CDC updates “How COVID is Spread” webpage to include airborne spread

Oct. 6, 2020

The Centers for Disease Control and Prevention (CDC) stated it has issued updated guidance to its How COVID-19 Spreads website, which includes information about the potential for airborne spread of the virus that causes COVID-19. 

CDC continues to believe, based on current science, that people are more likely to become infected the longer and closer they are to a person with COVID-19.  The update acknowledges the existence of some published reports showing limited, uncommon circumstances where people with COVID-19 infected others who were more than six feet away or shortly after the COVID-19-positive person left an area.  In these instances, transmission occurred in poorly ventilated and enclosed spaces that often involved activities that caused heavier breathing, like singing or exercise.  Such environments and activities may contribute to the buildup of virus-carrying particles.

 COVID-19 is thought to spread mainly through close contact from person to person, including between people who are physically near each other (within about six feet). People who are infected but do not show symptoms can also spread the virus to others. We are still learning about how the virus spreads and the severity of illness it causes. 

The guidance includes: 

COVID-19 spreads very easily from person to person

How easily a virus spreads from person to person can vary. The virus that causes COVID-19 appears to spread more efficiently than influenza but not as efficiently as measles, which is among the most contagious viruses known to affect people. 

COVID-19 can sometimes be spread by airborne transmission

·        Some infections can be spread by exposure to virus in small droplets and particles that can linger in the air for minutes to hours. These viruses may be able to infect people who are further than 6 feet away from the person who is infected or after that person has left the space.

·         This kind of spread is referred to as airborne transmission and is an important way that infections like tuberculosis, measles, and chicken pox are spread.

·         There is evidence that under certain conditions, people with COVID-19 seem to have infected others who were more than 6 feet away. These transmissions occurred within enclosed spaces that had inadequate ventilation. Sometimes the infected person was breathing heavily, for example while singing or exercising.

·         Under these circumstances, scientists believe that the amount of infectious smaller droplet and particles produced by the people with COVID-19 became concentrated enough to spread the virus to other people. The people who were infected were in the same space during the same time or shortly after the person with COVID-19 had left.

·         Available data indicate that it is much more common for the virus that causes COVID-19 to spread through close contact with a person who has COVID-19 than through airborne transmission. 

COVID-19 spreads less commonly through contact with contaminated surfaces

·         Respiratory droplets can also land on surfaces and objects. It is possible that a person could get COVID-19 by touching a surface or object that has the virus on it and then touching their own mouth, nose, or eyes.

·         Spread from touching surfaces is not thought to be a common way that COVID-19 spreads 

COVID-19 rarely spreads between people and animals

It appears that the virus that causes COVID-19 can spread from people to animals in some situations. CDC is aware of a small number of pets worldwide, including cats and dogs, reported to be infected with the virus that causes COVID-19, mostly after close contact with people with COVID-19. Learn what you should do if you have pets. 

The best way to prevent illness is to avoid being exposed to this virus. You can take steps to slow the spread.

·         Stay at least six feet away from others, whenever possible. This is very important in preventing the spread of COVID-19.

·         Cover your mouth and nose with a mask when around others. This helps reduce the risk of spread both by close contact and by airborne transmission.

·         Wash your hands often with soap and water. If soap and water are not available, use a hand sanitizer that contains at least 60 percent alcohol.

·         Avoid crowded indoor spaces and ensure indoor spaces are properly ventilated by bringing in outdoor air as much as possible. In general, being outdoors and in spaces with good ventilation reduces the risk of exposure to infectious respiratory droplets.

·         Stay home and isolate from others when sick.

·         Routinely clean and disinfect frequently touched surfaces. 

Pandemics can be stressful, especially when you are staying away from others. During this time, it’s important to maintain social connections and care for your mental health. 

CDC has the release

More COVID-19 coverage HERE.