Coronavirus can travel beyond 6 feet, says CDC as it finally admits airborne transmission is possible
Limiting close face-to-face contact with others is the best way to reduce the spread of coronavirus disease, and the US guidelines suggest maintaining a distance of six feet from other people. However, six feet may not always be sufficient to protect a person from catching the virus from an infected person, according to updated guidance issued by the US Centers for Disease Control and Prevention (CDC). The agency says there is evidence that under certain conditions, people with Covid-19 seem to have infected others who were more than six feet away, and these transmissions occurred within enclosed spaces that had poor ventilation. The latest advisory, issued on October 5, also finally acknowledges that Covid-19 can ‘sometimes’ be spread by airborne transmission.
“Today (October 5), CDC 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. Today’s update acknowledges the existence of some published reports showing limited, uncommon circumstances where people with Covid-19 infected others who were more than 6 feet away or shortly after the Covid-19-positive person left an area,” explains the agency. It adds, “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.”
Stating that scientists and researchers are still learning about how the virus spreads and the severity of illness it causes, the guidelines say that 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.
In September, the CDC said the coronavirus may spread through droplets and airborne particles that are formed when an infected person coughs, sneezes, sings, talks, or breathes. However, the warning on the airborne spread was soon removed, and the agency said it had posted the guidance “in error” and will be updating its recommendations soon.
The latest advisory states that some infections can be spread by exposure to a 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 six feet away from the infected person 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 chickenpox are spread, the agency explains. It further says it is possible to get infected with coronavirus from another person, even if there is a distance of six feet between them, in places with 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 droplets 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,” write experts.
The CDC, however, suggests that 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. “When people with Covid-19 cough, sneeze, sing, talk or breathe they produce respiratory droplets. These droplets can range in size from larger droplets (some of which are visible) to smaller droplets. Small droplets can also form particles when they dry very quickly in the airstream. Infections occur mainly through exposure to respiratory droplets when a person is in close contact with someone who has Covid-19. People who are physically near (within six feet) a person with Covid-19 or have direct contact with that person are at greatest risk of infection,” the advisory maintains.
According to the CDC, coronavirus 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,” the guidance emphasizes.
The CDC says that its recommendations remain the same based on existing science and after a thorough technical review of the guidance. The experts suggest that people can protect themselves from coronavirus by staying at least six feet away from others, wearing a mask that covers their nose and mouth, washing their hands frequently, cleaning touched surfaces often, and staying home when sick.