Break the chain of infection: Respiratory infectious diseases

The chain of infection demonstrates how germs (like viruses and bacteria) can spread and make someone sick. To help keep yourself and others from getting sick, you can practise personal protective measures. These measures work by breaking the chain of infection so that germs don’t spread from an infected person or a contaminated object to a person who is not infected. It’s best to use more than one personal protective measure at a time to help prevent the spread of germs at any point throughout the chain of infection.

Germs (infectious agent)

• Viruses
• Bacteria

Where germs can exist (reservoir)

• People
• Animals (pets and wildlife)
• High-touch surfaces and objects

How germs exit (portal of exit)

• Breathing
• Coughing
• Singing
• Sneezing
• Talking
• Shouting

How germs travel (modes of transmission)

• From person-to-person (direct transmission)
• Through contaminated surfaces or objects (indirect transmission)

How germs enter (portal of entry)

• Breathing in infectious respiratory particles like droplets or aerosols
• Touching contaminated surfaces or objects, then touching your eyes, nose or mouth with unclean hands

Who’s at risk (susceptible host)

While many people can get sick with a contagious respiratory disease, some people are at risk of experiencing more serious complications from infection, including:

• infants and young children
• older persons
• people who are immunocompromised
• people who are pregnant
• people with lung disease
• people who aren't vaccinated

Break the chain

• Get vaccinated.
• Stay at home when sick.
• Wear a mask or respirator when appropriate, for example, when you’re sick and must enter a public setting.
• Improve indoor ventilation when possible.
• Cover your coughs and sneezes with a tissue or the bend of your arm if you’re not wearing a mask.
• Clean your hands regularly.
• Clean and disinfect high-touch surfaces and objects.