How Is COVID-19 Actually Spreading?

by Kroger Health Staff

Last Updated: April 12, 2020

With new scientific findings coming to light daily, it can be difficult to keep track of everything our experts are learning about how COVID-19 is making its way across the globe. While studies are still ongoing, we have compiled our learnings about how the virus is spreading, and, more importantly, how to stop it.

According to the CDC, the virus continues to spread mainly through close contact interactions. It is transported through respiratory droplets caused by coughing, sneezing, or speaking, and these droplets then enter the body through the mouth, nasal passages, or eyes. Although coughing and sneezing are two symptoms of the virus, it is also possible to be spread by asymptomatic people, which accounts for up to 25% of people currently infected. To lower the likelihood of infection, the CDC recommends 6 feet of separation, which is based on a study showing gravity’s effect on large droplets, causing them to fall to the ground within this distance. However, as these studies are fairly dated (from the 1930’s and 1940’s), it is possible that 6 feet may not be enough space. It is recommended to create as much separation as possible, particularly from someone who is known to be infected. If you’ve been exposed to someone with COVID-19, check out this article.

Contact with Contaminated Surfaces
Although infection through contact with contaminated surfaces is less common than person-to-person interactions, studies have shown that the virus can live on different materials for varying amounts of time. In a study conducted by the New England Journal of Medicine, researchers found that the COVID-19 virus can live on plastics for up to 72 hours, stainless steel for up to 48 hours, cardboard for up to 24 hours, and on copper for up to 4 hours. According to Carolyn Machamer, a professor of cell biology at the Johns Hopkins School of Medicine, it is important to consider that the amount of the virus remaining after these lengths of time is very small. While infection is theoretically possible, it is unlikely. Still, the CDC encourages taking precautions and using an EPA-registered household disinfectant to “deactivate” the virus on surfaces.

Airborne/Aerosol Transmission
Recently, a study conducted by the New England Journal of Medicine showed that the COVID-19 virus can live in aerosol form for up to three hours. “Aerosol form” is a term you may have heard in regards to COVID-19, meaning the virus can remain airborne in tiny particles for a longer period of time (up to 3 hours) and can be produced by other means than by coughing or sneezing. The risk of infection by aerosol transmission is important in the case of healthcare workers who can be potentially exposed when inserting breathing tubes for patients or through mist generated by these breathing machines and other types of breathing treatments. While this initial finding seems to be plausible, studies show a greater correlation of virus transmission with larger droplets versus smaller aerosols, as it is still unclear how high of a concentration of the virus is needed to cause infection.

Thankfully, researchers all over the globe are furiously working to better understand how COVID-19 moves from person-to-person in an effort to manage, and ideally eliminate, its spread. In the meantime, continuing to practice social distancing, wearing masks in accordance with CDC guidance, and washing hands often are still key strategies to stay safe in this early period of coping with the virus.

Disclaimer: The information in this story is accurate as of its publication. However, the situation surrounding COVID-19 is ever-evolving. We are working to keep our stories up-to-date as changes occur, but we also encourage everyone to check news and recommendations from the CDC, WHO, and their local authorities.