmission, this statement from Lisa Brosseau, a national expert on respiratory protection and infectious diseases, is an important preamble:

Infection prevention, medical, and public health professionals should be communicating to everyone that the exact modes of transmission for SARS-CoV-2 – the technical name of the virus that causes COVID-19 – are unknown. There are no studies, yet, to support any particular mode of transmission over another.

Terminology Causes Confusion

At the present time, there persists a considerable amount of confusion about how a person can become infected with COVID-19, in part because of the limited research data available at this time. Moreover, what fairly can be called a COVID-19 terminology “word salad” is contributing to the problem. Simply, people from all walks of life remain at least partially puzzled regarding COVID-19 transmission issues because of confusing terminology. 

A person reading what purports to be official information from different resources about COVID-19 airborne transmission is likely to find a term of art used one way here and another way there. For example, official information from one health agency discussing the transmission of COVID-19 through the air may use terms like “airborne” and “aerosolized” one way while another equally authoritative organization uses them differently. 

As a consequence, in presenting information to you today regarding the airborne transmission of COVID-19, we are going to bypass spending time trying to sort out the various definitions assigned to words like “airborne” and “aerosolized.” Rather, we’re going to engage in a very basic discussion of the potential for airborne transmission of COVID-19.

Basic Terms That Work for You

In order to educate on the current understanding of the risk of airborne transmission of COVID-19, we’re going to reference two terms that we believe will be easily understood by people from all walks of life:

• Big droplets 
• Small droplets

While these certainly aren’t “scientific terms,” this pair of phrases permits us the ability to discuss what is understood at this moment in time about the risk of airborne exposure to COVID-19. We can’t note enough that data about the transmission of COVID-19 remains in a state of flux. As a consequence, it’s incumbent upon every individual to stay abreast of issues associated with COVID-19, including transmission. You can accomplish this by accessing reliable resources, including the California Department of Public Health COVID-19 online update and information center. 

In basic terms, you currently need to think of two factors that are believed to play into the transmission of airborne transmission of COVID-19 today. As noted previously, these factors are big droplets versus small droplets. The possibility does exist for some big droplets to be seen with the naked eye. On the other hand, small droplets do refer to tiny elements of matter that leave an infected person via a cough or sneeze that are microscopic. 

We do know that COVID-19 can transfer between one person to another via fluid expressed through coughing or sneezing. This infection prospect is what brings the matter of big droplets and small droplets to the forefront.

When a person coughs or sneezes, and the cough or sneeze isn’t properly shielded, both big and small droplets spew into the air. If big droplets are sprayed outward through coughing or sneezing, they can land on other individuals or objects located within a six feet range. This is the reason why the current recommendation for physical distancing calls for a six foot range from one person to another. Large droplets are capable of being conveyed through the air based on the energy or force provided by a sneeze or cough. On the other hand, small droplets are capable of “floating” in the air for a more extended period of time.

Latest Best Evidence on Airborne COVID-19 Transmission

We simply cannot say this enough. Information on COVID-19, including manners of transmission, is evolving. Thus, we present the best evidence available at this time.

The best evidence provides the following in regard to airborne transmission of COVID-19:

• If a person infected with COVID-19 coughs or sneezes without proper coverage over his or her mouth or nose, the virus can be expelled into the air, contained in both big droplets and small droplets.
• If the big droplets land on another person, that individual can become infected with COVID-19.
• Another individual needs to be within six feet to be “hit” by big droplets spewed forth by an infected person’s cough or sneeze.
• Large droplets do not remain airborne and nearly immediately land on or fall to a surface or object.
• Small droplets initially do radiate outward by way of the power of an infected person’s cough or sneeze.
• Small droplets can land on a person within a three- to six-foot range.
• Small droplets can remain airborne for a period of time that is longer than that of big droplets; however, as the small droplets remain in the air for a bit longer period of time, they become more diffuse or spread out.
• Like big droplets, small droplets will start to move downward, landing on surfaces and objects. 
• There is a growing consensus among infectious disease experts that inhaling and becoming infected by small droplets outside the six-foot zone even a short time after an infected person sneezes or coughs is not likely. Infectious disease experts have not absolutely concluded contamination in this way is impossible. As of this time, there are no cases that specifically can be traced to this type of small droplet transmission. 
• The COVID-19 virus can end up on surfaces and objects and remain viable and transmittable for a period of time. The timeframe during which COVID-19 can remain viable depends on a number of factors, including the material from which a surface or object is made. With that said, current data indicates that COVID-19 on a surface (or certain type of objects) can remain viable and transmittable for days. 

Latest Best Safety Practices

The California Department of Public Health established the current best safety practices to protect against COVID-19 infection:

• Washing hands with soap and water.
• Clean and disinfect frequently touched surfaces daily. If surfaces are dirty, clean them using detergent or soap and water prior to disinfection.
• Avoid touching eyes, nose or mouth with unwashed hands.
• Cover your cough or sneeze with a tissue or your elbow.
• Avoiding close contact with people who are sick.
• Staying away from work, school or other people if you become sick with respiratory symptoms like fever and cough.
• If you smoke or vape, consider quitting. 
• Following guidance from public health officials.

If a person infected by COVID-19 has been in your home, place of business, rental property, or another location you own, serious consideration needs to be given to hiring a reputable, reliable, experienced COVID-19 cleaning specialist, also known as an infectious disease cleanup company. Professional assistance from an infectious disease cleanup company provides the peace of mind that the COVID-19 virus has been properly eradicated from your home, business, or other location.