COVID-19 (coronavirus) Featured

How does COVID-19 spread?

graphic of person coughing

When I chat with friends and family, there’s a lot of talk of COVID-19 and a lot of confusion and questions around how the virus spreads.

Dr. Samira Mubareka, infectious diseases physician and microbiologist, says research into COVID-19 shows that the virus is spread through close contact with an infected person.

“This close contact can occur in two ways: droplet and contact,” she said.

Droplet means respiratory droplets produced by an infected person’s sneeze or cough. These can travel up to 6 feet (1.8 metres). A person becomes infected when droplets from a cough or sneeze directly enter the body through the eyes, mouth or nose. 

“These droplets are large, and they tend to fall to the ground by gravitational pull,” Dr. Mubareka explained. “But droplets from a sneeze or cough can travel nearly 2 metres, so keeping a distance from someone who is coughing or sneezing is important.”

Contact means touching a person or object directly, such as door handles, that have droplets on them from an infected person’s cough or sneeze. Unwashed hands contaminated with COVID-19 can introduce the virus to your body when you touch your eyes, mouth or nose.   

As a member of the public, how can I protect myself? 

To protect yourself from COVID-19: 

  • Wash your hands often with either soap and water or alcohol-based hand sanitizers. Both of these are effective in killing COVID-19.
  • Avoid touching your face – your eyes, nose and mouth are the ports of entry for the virus.
  • Keep a 2-metre separation from sick people.

Should I wear a mask in public? 

Because COVID-19 is spread with close contact with a sick person or by contaminated hands, your best defence is to maintain that 2-metre separation from sick people, wash your hands frequently and avoid touching your face.  

If you are sick, you may be asked to wear a surgical mask to contain your coughs and sneezes when visiting a healthcare facility. This helps reduce the distance your coughs and sneezes travel and prevents surrounding surfaces from becoming contaminated. 

Otherwise, wearing a mask to prevent yourself from getting sick may have the opposite effect – it actually increases your chance of becoming infected because masks are often worn improperly, and you are more likely to touch your face.  

“People can actually inadvertently contaminate themselves by manipulating the mask or by not using them properly,” Dr. Mubareka said. “Also, masks don’t protect your eyes, so you still have a potential portal of entry open for viruses, and the mask can give you a false sense of security. So for all of those reasons, day-to-day mask use is not recommended.”

Your best defence against COVID-19 and many other illnesses: clean your hands well and often, don’t touch your face (particularly your eyes, nose and mouth) and keep your distance from people who are unwell.

About the author


Alexis Dobranowski

Alexis Dobranowski is a Communications Advisor at Sunnybrook.