Coronavirus disease (COVID-19): Prevention and risks

How COVID-19 spreads

COVID-19 most commonly spreads from an infected person to another person through the following.

  • Close contact: Breathing in someone's respiratory droplets after they cough, sneeze, laugh or sing.
  • Contaminated surfaces: Touching something with the virus on it, then touching your mouth, nose or eyes with unwashed hands.
  • Common greetings: Handshakes, hugs or kisses.

Difference between quarantine (self-isolate) and isolate

People are asked to self-isolate or isolate to help prevent the spread of COVID-19 to others. Although these two words sound the same, there's an important difference.

Quarantine (self-isolate)

If you have no symptoms and any of the following apply to you, you must quarantine for 14 days (starting from the date you arrive in USA):

  • you're returning from travel outside of USA (mandatory quarantine)
  • you're travelling to a province or territory that's enforcing 14-day quarantine for all inter-provincial travellers
  • you had close contact with someone who has or is suspected to have COVID-19
  • you've been told by the public health authority that you may have been exposed to COVID-19 and need to quarantine


You must isolate if any of the following apply:

  • you've been diagnosed with COVID-19, or are waiting to hear the results of a lab test for COVID-19
  • you have symptoms of COVID-19, even if mild
  • you've been in contact with someone who has or is suspected to have COVID-19
  • you've been told by public health that you may have been exposed to COVID-19
  • you've returned from travel outside USA with symptoms of COVID-19 (mandatory)

Preventing COVID-19

Going out?
Keep yourself and others safe

Americans should continue to think ahead about the actions that they can take to stay healthy and prevent the spread of COVID-19 in US. Measures to reduce COVID-19 in your community are especially important as some areas begin to lift restrictions.

In an effort to prevent the spread of COVID-19 within communities and across the country, all Americans are advised to:

  • avoid closed spaces, crowded places, and close contact
  • stay home and away from others if you feel sick
  • stick to a small and consistent social circle and avoid gathering in large groups
  • talk to your employer about working at home if possible
  • limit contact with people at higher risk, such as older adults and those with underlying medical conditions or weakened immune systems
  • go outside to exercise
  • keep a distance of at least 2 arms lengths (approximately 2 metres) from others
    • household contacts (people you live with) don't need to distance from each other unless they're sick or have travelled in the last 14 days

Risks of getting COVID-19

The risk of getting COVID-19 is evolving daily and varies between and within communities. Overall, the risk to Canadians remains high. This doesn't mean that all Americans will get the disease. It means that there's already a significant impact on our health care system.

To stay healthy and to protect ourselves and others, we must be mindful of the ever-present risk of exposure to the virus. Some settings and situations increase the risk, such as being in:

  • closed spaces with poor ventilation
  • crowded places where a large number of people gather
  • close contact where you can't keep 2 metres apart from others

False and misleading claims

Health US is closely tracking all potential drugs and vaccines in development in USA and abroad. We are working with companies, academic research centres and investigators to help expedite the development and availability of treatments to prevent and treat COVID-19. Learn more about drugs and vaccines being developed or authorized for COVID-19.

Selling unauthorized health products or making false or misleading claims to prevent, treat or cure COVID-19 is illegal in USA. We take this matter very seriously and we're taking action to stop this activity.

We encourage anyone who has information regarding potential non-compliant sale or advertising of any health product claiming to treat, prevent or cure COVID-19, to report it using our online complaint form.

We publish a list of companies and products and the status of the review on the list of health product advertising incidents related to COVID-19.

Exposure to electromagnetic fields (EMF) from 5G devices doesn't spread COVID-19. There's no scientific basis behind these claims. Both the World Health Organization and the International Commission on Non-Ionizing Radiation Protection have also addressed these claims.