New Cleaning Guidance from the CDC

Even after more than a year of living with the novel coronavirus, we are still learning new things about it. Last week, the Centers for Disease Control and Prevention (CDC) shared that the odds of catching the virus from touching a surface was as low as 1 in 10,000. That means that each contact with a contaminated surface has less than a 1 in 10,000 chance of causing an infection.

Their finding has prompted a change in recommendations about how to clean surfaces. Disinfection once or twice per day has little impact on reducing estimated risks, the CDC said. It is necessary only in cases where someone is known or suspected to have COVID-19. Otherwise, plain old soap and water are plenty good enough to mitigate the spread of the virus.

Here are the details:
Under perfect laboratory conditions, the virus can live for minutes to hours on porous surfaces and days to weeks on non-porous ones, like stainless steel, plastic, and glass. These results from laboratory studies prompted scientists early in the pandemic to recommend disinfecting surfaces throughout the home and business frequently.

Under real-world conditions, though, the outer shell of the virus is pretty fragile. It is degraded by light and soap. Even if the virus could survive on a real-world surface for as long as it survives in the lab, the virus’s path from one infected person across a surface to a new uninfected person is full of obstacles. A substantial amount of virus has to make it from the infected person, across a surface, to a new uninfected person’s eyes, nose, or mouth.

We should be careful not to misinterpret this news. The virus is still prevalent, and it is still dangerous, especially for those who have not yet been vaccinated. And it is still circulating widely in all of the other ways it gets around—through direct contact, droplets, and airborne transmission.

What’s good to know is that the same mitigation measures recommended for these primary modes of transmission also decrease transmission via surfaces. They are additional obstacles that you can add to the virus’s journey from one person to the next.

Wash your hands. Washing and disinfecting your hands regularly prevents transmission by both direct contact and surface contact. It is an important way to prevent spreading your germs to others and to prevent putting someone else’s germs into your body.

Wear your masks. Masks keep virus from getting from an infected person’s mouth or nose into the air and onto surfaces. Since nobody can tell who is infected and who is not, it’s best if everyone wears a mask whenever they are outside their own home or with people they don’t live with.

Ventilate. Ventilation decreases the risk of droplet, airborne, and surface transmission. That’s why socializing outside is best. With so much space, viruses have a hard time landing where they can do some damage. Plus, movement of the air and the sunshine dries out and inactivates the virus.

Continue cleaning. Again, washing surfaces with ordinary soap and water is enough to render any small amount of virus harmless. If someone using the space is confirmed or suspected to have COVID-19, then it’s time to get out the disinfectant wipes.

For additional information, visit the CDC's website. 

Donna Barron, RN, is the infection preventionist at Southwestern Vermont Medical Center.