How Do Viruses Spread from Surfaces to People?  

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The main way that SARS-CoV-2, the virus that causes COVID-19, spreads between people is by respiratory droplets. These are the tiny droplets of water that come out when you talk, cough, and breathe out and that other people can breathe in.

The most common way we get infected with COVID-19 is when we breathe in the virus.

Although less common, we can also get infected when we touch a surface that has virus on it.

“When you touch something that has live virus on it and then you touch your face without cleaning your hands first, you can get virus into your eyes, your nose, and your mouth,” said Dr. Abigail Carlson, an infectious diseases physician with the Centers for Disease Control & Prevention (CDC), as part of CDC Project Firstline’s Inside Infection Control video series.

Respiratory Droplets and Travel  

Respiratory droplets are a mix of different sizes, but they are all very small.

Some of the smallest droplets will get carried away by the air and travel with the flow of air currents.

Other droplets are bigger, and they do not travel very far. Instead, they will fall toward the ground and land on nearby surfaces.

“You can think of it a little bit like leaves on a tree,” Dr. Carlson said. “A lot of the leaves are going to fall near the tree. But some of them will be caught by the wind and they will move with the direction of the wind. They will fall a little further away. Just like that, respiratory droplets fall on things that are nearby, like patient beds and waiting room chairs, desks, and clothes.”

From Surfaces to People 

When respiratory droplets land on a surface, the virus can survive there for a while.

If you touch that surface, you can get the virus on your hands and then into your body if you touch your face without cleaning your hands first.

“You’re exhausted at the end of your shift and you rub your eyes, or you’re running from place to place and you forget to clean your hands,” Dr. Carlson said. “It’s one of those habits that’s just hard to recognize and hard to break.”

Another way the virus can get onto surfaces is when an infected person touches their eyes, nose, or mouth, and gets the virus on their hands and then touches a surface like a door handle, a keyboard, or an IV pole. This spreads the virus to that surface, which someone else can touch and can get infected.

“For any of us in healthcare, we know that the body fluids, including spit and snot, can get onto things like linens and things near a patient,” Dr. Carlson said.  “And if anyone touches those surfaces and doesn’t clean their hands, they can spread the virus from themselves to other surfaces and people.”

Regular hand hygiene and good cleaning and disinfection practices for the environment are important for infection control to stop the spread of viruses and other germs from surfaces to people.

What Can You Do to Promote Infection Control in Your Healthcare Setting?

Access more information about infection prevention and control in healthcare by visiting resources from CDC Project Firstline.

Project Firstline creates resources, including videos and shareable images, web buttons, posters, and print materials. They also have facilitator toolkits to help workers lead trainings even if they are not an infection control expert.

Salud America! at UT Health San Antonio is working with the National Hispanic Medical Association to bring Project Firstline infection control educational content to healthcare workers, so they are equipped with the knowledge they need to protect themselves, their facilities, and their patients (Latinos and all communities) from infectious disease threats in healthcare settings.

You can read these articles:

• What is Project Firstline?
• What’s a Virus?
• How Does Infection Control Work on COVID-19 Variants Like Omicron?
• Contact Time: What is It and How Does it Impact Infection Control?
• The Surprising Difference Between Cleaning and Disinfection
• What’s a Respiratory Droplet and Why Does It Matter?
• Why Do Cleaning and Disinfection Matter in Healthcare?
• We Need to Talk about Hand Hygiene Again
• What is the Goal of Infection Prevention and Control in Healthcare Settings?
• The Intersection of Infection Prevention and Control and Healthcare Equity
• N95 Respirators: Everything You Need to Know
• How Do I Safely Use a Multi-Dose Vaccine Vial?

“Healthcare teams in hospitals, nursing homes, and other care settings are the front lines against the spread of infection,” said Dr. Amelie G. Ramirez, director of Salud America! at UT Health San Antonio. “CDC’s Project Firstline is bolstering those efforts by developing evidence-based tools that can be delivered in a variety of ways to make infection control learning convenient and accessible for busy healthcare staff.”

Learn More about Project Firstline!

Editor’s Note: This article is part of a collaboration between Salud America!, the National Hispanic Medical Association, and the CDC’s Project Firstline. To find resources training materials, and other tools to bolster knowledge and practice of infection control, visit Project Firstline and view Salud America!’s infection control content.